Category Archives: brain

Do Smaller Species See in Slow Motion?

A few years ago I was playing about with the slow motion feature on my camcorder and had a bit of fun speculating about why we don’t see in slow motion. I wondered why flies seem to respond so quickly to stimuli in the environment. Little did I know that a few years later researchers would look at this question in more detail and find some very interesting correlations.

The researchers have recently published this study in the Journal of Animal Behaviour. They hypothesised that species with a higher basal metabolic rate would have more energy to invest in the high resource activity of high resolution motion processing. They also hypothesised that larger species, being less manoeuvrable would have less need for high resolution motion processing with the converse being true for smaller species.

The research group then looked at basal metabolic rate data for several species (although there were a few adjustments explained in the paper).

slowmotionvision

In the graphs above, the researchers have plotted critical flicker fusion frequency (CFF) against Body Mass and Basal Metabolic Rate respectively. Critical flicker fusion frequency is the lowest frequency at which a flashing light source is perceived as constant.

The researchers found the correlation they expected in the graphs above. Correlation doesn’t necessarily imply causation but it certainly does provide some strong evidence in support of their hypotheses. So flies may be able to visually process the world much more quickly than we are. Could this apply to humans during development?

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.

Questions Raised by the Model: Building a Model of the Insular Cortex – Part 21

A Model of the Insular Cortex

In the last post we looked at some of the features of the model as it begins to take shape. Could the Insular Cortex act as a transformer in a simple system where physiological responses are translated into emotional experiences in a single part of the brain.

Such a model as it is stated is simple, perhaps too simple and raises a number of questions

1. Does information from physiological responses require more than one step to be transformed into emotional experiences?

2. If a transformative function is required should this occur in just a single location or like many functions would this be distributed?

3. If the Insular Cortex were the only location for this transformation then would that determine many of the anatomical relationships it has with other structures e.g. would it need a direct or indirect connection with all other areas involved in emotional experience or regulation?

4. What constitutes a physiological response? The perception of neutral stimuli in the environment is a physiological response involving the sensory and perceptual apparatus. Do the physiological responses relevant to this discussion have to be characterised?

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: Reviewing a Model by Craig – Part 1

Building a Model of the Insular Cortex – Part 3: Reviewing a Model by Craig – Part 2

Building a Model of the Insular Cortex – Part 4: Reviewing a Model by Craig – Part 3

Building a Model of the Insular Cortex – Part 5: The Evolution of the Insular Cortex

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

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

Building a Model of the Insular Cortex – Part 8: The Cannon-Bard Thalamic Theory of Emotions

Building a Model of the Insular Cortex – Part 9: Charles Darwin on the Expression of the Emotions

Building a Model of the Insular Cortex – Part 10: The Limbic System

Building a Model of the Insular Cortex – Part 11: A Second Recap

Building a Model of the Insular Cortex – Part 12: GABA receptors and Emotions

Building a Model of the Insular Cortex – Part 13: GABA receptors and Nematode Worms

Building a Model of the Insular Cortex – Part 14: Are GABA Receptors Related to Anxiety in Humans Because Worms Wriggle?

Building a Model of the Insular Cortex – Part 15: Another Recap

A Diversion into the Limbic System: Building a Model of the Insular Cortex – Part 16

A Look at the Amygdala-PFC Dyad – Building a Model of the Insular Cortex – Part 17

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

Contributors to the Model (links are to the posts in which contributions were made – these links may contain further links directly to the contributors)

Ann Nonimous

The Neurocritic

Psico-logica

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 Science of Magic…. and it Involves Attention

“You see, but you do not observe. The distinction is clear. For example, you have frequently seen the steps which lead up from the hall to this room.”
“Frequently.”
“How often?”
“Well, some hundreds of times.”
“Then how many are there?”
“How many? I don’t know.”
“Quite so! You have not observed. And yet you have seen. That is just my point. Now, I know that there are seventeen steps, because I have both seen and observed.”
from ‘A Scandal in Bohemia’, Sir Arthur Conan Doyle, 1891

iStock_000013481752Small

In this TEDx talk, psychologist Gustav Kuhn takes us through the science of magic. As a magician himself he has the advantage of having two perspectives on this subject. The analogy between magic and research studies where subjects are distracted from the aim of the study is an interesting point.

