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Archive for March 2012
Heart and brain
30/03/2012 by admin.
I really do try to keep an open mind about this sort of thing. My usually view is very conventional, scientific, no nonsense on most matters; what counts is evidence and logical thinking. But this is something I try to keep from blinding me to possibilities from outside the scientific mainstream. So here is something interesting from IHM (which takes donations and sells products and so may not be a trustworthy scientific source).
Research in the new discipline of neurocardiology shows that the heart is a sensory organ and a sophisticated center for receiving and processing information. The nervous system within the heart (or “heart brain”) enables it to learn, remember, and make functional decisions independent of the brain’s cerebral cortex. Moreover, numerous experiments have demonstrated that the signals the heart continuously sends to the brain influence the function of higher brain centers involved in perception, cognition, and emotional processing.
In addition to the extensive neural communication network linking the heart with the brain and body, the heart also communicates information to the brain and throughout the body via electromagnetic field interactions. The heart generates the body’s most powerful and most extensive rhythmic electromagnetic field. Compared to the electromagnetic field produced by the brain, the electrical component of the heart’s field is about 60 times greater in amplitude, and permeates every cell in the body. The magnetic component is approximately 5000 times stronger than the brain’s magnetic field and can be detected several feet away from the body with sensitive magnetometers.
The heart generates a continuous series of electromagnetic pulses in which the time interval between each beat varies in a dynamic and complex manner. The heart’s ever-present rhythmic field has a powerful influence on processes throughout the body. We have demonstrated, for example, that brain rhythms naturally synchronize to the heart’s rhythmic activity, and also that during sustained feelings of love or appreciation, the blood pressure and respiratory rhythms, among other oscillatory systems, entrain to the heart’s rhythm.
In the context of the neurons in other parts of the body, especially the gut, it would not be surprising if the heart had a similar effect on the brain. The report goes on into various ideas what have less firm foundations, but maybe some grains of truth as well. I am not competent to sort the wheat from the chaff. This part that I have included here does seem fairly reasonable. I have long identified the idea of life with the rhythms of living things and identified the central essence of my ’self’ with the rhythms of my whole body. This may be my illusion (rather than the more common illusion of the conscious mind being the essence of self).
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Animal metacognition
27/03/2012 by admin.
Metacognition, thinking about thinking, is sometimes said to distinguish humans from other animals. It seems that dolphins and some primates, at least, are capable of metacognition. This is reported in a press release from the University of Buffalo, carried by ScienceDaily (here).
Smith and his colleagues provide a comprehensive review of the current state of the animal-metacognition literature. They describe how Smith inaugurated animal metacognition as a new field of study in 1995 with research on a bottlenosed dolphin. The dolphin assessed correctly when the experimenter’s trials were too difficult for him, and adaptively declined to complete those trials. The dolphin also showed his own distinctive set of hesitation, wavering and worrying behaviors when the trials were too difficult. In sharp contrast, when the trials were easy, he swam to the responses so fast that he would make a bow-wave around himself that would swamp Smith’s delicate electronics.
Subsequently, Smith and many collaborators also explored the metacognitive capacities of joystick-trained macaques. These Old-World monkeys, native to Africa and Asia, can make specific responses to declare uncertainty about their memory. They can respond, “Uncertain,” to gain hints from the experimenters of what to do on the first trial of new tasks. They can even respond, “Uncertain,” when their memory has been erased by trans-cranial magnetic stimulation… supports the consensus that animals share with humans a form of the self-reflective, metacognitive capacity. “In all respects,” says Smith, “their capacity for uncertainty monitoring, and for responding to uncertainty adaptively, show close correspondence to the same processes in humans.
Posted in animals | 1 Comment »
Separation of memory and belief
24/03/2012 by admin.
