an autodidact meets a dilettante…

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Posts Tagged ‘neurology

the short life and strange brains of the octopus, and other thoughts

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a meeting of minds?

Canto: So we’ve been reading about the strange world of the octopus, and her fellow cephalopods, the squid and the cuttlefish, and what they might tell us about other intelligent forms of life. So what might they?

Jacinta: This is quite a new field of investigation, but certainly an exciting one. The octopus appears to be the most intelligent invertebrate on earth, though we still have lots to learn about it, and we know even less about its cephalopod cousins.

Canto: And we need to be careful about the ‘it’ word, as there are at least 300 species of the beasties, which vary considerably in size, habitat and even quite possibly in life-span.

Jacinta: Yes, some octopuses appear to have very short life-spans, a mere two years, but so little is known about so many of the deeper water species out there…

Canto: They’re predators, of course, feeding mainly on crabs, but some of the shallow-water species are known to scavenge off human activities, stealing bait and the like. They have incredibly flexible, almost amorphous bodies that aren’t co-ordinated simply by a central brain. In fact their nervous systems are still very much a source of mystery.

Jacinta: Like our own. Well, okay we know a helluva lot more about ours. Some other facts: they have three hearts, their eight arms or tentacles are made up of four pairs, they’re all more or less venomous, they’re famously able to match their colour to their surroundings pretty well instantly, they can unscrew the lids of jars to get at the contents, some species collect shells to use as constructions around their homes, they have very high brain-to-body mass ratios, and they appear to be very quick to learn new stuff.

Canto: Apparently tentacles are out, they’re called arms. Tentacles are another thing. A cuttlefish has two tentacles and eight arms. Snails have tentacles. As to the brain and nervous systems of octopuses, here’s what we know. Two thirds of its neurons are to be found in its arms, and they can allow the arms to act independently to some extent. Interestingly, although octopuses have complex motor systems, they don’t have an internalised map of the body as vertebrates apparently do. It’s called a somatotopic map, and it’s found in humans in the primary somatosensory cortex, at the top of the brain. Octopuses’ brains/nervous systems are organised quite differently, and that’s the point – their relationship to us on the evolutionary bush is very distant indeed.

Jacinta: Yes, that’s exactly what makes them fascinating – they’ve evolved a complex nervous system on a completely different plan, like aliens.

Canto: Not quite – they still have neurons after all, and DNA. But the link between humans and octopuses probably goes back at least 500 million years, to some of the earliest complex life forms.

Jacinta: Not so complex by modern standards…

Canto: Indeed, something like a sea worm or sea sponge. Anyway, although they appear to have highly developed intelligence, their learning capacity is really hard to ascertain. They’re not highly social animals like many primates and cetaceans are, and they certainly don’t learn from their parents, since both parents ‘fall apart’ and die shortly after breeding.

Jacinta: They’re quite inventive, even playful, they’ve been observed pushing objects into circular currents and catching them. They also board fishing boats in search of food and find ways of getting out of lab aquariums. Their ability to flatten and elongate or bunch up when required makes them very slippery little suckers, you always have to keep an eye on them.

Canto: Well no doubt researchers will be keen to learn more about their neurology, but this relatively new understanding of their smarts raises questions about their treatment by researchers – not to mention eating them en masse. 

Jacinta: Well just sticking with lab treatment, I remember reading in The Lab Rat Chronicles how the rather complacently cruel treatment of lab rats, and all experimental animals, is being questioned more and more, leading to the use of less invasive neurological and other operational approaches..

Canto: Which would in any case be a good thing – the more we can learn without destroying the living thing we’re seeking to learn about, the better, for obvious reasons.

Jacinta: Rats are really smart animals – and just about the most successful animals on the planet – and they certainly feel pain and become depressed, and it’s clear that octopuses do too. In fact some countries have rules against surgical procedures without anaesthetic for octopuses, presumably based on a growing body of knowledge about them.

Canto: They often lose an arm to predators – which by the way they’re able to regrow – and have been observed to favour and tend to damaged or lost arms and other parts, which is a clear sign of ‘feeling’ the damage. But really, the idea that animals don’t feel pain  – any animal – has surely had its day.

Jacinta: So what about eating them? I gather that in some parts, eating them live is a thing.

Canto: Well I’ve always been of two minds about this, about eating other animals. And Peter Wohlleben argues for the smartness and the communal life of trees and plants, so that doesn’t leave us with anything to eat at all, if we’re being truly sensitive to others. But there’s no doubt we’re eating too much, we’re destroying the habitats of huge number of species, on land and sea, to feed our growing and increasingly voracious human population. Nobody knows how that’s going to end, though some are hoping, as ever, for technological fixes – artificial meat, ways of creating bumper harvests using less and less land and so forth.

Jacinta: Another whole realm of discussion, but getting back to octopuses, can they tell us anything about consciousness, given their vastly different origin, compared to us?

Canto: Well I don’t want to get into consciousness now – that’s such a massive subject – but they can tell us a lot about a different neurological system, obviously. The fact is, though, that we observe whales, crows, elephants, octopuses, rats and other creatures that are vastly different from each other behaving in ways we, in our indulgent and sometimes condescending manner, consider intelligent, but we know barely anything about, to paraphrase a philosopher, what it’s like to be any of those creatures. Do they have thoughts like us? Or do they have thoughts, but nothing like our own? Which of course raises the question, what exactly is a thought? Can it be reduced to brain processes or do we lose too much in the reduction? Will our endless and increasing probing of human and other brains definitively answer this question?

