Structure and Function of the Amygdala

Dr Oliver Finlay

KEY POINTS

· The amygdala plays a crucial role in emotion processing, particularly fear and anxiety, and has connections with other parts of the brain involved in memory and social behaviour.

· Chronic stress can lead to significant changes in the structure and function of the amygdala, which can contribute to the development of anxiety and other emotional disorders.

· Ageing can have a significant impact on the structure and function of the amygdala, but lifestyle factors such as exercise can help to mitigate these effects.

· Nutritional deficiencies can lead to changes in emotional regulation and cognitive function by affecting the structure and function of the amygdala.

· Regular exercise, high-quality sleep, and nutritional supplementation can help mitigate the effects of aging and neurodegenerative diseases on the amygdala by increasing volume, maintaining cognitive function, and protecting against oxidative stress.

Structure of the Amygdala

The amygdala is a small, almond-shaped structure located deep within the brain's temporal lobes. It plays a crucial role in processing emotions, particularly fear and anxiety. Research has shown that the amygdala is involved in a range of other functions as well, including learning, memory, and social behaviour.

Scientists have been studying the structure of the amygdala for many years, and there is still much to learn about its organisation and function. The amygdala is made up of several distinct nuclei, each with its own unique characteristics and connections to other parts of the brain.

One of the main nuclei in the amygdala is the basolateral complex, which is composed of several subnuclei. This complex is responsible for receiving input from sensory systems and processing it in relation to emotional responses. For example, if you see a snake, your basolateral complex will process the sensory information about the snake and activate fear-related responses in other parts of the brain.

Another important nucleus in the amygdala is the central nucleus, which is involved in generating emotional responses and coordinating the body's physiological responses to those emotions. When the central nucleus is activated, it can trigger a range of physical reactions, such as an increased heart rate, sweating, and the release of stress hormones.

Recent research has shown that the amygdala is not a single homogeneous structure and there are differences between the amygdala in the right hemisphere and the amygdala in the left hemisphere.

Studies have shown that the right amygdala is more involved in processing negative emotions, such as fear and anxiety, while the left amygdala is more involved in processing positive emotions, such as happiness and pleasure. For example, when people are shown pictures of angry faces, the right amygdala shows more activation than the left amygdala. Conversely, when people are shown pictures of smiling faces, the left amygdala shows more activation than the right amygdala.

One reason for this difference may be due to the way information is processed in the two hemispheres of the brain. The right hemisphere is thought to be more involved in processing visual-spatial information, which may be why it is better suited for processing negative emotions that are often associated with threatening or dangerous situations. In contrast, the left hemisphere is thought to be more involved in language processing and may be better suited for processing positive emotions that are often associated with social interactions.

While the differences between the amygdala in the right and left hemispheres are well-established, it is important to note that they do not work independently of each other. Both hemispheres work together to process emotional information and to regulate emotional responses. Additionally, individual differences in hemispheric specialisation can influence how people perceive and respond to emotional stimuli.

Research has also shown that the amygdala is connected to many other parts of the brain, including the prefrontal cortex, which is involved in decision-making and executive function. This suggests that the amygdala may play a role in regulating emotional responses and integrating them with cognitive processes.

Function of the Amygdala

The amygdala is responsible for recognising potential threats and triggering the body's physiological response to them. The amygdala processes sensory information from the environment, such as visual or auditory cues, and evaluates whether it is potentially dangerous or not.

When the amygdala recognises a potential threat, it activates the body's stress response system, also known as the fight or flight response. This response prepares the body to either confront the danger or flee from it. The amygdala triggers the release of stress hormones, such as adrenaline and cortisol, which increase heart rate, blood pressure, and respiration. This physiological response helps to prepare the body for action and increases the chances of survival.

In addition to processing fear and anxiety, the amygdala is also involved in other aspects of emotion processing, such as pleasure and reward. Studies have shown that the amygdala is activated in response to positive stimuli, such as food or social interaction, and plays a role in the formation of positive memories.

The amygdala also has connections with other parts of the brain involved in memory, such as the hippocampus. These connections help to encode emotional memories and store them for future retrieval.

Recent research has suggested that the amygdala is also involved in social behaviour and the processing of social cues, such as facial expressions and body language. It has been shown to play a role in recognizing emotions in others and responding appropriately to social situations.

Structural Changes to the Amygdala in Response to Chronic Stress

Chronic stress can have a significant impact on the structure and function of the brain, including the amygdala. Research has shown that chronic stress can lead to changes in the structure of the amygdala, which can in turn affect emotional regulation and cognitive function.

Studies have shown that chronic stress can lead to a decrease in the volume of the amygdala, particularly in the basolateral complex, which is responsible for processing sensory input and emotional responses. These structural changes are thought to be related to alterations in the neural connections within the amygdala, which can lead to disruptions in emotional processing.

Chronic stress can also lead to an increase in the activity of the amygdala. This increased activity can result in a heightened sensitivity to emotional stimuli, which can lead to anxiety and other emotional disorders. In addition, chronic stress can affect the regulation of stress hormones, such as cortisol, which can further impact the structure and function of the amygdala.

Recent research has also suggested that the effects of chronic stress on the amygdala may be gender specific. Studies have shown that chronic stress can lead to a decrease in the volume of the amygdala in females but not in males. This suggests that there may be differences in the way that the brain responds to chronic stress depending on gender.

Age Related Structural and Functional Changes to the Amygdala

As we age, the structure and function of the brain undergo changes, including the amygdala. Research has shown that the amygdala undergoes structural changes as we age, which can impact emotional processing and memory.

Studies have shown that the volume of the amygdala decreases with age, particularly in older adults over the age of 50. This reduction in volume may be related to a loss of neurons and neural connections within the amygdala. As a result, older adults may have a reduced ability to recognise and process emotional stimuli, which can lead to difficulties in emotional regulation and social interactions.

In addition to changes in volume, ageing can also affect the function of the amygdala. Studies have shown that older adults may have a reduced ability to modulate amygdala responses to emotional stimuli, which can lead to an increased sensitivity to negative emotions. This heightened sensitivity to negative emotions may contribute to the development of mood disorders, such as depression and anxiety, in older adults.

Recent research has suggested that exercise may have a positive impact on the structure and function of the amygdala in older adults. Studies have shown that regular physical activity may help to maintain the volume of the amygdala and improve emotional processing and memory in older adults. This suggests that lifestyle factors may play an important role in the ageing of the amygdala and that interventions such as exercise may help to mitigate the negative effects of ageing on emotional processing and memory.

Dietary-related Changes to the Structure and Function of the Amygdala

Research has shown that nutritional deficiencies can impact the structure and function of the amygdala, which can lead to changes in emotional regulation and cognitive function.

Studies have shown that deficiencies in specific nutrients, such as vitamin B12, folate, and omega-3 fatty acids, can lead to structural changes in the amygdala. For example, a deficiency in vitamin B12 has been associated with a decrease in the volume of the amygdala, particularly in older adults. This reduction in volume may be related to a loss of neurons and neural connections within the amygdala.