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 20

A Model of the Insular Cortex

In preceding posts we have looked at various models of emotions in the brain which have allowed the contextualisation of a model of the Insular Cortex. Two early and general models of emotions look at the relationship between emotions and physiological responses to stimuli.

There are at least two ways in which this relationship can happen. We sense a stimulus – a spider for example. When we see the spider we experience fear and our heart starts to race. Or else we see the spider and our heart races and we respond with the sense of fear.

In this simplistic model there would need to be a means of transforming information from physiological responses into emotional experiences. In this context we can start with the hypothesis that the Insular Cortex is a transformer. In just the same way we could also argue that the Insular Cortex transmits information from physiological responses or else that it is the location for emotional experiences.

Regardless of whether this is correct or not, this explicit hypothesis enables us to explore the function of the Insular Cortex and also the question of whether information from physiological responses can be converted directly into emotional experiences or whether one or more transformative steps are required.

There are still a few steps before the contextualised model can be stated.

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: Reviewing a Model by Craig – Part 1

Building a Model of the Insular Cortex – Part 3: Reviewing a Model by Craig – Part 2

Building a Model of the Insular Cortex – Part 4: Reviewing a Model by Craig – Part 3

Building a Model of the Insular Cortex – Part 5: The Evolution of the Insular Cortex

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

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

Building a Model of the Insular Cortex – Part 8: The Cannon-Bard Thalamic Theory of Emotions

Building a Model of the Insular Cortex – Part 9: Charles Darwin on the Expression of the Emotions

Building a Model of the Insular Cortex – Part 10: The Limbic System

Building a Model of the Insular Cortex – Part 11: A Second Recap

Building a Model of the Insular Cortex – Part 12: GABA receptors and Emotions

Building a Model of the Insular Cortex – Part 13: GABA receptors and Nematode Worms

Building a Model of the Insular Cortex – Part 14: Are GABA Receptors Related to Anxiety in Humans Because Worms Wriggle?

Building a Model of the Insular Cortex – Part 15: Another Recap

A Diversion into the Limbic System: Building a Model of the Insular Cortex – Part 16

A Look at the Amygdala-PFC Dyad – Building a Model of the Insular Cortex – Part 17

Building a Model of the Insular Cortex – Part 19

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

Contributors to the Model (links are to the posts in which contributions were made – these links may contain further links directly to the contributors)

Ann Nonimous

The Neurocritic

Psico-logica

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.

Auditory Ambigrams? Do These Auditory Illusions Tell Us Something About Auditory Hallucinations?

The video above from Kyle Manley’s channel illustrates a range of auditory illusions. The reader may recognise the initial Shepard tones from a previous post. Although the sounds are rather ominous, working through the video the most remarkable segment contains the words ‘high’ and ‘low’. When different words are presented on the screen the spoken words take on the appearance of the written words. I was able to hear these words convincingly for the first few words although it was a little less convincing for later words. I will refer to the effect eponymously as the Manley Words.

These illusions are quite impressive and have some similarities to the McGurk Effect examined in a previous post. In both cases, if you are expecting something from a visual cue then this can influence your perception of sounds. To hear the same sound as pine, magpie and bagpipe as simple examples suggests that these effects are quite powerful.

Ambigrams are symbols that manifest a different meaning when viewed from another perspective. The sounds in the videos above are effectively auditory ambigrams and the perspective is contextualised by the presented visual information. If we can characterise the McGurk Effect and the Manley Words as auditory ambigrams contextualised by visual stimuli then we can look at auditory hallucinations from another perspective.

There will be no explanation for all cases of auditory hallucinations as they are symptoms with a heterogenous collection of causes. In some cases however, these causes relate to hearing impairment. In such cases we can hypothesise that

p(H) = c (B/A)

where

p(H) is the probability of an auditory hallucination

A is the clarity of a stimulus

B is the strength of the contexualising stimulus

c is a constant

Unfortunately this equation is only useful in demonstrating relationships. The difficulty is that B is difficult to define. In the case above the meme is this:- what we are hearing is actually the visually presented word. The clarity of the stimulus is dependent on the person’s hearing, the loudness and proximity of the auditory stimulus and also the number of similar words that the stimulus must be distinguished from.