Jacinta: I think we’ll have to wait till after we die to find out…

 

References

Other minds: the octopus and the evolution of intelligent life, by Peter Godfrey-Smith

https://en.wikipedia.org/wiki/Octopus

https://onekindplanet.org/animal/octopus/

 

Written by stewart henderson

May 21, 2018 at 10:17 am

The philosophers want more power

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tamsin shaw

tamsin shaw

Canto: Well I suppose the apparent detection of gravitational waves should be capturing our attention more than anything else right now, but it’s very well described in The Economist, and in many other places, and we’re no astrophysicists, and we did promise to focus a bit more on philosophical issues, so…

Jacinta: But we’re no philosophers. But we’re philosophasters at least, so let’s have a go.

Canto: Well I came across an article on Three Quarks Daily which vaguely gave me the irrits, so with your help I want to explore why.

Jacinta: Right. The essay is called ‘The psychologists take power’, the author is Tamsin Shaw and it was originally published in the New York review of books.

Canto: Yes, and on reading it in full I find it an interesting but confused piece, which seems to take the failings of certain individual psychologists as an example of the failings of psychology as a whole, and even of neurology. Shaw seems to be entering the philosophy versus science debate, on the side of philosophy, but I don’t find her arguments convincing.

Jacinta: The essay seems to divide into two parts, first a general critique of psychology and neurology, which can be summed up by the title of a philosophical essay by Selim Berker, which she quotes approvingly, ‘the normative insignificance of neuroscience’. The second part is an account of how certain professional psychologists, practitioners of the ‘positive psychology’ pioneered by the influential Martin Seligman, colluded with the US government in providing dubious evidence for the psychological effectiveness of torture in eliciting valuable information from ‘enemies of the state’. Shaw clearly wants to link these unethical practices to what she might want to call ‘the normative insignificance of psychology’.

Canto: Yes, and it’s a bit of a dangerous game – you might as well label Heidegger’s allegiance to the Nazi party, or Althusser’s murder of his wife, as examples of ‘the normative insignificance of philosophy’.

Jacinta: Ha, well Althusser was declared insane at the time, no doubt by psychologists, who would be examining Althusser to determine whether he was, while strangling his wife, capable of understanding and following the normative rules of his society. Such determinations are hardly normatively insignificant, even though, no doubt, individual psychologists might make different determinations, due to levels of competence, corruption, ideological considerations and so forth.

Canto: Right, but let’s look more closely at Shaw’s essay, and pick it apart.

Jacinta: Okay, but first let’s make a philosophasters’ confession. Shaw mentions eight or so books or sources at the head of her essay, which form the basis of her discussion, but of those we’ve only read one – Pinker’s eloquent tome, The better angels of our nature. And we don’t intend to bone up on those other texts, though no doubt we’ll refer to our own reading in our responses.

Canto: And we are reasonably familiar with Jonathan Haidt’s work and ideas.

Jacinta: So Shaw begins her essay with the overweening ambition of behaviourist extraordinaire B F Skinner, a pretty soft target these days. I have no problems with criticising him, or Freud or any other psychologist whose theories get way out of hand. Shaw’s concerns, though, are specifically about the moral sphere. She feels that a new breed of psychologists, armed with neurological research, are making big claims about moral expertise. Here’s a quote from her essay:

Neuroscience, it is claimed, has revealed that our brains operate with a dual system for moral decision-making.

Canto: I like the ‘it is claimed’ bit. Claimed by who? Someone has put forward that hypothesis I’m sure, along with their reasons, but most neurologists bang on about neurology being a field in its infancy, and most findings are highly contested, it seems to me.

Jacinta: Shaw may be referring to the work of Daniel Kahneman – a psychologist not a neurologist – who distinguished between system 1 thinking (intuitive, less conscious, rough-and ready) and system 2 thinking (reasoned, conscious, more changeable depending on inputs and knowledge). But really there are many dual-process theories going back at least to William James. But Shaw is explicitly referring to the fMRI imaging work of the neurologist Jonathan Cohen, who analysed brain activity when subjects were asked to think about moral hypotheticals.

Canto: Yes and she’s quite straight about describing the two systems apparently highlighted by Cohen’s research and the brain regions associated with them, but becomes scathing in dealing with Joshua Greene, Cohen’s co-researcher, whom she quite deliberately introduces as a mere ‘philosophy graduate student’, whose interpretation of the research she describes thus:

Greene interpreted these results in the light of an unverifiable and unfalsifiable story about evolutionary psychology. Since primitive human beings encountered up-close dangers or threats of personal violence, their brains, he speculated, evolved fast and focused responses for dealing with such perils. The impersonal violence that threatens humans in more sophisticated societies does not trigger the same kind of affective response, so it allows for slower, more cognitive processes of moral deliberation that weigh the relevant consequences of actions. Greene inferred from this that the slower mechanisms we see in the brain are a later development and are superior because morality is properly concerned with impersonal values—for example, justice—to which personal harms and goals such as family loyalty should be irrelevant. He has taken this to be a vindication of a specific, consequentialist philosophical theory of morality: utilitarianism.

Jacinta: Okay, so here’s where psychology – especially evolutionary psychology – first comes under attack. It’s often said to present just so stories, which are necessarily highly speculative, as if they are facts. But I would question whether these speculations, or hypotheses, are unverifiable (forget about falsifiability, a term made popular by Karl Popper but which has come under heavy criticism since, both by scientists and philosophers of science, and I suspect Shaw has simply used it as a ‘double whammy’ to vilify Greene), to me they’re important and useful, and in any case are rarely presented as facts, at least not by the best psychologists.