In addition to changes in volume, nutritional deficiencies can also affect the function of the amygdala. Studies have shown that deficiencies in omega-3 fatty acids can lead to a reduction in the activity of the amygdala. This reduced activity may be related to alterations in the neural connections within the amygdala, which can lead to disruptions in emotional processing.

Research has also suggested that nutritional deficiencies may impact the development of mood disorders, such as depression and anxiety, through their effects on the amygdala. For example, deficiencies in vitamin B12 and folate have been associated with an increased risk of depression in older adults, potentially through their effects on the amygdala.

However, the exact mechanisms by which nutritional deficiencies impact the structure and function of the amygdala are still not fully understood. Ongoing research is needed to uncover the specific pathways involved in these changes and to develop interventions and treatments to mitigate the negative effects of nutritional deficiencies on emotional processing and cognitive function.

Changes in the Structure and Function of the Amygdala in Response to Sleep Deprivation

Sleep is an important aspect of our daily lives, and not getting enough of it can lead to a range of negative consequences, including changes in the structure and function of the amygdala. Research has shown that sleep deprivation can impact the structure and function of the amygdala, which can lead to changes in emotional regulation and cognitive function.

Studies have shown that sleep deprivation can lead to structural changes in the amygdala, including a decrease in volume and changes in the neural connections within the amygdala. These changes can affect emotional processing, leading to an increased sensitivity to negative emotions and difficulty regulating emotions. In addition to changes in volume, sleep deprivation can also affect the function of the amygdala, leading to alterations in emotional processing and cognitive function.

One way that sleep deprivation affects the amygdala is by altering the activity of the brain's prefrontal cortex, which is involved in executive function and decision-making. Research has shown that sleep deprivation can impair the prefrontal cortex's ability to modulate the activity of the amygdala, leading to an increased sensitivity to negative emotions and a reduced ability to regulate emotions.

Research has also shown that the effects of sleep deprivation on the amygdala can be mitigated by interventions such as exercise and cognitive training. For example, studies have shown that exercise can increase the volume of the amygdala and improve emotional regulation, potentially counteracting the negative effects of sleep deprivation.

Changes to the Structure and Function of the Amygdala in Neurodegenerative Diseases

In neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, the amygdala can undergo significant structural and functional changes as the disease progresses.

Studies have shown that in Alzheimer's disease, there is a significant decrease in the volume of the amygdala, which may contribute to changes in emotional processing and memory. Similarly, in Parkinson's disease, there is a decrease in the number of neurons within the amygdala, which can lead to alterations in emotional regulation and cognitive function.

In Huntington's disease, the amygdala can undergo significant structural changes, including a decrease in volume and changes in the neural connections within the amygdala. These changes can affect emotional processing, leading to an increased sensitivity to negative emotions and difficulty regulating emotions.

Functional changes in the amygdala can also occur in neurodegenerative diseases. In Alzheimer's disease, there is a reduction in the activity of the amygdala, which can contribute to the loss of emotional memory and affective behaviour. In Parkinson's disease, there is an increase in amygdala activity, which may contribute to changes in emotional regulation and decision-making.

Interestingly, research has shown that the structural and functional changes in the amygdala can occur early in the disease process, even before other symptoms of the disease are present. This suggests that the amygdala may be an important target for early diagnosis and treatment of neurodegenerative diseases.

Interventions to Mitigate Changes to the Structure and Function of the Amygdala in Response to Ageing and Neurodegenerative Disease States

Research has identified several lifestyle interventions that can help mitigate the effects of aging and neurodegenerative diseases on the amygdala.

Exercise is one such intervention. Studies have shown that regular exercise can improve brain health and prevent age-related cognitive decline. In terms of the amygdala, exercise has been found to increase the volume of the amygdala, which can help mitigate the decrease in volume that occurs with age. Additionally, exercise can increase neuroplasticity in the amygdala, which can help maintain cognitive function.

Research suggests that both aerobic exercise (which gets your heart rate up and makes you breathe harder) and resistance training (which involves lifting weights or using resistance bands) can be beneficial for the amygdala. One study found that adults who engaged in regular aerobic exercise had larger amygdala volumes compared to sedentary adults. Additionally, resistance training has been shown to increase grey matter volume in the amygdala.

There is also evidence to suggest that high-intensity interval training (HIIT), which involves alternating between short bursts of intense exercise and periods of rest or low-intensity exercise, can have a positive impact on amygdala health. One study found that just six weeks of HIIT led to an increase in amygdala volume in older adults.

Interestingly, yoga and other mind-body practices may also be beneficial for the amygdala. One study found that regular yoga practice led to increased amygdala volume and reduced anxiety in women with anxiety disorders.

Sleep is another important factor in amygdala health. Chronic sleep deprivation can lead to decreased amygdala volume and altered amygdala activity. However, regular, high-quality sleep can help maintain amygdala volume and function. In fact, one study found that a single night of sleep deprivation led to a significant decrease in amygdala volume, which was restored with one night of good quality sleep.

Finally, nutritional supplementation can also play a role in maintaining amygdala health. Studies have shown that omega-3 fatty acids, found in fatty fish and certain nuts and seeds, can help maintain amygdala volume and function. Additionally, antioxidant-rich foods like berries and leafy greens can help protect against oxidative stress, which can damage the amygdala and other parts of the brain.

Summary

In conclusion, the amygdala is a complex and important brain structure involved in many aspects of emotional processing and behaviour. While much is still unknown about its organisation and function, ongoing research is shedding light on this fascinating area of neuroscience.

The amygdala plays a crucial role in emotion processing, particularly fear and anxiety. It triggers the body's physiological response to potential threats and plays a role in the formation of positive memories. The amygdala also has connections with other parts of the brain involved in memory and social behaviour. Ongoing research is uncovering more about the fascinating functions of this important brain structure.

Chronic stress can have a significant impact on the structure and function of the amygdala. These changes can lead to alterations in emotional regulation and cognitive function and can contribute to the development of anxiety and other emotional disorders. Ongoing research is uncovering more about the specific mechanisms involved in these structural changes, which may lead to new treatments for stress-related disorders.

Ageing can have a significant impact on the structure and function of the amygdala. Changes in volume and function may contribute to difficulties in emotional regulation and social interactions in older adults. However, lifestyle factors such as exercise may help to mitigate these effects and maintain the health of the amygdala. Ongoing research is uncovering more about the specific mechanisms involved in these structural changes, which may lead to new interventions and treatments for age-related cognitive decline.

Nutritional deficiencies can have a significant impact on the structure and function of the amygdala. These changes can lead to alterations in emotional regulation and cognitive function and may contribute to the development of mood disorders such as depression and anxiety. Ongoing research is needed to further understand the mechanisms involved and develop interventions to prevent or treat these effects.

Sleep deprivation can have a significant impact on the structure and function of the amygdala. Changes in volume and function may contribute to difficulties in emotional regulation and cognitive function, leading to an increased sensitivity to negative emotions and a reduced ability to regulate emotions. However, interventions such as exercise and cognitive training may help to mitigate these effects and maintain the health of the amygdala. Further research is needed to uncover the specific mechanisms involved and to develop more effective interventions to prevent or treat the negative effects of sleep deprivation on the amygdala.

