Category Archives: neuroanatomy

The Inferior Temporal Area (AKA Brodmann Area 20): A Video Overview

I put together this video about the Inferior Temporal Area (Brodmann Area 20). There is an overview of the function of Brodmann Area based on a brief review of the literature (which features in an earlier post). On the top right there is a rotating 3-d view of the Inferior Temporal Gyrus to aid with understanding. The video is best viewed full screen.

Appendix

Neuroanatomy Resources

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

The Neuroanatomy of the Somatosensory Cortex

I put together this video about Brodmann Area 1 – which is the Somatosensory Cortex. The video features an outline of Brodmann’s description of this area as well as videos illustrating the central sulcus (upper right) and post-central gyrus (lower right).

Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

New Video on the Hippocampus

I’ve just uploaded a creative commons video of the Hippocampus. The data was derived from the Japanese Life Science Database and the video was originally sourced from Wikimedia Commmons and i’ve added a soundtrack.
Feel free to remix the video if you have a YouTube account.

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

Building a Model of the Insular Cortex – Part 7: The James-Lange Theory

In developing a model of the emotional regulation in the Insular Cortex it is almost impossible to continue without reference to one of the landmark theories on emotions – the James-Lange theory. William James was an American physician and psychologist who wrote the widely regarded Principles of Psychology textbook and other landmark texts on psychological phenomenon with an emphasis on introspection. Carl Lange was a physician who made important contributions to Neurology and Psychiatry including the James-Lange Theory.

Essentially the James-Lange Theory states that we perceive environmental stimuli which trigger physiological responses which in turn lead to emotional experiences. In other words our body reacts physiologically and only then do we have an emotional response. Our emotions are in effect responses to the world around us rather than being triggered by an inner self. If this theory is correct then we do not choose to be joyful but rather we experience a ‘joyful’ stimulus which then triggers a physiological response and then the emotion of joy. William James put it in these terms

Our natural way of thinking about these standard emotions is that the mental perception of some fact excites the mental affection called the emotion and this latter state of mind gives rise to the bodily expression. My thesis on the contrary is that the bodily changes follow directly the perception of the exciting fact, and that our feeling of the same changes as they occur is the emotion. Common sense says, we lose our fortune, are sorry and weep; we meet a bear, are frightened and run; we are insulted by a rival, are angry and strike. The hypothesis here to be defended says that this order of sequence is incorrect that the one mental state is not immediately induced by the other, that the bodily manifestation must first be interposed between and that the more rational statement is that we feel sorry because we cry, angry because we strike, afraid because we tremble and not that we cry, strike or tremble because we are sorry, angry or fearful as the case may be. Without the bodily states following on the perception, the latter would be purely cognitive in form, pale, colorless, destitute of emotional warmth. We might then see the bear, and judge it best to run, receive the insult and deem it right to strike, but we should not actually feel afraid or angry

There are of course many critiques of this theory (e.g this one) but the James-Lange theory serves as a useful starting point for discussion of the emotions. In terms of this model it would also feature as one of the higher level concepts in the hierarchy of assumptions within the model. The opposite view can be taken – that the emotions direct the physiological response and this can certainly be considered in model-building. However the model resulting from this alternative consideration would take a different direction. The point is that a great multitude of different models are possible depending on the decisions taken about which theories or assumptions to incorporate.

In the model building process I will remain flexible, keeping alternative assumptions or theories in reserve. The larger model (or in one sense the gestalt) will be significantly influenced by these decisions.

 

Insular Cortex Resources on this Site

Developing a Model of the Insular Cortex and Emotional Regulation: Part 1

Building a Model of the Insular Cortex – Part 2

Building a Model of the Insular Cortex – Part 3

Building a Model of the Insular Cortex – Part 4

Building a Model of the Insular Cortex – Part 5

Building a Model of the Insular Cortex – Part 6

What does the Insular Cortex Do Again?

Insular Cortex Infarction in Acute Middle Cerebral Artery Territory Stroke

The Insular Cortex and Neuropsychiatric Disorders

The Relationship of Blood Pressure to Subcortical Lesions

Pathobiology of Visceral Pain

Interoception and the Insular Cortex

A Case of Neurogenic T-Wave Inversion

Video Presentations on a Model of the Insular Cortex

MR Visualisations of the Insula

The Subjective Experience of Pain

How Do You Feel? Interoception: The Sense of the Physiological Condition of the Body

How Do You Feel – Now? The Anterior Insula and Human Awareness

Role of the Insular Cortex in the Modulation of Pain

The Insular Cortex and Frontotemporal Dementia

A Case of Infarct Connecting the Insular Cortex and the Heart

The Insular Cortex: Part of the Brain that Connects Smell and Taste?