Canto: So how do you verify this hypothesis, that fast, rough-and-ready responses for dealing with immediate dangers are systematically different from slower, more sophisticated responses that deal with the ‘impersonal violence’, the many restraints, justified or not, on our personal freedoms that we deal with on a daily basis?

Jacinta: Well one obvious way is through neurology, a scientific field still in its infancy as you say. Clearly the system 1 responses would be shared by other complex social mammals, whereas system 2 thinking is much more language-dependent and unique to humans – unless cetaceans have developed complex language, which is far from being out of the question. New techniques for mapping and exploring neural pathways are coming up all the time, as well as non-invasive ways of exploring such pathways in our closest mammalian relatives.

Canto: Good point. So to go to the second part of the above quote, Greene is presented (and I wonder about whether Shaw is fairly or accurately presenting him) as finding system 2 thinking as superior because it deals with more abstract and less personal values, whereas I would prefer to think of this system as a further adaptation, to a human existence that has become more socially complex, systematic and language-based. And in this, I’m apparently in line with the thinking of psychologists Shaw takes aim at:

Many of the psychologists who have taken up the dual-process model claim to be dismissive of philosophical theories, generally. They reject Greene’s inferences about utilitarianism and claim to be restricting themselves to what can be proved scientifically. But in fact all of those I discuss here are making claims about which kinds of moral judgments are good or bad by assessing which are adaptive or maladaptive in relation to a norm of social cooperation. They are thereby relying on an implicit philosophical theory of morality, albeit a much less exacting one than utilitarianism.

Jacinta: But I detect a problem here. You’ve talked about adaptation to the fact of growing social complexity, and the need to co-operate within that complexity. Shaw has written of a ‘norm of social co-operation’, by which she means an ethical norm, because she claims that this is the implicit philosophical theory of morality these psychologists rely on. But that’s not true, they’re not claiming that there’s anything moral about social complexity or social co-operation. We just are more complex, and necessarily more co-operative than our ancestors. So it’s kind of silly to say they’re relying on a less exacting moral philosophy than utilitarianism. It’s not about moral philosophy at all.

Canto: And it gets worse. Shaw claims that this phantom moral ethic of social co-operation is greatly inferior to utilitarianism, so let’s look at that normative theory, which in my view is not so much exacting as impossible. Utilitarianism is basically about the maximising of utility. Act in such a way that your actions maximise utility (act utilitarianism), or create rules that maximise utility (rule utilitarianism). So what’s utility? Nothing that can be measured objectively, or agreed upon. We can replace it with happiness, or pleasure, or well-being, or Aristotle’s eudaemonia, however translated, and the problem is still the same. How do you measure, on a large-scale, social level, things so elusive, intangible and personal?

Jacinta: Yes, and look at how laws change over time, laws for example relating to homosexuality, women’s rights, the protection of minorities, and even business practices, taxation and the like; they’re all about our changing, socially evolving sense of how to co-operate in such a way as to produce the best social outcomes. This can’t be easily bedded down in some fixed normative ethic.

Canto: Yes, Shaw seems to imply that some deep philosophical insight is missing from these psychologists which makes them liable to go off the rails, as the second half of her essay implies, but I’m very doubtful about that. But let’s continue with our analysis:

Rather than adhering to the moral view that we should maximize “utility”—or satisfaction of wants—they are adopting the more minimal, Hobbesian view that our first priority should be to avoid conflict. This minimalist moral worldview is, again, simply presupposed; it is not defended through argument and cannot be substantiated simply by an appeal to scientific facts. And its implications are not altogether appealing.

Jacinta: But surely she’s just assuming that ‘they’ – presumably all the psychologists she doesn’t like, or is it all the psychologists who posit a two-tiered system of decision-making? – take the view that avoidance of conflict is the highest priority.

Canto: Well I must say that Jonathan Haidt seems to take that view, and it’s something I find uncomfortable. So I agree with Shaw that Haidt ‘presupposes that the norm of cooperation should take precedence over the values that divide us’, and that this view is dubious. It’s just that I suspect my own view, that there are values more important than co-operation, is also a ‘presupposition’, though I dislike that word. But more of that later perhaps.

Jacinta: Right, so Shaw refers to the sinister implications of a minimalist Hobbesian worldview, supposedly held by these psychologists. What are they?

Canto: We’ll get there eventually – perhaps. Shaw describes the work of the ‘positive psychology’ movement, stemming from Martin Seligman and practised by Haidt among others, including Steven Pinker, whose book The better angels of our nature was apparently influenced by this movement:

In that extremely influential work Pinker argues that our rational, deliberative modes of evaluation should take precedence over powerful, affective intuitions. But by “rationality” he means specifically “the interchangeability of perspectives and the opportunity the world provides for positive-sum games,” rather than any higher-order philosophical theory. He allows that empathy has played a part in promoting altruism, that “humanitarian reforms are driven in part by an enhanced sensitivity to the experiences of living things and a genuine desire to relieve their suffering.” But nevertheless our “ultimate goal should be policies and norms that become second nature and render empathy unnecessary.”

And here’s where I see another problem. Pinker is here criticised for not subscribing to any ‘higher-order philosophical theory’, but Shaw doesn’t attempt to outline or give examples of such higher-order theories, though she does refer to empathy – an important factor, but one that doesn’t obviously emerge from philosophy.