When we watch a show on stage, TV or movie, we do the little trick of suspending disbelief. We do not believe what we are experiencing but we treat the content ‘as if we believed it’ for the duration of the show. We can re-enter that disbelieved experience if we choose, as if it were a memory of something that actually happened. The show can have lasting effects on how we view the world and interact with others. It has all the hallmarks of a really personal experience except that we know it is fictional. Some books and story-tellers have enough power to activate the imagination in this way, even though we do not experience the sight and sound that we would in a show. What is the difference between this sort of memory and what we call false-memory? It is only the believe that the events remembered actually happened to us.
According to a recent paper (Clark, Nash, Fincham, Mazzoni – see citation), belief and memory are separate processes. We can have: memories that we believe were events, memories that we do not believe were events, beliefs about events that we do not remember, and events that we neither believe nor remember. So in the same way that sight is not like a camera, hearing is not like a microphone – memory is not like a video recording, and a good thing too, or we would have much less material to think with. But we have to be aware that there are such things as false-memories; they may even be quite common.
The authors found that belief is easier to modify than memory. It is easier to create a false belief in a subject that it is to create a false memory. And likewise, it is easier to destroy a false belief than a false memory. You can remain with a memory of an event, long after you have been convinced that the event did not happen and the memory is false.
The authors sound a note of caution:
Finally, our findings have broader implications for memory distortion research. To the extent that debriefing might not always completely ‘undo’ the effects of a suggestive manipulation, we might question the ethics of inducing false memories in experimental participants. Is it ethical for participants to leave research labs with remnants of nonbelieved false memory content in the forefront of their minds? A sensible approach to answering this question might be to consider whether the memories would likely be consequential. For example, it is conceivable that a person who ceased believing in a traumatic experience might nevertheless continue to be traumatised by intrusive mental images experienced as memories. We suggest that for most false-memory paradigms and study designs, this is highly unlikely to pose an ethical problem. Nevertheless, how participants might feel about any residual memory content should be an important question for researchers to consider when planning studies.
Clark, A., Nash, R., Fincham, G., & Mazzoni, G. (2012). Creating Non-Believed Memories for Recent Autobiographical Events PLoS ONE, 7 (3) DOI: 10.1371/journal.pone.0032998
Posted in memory | 2 Comments »
Blinking BOLD signal
21/03/2012 by admin.
Those that follow this blog know that one of the repeated messages is that the results of single experiments are not to be trusted. We should be convinced by those ideas that have been shown by a number of different people, methods and subjects. (Also nothing is falsified by single experiments.) Its is the fabric, not the thread, of results that is convincing. This is particularly important with new technical tools such as neural scans. We really don’t know how trustworthy they are; the equipment, the mathematical manipulations, the interpretations are in flux. But it is what we have for physical evidence and so we do the best we can with it.
Neuroskeptic (here) has posted on a paper by Hupe and others that shows that there is a BOLD signature from blinks of the eyes in the scans of the visual cortex. It appears that once the problem is known, it should be possible to avoid it affecting results.
it’s long been believed that blink suppression mechanisms in the eye and brain somehow block out the responses that would otherwise happen during a blink….Then they (Hupe etal) simply treated the blinks as events, and used standard analysis methods to find neural activation associated with them. Blinks caused a significant BOLD response over a number of “visual” areas….I don’t think we should be too worried yet….However, as the authors point out, there is a risk that alterations in blink rate, caused, perhaps, by emotional or cognitive stress, might be wrongly “found” to be causing visual cortex activation, which might call into question claims of “top-down” influences on early visual cortex… oh dear.
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The mind wanders
18/03/2012 by admin.
I once had a very boring task that was part of my research (to do with rayon chemistry not the brain). I have never done anything as boring before or since. I had to time how long it took for 100 drops to fall from a tiny hole. So I had to keep a count without losing my place and I had to see and register each drop. It usually took between 5 and 10 minutes for 100 drops to fall. The problem was that there was no rhythm. There might be 2 mins between a pair of drops or there could be 3 or 4 drops almost touching one another. This meant that my whole attention was taken up with watching and counting. I could not let my mind wander at all. After a run, I was worn out with fatigue and had to recover before I could face another run. I often failed in this simple (mindless) procedure and ended up not knowing where I was in the count or whether I had see the last drops. I was only using a tiny bit of my brain and forcing the rest to sit quietly and not even ‘drum its fingers’. An item in ScienceDaily reminded me of that long ago task. (here)
Levinson, Smallwood and Davidson looked at the relationship between working memory and attention. When the task does not use all of someone’s attention – how do they use their idle resources?