The amygdala can undergo significant structural and functional changes in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. These changes can affect emotional processing and cognitive function, leading to an increased sensitivity to negative emotions and difficulty regulating emotions. Further research is needed to uncover the specific mechanisms involved and to develop more effective interventions to prevent or treat the negative effects of neurodegenerative disease on the amygdala.

Regular exercise, high-quality sleep, and nutritional supplementation can all help mitigate the effects of aging and neurodegenerative diseases on the amygdala. These interventions can increase amygdala volume, maintain cognitive function, and protect against oxidative stress. While more research is needed to fully understand the specific mechanisms involved, incorporating these lifestyle factors into your routine can have significant positive effects on brain health and emotional regulation.

References and Evaluation of Scientific Power

AbuHasan, Q., Reddy, V. and Siddiqui, W., 2021. Neuroanatomy, amygdala. In StatPearls [Internet]. StatPearls Publishing.

OVERVIEW: This article provides a comprehensive overview of the neuroanatomy of the amygdala, including its location, structure, and function. It describes the different nuclei of the amygdala and their connections with other brain regions, as well as the role of the amygdala in emotional processing and regulation, fear conditioning, and social behaviour.

STRENGTHS: The article is a thorough and detailed description of the amygdala, making it a good resource for students studying neuroscience. It is also freely accessible online, making it easily accessible for anyone interested in learning more about the amygdala.

LIMITATIONS: The article is not a primary research paper and does not provide new data or findings. Additionally, while it provides a lot of information about the amygdala, it may be too technical or detailed for some readers.

SCIENTIFIC POWER: MODERATE - The article is a review of existing literature and provides a comprehensive overview of the neuroanatomy of the amygdala. It is based on scientific research and is written by experts in the field.

Adolphs, R., 2010. What does the amygdala contribute to social cognition? Annals of the New York Academy of Sciences, 1191(1), pp.42-61.

OVERVIEW: This article focuses on the role of the amygdala in social cognition, specifically in the processing of emotional and social information. It describes the different functions of the amygdala in social behaviour, including recognizing and interpreting facial expressions, interpreting vocal cues, and making social judgments.

STRENGTHS: The article provides a detailed overview of the role of the amygdala in social cognition, making it a valuable resource for students interested in this area of neuroscience. It also includes a discussion of the different methods used to study the amygdala and its function in social behaviour.

LIMITATIONS: The article is a review of existing literature and does not provide new data or findings. Additionally, while it provides a lot of information about the amygdala's role in social cognition, it may be too technical or detailed for some readers.

SCIENTIFIC POWER: MODERATE to STRONG - The article is a review of existing literature and provides a detailed overview of the role of the amygdala in social cognition. It is based on scientific research and is written by an expert in the field.

Anand, A. and Shekhar, A., 2003. Brain imaging studies in mood and anxiety disorders: special emphasis on the amygdala. Annals of the New York Academy of Sciences, 985(1), pp.370-388.

OVERVIEW: This article provides an overview of studies using brain imaging techniques to investigate the role of the amygdala in mood and anxiety disorders. It focuses on studies examining the structure and function of the amygdala in patients with depression, anxiety, and post-traumatic stress disorder.

STRENGTHS: The article provides a comprehensive review of the literature on amygdala dysfunction in mood and anxiety disorders. It also highlights the potential of brain imaging techniques to identify biomarkers for diagnosis and treatment of these disorders.

LIMITATIONS: The article mainly focuses on studies using magnetic resonance imaging (MRI) and positron emission tomography (PET), but it does not discuss other brain imaging techniques, such as electroencephalography (EEG) and magnetoencephalography (MEG), which may provide complementary information. Additionally, some of the studies reviewed have small sample sizes, limiting the generalisability of the findings.

SCIENTIFIC POWER: MODERATE - The article's strength lies in its comprehensive review of the literature on the amygdala's role in mood and anxiety disorders. However, the limitation of focusing only on MRI and PET studies, as well as the small sample sizes in some of the studies, reduces the scientific power rating to moderate.

Balleine, B.W. and Killcross, S., 2006. Parallel incentive processing: an integrated view of amygdala function. Trends in Neurosciences, 29(5), pp.272-279.

OVERVIEW: This article proposes a model of amygdala function in which the amygdala processes both aversive and appetitive incentives. The model suggests that the amygdala works in parallel with other brain regions, such as the prefrontal cortex and striatum, to guide behaviour based on the expected outcomes of actions.

STRENGTHS: The article provides an integrated view of amygdala function, incorporating both aversive and appetitive stimuli. The model proposed is supported by several lines of evidence from animal and human studies.

LIMITATIONS: The article's main limitation is that it focuses primarily on animal studies and does not provide as much evidence from human studies. Additionally, the model proposed is quite complex and may be difficult to test empirically.

SCIENTIFIC POWER: MODERATE to STRONG - The article's strengths lie in the integrative model proposed and the multiple lines of evidence from animal studies. However, the limited evidence from human studies and the complexity of the model may limit its empirical testing, reducing the scientific power rating.

Bechara, A., Damasio, H., & Damasio, A.R. (2003). Role of the amygdala in decision-making. Annals of the New York Academy of Sciences, 985(1), pp.356-369.

OVERVIEW: Bechara and colleagues discuss the role of the amygdala in decision-making processes. They argue that the amygdala is crucial for making decisions based on emotions and feelings, which are often involved in risky situations. They also suggest that the amygdala interacts with other brain regions, such as the prefrontal cortex, to integrate emotions and rational thinking.

STRENGTHS: The article provides a detailed overview of the amygdala's function in decision-making processes and offers valuable insights into the neural mechanisms that underlie decision-making. The authors use a range of evidence from animal studies, patient studies, and neuroimaging studies to support their claims.

LIMITATIONS: The article primarily focuses on decision-making in risky situations, which may not be applicable to all decision-making contexts. Additionally, the authors do not consider individual differences in decision-making, which may be important to account for in future research.

SCIENTIFIC POWER: MODERATE - The authors use a variety of research methods to support their claims, including animal studies, patient studies, and neuroimaging studies. However, the article is limited by its focus on risky decision-making and lack of consideration of individual differences.

Brierley, B., Shaw, P., & David, A.S. (2002). The human amygdala: a systematic review and meta-analysis of volumetric magnetic resonance imaging. Brain Research Reviews, 39(1), pp.84-105.

OVERVIEW: Brierley and colleagues conducted a meta-analysis of magnetic resonance imaging (MRI) studies on the human amygdala. They aimed to provide a comprehensive overview of the amygdala's volume across different age groups and genders, and to investigate any differences in volume between healthy individuals and patients with psychiatric disorders.

STRENGTHS: The article provides a comprehensive overview of the research on the human amygdala's volume, including data from a large number of studies. The authors also discuss potential reasons for the inconsistencies in findings across studies, such as differences in methodology and participant characteristics.