Jacinta: Right, and we’ve already referred to utilitarianism and its problems. This reminds me that years ago  I read a sort of primer on ethics, I think it was called Moral Philosophy, in which the author devoted chapters to utilitarianism, Kantianism, rights theory and other ethical approaches. In the final chapter he presented his own preferred approach, a sort of neo-Aristotelianism. I was intrigued that he felt we hadn’t made much progress in philosophical ethics in almost 2,500 years.

Canto: Well, his may be a minority view, but it’s doubtful that our changing laws derive from philosophical work on normative ethics, though this may have had an influence. I do think, with Haidt, that there’s a great deal of post-hoc rationalisation going on, though I’m reluctant – very reluctant actually – to embrace the relativism of values. And this brings me to the nub of the matter, IMHO. To go back to an old favourite of mine, Hume: ‘reason is and ought only to be the slave of the passions’. A fairly notorious pronouncement, but I take the passions here to be something very basic – the fundamental drives and instincts, largely unconscious, that characterise us as humans…

Jacinta: But doesn’t Hume break his own is-ought rule here? He says that our passions rule our reason, which may or may not be true, but does it follow that they ought to?

Canto: Please don’t complicate matters. Hume also wrote this, in An Enquiry Concerning the Principles of Morals:

In all determinations of morality, this circumstance of public utility is ever principally in view, and wherever disputes arise, either in philosophy or common life, concerning the bounds of duty, the question cannot, by any means, be decided with greater certainty, than by ascertaining, on any side, the true interests of mankind.

So these true interests of mankind…

Jacinta: Hang on, so there he goes again, gaily bounding over his own is-ought barrier, saying that in order to work out what we ought to do we need – pretty well absolutely – to determine our interests, what in fact makes us human, what we actually are.

Canto: Well, precisely…

Jacinta: Or what we have evolved to become, which might amount to the same thing. So we need to study our evolution, our genes and genetic inheritance, our brain and its inheritance, and adaptive growth, and maybe the physics of our bodies…

our old Scottish mate Davey Hume, doyen of skeptics, whose is-ought distinction has been widely misinterpreted, we suspect

our old Scottish mate Davey Hume, doyen of skeptics, whose is-ought distinction has been widely misinterpreted, we suspect

Canto: So we need neurology, and genetics, and palaeontology, and physics and psychology, all of which contribute to an understanding of what we are. Without them, normative ethics would be empty theorising.

Jacinta: So I suppose you’re going to write a rejoinder to this ‘normative insignificance of neurology’ essay? Something like ‘the insignificance of normative ethics without neurology’?

Canto: Ha, well that would require reading Selim Berker’s essay, which I’m not sure about – so many other things to explore. But I should end this discussion by saying a few words about the second half of Shaw’s article – and I’ll pass over many other points she’s made. This section deals with the collusion of some psychologists, practitioners of the above-mentioned ‘positive psychology’, with the CIA and the US Department of Defence in the commission of torture.

Jacinta: And what exactly is this ‘positive psychology’?

Canto: Well, to explain that would require a large digression. Suffice to say for now that it’s about using psychology to make us more resilient, and in some sense ethically superior, or more benign, humans. Shaw dwells on this at some length, but claims that in spite of much rhetoric, these psychologists can only offer what she calls the bare, Hobbesian ethic of avoidance of strife. However, she herself is unable to point to a more robust, or a deeper, ethic. She presumably believes in one, but she doesn’t enlighten us as to what it might be. And this is very striking because the tale of these psychologists’ collusion with the Bush administration  on torture, and the huge financial gain to them in applying ‘learned helplessness’, a theory of Seligman’s, to the application of torture, is truly shocking.

Jacinta: So it would be a question of what, in their make-up, allowed them to engage in such unethical behaviour, and was it the lack of a deep ethical understanding, beyond ‘bare Hobbesianism’?

Canto: Right, and my answer would be that, although two psychologists took up this lucrative offer to ‘serve the state’, there would have been others who refused, and would any of them, on either side, have made their decision on the basis of some rigorous normative ethic?

Jacinta: I’m quite sure I wouldn’t have colluded with that sort of thing for all the terracotta warriors in China, but I’m also sure it wouldn’t have been for deep philosophical reasons. I just have a kind of visceral revulsion for physical violence and bullying as you know, and I wouldn’t be able to live with myself if I’d facilitated the premeditated cruel and unusual punishment of others. I’m not even sure if it’s about empathy, but it’s not a particularly reasoned position.

Canto: Yes, and so the only way to understand why some people are more prone to do unethical things – actions outside of the ever-changing standards of community ethics – might be to look at individual psychology, and neurology, and genetics, which takes us further away from normative ethics than ever.

Jacinta: Yes, and didn’t we read, in Sam Kean’s The tale of the duelling neurosurgeons, about a poor fellow in his mid-fifties who suddenly started engaging in paedophile acts, something he had never showed any signs of before? A brain scan revealed a large tumour pressing on parts of the brain responsible for higher-order decision-making (to put it over-simplistically). When the tumour was removed he returned to ‘normal’, until some time later he regressed to paedophile acts. A further scan showed they didn’t remove all the tumour and it had regrown. After another more successful operation he was cured and never diddled again. But the consequences of his actions for his victims when ‘not himself’ would have required him to be punished, on a consequentialist ethical view, wouldn’t they?

Canto: Very good point. And yet, and yet… can it be true that we’ve barely gone further in our ethics than the Golden Rule, or Aristotle’s mean between extremes?