The researchers asked volunteers to perform one of two simple tasks, either pressing a button in response to the appearance of a certain letter on a screen, or simply tapping in time with one’s breath - and compared people’s propensity to drift off… People with higher working memory capacity reported more mind wandering during these simple tasks, though their performance on the test was not compromised…. What this study seems to suggest is that, when circumstances for the task aren’t very difficult, people who have additional working memory resources deploy them to think about things other than what they’re doing.
Interestingly, when people were given a comparably simple task but filled with sensory distractors, the link between working memory and mind wandering disappeared. Giving your full attention to your perceptual experience actually equalized people, as though it cut off mind wandering at the pass….In essence, working memory can help you stay focused, but if your mind starts to wander those resources get misdirected and you can lose track of your goal. Many people have had the experience of arriving at home with no recollection of the actual trip to get there, or of suddenly realizing that they’ve turned several pages in a book without comprehending any of the words. It’s almost like your attention was so absorbed in the mind wandering that there wasn’t any left over to remember your goal to read.
Where your mind wanders may be an indication of underlying priorities being held in your working memory, whether conscious or not. But it doesn’t mean that people with high working memory capacity are doomed to a straying mind. The bottom line is that working memory is a resource. If your priority is to keep attention on task, you can use working memory to do that, too. (But it can be very tiring, I remember.)
Posted in attention, memory | 1 Comment »
Why mislead people?
15/03/2012 by admin.
Is it important to society that the public believes in free will even if learned scientists and philosophers do not. Apparently there are those that hold that view. James Miles (see citation) writes that this is irresponsible and a disservice.
Here is the abstract:
Over the last few years, a number of works have been published asserting both the putative prosocial benefits of belief in free will and the possible dangers of disclosing doubts about the existence of free will. Although concerns have been raised over the disservice of keeping such doubts from the public, this does not highlight the full danger that is presented by social psychology’s newly found interest in the ‘hard problem’ of human free will. Almost all of the work on free will published to date by social psychologists appears methodologically flawed, misrepresents the state of academic knowledge, and risks linking social psychology with the irrational.
My nit-picking would not change Miles’ case, just the way in is laid out – and so I will forebear and not discuss his definitions.
Here is the heart of his argument against giving lip service to free will:
Vohs and her co-authors have suggested that perhaps ‘denying free will simply provides the ultimate excuse to behave as one likes’, and that a scientifically backed repudiation of free will ‘may encourage debauched behavior’ as people disabused of the illusion ‘seem to, at least temporarily, abandon their moral code’. Baumeister has claimed that belief in free will ‘supports honest, responsible, moral, helpful, non-aggressive, and otherwise prosocial behavior’. Moral code? Honest, moral, and prosocial?
The myth of free will has been linked to deceit for four hundred years now; the illusionist camp of Wegner is tied to, well, illusion; the compatibilist camp has been accused above of ‘wretched subterfuge’ and of being ‘a quagmire of evasion’; and the libertarian camp of Vohs and Baumeister is at least guilty of not examining too closely. We have seen evidence that the myth of free will is inextricably linked to contempt for the poor and the unlucky, that it undermines both legal and natural justice, and may even make a mockery of the conceit of Christian compassion for the poor and marginalized. According to Anders Kaye, the myth of free will even allows racial prejudice to find a home within the Western law. Honest, moral, and prosocial?