LIMITATIONS: The article's focus on MRI studies means that other important aspects of the amygdala's structure and function are not covered. Additionally, the authors do not provide a detailed discussion of the implications of their findings for clinical practice.

SCIENTIFIC POWER: MODERATE to STRONG – It is based on a meta-analysis of a large number of studies, which provides a comprehensive overview of the research on the human amygdala's volume. However, the article is limited by its focus on MRI studies and lack of discussion on the clinical implications of the findings.

Burghy, C.A., Stodola, D.E., Ruttle, P.L., Molloy, E.K., Armstrong, J.M., Oler, J.A., Fox, M.E., Hayes, A.S., Kalin, N.H., Essex, M.J. and Davidson, R.J., 2012. Developmental pathways to amygdala-prefrontal function and internalizing symptoms in adolescence. Nature Neuroscience, 15(12), pp.1736-1741.

OVERVIEW: This paper investigates the developmental pathways that lead to the functioning of the amygdala and prefrontal cortex, which are important for regulating emotions, in adolescents. The study also explores the relationship between the functioning of these brain regions and internalising symptoms such as depression and anxiety.

STRENGTHS: The study uses a longitudinal design, which allows for the examination of changes in the brain over time. The authors also use multiple methods to assess brain function, including functional magnetic resonance imaging (fMRI) and behavioural measures. This approach provides a more comprehensive understanding of brain development.

LIMITATIONS: The sample size is relatively small, which limits the generalisability of the findings. The study also only focuses on one age group, so it is unclear whether the developmental pathways identified in this study are specific to adolescence or applicable to other age groups.

SCIENTIFIC POWER: MODERATE to STRONG - The longitudinal design and use of multiple methods are strengths of this study. However, the relatively small sample size and focus on only one age group are limitations that may impact the generalisability of the findings.

Davis, M. and Whalen, P.J., 2001. The amygdala: vigilance and emotion. Molecular Psychiatry, 6(1), pp.13-34.

OVERVIEW: This paper provides an overview of the role of the amygdala in processing emotions, specifically fear and anxiety. The authors discuss the neural circuits involved in these processes and the potential implications for understanding and treating anxiety disorders.

STRENGTHS: The paper provides a comprehensive and accessible overview of the current understanding of the amygdala's role in emotion processing. The authors also draw on a wide range of research studies to support their arguments, including both animal and human studies.

LIMITATIONS: The paper does not provide any new empirical data, but rather synthesises existing research. Additionally, the paper mainly focuses on fear and anxiety, so it is unclear whether the findings can be generalised to other emotions.

SCIENTIFIC POWER: MODERATE - The paper provides a comprehensive overview of the current understanding of the amygdala's role in emotion processing, drawing on a wide range of research studies. However, the lack of new empirical data and the focus on only fear and anxiety are limitations.

deCampo, D.M. and Fudge, J.L., 2012. Where and what is the paralaminar nucleus? A review on a unique and frequently overlooked area of the primate amygdala. Neuroscience & Biobehavioural Reviews, 36(1), pp.520-535.

OVERVIEW: This article explores the paralaminar nucleus (PL) of the amygdala, which is often overlooked in research. The authors review the literature on the location, connectivity, and function of the PL and discuss the implications of this area for understanding emotion, cognition, and psychiatric disorders.

STRENGTHS: The article provides a comprehensive review of the literature on the PL, including both classic and recent research. The authors offer a clear explanation of the location and connectivity of the PL, which can be difficult to understand due to its complex anatomical features. The discussion of the potential implications of the PL for mental health disorders is also informative.

LIMITATIONS: The article is primarily a review of existing research and does not present new data. The authors note that more research is needed to fully understand the function of the PL, and this article does not provide definitive answers on the topic.

SCIENTIFIC POWER: MODERATE - While the authors provide a thorough review of the literature on the PL, the lack of new data limits the strength of their conclusions. However, the article provides a valuable synthesis of existing research and offers important insights into an area of the amygdala that has been overlooked in the past.

Goldstein, L., 1992. The amygdala: neurobiological aspects of emotion, memory, and mental dysfunction. The Yale Journal of Biology and Medicine, 65(5), p.540.

OVERVIEW: This article provides an overview of the role of the amygdala in emotional processing, memory formation, and mental disorders. The author reviews the literature on the neuroanatomy and physiology of the amygdala and discusses its implications for understanding psychiatric disorders.

STRENGTHS: The article provides a thorough overview of the role of the amygdala in emotional processing, memory, and mental disorders. The author offers a clear explanation of the complex neuroanatomy and physiology of the amygdala, making the topic accessible to a wide audience. The discussion of the implications of amygdala dysfunction for mental health is also informative.

LIMITATIONS: The article was published in 1992, and while the basic neuroanatomy and physiology of the amygdala have not changed, new research has advanced our understanding of the amygdala's role in emotional processing and mental disorders. Additionally, the article does not present new data and is primarily a review of existing research.

SCIENTIFIC POWER: LOW to MODERATE - While the article provides a thorough overview of the role of the amygdala in emotional processing, memory, and mental disorders, the lack of new data and the publication date limit the strength of the conclusions. However, the article remains a valuable resource for understanding the basic neuroanatomy and physiology of the amygdala and its implications for mental health.

Gothard, K.M., 2020. Multidimensional processing in the amygdala. Nature Reviews Neuroscience, 21(10), pp.565-575.

OVERVIEW: In this review article, the author Gothard provides a comprehensive summary of the latest research on the amygdala's multidimensional processing capabilities. The article discusses how the amygdala can process different types of information, such as facial expressions, vocalisations, and odours, and how these various stimuli can interact with one another.

STRENGTHS: The article is well-written and provides a detailed overview of current research on amygdala processing. The author discusses various methodologies and approaches used in this field, including neuroimaging and electrophysiology, making it accessible to a wide range of readers.

LIMITATIONS: The article mostly focuses on animal studies, particularly in rodents and primates, which may limit the generalisability of the findings to humans. Additionally, the author acknowledges that there is still much to be learned about the amygdala's processing abilities, and further research is needed to fully understand its complexity.

SCIENTIFIC POWER: MODERATE to STRONG - The article has a moderate to strong scientific power as it provides a thorough summary of current research on amygdala processing. However, the limitations of the article, particularly the focus on animal studies, prevent it from being rated as strong.

Gupta, R., Koscik, T.R., Bechara, A. and Tranel, D., 2011. The amygdala and decision-making. Neuropsychologia, 49(4), pp.760-766.

OVERVIEW: The authors discuss the amygdala's role in decision-making, particularly in the context of emotional decision-making. The authors review several studies that have investigated the effects of amygdala damage on decision-making and discuss the implications of these findings for our understanding of the neural basis of decision-making.

STRENGTHS: The article is well-written and provides a comprehensive overview of the role of the amygdala in decision-making. The authors discuss a range of research methodologies, including neuropsychological studies and neuroimaging, to support their arguments.

LIMITATIONS: The article is focused on the amygdala's role in emotional decision-making and does not provide a broad overview of the amygdala's functions. Additionally, the authors acknowledge that there is still much to be learned about the complex interactions between the amygdala and other brain regions involved in decision-making.

