Monthly Archives: February 2013

MedFest Film Festival 2013

The UK medical film festival MedFest is taking place across the UK in February and March 2, 2013. The festival was founded by psychiatrist Dr Kamran Ahmed. The theme of this year’s festival is ‘The Power of Medicine’. The medfest website can be found here. There is also a video of the 2011 film festival on the Royal College of Psychiatrists YouTube Channel shown below.

A Short Film About the 2011 MedFest Film Festival

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.

Updated Links

links

The site links have been updated. On the right hand side of the screen there is a Blogroll followed by other links to external sites. Broken links have been removed and new links added. These represent a portion of the high quality sites on the web and are not affiliated to this site.

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 Centre for the Emotions? – The Limbic System: Building a Model of the Insular Cortex – Part 10

The Hippocampus

In this post we will continue to look at key models of emotions – this time focusing on the Papez circuit and its later development into the concept of the Limbic System.

Roxo and colleagues have published an article in the ‘Scientific World Journal’ titled ‘The Limbic System Conception and its Historical Evolution’. The article is freely available at PubMedCentral. This article is well worth looking out for the interested reader as the authors have have written an engaging article which provides an overview of the history of the limbic lobe and they communicate this clearly.

In the following I will take some of the important points from their document which will be helpful in building a model of emotional regulation.

1. Broca referred to the Great Limbic Lobe. This term was derived from the French word limbique meaning hoop. The limbic lobe was then referred to as the Rhinencephalon. Various other structures were incorporated into the Rhinencephalon by subsequent researchers.

2. In 1939 Kluver and Bucy showed that bilateral Temporal lobectomy produced an eponymous syndrome characterised by oral behaviour and passivity.

3. In 1937 Papez described the circuit of Papez. He proposed this as a circuits for the emotions which included the mesial Cerebral Cortex, Hypothalamus, Anterior Cingulate Cortex and the Hippocampus. Papez also believed that activity in the cerebral cortex was necessary for the experience of the emotions.

The Anterior Cingulate Cortex

4. McLean referred to the Rhinencephalon as the visceral brain. He suggested a role for the visceral brain in physical illnesses. McLean deemphasised the importance of the olfactory system in the emotions. He also suggested that the Hippocampus was the nucleus of the limbic system. McClean also suggested that emotional experiences resulted from an integration of sensations originating internally and externally. McLean looked at ways in which the limbic system could integrate these types of sensation.

5. McLean suggested the concept of the Tri-Une brain in 1969 which was divided into the Reptilian Brain, the Visceral Brain i.e. Limbic System and the Neocortex. McLean proposed that the Reptilian Brain was optimised for survival at an individual and group level.

6. LeDoux has suggested that there are additional systems involved in emotions and makes numerous points about the limbic system and its limitations based on research data.

Related 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

Building a Model of the Insular Cortex – Part 7

Building a Model of the Insular Cortex – Part 8

Building a Model of the Insular Cortex – Part 9

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.

Visuospatial Performance Associated with Visual Hallucinations in Dementia : News Roundup: February 2013 3rd Edition

In a longitudinal study by Bobo and colleagues the researchers looked at men aged 50 and over during a 10 year period to identify predictors of alcohol use. The researchers found that 30.7% of the men in the study were classed as moderate drinkers during the study period. The results were complex and dependent on the baseline characteristics and interacted with the number of variables including age education and self-reports of health. The researchers recruited people from the health and retirement study and the research was undertaken by the Centre for Public health research and evaluation in Seattle Washington.

In a meta-analysis of Magnetic Resonance Imaging studies Sexton and colleagues identified a reduction in the volume of the Hippocampus in older adults with Depression compared to control groups. The researchers also identified similar volume reductions in the Thalamus, Putamen and Orbitofrontal Cortex.