Of course, even if we were to begin to acknowledge the moral and intellectual downsides to the free will myth, this would not suggest that Vohs and Baumeister were right to claim that belief in free will may also have prosocial upsides. We have seen that Vohs and Baumeister appear as yet to have shown no such thing, because all they have been studying appears to have been the effect of an acceptance of fatalism, not disbelief in free will. Contrary to the claims made in social psychology journals, we appear to have seen no evidence to date that disabusing people of the myth of free choice encourages anti-social behaviour, yet significant evidence that the myth of free choice encourages immoral, unjust, prejudiced, and anti-intellectual behaviour. If nothing else, this paper should stand as an important corrective within the psychological literature on free will. …
Wegner echoes this turning-of-a-blind-eye sentiment when he says that ‘sometimes how things seem is more important than what they are’, but how things seem is never more important than what they are for those, such as the poor and racial minorities, who are being discriminated against on this issue. It is time social psychologists stopped advocating illogic and the suppression of knowledge.
Miles, J. (2011). ‘Irresponsible and a Disservice’: The integrity of social psychology turns on the free will dilemma British Journal of Social Psychology DOI: 10.1111/j.2044-8309.2011.02077.x
Posted in will | 3 Comments »
The intelligence divide
12/03/2012 by admin.
So most people believe that human intelligence is a different thing than animal intelligence, or if not really different, at least so much greater in amount that the effect is the same. Think of the quote that Stalin either said or didn’t - “a quantitative difference, if it is big enough, has a quality of difference all its own”. This is a sort of dogma: there is no comparison or likeness between animal and human intelligence. We don’t actually agree on how to define or measure it; we cannot clearly explain its neurobiology. So why be so sure that it is unique in its mechanism and/or orders of magnitude larger in humans over others?
In an article in Discovery (here), Changizi does an excellent job of looking at our underestimation of other animals and overestimation of ourselves. It is good, so follow the link if you have time.
First he points out that we are very good at seeing and judging the intelligence of other people but not good at seeing it in animals. This is to be expected considering evolutionary pressures. I was reminded of someone describing an episode that was burnt into their memory. They were on a fast boat in the Med and some dolphins came along side the started playing in and with the bow wave of the boat. One of the dolphins in a jump catch his eye. “Catch his eye”, he went on talking about this for a long time trying to get us listeners to understand the significance. Somehow the dolphin picked him out, knew he was watching the jump, and ‘catch his eye’ to communicate that spark of recognition. That is the sort of experience that we have with other humans but not that often with animals. We underestimate what we have in common with animals because they cannot read them well. We just have trouble seeing an animal as an individual character that thinks and feels.
Next Changizi points out how little is needed biologically to give us our language and culture and therefore we overestimate our own intelligence. Culture harnessed (Harnessed is the name of his book on the subject) what we had for brains in our cultural evolution without there needing to be much change to our biology in the past couple of hundred thousand years. This would indicate that our brains are not very different in basic mechanisms from other vertebrates and especially other mammals. It is the culture that makes the gap. It is interesting to look at dogs and their owners. It would seem that dogs are much better at reading the thoughts, feelings and intentions of their owners then their owners are attuned to their dogs. Does this mean that dogs are better at non-verbal communication than humans? I think not; humans are just a bit lazy or arrogant and could read their dogs better if they cared to. But it does indicate that dogs do not have a different sort of intelligence or a huge different in amount or they would not be so good at reading us.
Changizi’s final paragraph make clear how complex he thinks intelligence is.
Now, I’d hate to give the impression that, because we humans are much less smart than is commonly thought, that building artificial intelligence is on the horizon. The intelligence of all animals - especially birds and mammals - is so deeply complex that I believe we’re centuries, not decades, away.
My intent in knocking ourselves down a peg is not so much to lower us, but to raise our appreciation of the intelligence found in other animals.
Centuries may be an exaggeration.
Posted in intelligence | 2 Comments »
Crib-sheet wanted
09/03/2012 by admin.
D Bishop has a post on BishopBlog (here), “Time for neuroimaging (and PNAS) to clean up its act”. This is a great posting: well argued and organized.
She has found a paper (for other reasons) that appears to have a good reputation but breaks a number of rules. All its conclusions are invalid. Because some authors had a financial interest in the results, it should have been reviewed carefully but it was not found wanting by the original peer reviewers or later authors who cited it or used its graphics. Wow – what an example.