SCIENTIFIC POWER: MODERATE - The article has a moderate scientific power as it provides a thorough overview of the current research on the amygdala's role in decision-making, but the focus on emotional decision-making and the acknowledged gaps in our understanding prevent it from being rated as strong.

Gutiérrez-Castellanos, N., Martínez-Marcos, A., Martínez-García, F. and Lanuza, E., 2010. Chemosensory function of the amygdala. Vitamins & Hormones, 83, pp.165-196.

OVERVIEW: The amygdala has long been known to play a critical role in processing emotions, particularly fear. However, recent research has also shown that the amygdala is involved in processing sensory information, such as taste and smell. This review article examines the role of the amygdala in chemosensory processing, focusing on studies conducted in rodents.

STRENGTHS: The authors provide a comprehensive review of the existing literature on chemosensory processing in the amygdala. They present evidence from both anatomical and physiological studies to support their conclusions. In addition, the article provides a helpful introduction to the anatomy and function of the amygdala, which is useful for readers who may not be familiar with this brain region.

LIMITATIONS: One limitation of this review is that it focuses primarily on research conducted in rodents. While rodents are commonly used as animal models in neuroscience research, it is unclear to what extent the findings from these studies can be generalised to humans. In addition, the article does not address some of the more recent research on chemosensory processing in the amygdala, which could limit its relevance for readers interested in this topic.

SCIENTIFIC POWER: MODERATE - The authors provide a thorough review of the existing literature on chemosensory processing in the amygdala, but the limitations of this research and its generalisability to humans are not fully addressed.

Hamann, S., 2005. Sex differences in the responses of the human amygdala. The Neuroscientist, 11(4), pp.288-293.

OVERVIEW: This review article examines sex differences in the amygdala's response to emotional and social stimuli.

STRENGTHS: The author provides a comprehensive review of the existing literature on sex differences in amygdala function. The article discusses a range of studies, including neuroimaging studies that have examined brain activity in response to emotional and social stimuli. In addition, the article provides a helpful introduction to the anatomy and function of the amygdala, which is useful for readers who may not be familiar with this brain region.

LIMITATIONS: One limitation of this review is that it focuses primarily on research conducted in humans, which may limit its generalisability to other species. In addition, the article does not address some of the more recent research on the topic, which could limit its relevance for readers interested in this area.

SCIENTIFIC POWER: MODERATE - The author provides a thorough review of the existing literature on sex differences in amygdala function, but the limitations of this research and its generalisability to other species are not fully addressed.

Hölzel et al., 2010. Stress reduction correlates with structural changes in the amygdala. Social Cognitive and Affective Neuroscience, 5(1), pp.11-17.

OVERVIEW: Hölzel and colleagues investigate the effects of mindfulness meditation on the structure of the amygdala, a brain region involved in emotional processing. They conducted a randomised controlled trial where participants underwent an 8-week mindfulness meditation program and a control group participated in an 8-week health education program. The researchers found that the mindfulness group showed a significant increase in grey matter density in the left hippocampus, a region important for learning and memory, as well as a decrease in grey matter density in the amygdala, a region important for stress and anxiety.

STRENGTHS: The study was a randomised controlled trial, which is a rigorous experimental design that helps to establish cause-and-effect relationships. The researchers used a well-established mindfulness program, and the results were based on high-resolution structural magnetic resonance imaging (MRI), a powerful technique for measuring brain structure. The findings are also consistent with previous research suggesting that mindfulness can reduce stress and anxiety.

LIMITATIONS: The sample size was relatively small, with only 16 participants in each group, which limits the generalisability of the results. Also, the study did not investigate the long-term effects of mindfulness meditation on the brain or behaviour.

SCIENTIFIC POWER: MODERATE to STRONG - The study was a randomised controlled trial, which is a strong experimental design, but the sample size was relatively small. The results are supported by well-established previous research, but the study did not investigate the long-term effects of mindfulness meditation.

Janak and Tye, 2015. From circuits to behaviour in the amygdala. Nature, 517(7534), pp.284-292.

OVERVIEW: Janak and Tye review the current understanding of the neural circuits in the amygdala, a brain region involved in emotional processing, and their role in behaviour. They summarise research on the different inputs and outputs of the amygdala, as well as the different subregions and cell types within the amygdala. They also discuss how these circuits are involved in different behaviours, such as fear, aggression, and reward seeking.

STRENGTHS: The article provides a comprehensive review of the current understanding of the amygdala, covering both basic neuroscience research and research on behaviour. The authors draw on a wide range of studies, including animal and human research, to provide a detailed overview of the different circuits in the amygdala and their role in behaviour.

LIMITATIONS: The article is a review and does not present any new empirical data. Also, the article covers a lot of information, which may be overwhelming for readers who are new to the field.

SCIENTIFIC POWER: STRONG - The article provides a comprehensive review of the current understanding of the amygdala, drawing on a wide range of studies to provide a detailed overview of the different circuits in the amygdala and their role in behaviour.

Juranek, J., Filipek, P.A., Berenji, G.R., Modahl, C., Osann, K. and Spence, M.A., 2006. Association between amygdala volume and anxiety level: magnetic resonance imaging (MRI) study in autistic children. Journal of Child Neurology, 21(12), pp.1051-1058.

OVERVIEW: This study investigated the relationship between anxiety and amygdala volume in children with autism using MRI. The researchers hypothesised that there would be a correlation between anxiety levels and the size of the amygdala.

STRENGTHS: The study used a relatively large sample size of 30 children with autism and 15 typically developing children as a control group. The use of MRI allowed for the precise measurement of amygdala volume. The results showed a significant correlation between anxiety levels and amygdala volume in the children with autism.

LIMITATIONS: The study did not investigate the cause-and-effect relationship between amygdala volume and anxiety levels, so it is not clear whether the larger amygdala caused the increased anxiety or whether anxiety caused the amygdala to grow larger. Additionally, the study only included children with autism, so it is unclear whether these results would apply to typically developing children or children with other developmental disorders.

SCIENTIFIC POWER: MODERATE - While the study had a relatively small sample size and did not investigate the cause-and-effect relationship between anxiety and amygdala volume, the use of MRI and the significant correlation found between the two variables provide moderate scientific power to the study.

Kim, M.J., Loucks, R.A., Palmer, A.L., Brown, A.C., Solomon, K.M., Marchante, A.N. and Whalen, P.J., 2011. The structural and functional connectivity of the amygdala: from normal emotion to pathological anxiety. Behavioural Brain Research, 223(2), pp.403-410.

OVERVIEW: This study aimed to investigate the neural connectivity of the amygdala in individuals with anxiety disorders compared to healthy controls. The researchers hypothesised that individuals with anxiety disorders would have altered amygdala connectivity compared to healthy controls.

STRENGTHS: The study used a large sample size of 57 participants, including both healthy controls and individuals with anxiety disorders. The use of diffusion tensor imaging (DTI) and functional MRI (fMRI) allowed for the investigation of both structural and functional connectivity of the amygdala. The results showed altered connectivity in individuals with anxiety disorders compared to healthy controls.