The Hippocampus

Feng and colleagues looked at 228 people aged 55 and above using Magnetic Resonance Imaging of the brain as well as a number of blood tests and physical measures. The researchers were interested in the associations with elevated Homocysteine. The researchers found that elevated Homocysteine levels were associated with lower performance on cognitive testing and reduced white-matter volume. However the elevated Homocysteine levels were not correlated with decreased Hippocampal volume or the volume of white-matter hyperintensities.

Hamilton and colleagues looked at the relationship between performance on a visuospatial task (Block design task) and subsequent development of visual hallucinations in people with Alzheimer’s disease and Lewy body dementia. The researchers found that severe visuospatial deficits (2.5 standard deviations below the mean) were associated with conversion to visual hallucinations of new onset in 61% of cases of people we’ve Lewy body dementia and 38% of those with Alzheimer’s disease. Mild visuospatial deficits were associated with a much lower percentage of people come developing new onset visual hallucinations. These findings therefore suggest that visuospatial performance may influence the likelihood of visual hallucinations in both Alzheimer’s disease and Lewy body dementia but more so in the latter condition.

Simon and colleagues looked at how well people were able to recall their response to antidepressants. The researchers looked at 1878 people who had two more episodes of clinical depression. The subjects were asked to complete structured recall of response to previous medications. This was then compared against the medical records. In the medical records treatment response was evaluated using PHQ-9 scores. The researchers concluded that there was a low agreement (Kappa 0.10 with a 95% confidence interval of 0 to 0.25) between structured recall and PHQ-9 scores for response attributed to treatment. The researchers comment on the utility of interview assessments on the basis of their results.

Appendix

News Round-Up 2008-2011

News Round-Up 2012

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.

Looking at the Genetics of Bipolar Disorder

The Australian National University Channel features interesting educational videos about numerous subjects including Psychiatry. One of the videos (with a creative commons license) is given by Psychiatry Professor Philip Mitchell (see above). In this video he talks about a study he has initiated looking at the offspring of people with Bipolar Disorder where the researchers are trying to understand more about the factors predicting conversion. However Professor Mitchell also takes the time to summarise some of the Genome Wide Association Studies as well as taking a closer look at individual gene candidates which are associated with an increased risk of Bipolar Disorder.

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.

Revising the Three Structure Model: Integration in Neuroscience: A Core Problem – Part 8

Slide1

A Three Structure Model of Neural Activity in Relation to Consciousness and Language

In the last post I expended on the three model structure relating unconscious activity,conscious experience and language. In particular I looked at is how unconscious activity could be divided into absolute unconscious activity which would never reach conscious experience and transient unconscious activity which could. These changes are reflected in the diagram below.

ThreeStructureModelRevisedHow do these two types of unconscious activity that I’m proposing relate to language? A valid model would need practical applications and be able to say something useful about reality. Let us consider the example of the optic nerve. I have assumed that as one of the cranial nerves which conveys information to the visual cortex that it would be devoid of conscious experience. I don’t think this is too unreasonable. Now the question is how does absolute unconscious activity reach the stage of language? In the three structure model I have proposed that language would need to be preceded by conscious experience.

Intuitively we might suppose it is obvious that the information being transmitted from the eye via the optic nerve could be directly translated into language. However although there is processing in the retina before the information is transmitted down the optic nerve I am assuming that this is absolute unconscious activity. Therefore there has to be an indirect way for this activity to reach the stage of language. My suggestion is that this would occur by inference.

The reader may suppose that it is simple enough to demonstrate that activity in the retina leads directly to language describing this experience. For instance the simple act of opening one’s eyes in the morning allows the rays of sunshine to permeate the retinal layer. We might then say “it is very bright this morning”. Surely the activity in the retina has led directly to language? However the answer in this case is that it has not. Activity in the retinal layer is conveyed by the optic nerve to the visual cortex and also to other areas by the accessory optic tract. I would argue that it is in the visual cortex and visual association cortices where the conscious experience is occurring that precedes language.