There is still some difficulty in distinguishing the above from an illusion. If one word is mistaken for another then it is more likely to be an illusion. Background sounds such as the wind or the sea are more difficult to interpret. There can be a case for referring to them as hallucinations although this will dependent on the context (strictly speaking hallucinations occur in the absence of a stimulus – however visual hallucinations occur on a background of a visual stimulus – it is just that they are considered significantly different).

Looking at the formula above it reads that the likelihood of an auditory hallucination is proportional to the strength of the contextualising stimulus (e.g. a strong belief about the world) divided by the clarity of the stimulus (e.g. someone saying Hello very loudly and clearly is a clear stimulus). If a person is driven by a strong belief then this can cause them to misinterpret what it is that they are hearing. In the example above if we look for the word bagpipe or the word pine that is what we will hear particularly where the stimulus is ambiguous.

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.

Returning to the Beginning: Building a Model of the Insular Cortex – Part 19

A Model of the Insular Cortex

Almost 5 years ago, we looked at a model of the Insular Cortex that started with a few assumptions from some papers which included one looking at GABA receptors in the Insular Cortex and anxiety. Along the way we looked at works by Antonio Damasio and A.Bud.Craig. More recently we have looked at other areas of the brain implicated in our emotional experiences as well as some of the influential models of the Limbic System.

Returning to the beginning and looking at how to build such a model it seems sensible to contextualise the model in terms of the most influential theories in this area. William James and Carl Lange raised the question of whether we first experience physiological reactions and then emotions whilst in the Cannon-Bard theory the reverse is stated. In either case there is a stated connection between physiological reactions to events and emotions.

These physiological reactions in the body produce information. The process of responding to this information is interoception. The Insular Cortex receives interoceptive input from the body leading to a posited role in interoception. Referring to the discussion above we can see that the Insular Cortex is therefore a natural point of enquiry for exploring the relationship between physiological responses to events and our emotional experiences.

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: Reviewing a Model by Craig – Part 1

Building a Model of the Insular Cortex – Part 3: Reviewing a Model by Craig – Part 2

Building a Model of the Insular Cortex – Part 4: Reviewing a Model by Craig – Part 3

Building a Model of the Insular Cortex – Part 5: The Evolution of the Insular Cortex

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

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

Building a Model of the Insular Cortex – Part 8: The Cannon-Bard Thalamic Theory of Emotions

Building a Model of the Insular Cortex – Part 9: Charles Darwin on the Expression of the Emotions

Building a Model of the Insular Cortex – Part 10: The Limbic System

Building a Model of the Insular Cortex – Part 11: A Second Recap

Building a Model of the Insular Cortex – Part 12: GABA receptors and Emotions

Building a Model of the Insular Cortex – Part 13: GABA receptors and Nematode Worms

Building a Model of the Insular Cortex – Part 14: Are GABA Receptors Related to Anxiety in Humans Because Worms Wriggle?

Building a Model of the Insular Cortex – Part 15: Another Recap

A Diversion into the Limbic System: Building a Model of the Insular Cortex – Part 16

A Look at the Amygdala-PFC Dyad – Building a Model of the Insular Cortex – Part 17

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

Contributors to the Model (links are to the posts in which contributions were made – these links may contain further links directly to the contributors)

Ann Nonimous

The Neurocritic

Psico-logica

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.

Neurogenesis in the Brain: A Talk by Professor Richard Faull

In this TEDx talk, Professor Richard Faull talks about his research into neurogenesis in the brain. When the brain matures it doesn’t produce new neurons – at least that used to be a central dogma of neuroscience.  Professor Faull’s research initially into people with Huntington’s Disease and then into models of neurogenesis uncovered a neurogenesis pathway in the brain. His team located the origin of the stem cells that gave rise to the new neurons. This knowledge also had many practical applications. Stimulation and exercise promote this neurogenesis and fit in with our understanding of such activities from other areas of research.

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.