Blocking in Learning

Sometimes I stumble across a really simple concept that I feel like I should have known, and perhaps even at one point did know. "Blocking" is just one of those concepts, which I found in David Shanks' Annual Review of Psychology paper Learning: From association to cognition.

The basic idea is pretty simple. In classical conditioning, when a neutral stimulus is presented alongside an unconditioned stimulus that generates an unconditioned response, that neutral stimulus normally becomes a conditioned stimulus that causes a conditioned response. The classic example is, quite obviously, Pavlov's dogs; the smell of food (US) caused salivation (UR). When a bell was rung (NS) at the same time as the dogs' food was served, the dogs eventually began to salivate when they heard the bell - a conditioned response. The dogs had learnt to associate the bell with being fed.

That's all well and good. If, however, a second neutral/conditioned stimulus is introduced after an association has been made between CS1 and the US, and presented consistently with CS1, then little to no association will be made between CS2 and the US. To demonstrate with a thought experiment; if I make an association between, say, eating peanuts and having an allergic reaction, then experiencing an allergic reaction after eating peanuts and drinking beer won't make me associate beer with an allergic reaction. The association between CS2 (beer) and US (allergic reaction) has been blocked.

It's simple enough, but I found the effect interesting due to the implications it raises as to how the learning process actually works in humans and other organisms.

The BPS on the APA's DSM

So the British Psychological Society have published a response to the American Psychiatric Association's development of the DSM-5, the forthcoming edition of what is frequently (and perhaps worryingly) referred to as the "bible" of mental illness. The response is public and worth, at the very least, a quick read. Some points I found noteworthy;

"The Society recommends a revision of the way mental distress is thought about, starting with recognition of the overwhelming evidence that it is on a spectrum with 'normal' experience, and that psychosocial factors such as poverty, unemployment and trauma are the most strongly-evidenced causal factors. Rather than applying preordained diagnostic categories to clinical populations, we believe that any classification system should begin from the bottom up – starting with specific experiences, problems or ‘symptoms’ or ‘complaints’."

"While some people find a name or a diagnostic label helpful, our contention is that this helpfulness results from a knowledge that their problems are recognised (in both senses of the word) understood, validated, explained (and explicable) and have some relief. Clients often, unfortunately, find that diagnosis offers only a spurious promise of such benefits. Since – for example – two people with a diagnosis of ‘schizophrenia’ or ‘personality disorder’ may possess no two symptoms in common, it is difficult to see what communicative benefit is served by using these diagnoses. We believe that a description of a person’s real problems would suffice."

On gender dysphoria;

"Of particular concern are the subjective and socially normative aspects of sexual
behaviour. We are very concerned at the inclusion of children and adolescents in
this area. There is controversy in this particular area – the concept of a ‘diagnosis’ of
a ‘psychiatric disorder’ disputed.

Labelling people who need help as ‘ill’ may make supportive and therapeutic
responses more difficult."

On neurocognitive disorders;

"We have no specific comments on these disorders, other than to say that, in our
opinion, the use of diagnostic labels has greater validity, both on theoretical and
empirical grounds in these areas."

On paraphilias;

"We believe that classifying these problems as ‘illnesses’ misses the relational
context of problems and the undeniable social causation of many such problems. ... of particular concern are the subjective and socially normative aspects of sexual behaviour. It is a matter of record that homosexuality used to be considered a symptom of illness. The Society would not be able to support considering sexual differences as symptoms of illness.

We, finally, have severe misgivings about the inclusion of “Paraphilic Coercive
Disorder” in the appendix. Rape is a crime, not a disorder. Such behaviours can, of
course, be understood, but we disagree that such a pattern of behaviour could be
considered a disorder, and we would have grave concerns that such views may offer
a spurious and unscientific defence to a rapist in a criminal trial."

Checking In

I haven't completely forgotten about this blog, just so any readers know, and I should be giving it a redesign at some point in the near future.

While I'm here, some (very) quick thoughts on a BBS paper that hit headlines a few weeks back - Hugo Mercier and Dan Sperber's "Why do humans reason?" The vague premise of the article is that humans developed the ability to reason primarily as a method of devising and evaluating arguments in social settings.

To Mercier and Sperber, reasoning is both a primarily social phenomenon, and also a uniquely human one; they even explicitly state that "there is no evidence that [reasoning] occurs in nonhuman animals or preverbal children". This possibly counter-intuitive claim is because they make a distinction between reasoning and inferences, the latter of which are unconscious processes. They do clarify that what they're calling "reasoning" is also referred to as system 2 reasoning in dual process theories (with "inferences" being system 1 reasoning), which is language I'm considerably more comfortable with. But anyways.

There's definitely merit to their proposal (as suggested by the large proportion of respondents who are supportive of the paper, which is - as far as I know - a rarity for BBS articles), but I suspect that Mercier and Sperber are a little too quick to dismiss the alternative (or, perhaps, complimentary) hypothesis that (system 2) reasoning evolved in order to facilitate long-term planning.

Keele's philosophy department not to be closed

Thanks to campaigning by students, faculty, alumni and others, it appears that Keele's administration has decided to not pursue the possible plans to close its philosophy department and centre for professional ethics. The university will still be attempting to reduce costs in the departments concerned and their respective schools, but closure is apparently off the table and there will be a fresh intake of students this September.

A good day for UK philosophy. Congratulations to all at Keele.