Jacinta: We’re animals, don’t forget. Okay we’re animals that have managed to detect waves from space that are a tiny fraction of the diameter of a proton, but we’re still not that good at being nice to each other. And the extent to which we’re able to be nice to each other, and follow social norms, that’s a matter of our individual psychology, our neurology, our individual and cultural circumstances, our genes and our epigenetic profile, so much particular stuff that philosophical ethics, with its generalities, can’t easily deal with.

Written by stewart henderson

February 26, 2016 at 8:37 am

what is autism and what causes it?

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Brain_Autism

The term ‘autism’ was coined in the 1940s by two physicians working independently of each other, Hans Asperger in Austria and Leo Kanner in the USA, to describe a syndrome the key feature of which was a problem with interacting with others in ‘normal’ ways. Sounds vague, but the problem was anything but wishy-washy to these individuals’ parents and families, and over time a more detailed profile has built up.

The term itself is from the Greek autos, or ‘self’, because those with the syndrome had clear difficulties in interpreting others’ moods and responses, resulting in a withdrawn, often antisocial state. Autistic kids often avoid eye contact and are all at sea over the simplest communication.

Already though, I feel I’m saying too much. When describing autism, it’s common to use words like ‘often’ or ‘sometimes’ or ‘some’, because the symptoms are seemingly so disparate. Much of what follows relies on the neurologist V S Ramachandran’s book The tell-tale brain, especially chapter 5, ‘Where is Steven? The riddle of autism’.

Autistic symptoms can be categorised in two major groups, social-cognitive and sensorimotor. The social-cognitive symptoms include mental aloneness and a lack of contact with the world of other humans, an inability to engage in conversation and a lack of emotional empathy. Also a lack of any overt ‘playfulness’ or sense of make-believe in childhood. These symptoms can be ‘countered’ by heightened, sometimes obsessive interest in the inanimate world – e.g. the memorising of ostensibly useless data, such as lists of phone numbers.

On the sensorimotor side, symptoms include over-sensitivity and intolerance to noise, a fear of change or novelty, and an intense devotion to routine. There’s also a physical repetitiveness of actions and performances, and regular rocking motions.

These two types of symptoms raise an obvious question – how are the two types connected to each other? We’ll return to that.

Another motor symptom, which Ramachandran thinks is key, is a difficulty in physically imitating the actions of others. This has led him to pursue the hypothesis that autism is essentially the result of a deficiency in the mirror neuron system.

In recent years there’s been a lot of excitement about mirror neurons – possibly too much, according to some neurologists. A mirror neuron is one that fires not only when we perform an action but also when we observe it being performed by others. They’ve been found to act in mammals and also, it seems, in birds, and in humans they’ve been found in the premotor cortex, the supplementary motor area, the primary somatosensory cortex and the inferior parietal cortex. It’s easier, however, to locate them than it is to determine their function. Clearly, to describe them as ‘responsible’ for empathy, or intention, is to go too far. As Patricia Churchland points out, ‘a neuron is just a neuron’, and what we describe as empathy or intention will likely involve a plethora of high-order processes and connections, in which mirror neurons will play their part.

With that caveat in mind, let’s continue with Ramachandran’s speculations on autism and mirror neurons. First, we’ll need to be reminded of the term ‘theory of mind’, used regularly in psychology. It’s basically the idea that we attribute to others the same sorts of intentions and desires that we have because of the assumption that they, like us, have that internal feeling and processing and regulating system we call a ‘mind’. A sophisticated theory of mind is one of the most distinctive features of the human species, one which gives us a unique kind of social intelligence. That autism would be related to theory-of-mind deficiencies seems a reasonable assumption, so what is the brain circuitry behind theory of mind, and how do mirror neurons fit into this picture?

Although neuro-imaging has revealed that autistic children have larger brains with larger ventricles (brain cavities) and notably different activity within the cerebellum, this hasn’t helped researchers much, because autism sufferers don’t present any of the usual symptoms of cerebellum damage. It could be that these changes are simply the side effects of genes which produce autism. Some researchers felt it was better to focus on mirror neurons straight-off, as obvious suspects, and to see how they fired and where they connected in particular situations. They used EEG (electroencephalography) as a non-invasive way to observe mirror neuron activity. They focused on the suppression of mu waves, a type of brain wave. It has long been known that mu waves are suppressed when a person makes any volitional movement, and more recently it has been discovered that the same suppression occurs when we watch others performing such movements.

So researchers used EEG (involving electrodes placed on the scalp) to monitor neuronal activity in a medium-functioning autistic child, Justin. Justin exhibited a suppressed mu wave, as expected, when asked to make voluntary movements. However, he didn’t show the same suppression when watching others perform those movements, as ‘neurotypical’ children do. It seemed that his motor-command system was functioning more or less normally, but his mirror-neuron system was deficient. This finding has been replicated many times, using a variety of techniques, including MEG (magnetoencephalography). fMRI, and TMS (transcranial magnetic stimulation). Reading about all these techniques would be a mind-altering experience in itself.

According to Ramachandran, all these confirmations ‘provide conclusive evidence that the [mirror neuron] hypothesis is correct.’ It certainly helps to explain why a subset of autistic children have trouble with metaphors and literality. They have difficulty separating the physical and the referential, a separation that mirror neurons appear to mediate somehow.

