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MIT to offer free online access to all its courses March 12, 2007

Posted by Johan in Off Topic, Raves.
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MIT is already offering a selection of courses online, but according to this story, the rest of the course catalogue is to appear at the end of the year on their OpenCourseWare site. Already, a fair number of modules are available from the Brain and Cognitive Sciences department. Look out for the dates though, as some of the materials are a few years old now.

I think this is quite brilliant, personally. Sure, MIT will incur some extra costs in bandwidth, but in exchange, they get plenty of positive publicity. Another advantage is that prospective applicants get a chance to see for themselves exactly what the courses are like at the Institute. This is going to get them (even more) applicants.

When revising for a perception module last term, I was helped quite a bit by some Sensation and Perception materials available at Stanford. Getting another lecturer’s take on a topic can help clear up confusing issues, and may also point you towards the truly crucial bits (i.e., what both the MIT guy and the guy in your department went over in detail is likely important).

Mirror Neurons and Communicative Actions January 9, 2007

Posted by Johan in Neuroscience, Raves.
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Ah, what one is not willing to go through in the name of science. This figure comes from an article by Ferrari et al (2003), which investigated mirror neuron responses to mouth actions. Mirror neurons are neurons which have been found in the premotor cortex of monkeys and apes, and are believed to exist in humans as well. These neurons fire when the animal performs a specific action (e.g., making a face with portruded lips, as above), but also when the animal sees someone else perform a similar action (Rizzolatti & Craighero, 2004).

This is terribly interesting because it appears to offer an explanation for how we make sense of the actions of other people: in this view, we understand actions by “mirroring” them in our own motor system.

The study by Ferrari et al (2003) is interesting because it contradicts the previously canonical knowledge that mirror neurons only respond to object-oriented actions, i.e., miming a grasping action yields no response, nor does the object itself. Only when an object is grasped does the neuron respond (Rizzolatti & Craighero, 2004). Ferrari et al identified a group of mirror neurons in the macaque monkey’s area F5 which responded to mouth movements. The bulk of these “mouth” neurons responded to eating-related actions, but a small group responded to communicative mouth movements, such as the lip portrusion pictured above. While you could argue that eating by necessity is an object-oriented action, the communicative movements are not so easily put into this framework.

The implication for what I’m working with right now is that mirror neurons may play a role in detecting facial expressions in humans. There is considerable evidence that faces and in particular facial expressions are perceived quite differently from other stimuli. Mirror neurons may play some part in explaining these differences.

References

Ferrari, P.F., Gallese, V., Rizzolatti, G., & Fogassi, L. (2003). Mirror Neurons Responding to the Observation of Ingestive and Communicative Mouth Actions in the Monkey Ventral Premotor Cortex. European Journal of Neuroscience, 17, 1703-1714.

Rizzolatti, G., & Craighero, L. (2004). The Mirror-Neuron System. Annual Review of Neuroscience, 27, 169-192.

Brain Voyager: Brain Tutor – Neuroimaging for Free December 9, 2006

Posted by Johan in Neuroscience, Raves.
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In my last post I discussed how some aspects of Psychology just aren’t well explained through long paragraphs of text. Neuroscience is certainly one example, where the location of each bit can seem more than a little abstract (which is closer to the side of the head, the medial frontal or the precentral gyrus?). A free application available for Mac, Windows and Linux comes to the rescue: Brain Voyager: Brain Tutor. The full-scale Brain Voyager program deals with visualising and analysing fMRI data. The Brain Tutor simply has one structural MRI image pre-loaded, and lets you zoom around it. It even highlights gyri, sulci, or lobes for you, as you click on them.

Unfortunately, Brain Tutor can be confusing to use at first, and its documentation is a bit lacking. So I wrote a guide to Brain Tutor. Hopefully it will prove useful. If you’ve never used Brain Tutor, there are some pictures of the application in action in the guide. Here is a sneak peek:

Understanding connectionism December 5, 2006

Posted by Johan in Connectionism, Neural Networks, Raves.
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Like many Psychologists, equations make me a little uneasy. So connectionist models are typically not my choice of reading, when I have a choice in the matter. This is a shame really, because these models tend to be extremely powerful: with a relatively simple model, complex phenomena can be explained in a framework that maps closely on to what is known about how the brain works.

Take McClelland’s model of memory*. Reading the original article is painful, yet, the model itself is not complicated, when presented in a different way. The Belgian Cognitive Science Research Unit has an extremely enlightening demonstration of the model, called a Tribute to Interactive Activation. Just click individual nodes of the model (to simulate activation), and see the associated nodes light up as well. Start clicking a few nodes (e.g., 40’s, married, college), and soon, one of the name nodes receives more total activation than the others. This is a pretty neat way of representating how the memory of one concept is evoked by the activation of related concepts.