What was wrong? The first conclusion was not valid because an important control group was missing – a group who had the condition but was not treated. The second conclusion was not valid because it was based on a faulty statistical procedure. The third is invalid it does not take account of within-group variance. Conclusion 4 relied on unusual outliers and some dodgy stats.
She makes some recommendation to correct this sort of thing which she had found in a number of papers.
Is there a solution? One suggestion is that reviewers and readers would benefit from a simple cribsheet listing the main things to look for in a methods section of a paper in this area. Is there an imaging expert out there who could write such a document, targeted at those like me, who work in this broad area, but aren’t imaging experts? Maybe it already exists, but I couldn’t find anything like that on the web.
Imaging studies are expensive and time-consuming to do, especially when they involve clinical child groups. I’m not one of those who thinks they aren’t ever worth doing. If an intervention is effective, imaging may help throw light on its mechanism of action. However, I do not think it is worthwhile to do poorly-designed studies of small numbers of participants to test the mode of action of an intervention that has not been shown to be effective in properly-controlled trials. It would make more sense to spend the research funds on properly controlled trials that would allow us to evaluate which interventions actually work.
Good idea!
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Folk neuropsychology
06/03/2012 by admin.
I find the traces of old theories in our language intriguing. We still talk about heat in ways that hark back to the phlogiston theory – we talk of the flow of heat like it was a fluid. We talk of the sun rising, as if Galileo had never been, although we all know it is the earth that is turning. The language always carries fossils of long-gone beliefs. So it will be with our theories of thought and behavior; the old phrases will remain along side newer understandings.
In our minds we have a simplified version of how the world works. For example infants have a folk physics. They can roughly estimate the path of a falling object. We have the ‘theory of mind’ that gives us a rough understanding of what goes on in the heads of others (and ourselves). We all have a folk psychology that we have built up over the years from what we have read and what we have experienced as a refinement of our theory of mind. Even than it is still a rough estimate of how brains work. It seems we are now creating a folk neuropsychology. Paul Rodriguez has studied this emerging folk ‘knowledge’ using its effect on language (see citation below). This is brought to my attention by an item in the Mind Hacks blog (here).
Rodriguez studied ordinary language in ordinary situations, not the language of experts, and looked for the metaphors and metonymies in use – the method of cognitive semantics. He found that in many statements, ‘mind’ and ‘brain’ were interchangable.
I will argue that for the most part “brain” and “mind” are used in similar ways with similar meanings, but whereas “mind” may have an aspect of subjectivity, “brain” has a concrete and physical dimension.
Examples are given.
THE MIND IS A CONTAINER: in my mind, clear your mind – THE BRAIN IS A CONTAINER: in my brain but not yet on paper, stuff that sticks in our brain
THE MIND IS A MACHINE: crank out ideas – THE BRAIN IS A MACHINE: her brain was churning, my brain wasn’t switched on
THE MIND IS A RECORDING MEDIUM FOR MEMORY (LIKE A COMPUTER): my mind was blank, etched in my mind – THE BRAIN IS A RECORDING MEDIUM: etched onto the brain, imprinted on the brain
THE MIND IS A MUSCLE: mental leaps, mental exercise – THE BRAIN IS A MUSCLE: flex your brain
IDEAS ARE FOOD: hard to swallow, chewing over – THE BRAIN NEEDS IDEAS FOR NOURISHMENT: feed your brain
UNDERSTANDING IN GRASPING: get a handle on, grasp the concept – THE BRAIN CAN UNDERSTAND CONCEPTS BY GRASPING: trying to wrap my brain around it
But there are differences between the metaphoric use of the two words.
Despite the possible overlap in meaning between mind and brain, they are not completely interchangeable. One trivial example is that “mind” can be a verb related to thinking, as in “never mind.” More interestingly, there are common phrases about the mind as a noun that do not seem to apply so easily to the brain. Consider the following examples: “I want to give you a piece of my brain” versus “I want to give you a piece of my mind,” “Will you change your brain?” versus “Will you change your mind?” “Open your brain” versus “Open your mind.”