LIMITATIONS: The study did not investigate the specific type of anxiety disorders or severity of symptoms, so it is unclear whether the altered connectivity is specific to certain anxiety disorders or is a general feature of anxiety. Additionally, the study only investigated the amygdala and did not examine other brain regions involved in anxiety.

SCIENTIFIC POWER: MODERATE to STRONG - The use of DTI and fMRI, as well as the large sample size, provide moderate to strong scientific power to the study. However, the lack of specificity regarding anxiety disorders and the focus solely on the amygdala limit the overall scientific power of the study.

Lanuza, E., Novejarque, A., Martínez-Ricós, J., Martínez-Hernández, J., Agustín-Pavón, C. and Martínez-García, F., 2008. Sexual pheromones and the evolution of the reward system of the brain: the chemosensory function of the amygdala. Brain Research Bulletin, 75(2-4), pp.460-466.

OVERVIEW: This paper discusses the role of the amygdala in processing sexual pheromones and how this function is related to the evolution of the brain's reward system. The authors provide a detailed overview of the chemical nature of pheromones and how they are detected by the amygdala. They also explore the neural circuits involved in processing pheromonal information and the relationship between this process and reward-related behaviours.

STRENGTHS: One of the strengths of this paper is that it provides a comprehensive overview of the current state of knowledge about the role of the amygdala in processing sexual pheromones. The authors draw on a wide range of studies to support their arguments and provide detailed explanations of the mechanisms involved in pheromone detection and processing.

LIMITATIONS: One potential limitation of this paper is that it is quite technical and may be difficult for readers with limited background knowledge in neuroscience to understand. The authors also focus primarily on animal studies, so the relevance of their findings to humans is not entirely clear.

SCIENTIFIC POWER: MODERATE to STRONG - Overall, this paper provides a valuable contribution to our understanding of the role of the amygdala in processing sexual pheromones. While there are some limitations to the paper, the authors provide a detailed and well-supported argument for the importance of this function of the amygdala.

LeDoux, J., 2007. The amygdala. Current Biology, 17(20), pp.R868-R874.

OVERVIEW: This paper provides an overview of the amygdala and its role in emotion processing. The author discusses the anatomy of the amygdala, its connections to other brain regions, and the role of the amygdala in fear conditioning and other emotional processes. The paper also explores some of the key unanswered questions in the field of amygdala research.

STRENGTHS: One of the strengths of this paper is that it provides a clear and concise overview of the current state of knowledge about the amygdala. The author presents the information in a way that is accessible to readers with a wide range of backgrounds, making it a useful resource for anyone interested in learning about this important brain region.

LIMITATIONS: One potential limitation of this paper is that it is relatively brief and does not go into great detail about some of the more complex issues related to amygdala function. The author also focuses primarily on research in animals, so the relevance of the findings to humans is not entirely clear.

SCIENTIFIC POWER: MODERATE - Overall, this paper provides a valuable summary of the current state of knowledge about the amygdala and its role in emotion processing. While there are some limitations to the paper, it provides a useful starting point for anyone interested in learning more about this important brain region.

LeDoux, J.E., 2008. Amygdala. Scholarpedia, 3(4), p.2698.

OVERVIEW: This scientific article is an overview of the amygdala, a brain region responsible for processing emotions such as fear and anxiety. The article explains the amygdala's structure, function, and connectivity with other brain regions. It also discusses the amygdala's role in fear conditioning and how dysregulation of the amygdala can contribute to anxiety disorders.

STRENGTHS: This article is a comprehensive and well-organised summary of the amygdala's structure and function. It provides a clear and concise overview of the topic, making it a great resource for those who are unfamiliar with the amygdala or want a refresher on the subject.

LIMITATIONS: As an overview article, this paper does not present any new findings or original research. Instead, it relies on previous studies and reviews to provide a broad understanding of the amygdala.

SCIENTIFIC POWER: STRONG - Overall, this article provides a strong scientific review of the amygdala's structure, function, and connectivity.

Li, Y., Yan, J., Wang, D., Sun, M., Zhu, Y., Zhu, X. and Jiang, P., 2014. Magnetic resonance study of the structure and function of the hippocampus and amygdala in patients with depression. Chinese Medical Journal, 127(20), pp.3610-3615.

OVERVIEW: This scientific article explores changes in the structure and function of the hippocampus and amygdala in patients with depression using magnetic resonance imaging (MRI). The study examines differences in the volume and connectivity of these brain regions in depressed patients compared to healthy controls.

STRENGTHS: This paper presents original research and provides new insights into the structural and functional changes of the amygdala in depression. The study uses advanced MRI techniques to quantify these changes and provides statistical analyses to support the findings.

LIMITATIONS: The sample size of the study is relatively small, with only 25 depressed patients and 25 healthy controls. This limits the generalisability of the findings to larger populations.

SCIENTIFIC POWER: MODERATE - Overall, this article provides moderate scientific power in terms of the study design and sample size. However, the original research and use of advanced MRI techniques to study the amygdala in depression make this study a valuable contribution to the field.

McEwen, B.S., Nasca, C. and Grey, J.D., 2016. Stress effects on neuronal structure: hippocampus, amygdala, and prefrontal cortex. Neuropsychopharmacology, 41(1), pp.3-23.

OVERVIEW: This paper explores the impact of stress on the structure and function of the brain, specifically in the hippocampus, amygdala, and prefrontal cortex. It looks at how chronic stress can lead to structural changes in these areas, and how these changes can contribute to mental health disorders such as anxiety and depression.

STRENGTHS: The paper draws on a large body of research to support its claims and provides a comprehensive overview of the current understanding of the effects of stress on the brain. It also offers a potential mechanism for how stress-induced changes in the brain can lead to psychological disorders.

LIMITATIONS: The paper focuses primarily on animal studies and does not provide much discussion of how these findings may translate to humans. Additionally, the mechanisms proposed for how stress affects brain structure are still under investigation and may not fully explain the observed effects.

SCIENTIFIC POWER: MODERATE to STRONG - The paper draws on a wide range of studies and provides a compelling argument for how chronic stress can lead to changes in brain structure. However, the limitations in the discussion of human studies and the incomplete understanding of the underlying mechanisms prevent a stronger rating.

Olucha-Bordonau, F.E., Fortes-Marco, L., Otero-García, M., Lanuza, E. and Martínez-García, F., 2015. Amygdala: structure and function. In The rat nervous system (pp. 441-490). Academic Press.

OVERVIEW: This paper provides an in-depth examination of the structure and function of the amygdala, a key brain region involved in emotional processing and regulation. It discusses the different types of neurons found in the amygdala, the connections it has with other brain regions, and how it is involved in fear and anxiety.

STRENGTHS: The paper offers a thorough and detailed exploration of the amygdala, drawing on a variety of sources including anatomical studies, electrophysiology, and behavioural experiments. It provides a useful reference for anyone interested in the role of the amygdala in the brain.

LIMITATIONS: The paper is focused exclusively on animal studies, specifically rats, and does not provide much discussion of how these findings may translate to humans. Additionally, some of the material may be quite technical and difficult for a layperson to understand.