Stuttered Swallowing and the Insular Cortex

YouTubing the Insular Cortex (Brodmann Areas 13, 14 and 52)

New Version of Video on Insular Cortex Uploaded

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

Building a Model of the Insular Cortex – Part 6: A Recap

Figure showing the insular cortex (circled) in a coronal section indicated by the blue line in the inset, Modified from Original Image by John Beal PhD, Dep’t. of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center Shreveport, CC-BY

In this series of posts I am describing the process of building a model of the Insular Cortex. I thought the most straightforward way to develop such a model is to begin with a narrative. This informs a top-down approach where an overview is gained before the details are filled out. Although this model is specific to the Insular Cortex, the approach can be applied to other brain regions. I have described this as an open model – one which uses the principles of the web which is collaboration. There have been numerous contributions which I can delineate more clearly once the basic structure starts to take shape.

In the series so far there have been four parts each focusing on a different narrative.

Part 1 – The intensity of emotional experience is dependent on two factors

1. The GABA receptor density in the Anterior Insular Cortex

2. The sensory input to the Anterior Insular Cortex

Furthermore a reduction in emotional experience can lead to difficulties in relationships with others.

Part 2 – Looking at Craig’s work there is a brief look at Craig’s idea that the Von Economo Neurons which are highly interconnected to other widely dispersed neurons, form the basis for conscious experience.

Part 3 – Looking again at Craig’s model of the Insular Cortex he proposes that

1. The Anterior Cingulate Cortex and the Anterior Insular Cortex are tightly linked

2. The Anterior Insular Cortex acts as the Limbic Sensory Cortex

3. The Anterior Cingulate Cortex acts as the Limbic Motor Cortex

4. That emotions are associated with actions

5. The Anterior Cingulate Cortex is the locus for our sense of agency associated with an emotion

6. The Anterior Insular Cortex is the locus for our experience of an emotion

Part 4 – Looking again at Craig’s model, he argues that the Anterior Insular Cortex is the locus for human awareness or consciousness as it is activated in numerous functional Magnetic Resonance Imaging studies.

I argue that this narrative is countered by critiques of functional Magnetic Resonance Imaging methodology where there are alternative explanations for apparent Anterior Insular Cortex activity. Instead consciousness exists as a modular phenomenon which is mapped onto distributed brain regions.

Part 5 – Looking again at Craig’s model, he looks at an evolutionary explanation of the Insular Cortex in which

1. The Hippocampus and Amgygdala received olfactory inputs in early mammals

2. The Anterior Cingulate Cortex initiated actions in response to the processing of these stimuli

3. Mammals organised group behaviours in response to olfactory stimuli

4. They started to respond to autonomic activity which was processed by the Insular Cortex

5. The Insular Cortex expanded and utilised the Anterior Cingulate Cortex to effect motor responses to the autonomic input

There are many other aspects of Craig’s model to examine and a wider body of research literature and comments to incorporate into the model.

Insular Cortex Resources on this Site

Developing a Model of the Insular Cortex and Emotional Regulation: Part 1

Building a Model of the Insular Cortex – Part 2

Building a Model of the Insular Cortex – Part 3

Building a Model of the Insular Cortex – Part 4

What does the Insular Cortex Do Again?

Insular Cortex Infarction in Acute Middle Cerebral Artery Territory Stroke

The Insular Cortex and Neuropsychiatric Disorders

The Relationship of Blood Pressure to Subcortical Lesions

Pathobiology of Visceral Pain

Interoception and the Insular Cortex

A Case of Neurogenic T-Wave Inversion

Video Presentations on a Model of the Insular Cortex

MR Visualisations of the Insula

The Subjective Experience of Pain

How Do You Feel? Interoception: The Sense of the Physiological Condition of the Body

How Do You Feel – Now? The Anterior Insula and Human Awareness

Role of the Insular Cortex in the Modulation of Pain

The Insular Cortex and Frontotemporal Dementia

A Case of Infarct Connecting the Insular Cortex and the Heart

The Insular Cortex: Part of the Brain that Connects Smell and Taste?