This ties in with something I noticed during this term’s Perception module: a lot of these concepts are just not well explained in the traditional, academic journal style of writing. Reading something like van de Grind et al’s (2004) gains-equalisation model is quite painful. I could not grasp what was going on until I started drawing figures for myself… And I would most likely never have bothered with going that far unless the paper had carried so much promise in explaining storage of the motion after-effect, which was the topic of an assessed practical. Similar measures were necessary to process the wealth of research reviewed in Livingstone and Hubel’s (1988) paper on the perceptual properties of the magno- and parvocellular layers of the Lateral Geniculate Nucleus. No real structure emerges until you make a table and start listing the things that the article claims the different cells can and cannot do.

Some kinds of information are better conveyed through figures, animations; anything but sentences. It is a little curious that despite this, so many textbooks and articles rely almost exclusively on sheer text. Probably, the maths that so unsettle me have similarly enlightening effects on those who speak its language. Perhaps there is some truth in my girlfriend, the Biologist’s repeated, pointed remark that “you can’t be a proper scientist without knowing calculus.”

* McClelland, J.L. (1981). Retrieving general and specific information from stored knowledge of specifics. Proceedings of the Third Annual Meeting of the Cognitive Science Society, 170-172.

Self-Management November 24, 2006

Posted by Johan in Learning, Raves, Self-Management.
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Mindhacks has an interesting post up on how Skinner was not a fascist, which deserves to be said in itself… But the really interesting bit is the article that is linked: Skinner as a Self-Manager, by Robert Epstein.

Self-management, for those unfamiliar with the Psychobabble, is basically how you get yourself to achieve your goals. If your goal is to write an essay, self-management would involve setting aside time to write, ensuring that your topic is appropriate, and so forth. By extension, self-management is the stuff that productivity websites like Lifehacker are concerned with. And it turns out that decades before GTD reared its ugly head, Skinner was already on it:

“a few examples and a brief analysis can’t begin to capture how pervasive self-management was in his life. It was much more than a few gizmos and timers. It was what many would call an attitude. He managed his own behavior almost continuously. When I was in graduate school, a fellow student mentioned that Fred seemed to dispose of envelopes and junk mail in an especially efficient way. I had never noticed this before, but it was true. When he opened his mail in the morning, he usually positioned his chair and trash can so that the very slightest flick of his wrist did the job. This was no accident, and it was part of the reason he was able to reply to virtually every letter he ever received, even until the end (Vargas, 1990).” (Epstein, 1997, p. 547)

More specifically:

“Fred kept lists of things to do, because people who keep lists of things to do do more things. He made schedules for himself to keep himself on track. We all use daily and weekly schedules, but Fred made longterm schedules as well —even 10- and 20-year schedules (Skinner, 1979, 1983b). “ (Epstein, 1997, p. 554)

“He knew that the best ideas are often fleeting, so he developed special ways to capture them. He kept a notebook or a tape recorder by his bed and by his pool, for example. He knew that writing was a delicate and easily disrupted activity, so he took pains to shelter it from disruptions. He built special shelves so that his dictionaries and other reference books were always at arm’s reach. He used his writing desk for serious writing only; he answered letters and paid bills elsewhere.” (Epstein 1997, 554)

Skinner was proud of his self-management skills, as he considered them a direct application of Behaviourism. And of course, this could be related to other scientific paradigms:

“Freud was unable to stop smoking cigars, up to 25 a day, though smoking must have been obviously related to the heavy ‘‘catarrh’’ he suffered from most of his life, as well as to the protracted cancer of the jaw in his last years . . . an astonishing lack of self-understanding or self-control. Was he not bothered by it, or did much of his theory spring from the need to acknowledge that the habit was ‘‘bigger than he was’’?
(Epstein, 1980, p. 341)

Of course, poking fun a psychoanalysis is a bit like shooting fish in a barrel. A final quote sums up the core of Skinner’s self-management:

“Fred’s most important self-management practice is implied in his writings but is nowhere clearly stated. He always spent a few minutes each day, often scattered throughout the day, searching for and analyzing variables of which his behavior seemed to be a function. It is not enough to live your life, he told me; you also need to analyze it and make changes in it frequently and regularly.” (Epstein, 1997, p. 559)

On reading Epstein’s article, you do not get the impression that this was an ascethic, disciplinarian lifestyle that Skinner imposed on himself. Self-management was a source of joy, a constant pet project that was carried out because it was a positive reinforcer, not a negative one.

I believe that this kind of constant, critical re-evaluation of your lifestyle is crucial, if you aim to achieve anything beyond the norm. Epstein goes as far as suggesting that this self-management skill was the crucial factor that enabled Skinner to achieve as much as he did. I’m not sure about that, but it’s nevertheless inspiring to see that at the base of it, it may not be just an abstract “genius” quality that separates those who achieve something from those who don’t. There is a method here, and it can be applied to just about anyone.

I will outline my own self-management attempts in a future post.

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