Last Update 6 Aug 2007

Human Cognition in the Human brain.

This site contains texts that I wrote about cognitive psychology, by which I mean the investigation of the way thinking (in its widest definition) is done. I started with a model of the way the human cognition works, and then added texts discussing points that have arisen from various comments I got.

If you have only casual interest in cognitive psychology, this page is probably the most useful for you, and maybe this one. General pages are: Blatant Nonsense Effect, Irrefutability of Nonsense-Arguments, "what is evidence".

If you are not familiar with scientific practice, you should read this first.

All the texts in this site in a zip file (0.9Mb), gzipped tar file (0.7Mb, out of date)

The main point that distinguishes my model from other models is that I try to make it plausible neurobiologically. By 'neurobiologically' I mean the characteristics of neurons and their connectivity in the brain. Very very briefly, the main logic is:
(a) Humans think in the cortex.
(b) The connectivity inside the cortex is mostly stochastic (varies randomly across individuals).
(c) Therefore the thinking system is not specified by the genes, i.e. not innate.
(d) Hence what is innate is a learning system.

As far as I can see, all the current models of human thinking ignore neurobiology, and more than that, they are neurobiologically implausible, because they ignore the stochastic nature of the low-level connectivity of neurons. See brain symbols for a discussion showing that symbolic systems are implausible because of this reason. This text was first submitted for publication in Apr96 and got quite impressive reviews. If reading these reviews will not convince you that the current cognitive science is rotten, nothing will.

The stochastic connectivity in the cortex is 'hidden' from the rest of the public by neuroscientists, and here are online examples. [2Oct98] I have submited a short letter to neuroscientists calling them to advertise the stochastic connectivity of the cortex. [19Aug2001] A recent paper in Science gives the impression that they found precise connectivity in the cortex, but a closer inspection shows they didn't. It also gives a good example of how the public is being mis-informed about the subject.

Here are some other various bits about the CNS.

New methods, like PET and fMRI, open new avenues in investigation of the brain. However, currently the results are not replicable, and there is a strong tendency to overinterpret the results, and worse, to avoid any discussion of these overinterpretations. I was trying to publish a paper that shows the lack of replicability in PET and fMRI. By now, the page also contains links to the many reviews that the paper got, which are also quite impressive. There is also a general discussion of cognitive brain imaging here, and here is an example of what happens when you try to challenge these overinterpretations. [6 Aug 2007] These pages are by now quite old, but the facts that they higlight haven't change: there is no studies in cognitive brain imaging which are reproducible acorss individuals in the details that they show. Only gross anatomy is reproducible (sometimes).

While ignoring neurobiology, cognitive psychologists use other evidence to support their models. In reasoning errors I list the typical reasoning errors that they make when trying to support their models. I believe that currently there is no model that is free from these reasoning errors, so if you think you know a good model of thinking, you are invited to check it against this list. In addition, there is also a list of myths and misconceptions that are common in cognitive psychology.

MIT put online an Encyclopaedia of Cognitive Science (MITECS). I am writing comments on MITECS, to show where the current consensus is wrong. The advantage of this is that you can read both of the source and the comments together (By now you can't, because they took it offline).

The most frequent criticism that I got about 'brain symbols' is that the models that it criticizes are 'computational', and therefore do not need to be implementable. This is based on Marr's ideas, as expressed in his book Vision, though in somewhat distorted way. As a result, I wrote a Critique of Vision by Marr, which, if you find Marr's ideas useful, is guaranteed to raise your blood pressure.

An important question is why do the nonsense arguments that are based on these reasoning errors, myths and misconceptions are effective in convincing people. The Irrefutability of nonsense-arguments and the blatant nonsense effect go some way to explain it. Probably a larger factor is the fundamental methodological errors in the way cognitive scientists approach the question of cognition.

Computer models form large portion of cognitive models. In Computer models of cognition I argue that these models are not as useful as they are supposed to be. I wrote this text because some people say they want to see comparison between the performance for my model and other computer models.

The current research in Psycholinguistics (by which I refer to anybody that tries to learn about human thinking by learning about language) is the most outrageous heap of nonsense around. Some more extended comments are here. Chomsky worth a special mention. Did you know that Chomsky thinks that science is 'blind luck'? Evolutionary Psychology is as bad as Psycholinguistics by now. Some of my message to the Evolutionary Psychology group that were rejected by the moderator.

The model itself is here. In short, it starts from the assumption that humans are not born with a thinking system, which is almost direct corollary of the stochastic connectivity of the cortex. Instead, humans are born with a learning system, which learns how to think. The model describes the learning system. Experience showed that people that haven't understood the point of stochastic connectivity in the cortex and its implications cannot actually see the point of the model, so unless you have read these pages (above), you are probably wasting time trying to read the model itself.

A list of the major hypotheses of the model, which maybe useful to navigate it can be found in Hypotheses.

The model's text does not contain a reference list. In Cognitive Psychology Reading I explain why, and suggest how to go about learning more about cognitive psychology.

A page trying to explain why cognitive psychology is so lousy.

Few other bits.

Comments are welcome, to, but if you are interested in some discussion, please read at least one neuroscience textbook before. Please state the URL of the page(s) that you have read. It would also be useful if you add some description of who you are, your ideas on the subject and your home page.

Here are the most negative messages I got about this site.

[6 Aug 2007] I still don't mush progress. Here I list what I see as actual progress in the field.

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Some personal details:

I work in Lispworks Ltd., which produces a Common Lisp implementation and IDE.

I did a degree in chemistry in Cambridge University, UK. I also did some research in protein engineering, and publish several papers, but I lost interest. Part of this is because of the stupid way scientific articles are published currently.

Yehouda Harpaz

Maldoo is here.

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