A well-developed theory of mind which can anticipate the behaviour of others is clearly a feature of understanding our own minds better. In Ramachandran’s words:

If the mirror-neuron system underlies theory of mind and if theory of mind in normal humans is supercharged by being applied inward, towards the self, this would explain why autistic individuals find social interaction and strong self-identification so difficult, and why so many autistic children have a hard time correctly using the pronouns ‘I’ and ‘you’ in conversation. They may lack a mature-enough self-representation to understand the distinction.

Of course, tons more can be said about the ‘mirror network’ and tons more research remains to be done, but there are many promising signs. For example, the findings about lack of mu wave suppression could be used as a diagnostic tool for the early detection of autism, and some interesting work is being done on the use of biofeedback to treat the disorder. Biofeedback is a process whereby physiological signals picked up by a machine from the brain or body of a subject are represented to the subject in such a way that he or she might be able to affect or manipulate that signal by a conscious change of behaviour or thinking. Experiments have been done to show that subjects can alter their own brain waves through this process. Some experimental work is also being done with drugs such as MDMA (otherwise known as the party drug ‘ecstacy’) which appear to enhance empathy through their action on neurotransmitter release.

So that’s a very brief introduction to autism. Hopefully I’ll come back to it in the future to explore the progress being made in understanding and treating the syndrome.

Written by stewart henderson

October 23, 2013 at 10:25 am

What do we currently know about the differences between male and female brains in humans?

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Having had an interesting conversation-cum-dispute recently over the question of male-female differences, and having then listened to a podcast, from Stuff You Should Know, on the neurological differences between the human male and the human female, which contained some claims which astonished me (and for that matter they astonished the show’s presenters), I’ve decided to try and satisfy my own curiosity about this pretty central question. Should be fun.

The above link is to How Stuff Works, which I think is the written version of the Stuff You Should Know podcast, that’s to say with more content and less humour (and less ads), but I do recommend the podcast, because the guys have lots of fun with it while still delivering plenty of useful and thought-provoking info. Anyway, the conversation I was talking about was one of those kitchen table, wine-soaked bullshit sessions in which one of the participants, a woman, was adamant that nurture was pretty well entirely the basis for male-female differences. I naturally felt sympathetic to this view, having spent much of my life trying to blur the distinctions between masculinity and femininity, having generally been turned off by ultra-masculine and ultra-feminine traits and wanting to push for blended behaviour, which obviously suggests we can control these things through nurturing such a blending. However, I had just enough knowledge of what research has revealed about the matter to say, ‘well no, there are distinct neurological differences between males and females’, but I didn’t have enough knowledge to give more than a vague idea of what these differences were. The podcast further whetted my appetite, but writing about it here should pin things down in my mind a bit more, here’s hoping.

I’ve chosen the title of this post reasonably carefully, with apologies for its clunkiness. For the fact is, we still know little enough about our brains. I’ve mentioned humans, but I expect there are gender differences in the brains of all mammals, so I’m particularly interested in that part of the brain that distinguishes us, though not completely, from other mammals, namely the prefrontal cortex.

Here’s an interesting summary, from a blurb on a New Scientist article by Hannah Hoag from 2008;

Research is revealing that male and female brains are built from markedly different genetic blueprints, which create numerous anatomical differences. There are also differences in the circuitry that wires them up and the chemicals that transmit messages between neurons. All this is pointing towards the conclusion that there is not just one kind of human brain, but two. …

Men have bigger brains on average than women, even accounting for sexual dimorphism, but the two sexes are bigger in different areas. A 2001 Harvard study found that some frontal lobe regions involved in problem-solving and decision-making were larger in women, as well as regions of the limbic cortex, responsible for regulating emotions. On the other hand, areas of the parietal cortex and the amygdala were larger in men. These areas regulate social and sexual behaviour.

The really incredible piece of data, though, is that men have about 6.5 times more grey matter (neurons) than women, while women have about ten times more white matter (axons and dendrites, that’s to say connections) than men. These are white because they’re sheathed in myelin, which allows current to flow much faster. On the face of it, I find this really hard, if not impossible, to believe. I mean, that’s one effing huge difference. It comes from a study led by Richard Haier of the University of California, Irvine and colleagues from the University of New Mexico, but this extraordinary fact appears to be of little consequence for male performance in intellectual tasks as compared to female. What appears to have happened is that two different ‘brain types ‘ have evolved alongside and in conjunction with each other to perform much the same tasks. Other research appears to confirm this amazing fact, finding that males and females access different parts of the brain for performing the same tasks. In an experiment where men and women were asked to sound out different words, Gina Kolata reported on this back in early 1995 in the New York Times:

The investigators, who were seeking the basis of reading disorders, asked what areas of the brain were used by normal readers in the first step in the process of sounding out words. To their astonishment, they discovered that men use a minute area in the left side of the brain while women use areas in both sides of the brain.

After lesions to the left hemisphere, men more often develop aphasia (problems with understanding and formulating speech) than women.

While I’m a bit sceptical about the extent of the differences between grey and white matter in terms of gender, it’s clear that these and many other differences exist, but they’re difficult to summarise. We can refer to different regions, such as the amygdala, but there are also differences in hormone activity throughout the brain, and so many other factors, such as ‘the number of dopaminergic cells in the mesencephalon’, to quote one abstract (it apparently means the number of cells containing the neurotransmitter dopamine in the midbrain). But let me dwell a bit on the amygdala, which appears to be central to neurophysiological sex differences.