Stuttered Swallowing and the Insular Cortex

YouTubing the Insular Cortex (Brodmann Areas 13, 14 and 52)

New Version of Video on Insular Cortex Uploaded

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

The History of the Insular Cortex? Building a Model of the Insular Cortex – Part 5

Figure showing the insular cortex (circled) in a coronal section indicated by the blue line in the inset, Modified from Original Image by John Beal PhD, Dep’t. of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center Shreveport, CC-BY

This is the fifth part of a series looking at building a model of the Insular Cortex, part of the brain that is thought to play an important role in emotions and awareness. ‘In the 2009 paper ‘How Do You Feel Now? The Anterior Insula and Human Awareness‘ Craig outlines an elegant model of the Insular Cortex which integrates neurophysiological findings. In developing the current model, I thought Craig’s model of the Insular Cortex would be a useful starting point for refining the model covered in Part 1 (see Appendix)’*.

In order to build a model of the Insular Cortex i’m following a two step process. Firstly i’m gaining an overview of Insular Cortex function. Secondly when this has been satisfactorily achieved I will fill out the details in the model. Craig covers a lot of ground in his review. Using this as a template is a little tricky but the reason is grounded in the problems facing Neuroscience. Essentially Craig cites numerous studies ranging from basic neurophysiology through to functional Magnetic Resonance Imaging studies investigating specific psychological phenomenon and also includes arguments based on behavioural evolution. An overview of the Insular Cortex necessarily broaches several paradigms and yet this may be necessary in order to gain insights into the emotions. However the structuring of this overview needs to be sensitive to the theoretical challenges posed by linking multiple paradigms.

I’ll focus here on one aspect of Craig’s model – the behavioural evolution of the Insular Cortex. Craig mentions a few things

1. In early mammalian evolution, group behaviour was directed by olfactory stimuli. Mammals cooperated and this group cooperation was driven by smells in the environment. A cursory examination of the footage of Lemurs below shows in some segments the Lemurs overtly smelling parts of the environment. The Lemurs diverged from our ancestors approximately 40 million years ago. Their behaviour can be contrasted with ours and provides supporting evidence for Craig’s assertions. Nevertheless there are other mammal species that demonstrate an even closer relationship between olfaction and behaviour.

2. The Hippocampus and Amygdala are closely related to the Olfactory Cortex both in ourselves and other mammals.

3. In early mammals the Hippocampus and Amygdala would integrate olfactory information

4. The Anterior Cingulate Cortex generated motor actions in response to the output from the Hippocampus and Amygdala

5. The Insular Cortex integrated autonomic activity

6. As behaviours moved away from Olfactory determined group behaviours to individual behaviours interoceptive information became more important in determining behaviour.

7. The Insular Cortex expanded

8. The Insular Cortex and Anterior Cingulate Cortex became linked enabling interoceptive stimuli to generate motor responses through the Anterior Cingulate Cortex

This is a rather simple overview of one aspect of the model. This allows for consideration of further evidence in order to refine the model. The comparative anatomy undertaken by Brodmann may offer insights in this regards.

Insular Cortex Resources on this Site

Neuroanatomy

Building a Model of the Insular Cortex – Part 4

Building a Model of the Insular Cortex – Part 3

Building a Model of the Insular Cortex – Part 2

Developing a Model of the Insular Cortex and Emotional Regulation Part 1 Developing a Model of the Insular Cortex: A Recap

Video Presentations on a Model of the Insular Cortex

What does the Insular Cortex Do Again?

How Do You Feel? Interoception: The Sense of the Physiological Condition of the Body

How Do You Feel – Now? The Anterior Insula and Human Awareness

Insular Cortex Infarction in Acute Middle Cerebral Artery Territory Stroke

The Insular Cortex and Neuropsychiatric Disorders

The Relationship of Blood Pressure to Subcortical Lesions

Pathobiology of Visceral Pain

Interoception and the Insular Cortex

A Case of Neurogenic T-Wave Inversion

MR Visualisations of the Insula

The Subjective Experience of Pain

Role of the Insular Cortex in the Modulation of Pain

The Insular Cortex and Frontotemporal Dementia

A Case of Infarct Connecting the Insular Cortex and the Heart

The Insular Cortex: Part of the Brain that Connects Smell and Taste?

Stuttered Swallowing and the Insular Cortex

YouTubing the Insular Cortex (Brodmann Areas 13, 14 and 52)

New Version of Video on Insular Cortex Uploaded

 

*Text taken from Part 3.

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

A Brain Dissection Video Showing Basic Neuroanatomy Concepts

This is an informative brief introduction to Neuroanatomy featuring a dissection of a brain by Evan Ehrenberg.

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.