The nature of some metaphors can be quite reductionist. Here are some examples:
THE BRAIN AS AGENT AND/OR LOCUS OF IDEAS: songs sped from brain to paper
THE BRAIN AS AGENT AND/OR LOCUS OF TRUE KNOWLEDGE: my brain knows what to do but me body won’t do it, they know in their brain but can’t vertalize
THE BRAIN AS AGENT AND/OR LOCUS OF DELIBERATION: how hard it is to ignore the famous even when your brain tells you to.
THE BRAIN AS EXPERIENCER OF PERCEPTIONS: this menu is confusing my brain
If you are as interested in language as you are in neuroscience, I recommend that you read the original paper and enjoy its many insights. It is very readable. You will be able to see the scope of this research from the papers conclusion:
In summary, I have shown that brain and mind have overlapping referents, brain and mind are conceptualized similarly, reporting brain states can be substituted for reporting mental states, and brain images engender new shared cultural symbols that characterize mental phenomena. The use of these brain references to talk about mental states and mental experiences is a reductionist mode of explaining behavior. In that sense, it is a rudimentary folk neuropsychology.
I have also applied a cognitive semantic analysis to the use of metaphors, speech acts, jokes, advertisements, and other images to the ordinary language of “brain.” Other work in the public understanding of genetics, or science and technology more generally, has also examined metaphors, such as frequency and types in popular media or development and change of analogies over time in popular science. For an analysis of lay understandings, some work has used interview techniques to evaluate how science is assimilated. Some analyses of culture and science have also focused on the nature of science narratives and their impact on policy discussions, legal decisions, and personal attitudes. The cognitive semantic analysis of metaphor, speech acts, and imagery in ordinary language is complementary to all these approaches because it focuses on the network of conceptual schemas underlying common sense understanding. As well as identifying and categorizing metaphors as a whole unit, deconstructing the meanings of cultural symbols, or situating social perspectives, a cognitive semantic analysis decomposes the underlying concepts that organize and structure the way we conceive and talk about things. The cognitive semantic analysis helps reveal the source of entailments, generalizations, inferences, discourse effects and social meanings involved in everyday language. This kind of analysis seems especially crucial for the public understanding of neuroscience because the mind is something abstract that we know subjectively, theories of brain function are still immature, and the dualist sense that the mind is not physical makes this a difficult matter to talk about in purely objective terms.
Rodriguez, P. (2006). Talking brains: a cognitive semantic analysis of an emerging folk neuropsychology Public Understanding of Science, 15 (3), 301-330 DOI: 10.1177/0963662506063923
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Change Deafness
03/03/2012 by admin.
A recent paper (K Fenna etal. 2011, When less is heard than meets the ear: Change deafness in a telephone conversation, The Quarterly Journal of Experimental Psychology) showed that there is change deafness as well as change blindness. If people are not expecting the stranger on the other end of a phone call to change, they will not notice the change. We really do not take in as much of what is happening as we think we do. Here is the abstract:
During a conversation, we hear the sound of the talker as well as the intended message. Traditional models of speech perception posit that acoustic details of a talker’s voice are not encoded with the message whereas more recent models propose that talker identity is automatically encoded. When shadowing speech, listeners often fail to detect a change in talker identity. The present study was designed to investigate whether talker changes would be detected when listeners are actively engaged in a normal conversation, and visual information about the speaker is absent. Participants were called on the phone, and during the conversation the experimenter was surreptitiously replaced by another talker. Participants rarely noticed the change. However, when explicitly monitoring for a change, detection increased. Voice memory tests suggested that participants remembered only coarse information about both voices, rather than fine details. This suggests that although listeners are capable of change detection, voice information is not continuously monitored at a fine-grain level of acoustic representation during natural conversation and is not automatically encoded. Conversational expectations may shape the way we direct attention to voice characteristics and perceive differences in voice.
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