Actually, there are 2 amygdalae, located within the left and right temporal lobes. They play a vital role in the formation of emotional memories, and their storage in the adjacent hippocampus, and in fear conditioning. They’re seen as part of the limbic system, but their connections with and influences on other regions of the brain are too complex for me to dare to elaborate here.  The amygdalae are larger in human males, and this sex difference appears also in children from age 7. But get this:

In addition to size, other differences between men and women exist with regards to the amygdala. Subjects’ amygdala activation was observed when watching a horror film. The results of the study showed a different lateralization of the amygdala in men and women. Enhanced memory for the film was related to enhanced activity of the left, but not the right, amygdala in women, whereas it was related to enhanced activity of the right, but not the left, amygdala in men.

This right-left difference is significant because the right amygdala connects differently with other brain regions than the left. For example, the left amygdala has more connections with the hypothalamus, which directs stress and other emotional responses, whereas the right amygdala connects more with motor and visual neural regions, which interact more with the external world. Researchers are of course reluctant to speculate beyond the evidence, but as a non-scientist, but as a pure dilettante I don’t give a flock about that – just don’t pay attention to my ravings. It seems to me that most female mammals, who have to tend offspring, would be more connected to the flight than the fight response to danger than the unencumbered males would be??? OMG, is that evolutionary psychology?

It’s interesting but hardly surprising to note that studies have shown this right-left amygdala difference is also correlated to sexual orientation. Presumably – speculating again – it would also relate to those individuals who sense from early on that they’re born into ‘the wrong gender’.

Neuroimaging studies have found that the amygdala develops structurally at different rates in males and females, and this seems to be due to the concentration of sex hormone receptors in the different genders. Where there’s a size difference there appears to be a big difference in number of sex hormones circulating in the area. Again this is difficult to interpret, and it’s early days for this research. One brain structure, the stria terminalis, a bundle of fibres that constitute the major output pathway for the amygdala, has become a focus of controversy in the determination of our sense of gender and sexual orientation. As a dilettante I’m reluctant to comment much on this, but the central subdivision of the bed nucleus of the stria terminalis is on average twice as large in men as in women, and contains twice the number of somatostatin neurons in males. Somatostatin is a peptide hormone which helps regulate the endocrine system, which maintains homeostasis.

What all this means for the detail of sex differences is obviously very far from being worked out, but it seems that the more we examine the brain, the more we find structural and process differences between the male and female brain in humans. And it’s likely that we’ll find similar differences in other mammals.

It’s important to note, though, that these differences, as in other mammals, exist in the same species, in which the genders have evolved to be codependent and to work in tandem towards their survival and success. Just as it would seem silly to say that female kangaroos are smarter/dumber than males, the same should be said of humans. The terms smart/dumb are not very useful here. The two genders, in all mammals, perform complementary roles, but they’re also also both able to survive independently of one another. The amazing thing is that such different brain designs can be so similar in output and achievement. It’s more impressive evidence of the enormous diversity of evolutionary development.

Written by stewart henderson

October 6, 2013 at 9:30 am

some thoughts on hypnotism

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hmm, are those waves or particles, or both, or neither?

hmm, are those waves or particles, or both, or neither?

Today I want to write about a subject I know bugger all about but which has always fascinated me – hypnotism. The first encounter with it that made an impression on me was as a schoolkid coming home for lunch, as we did every day – our parents were both at work – and catching some of the midday variety show, which regularly featured a bearded and mildly exotic hypnotist who, with nothing more, apparently, than snappings of fingers, intense gazes and a voice of calm command, got ordinary people to crawl on all fours and bark like dogs, or some other form of mild humiliation, to the incredibly complacent amusement of the studio audience – or so it seemed to me.

This was all very flummoxing to my nascent scepticality. Could this really be real? If so, the consequences, it seemed to me, were enormous for a person’s autonomy, or sense of self-ownership. More important, could this ever be done to me? My impulse would be to fight such an outrageous invasion of, indeed takeover of, what I held to be more dear to me than anything else – my independence of thought and action.

So I drew two conclusions from these observations. First, that it couldn’t be real – that there must be at least some fakery involved. Second, that if it was real, I, if not the entire human population, needed to be protected from such outrages, by law. If we could be made to bark like dogs, why couldn’t we be made, by an evil genius, to rip out each others’ throats, to murder our loved ones, to fly planes into buildings or to press nuclear buttons? In fact, if this power to control minds was real, no human law could prevent it from being abused. It followed, according to the Law of Wishful Thinking, that this power couldn’t be real.

But as life went on, the urgency of this issue receded, though the questions raised were never resolved. A lot of nasty things happened, people ripped each other apart, either physically or psychologically, and people murdered those they loved, and flew planes into buildings and declared wars that slaughtered thousands, but the motives seemed all too clear and basic and perennially human. No evil geniuses needed to be posited.  Manipulation might be suspected at times, but of the common and garden type. Hypnosis appeared surplus to requirements, so much that I never really considered it.

The old questions resurfaced on listening to Brian Dunning, of skeptoid.com, presenting a podcast on hypnosis, which provided some interesting historical background, for example that the term ‘hypnosis’ was coined by an English surgeon, James Braid, in the 1840s. Braid became obsessed with the practice after seeing a stage performance, and worked on utilising it for medical purposes. He even wrote a book about hypnotism which, according to Dunning, still stands up well today.

Dunning also addresses an issue that has always vexed me – that of susceptibility to hypnosis. In the 50s, Stanford University developed a rough measure of susceptibility which they named the Stanford Hypnotic Susceptibility Scales. Here’s Dunning’s description:

It’s a series of twelve short tests to gauge just how hypnotized you really are, scored on a scale of 0 (not at all) to 12 (completely). They are responses to simple suggestions like immobilization, simple hallucinations, and amnesia. Most people score somewhere in the middle, and nearly everyone passes at least one of the tests. There’s even a script you can follow to hypnotize anyone and put them through the scales, with a little bit of practice.