Possible closure of philosophy department at Keele University

Worrying, and not just because it's my alma mater. Keele isn't the first UK university in the past few years to attempt to close its philosophy department - Liverpool tried unsuccessfully, Middlesex successfully - but it's still very disappointing to see another institution attempt to shut down research into one of the oldest academic subjects.

Facebook group for saving philosophy at Keele
Facebook group for saving the Centre for Professional Ethics
Peter Kail comments on Brian Leiter's blog
New APPS has a brief post about the potential closure
Iain Brassington comments at the BMJ Group's blog
Andrew Willetts discusses the background of the proposal on his blog Political Details

There was also a petition calling for an emergency general meeting of Keele's student union, which has apparently been successful.

The Quantum Mind?

I can't say that I hold much sympathy for theories of either consciousness and/or cognition that invoke quantum mechanics, and I'm well aware that it's hardly a majority view, but after reading that Searle has apparently recently endorsed the view I became curious as to how many proponents there actually are.

Penrose and Hammeroff are, of course, the most famous quantum mind theorists; Penrose's two books The Emperor's New Mind (1989) and The Shadows of the Mind (1994) being the main explications of his idea that human thought features some non-algorithmic elements. There are plenty of critical replies to both ENM and SotM; Grush & Churchland (1996), Tegmark (2000) and Chalmers (1995) being some of the more well known names who have published responses.

Speaking of Chalmers, he himself has expressed some sympathy for the possibility that quantum mechanics might be linked to consciousness (Chalmers, 1996; 2002). I can't say that I received the impression whilst reading him that he thinks the possibility is likely, however; he merely thinks that it's an option that shouldn't be ruled out, similar to his views on panpsychism.

Henry Stapp is one name I occasionally hear in relation to quantum theories of mind, but I literally know almost nothing about his work.

Searle's (2007) argument, which caused me to start thinking about this topic, is as follows;

Premise 1. All indeterminism in nature is quantum indeterminism.
Premise 2. Consciousness is a feature of nature that manifests indeterminism.
Conclusion: Consciousness manifests quantum indeterminism.

I'm not sold on the truth of either premise (I'm honestly not knowledgeable enough about physics to either agree or disagree with the first, and the second seems untrue), but it's nonetheless an interesting claim. I've yet to properly read through the book which contains this argument, so perhaps Searle will manage to convince me of its veracity.

Apart from the views listed above, I can't really think of (or find) any other major proponents of quantum mind theories. If anyone stumbling across this blog can give me reading recommendations, I'd appreciate it!



References:

Chalmers, D.J., (1995), "Minds, machines and mathematics", Psyche, 2(9), 11-20
Chalmers, D.J., (1996), The Conscious Mind, Oxford, Oxford University Press.
Chalmers, D.J., (2002), Consciousness and its place in nature, in (S. Stich & F. Warfield, eds) The Blackwell Guide to the Philosophy of Mind, Blackwell
Grush, R. & Churchland, P.S. (1995), "Gap's in Penrose's Toilings", Journal of Consciousness Studies, 21, pp. 10–29
Penrose, R., (1989), The Emperor's New Mind, Oxford, Oxford University Press
Penrose, R., (1994), Shadows of the Mind, New York, Oxford University Press
Searle, J., (2007), Freedom and Neurobiology, Columbia University Press
Tegmark, M., (2000), "The importance of quantum decoherence in brain processes", Physical Review E, vol 61, pp. 4194–4206

Female PhDs in Psychology

There's a curious graph making the rounds, made by Kieran Healy, regarding the percentage of US PhDs awarded to women in 2009. Most of the discussion I've seen regarding said graph is related to the remarkably low levels of female philosophy PhDs (~30%), which is interesting enough, but the findings for psychology seem equally surprising to me; apparently over 70% of psychology PhDs were awarded to women. Why the skew?

I could wax lyrical about psychology possibly being a stereotypically female field and thus naturally attracting more women to it, but that would be mere conjecture. Let's look at the data, which Kieran helpfully provided. My first question is; what exactly is that "psychology" datapoint on the "Selected Disciplines" graph showing? Is it all psychology fields aggregated together, or merely generic psychology PhDs? I remain unsure; in the detailed data, "psychology/general" shows ~68% women, whereas "psychology/aggregated" shows ~66% - neither of which match the ~72% displayed on the "Selected Disciplines" graph.

Regardless of where that >70% figure cames from, the aggregated total for all psychology sub-fields is still very much female-dominated. Breaking that aggregate down into its components, however, yields some fairly interesting results; cognitive psychology and psycholinguistics is the most evenly distributed field, with 48% of PhDs being issued to women. Experimental (62%), physiological (63%) social (64%) and family (65%) psychology all show a slight female bias.

The really female-dominant fields, however, are counselling (76%), clinical (77%), school (77%) and educational (78%) psychology. The most female-heavy subfield is, without a doubt, developmental and child psychology, with apparently 85% of all PhDs issued being awarded to women. It's probably unsurprising that the female-heavy areas of psychology are the ones most associated with stereotypically "feminine" subjects; other educational subjects display an equally high percentage of PhDs issued to women.

So what this data shows us, then, is that generic psychology is not as female-slanted as it appears at first glance; rather, much of the subject seems to be surprisingly well-balanced in terms of gender population, with some certain subfields overwhelmingly populated by women. Not to say that this is a bad or undesirable state of affairs; I just thought that the initial placing of psychology was curious, and wondered what the explanation for it might be.