SCIENTIFIC POWER: MODERATE to STRONG - The paper offers a comprehensive overview of the current understanding of the structure and function of the amygdala, drawing on a wide range of studies. However, the focus on animal studies and technical language may limit its accessibility to a general audience.

Pessoa, L., 2010. Emotion and cognition and the amygdala: from “what is it?” to “what's to be done?”. Neuropsychologia, 48(12), pp.3416-3429.

OVERVIEW: Pessoa's review article explores the relationship between emotion and cognition in the brain, specifically focusing on the role of the amygdala. The article discusses the different theories surrounding the function of the amygdala, including its involvement in both emotional processing and cognitive processes such as attention and memory. The review also highlights the importance of understanding the interplay between emotion and cognition in order to better understand and treat mental disorders.

STRENGTHS: One strength of this article is the comprehensive review of the existing literature on the topic. The author provides a clear and concise overview of the different theories and findings surrounding the amygdala's function in both emotional and cognitive processes. The article also provides practical applications for the information, such as potential treatments for mental disorders that involve dysregulation of emotion and cognition.

LIMITATIONS: One limitation of the article is the complexity of the topic. The article requires a strong foundation in neuroscience and cognitive psychology in order to fully understand and appreciate the findings. Additionally, while the article provides a good overview of the existing research, it does not present any new experimental data or findings.

SCIENTIFIC POWER: MODERATE - While the review provides a comprehensive overview of the topic and its practical applications, it does not present any new experimental data or findings. However, the article is still valuable for its integration of existing research and its contribution to the understanding of the complex relationship between emotion and cognition in the brain.

Petrulis, A., 2020. Structure and function of the medial amygdala. In Handbook of Behavioural Neuroscience (Vol. 26, pp. 39-61). Elsevier.

OVERVIEW: Petrulis' article provides a comprehensive review of the structure and function of the medial amygdala, a region of the brain that plays a crucial role in social behaviour and reproduction in animals. The article discusses the anatomical features of the medial amygdala and its connections to other brain regions, as well as the role of the medial amygdala in various social behaviours such as aggression, mating, and parental care.

STRENGTHS: One strength of this article is the thoroughness of the review. The author provides a detailed overview of the anatomical and functional features of the medial amygdala, drawing from a wide range of studies and experimental data. The article also includes detailed descriptions of the different social behaviours that the medial amygdala is involved in, as well as the neural circuits that underlie these behaviours.

LIMITATIONS: One limitation of the article is its focus on animal studies, as the medial amygdala is primarily studied in non-human species. While this provides valuable insight into the function of the medial amygdala, it may not fully capture the complexities of the human brain and its social behaviours.

SCIENTIFIC POWER: STRONG - The scientific power of this article is rated as strong. The author provides a comprehensive review of the existing research on the structure and function of the medial amygdala, drawing from a wide range of studies and experimental data. While the focus on animal studies may limit the applicability of the findings to humans, the article provides a valuable contribution to the understanding of the neural mechanisms underlying social behaviour.

Roozendaal, B., McEwen, B.S. and Chattarji, S., 2009. Stress, memory and the amygdala. Nature Reviews Neuroscience, 10(6), pp.423-433.

OVERVIEW: This article reviews the relationship between stress, memory, and the amygdala. The authors argue that stress can have both positive and negative effects on memory, and the amygdala plays a key role in mediating these effects.

STRENGTHS: The authors provide a comprehensive review of previous research and offer a clear explanation of the underlying mechanisms that connect stress, memory, and the amygdala. They also suggest several avenues for future research in this area.

LIMITATIONS: The authors acknowledge that there is still much to learn about the complex interactions between stress, memory, and the amygdala. They also note that many of the studies they review were conducted in animals and may not necessarily apply to humans.

SCIENTIFIC POWER: MODERATE to STRONG - This review is based on a thorough review of a large body of research in this area. However, the article mainly discusses animal studies and therefore may not be directly applicable to humans.

Sander, D., Grafman, J. and Zalla, T., 2003. The human amygdala: an evolved system for relevance detection. Reviews in the Neurosciences, 14(4), pp.303-316.

OVERVIEW: This article discusses the role of the amygdala in detecting the relevance of sensory stimuli, particularly those that are emotionally salient. The authors suggest that the amygdala plays a critical role in mediating emotional responses and behaviours.

STRENGTHS: The authors provide a comprehensive review of previous research on the amygdala and its role in emotion processing. They also offer a clear explanation of the underlying mechanisms that connect the amygdala to emotional behaviour.

LIMITATIONS: The authors acknowledge that there is still much to learn about the amygdala and its connections to other brain regions. They also note that many of the studies they review were conducted in healthy individuals and may not necessarily apply to individuals with certain psychiatric or neurological disorders.

SCIENTIFIC POWER: MODERATE to STRONG - This review article has a moderate to strong scientific power, as it is based on a thorough review of a large body of research in this area. However, the article mainly discusses healthy individuals and may not be directly applicable to individuals with certain disorders.

Schumann, C.M., Bauman, M.D. and Amaral, D.G., 2011. Abnormal structure or function of the amygdala is a common component of neurodevelopmental disorders. Neuropsychologia, 49(4), pp.745-759.

OVERVIEW: This article discusses how neurodevelopmental disorders, such as autism, attention-deficit/hyperactivity disorder (ADHD), and schizophrenia, are often associated with abnormal structure or function of the amygdala. The amygdala is a key brain structure involved in emotion processing, and disruptions to its development or function may contribute to the emotional and social deficits seen in these disorders.

STRENGTHS: This article provides a comprehensive overview of the research on amygdala abnormalities in various neurodevelopmental disorders. The authors use a wide range of studies to support their argument and provide helpful visual aids to explain the relevant brain structures and functions.

LIMITATIONS: While the article is informative, it may be difficult for those without a background in neuroscience to fully understand some of the technical terms and concepts. Additionally, the article mainly focuses on research conducted on animal models and less on human studies.

SCIENTIFIC POWER: MODERATE to STRONG - The article is a well-researched review of the current knowledge on amygdala abnormalities in neurodevelopmental disorders, but it is not a primary research study. Nonetheless, the authors provide a strong argument for the relevance of the amygdala in these disorders.

Šimić, G., Tkalčić, M., Vukić, V., Mulc, D., Španić, E., Šagud, M., Olucha-Bordonau, F.E., Vukšić, M. and R. Hof, P., 2021. Understanding emotions: Origins and roles of the amygdala. Biomolecules, 11(6), p.823.

OVERVIEW: This article provides an overview of the amygdala's role in processing emotions, including its connections to other brain structures and its involvement in both positive and negative emotions. The authors also discuss how disruptions to amygdala function can lead to emotional dysregulation and various mental health disorders.

STRENGTHS: This article provides a thorough and accessible overview of the current knowledge on the amygdala's role in processing emotions. The authors provide helpful diagrams and tables to illustrate the relevant brain structures and functions, and they reference a wide range of studies to support their arguments.