However there is something quite curious that we need to explain. How is it that we can anticipate what the world will look like if one of our eyes is closed? We know intuitively that one part of the visual field will be obscured. I would argue that this is inference. We use our sensory apparatus almost continuously during wakefulness. We have developed through the course of our life a good understanding of what effects occur when we cover one eye, blink rapidly or look up suddenly. This understanding occurs through our conscious experience which is triangulated with a conscious experience occurring in the visual association cortex, visual cortex and associated areas.

The inferences that we make about the eye and its structures occurs in conscious experience and transient unconscious activity. If I close my eye I’m aware of the eye the eyelid and the surrounding structures. I know from past experience what will happen to my visual perception when I close the eye. When I close my eye my visual perception will alter. I’m combining direct conscious experience with a conscious experience based on inference about absolute unconscious activity. The direct conscious experience is exemplified by the statements

the wall in front of me is a pale blue in colour

The inference about absolute unconscious activity is exemplified by the statement

I will no longer see the blue wall in front of me when I close my eyes

 The study of physiology may lead to an improvement in the inferences that we are able to draw in our conscious experience. We are in effect model building. The conscious experience of inference about our sensory apparatus is most likely distinct from our conscious experience of visual perception. Continuing with this compartmentalisation both these types of conscious experience are very distinct from the absolute unconscious activity occurring in the retina. We might distinguish between the experiential conscious experience of immediate visual perception and the more formalised conscious experience of inference.

The Anatomy of the Eye

Accommodation – The Role of the Lens

Refraction in the Eye

Accommodation – The Role of the Iris

A Little Speculation

All of this follows from the assumptions set out in the three structure model. There is room for a little speculation although in doing this the conclusions are much less firm and this is really an exercise in opening up new vistas. Firstly the conscious experience of visual perception and that of inference may be expected to occur in distinct brain areas. The conscious experience of visual perception may be expected to be closely linked to the emotional centres in brain. The reason I suggest this is that when we are experiencing a landscape for instance, we can be caught up in the moment and access our feelings in response to what we are seeing. There are some difficulties with this however. The visual cortex is located at the back of the brain whereas the Limbic structures (e.g Anterior Cingulate Cortex) and Insular Cortex are located much further forward. However the experience of being able to access emotions more easily with visual perception needs to be balanced by hard calculations. For instance we can calculate how many neuron relays there are between one location and another and then utilise this information together with the conduction velocities. placing too much reliance on the timing of conscious experiences during introspection is fraught with difficulty.

Related Resources on the TAWOP Site

In Support of Method

A Review of the Structure of Scientific Revolutions

An Interpretation of Scientific Revolutions

Integration in Neuroscience: A Core Problem – Part 1

Integration in Neuroscience: A Core Problem – Part 2

Integration in Neuroscience:A Core Problem – Part 3

Integration in Neuroscience: A Core Problem – Part 4: A Language for Mind and Brain?

Integration in Neuroscience: A Core Problem – Part 5: A Three Structure Model

Integration in Neuroscience: A Core Problem – Part 6: Reflection on the Three Structure Model

Integration in Neuroscience: A Core Problem – Part 7: The Unconscious in the Three Structure Model

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.

Working with Pubmed – Part 5: Setting Filters

Medfilters

PubMed* is an extremely useful resource which allows researchers and clinicians to access biomedical databases. The use of PubMed has been discussed elsewhere on this site (see Appendix). Setting up a MyNCBI account allows you to access more features. By accessing the filters site at MyNCBI, the reader is able to get to the filters page (see screenshot). This is a useful feature that lets you set the default for future searches. Returning only research in humans for instance can be useful depending on the nature of the questions being asked.

Appendix – Related Resources on this Site

Working with PubMed – Part 1: Getting started with a shortcut

Working with PubMed – Part 2: Favoriting abstracts

Working with PubMed – Part 3: Bibliography

How to receive research paper e-mail alerts

A Video Celebrating 10 years of PubMed Central

How to improve your search results with Medline

* This article is not affiliated with NCBI

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.