Not only do people score very differently, there’s been little progress made in predicting what types of people are most susceptible. Subjects’ suppositions about their own susceptibility don’t correlate at all with test scores. Supposed predictors like intelligence, creativity, desire to become hypnotized, and imaginativeness also have no correlation. Most likely, you yourself are a decent candidate who will score near the middle of the scale, regardless of whether you think you will or not.

These findings are not reassuring. Maybe it’s a male thing (and one of the reasons males are less willing to visit the doctor), but I’ve always wanted to be, and so felt myself to be, ‘in control’ of my physical and mental health. For example, I didn’t need a doctor to tell me I was creeping up in weight towards obesity, with all the attendant health issues. I realised it myself, took control, reduced my general food intake, introduced an exercise regime, and brought my weight back to normal. Similarly, with issues of getting older, such as the possibility of dementia, I reckon that keeping mentally active, learning new things, firing up new pathways, is the self-help solution, and with hypnotism, the defence is a strong mind and a profound unwillingness to be hoodwinked by any evil geniuses out there. But I’m not silly, and I’ve always known that I’m at least partially kidding myself, and that I can’t fully bullet-proof myself against cancer, dementia, or even mind control. So maybe I should subject myself to the above-mentioned susceptibility scales, and face the facts.

For the susceptible ones, there are certainly medical benefits in the application of hypnosis, in relieving stress, in pain management, and in preparing patients for, and managing them through, surgery. Attempts have made to use hypnotherapy, and to analyse its success, in weight loss programs and in treating addictive behaviour, with mixed results.

But what of that worst-case scenario, where the susceptible are manipulated into performing dastardly deeds? Dunning’s conclusions on this seemed reassuring. The susceptible clients certainly reported losing their memory of actions performed under hypnosis, and they certainly did perform those actions, or ‘see’ things they were commanded to see, but, according to Dunning ‘only so long as they were consciously willing to go along.’ He ends with a recommendation to try hypnotism, saying ‘you can’t lose control’ and that ‘you might just have a really wild ride’, two statements that might seem to contradict each other.

But these reassurances were all blown away by Derren Brown’s program on hypnotism, one of a series he presented on how the human mind can be made to believe things and do things that aren’t always in its best interest. Brown is a thorough-going sceptic and an atheist, and so on the side of the angels. I was primed for a dose of debunking, but, frankly, was left with far more questions than answers. I have to rely on my memory here, but the program began with some references to Sirhan Sirhan, the killer of Robert Kennedy in the sixties. Sirhan’s lack of remorse over the years has told against him at parole board hearings and the like, but since he bizarrely claims to have no recollection of the act, his lack of remorse would in that sense be consistent. Without going into too much detail about the assassination (conspiracy theories abound), Brown plants in our minds the germ of an idea that this could’ve been a mind-control event. The rest of the program involves an elaborate set-up in which Brown hypnotises a susceptible subject into ‘killing’ Stephen Fry, with a gun, while Fry is performing onstage, and the hypnotised subject is in the audience. Fry, who’s in on the act, plays dead, and the audience – well, here’s where my memory fails me. I seem to remember shock and confusion, but I don’t recall any heroes grappling with the gunman, or reacting as the gunman stood up and took aim at Fry. Maybe that’s just the behaviour of well-primed security guards. After all, shooting someone when they’re onstage, though theatrical, is hardly a real-life scenario. In fact I don’t recall it ever having happened.

More importantly – in fact far more importantly – the scenario, if we’re to believe it, completely disproves Dunning’s claim that you can’t be persuaded to do something entirely uncharacteristic when under hypnosis. The young man who ‘shoots’ Fry seems to be a pleasant, gentle soul. In an after-event interview with Brown, at which Fry is also present, he has no recollection of firing the gun, though he does remember attending the show (if my memory serves me correctly).

I was really shaken by all this. I tried to wriggle out of the conclusions. Obviously the shooter was using a toy gun – or maybe a real gun with blank bullets. Could it be that he wouldn’t have gone through with it had it been a real gun? That didn’t make sense, really – the gun was in its own case, and looked real enough to me, inexpert though I am (I truly loathe guns). It was no water-pistol or cap-gun. But maybe the whole set-up was a sham? In this and in other Brown shows I found it incredible that subjects could be so easily put into a hypnotised state. In fact ‘ludicrous’ is the word that springs to mind. There’s a part of me – quite a big part in fact – that just wants to dismiss the whole thing as arrant bullshit, a kind of sick joke. How can the human brain, the most complex 1300g entity on the planet, be so easily hijacked?

Well, apparently it can. One has to accept the evidence, however reluctantly. And of course it’s not accurate to say that the entire brain is hijacked. Or rather, just as you don’t have to have complete control of every aspect of a plane in order to hijack it, you just have to control the pilot, so hypnotism must involve control of some kind of consciousness-controller in the brain. Something like what we describe as ‘the self’, no less. A big problem, especially when some psychologists, neurologists and philosophers deny the very existence of the self.

But I’ll leave an exploration of how hypnotism works from a neurophysiological perspective for another post. I suspect, though, that not much progress has been made in that area. Meanwhile, I’m left with a much greater concern about hypnotism than ever before. As if there wasn’t enough to worry about!

Written by stewart henderson

April 20, 2013 at 9:32 am