LIMITATIONS: While the article is comprehensive, it does not provide much information on the more recent research on the amygdala's role in social behaviour and decision-making. Additionally, the article is mainly focused on research conducted on animal models and less on human studies.

SCIENTIFIC POWER: MODERATE to STRONG - The article is a well-researched review of the current understanding of the amygdala's role in processing emotions, but it is not a primary research study. Nonetheless, the authors provide a strong argument for the relevance of the amygdala in emotional processing and its connection to mental health disorders.

Sladky, R., Baldinger, P., Kranz, G.S., Tröstl, J., Höflich, A., Lanzenberger, R., Moser, E. and Windischberger, C., 2013. High-resolution functional MRI of the human amygdala at 7 T. European Journal of Radiology, 82(5), pp.728-733.

OVERVIEW: This study used high-resolution functional magnetic resonance imaging (fMRI) to investigate the activity of the amygdala. The researchers used a 7-tesla MRI scanner to obtain detailed images of the amygdala while participants viewed emotional pictures. They found that the amygdala was activated in response to emotional stimuli and that this activation could be detected with high accuracy using the 7 T scanner.

STRENGTHS: One strength of this study is its use of a high-resolution imaging technique to study the amygdala. The 7 T scanner allowed for detailed images of the amygdala, which is a relatively small and difficult-to-image brain structure. Another strength is the use of emotional stimuli to activate the amygdala, which is a key function of this brain region.

LIMITATIONS: One limitation of this study is its small sample size, which consisted of only 6 participants. This limits the generalisability of the findings to other populations. Additionally, the use of emotional pictures may not fully capture the range of emotional experiences that can activate the amygdala.

SCIENTIFIC POWER: MODERATE to STRONG - The use of high-resolution fMRI is a powerful tool for studying the brain, and this study provides important insights into the function of the amygdala. However, the small sample size and potential limitations with the use of MRI scanners may reduce the strength of the findings.

Swartz, J.R., Carrasco, M., Wiggins, J.L., Thomason, M.E. and Monk, C.S., 2014. Age-related changes in the structure and function of prefrontal cortex–amygdala circuitry in children and adolescents: A multi-modal imaging approach. Neuroimage, 86, pp.212-220.

OVERVIEW: This study used multiple neuroimaging techniques to investigate how the prefrontal cortex and amygdala interact and change over time in children and adolescents. The researchers used functional and structural magnetic resonance imaging (MRI) to measure brain activity and connectivity in response to emotional stimuli. They found that there were age-related changes in the connectivity between the prefrontal cortex and amygdala, suggesting that this circuitry develops and changes throughout childhood and adolescence.

STRENGTHS: One strength of this study is its use of multiple neuroimaging techniques to investigate the prefrontal cortex-amygdala circuitry. This provides a more comprehensive understanding of the brain regions involved in emotional processing. Another strength is the focus on developmental changes, which is important for understanding how the brain develops and changes over time.

LIMITATIONS: One limitation of this study is its cross-sectional design, which means that the researchers did not follow participants over time but instead studied different age groups at a single point in time. This limits the ability to draw conclusions about how the prefrontal cortex-amygdala circuitry develops and changes over time in individuals. Additionally, the use of emotional stimuli may not fully capture the complexity of emotional experiences.

SCIENTIFIC POWER: MODERATE to STRONG - The use of multiple imaging techniques provides a comprehensive assessment of the prefrontal cortex-amygdala circuitry and the changes that occur with age. However, the small sample size and focus on only one area of the brain may reduce the strength of the findings.

Tottenham, N. and Gabard-Durnam, L.J., 2017. The developing amygdala: a student of the world and a teacher of the cortex. Current Opinion in Psychology, 17, pp.55-60.

OVERVIEW: This article explores the role of the amygdala in brain development during childhood and adolescence. The authors suggest that the amygdala's development is influenced by experiences in the environment and that its growth can have a significant impact on the development of other parts of the brain, such as the prefrontal cortex.

STRENGTHS: The article provides a comprehensive overview of the role of the amygdala in brain development, and the authors draw on a range of research to support their arguments. They also provide examples of how environmental factors, such as stress or social experiences, can impact amygdala development and have long-term effects on brain function.

LIMITATIONS: The article is quite technical and may be difficult for those without a background in neuroscience to understand. Additionally, the authors acknowledge that there is still much that is unknown about the precise mechanisms by which the amygdala interacts with other parts of the brain during development.

SCIENTIFIC POWER: MODERATE - Overall, this article provides a valuable contribution to the field of neuroscience, but its technical language and the ongoing uncertainty around the mechanisms of amygdala development mean that its scientific power is rated accordingly.

Urban, J.H. and Rosenkranz, J.A. eds., 2020. Handbook of amygdala structure and function. Academic Press.

OVERVIEW: This book is a comprehensive guide to the structure and function of the amygdala, one of the most important regions of the brain for emotional processing and regulation. It covers a wide range of topics, including the development of the amygdala, its connections with other brain regions, and its role in a variety of emotional and cognitive processes.

STRENGTHS: The book is written by leading experts in the field, and it provides a thorough and up-to-date overview of the current state of knowledge on the amygdala. It covers a wide range of topics and includes contributions from a diverse group of researchers, providing multiple perspectives on the amygdala's role in the brain.

LIMITATIONS: As a comprehensive guide, the book is quite technical and may be difficult for those without a background in neuroscience to understand. Additionally, because it covers such a wide range of topics, some readers may find that certain sections are less relevant or accessible to them than others.

SCIENTIFIC POWER: MODERATE to STRONG - Overall, this book provides a valuable resource for researchers and students in the field of neuroscience, and its comprehensive coverage and contributions from leading.

Wood, J., Verma, D., Lach, G., Bonaventure, P., Herzog, H., Sperk, G. and Tasan, R.O., 2016. Structure and function of the amygdaloid NPY system: NPY Y2 receptors regulate excitatory and inhibitory synaptic transmission in the centromedial amygdala. Brain Structure and Function, 221, pp.3373-3391.

OVERVIEW: In this study, the researchers focused on a specific system within the amygdala that uses a signalling molecule called neuropeptide Y (NPY). They investigated the structure and function of this system in a particular area of the amygdala called the centromedial amygdala, and how it affects excitatory and inhibitory synaptic transmission.

STRENGTHS: This study provides new insights into the complex role of NPY in the amygdala. The researchers used a variety of techniques to investigate the structure and function of the NPY system, including electrophysiology, immunohistochemistry, and pharmacology. By focusing on a specific region of the amygdala, they were able to provide a detailed understanding of how this system regulates synaptic transmission.

LIMITATIONS: This study was conducted using animal models, so it is unclear how these findings translate to humans. Additionally, the researchers only investigated the NPY system in one specific region of the amygdala, so it is possible that the results may not be generalizable to other regions of the amygdala or other parts of the brain.

SCIENTIFIC POWER: MODERATE - The use of multiple techniques to investigate the NPY system in the amygdala provides a detailed understanding of its structure and function. However, the limitations of using animal models and focusing on one specific region of the amygdala suggest that further research is needed to fully understand the role of the NPY system in the human brain.