idiolect

The order in which different brain areas reach maturity must be crucial to how activity-guided development creates functional specialisation (there’s good stuff on this in Rethinking Innateness). Here’s a maturational timetable (via) for different brain areas:

Notice that it’s areas associated with audition that finish myelination first (in the womb), and the neocortex which finishes last (about 25 years later).

Ref:

Elman, J., Bates, E., Johnson, M., Karmiloff-Smith, A., Parisi, D., & Plunkett, K. (1996). Rethinking innateness: A connectionist perspective on development. Cambridge, MA: MIT Press/Bradford Books.

Like a dutiful embodied cognitivist i believe that what we’re doing affects how we think. Or, on a more mircoscale, that the task we’re engaged in affects the how we process the stimuli we’re sensing. Not just how we process the stimuli in the sense of the parameters of the processes used to deal with it, but that the actual processes themselves alter – and not always in ways we have personal insight into.

So, as part of my duties i was re-reading Goodale & Milner’s (1992) classic paper “Separate visual pathways for perception and action”. They discuss research that shows that motor systems aren’t fooled by various illusions – so that with things like the muller-lyer illusion, our fingers reaching to grab the object are not fooled in the same way as our eyes are fooled in providing us with information on size. They go on to say:

The functional modules supporting perceptual experience of the world may have evolved more recently than those controlling actions within it

But that’s just an aside. The question that jumps out at me is, if the type of response affects stimulus processing, what kind of response is conscious experience?

Ref

1. Goodale MA, Milner AD (1992). Separate visual pathways for perception and action. Trends in Neurosciences, 15(1), 20-25.

Like i said, the rat is more spinal cord than cortex, whereas the human is more cortical than spinal cord by a factor of nearly forty. Does anything else happen as we stagger up up the phylogenetic ladder? Well there’s a whole lot of crinkles added…

Rat:

Man:

The unexpected consequences of a noisy environment
Xiaoqin Wang
Trends in Neurosciences
Volume 27, Issue 7 , July 2004, Pages 364-366
Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine

Abstract: A recent study found that the functional organization of auditory cortex was disrupted when rats were exposed to a moderate level of continuous noise during early development. However, this detrimental effect on auditory cortex could be remedied later by stimulating the noise-reared rats with structured sounds. These findings suggest that the endpoint of the ?critical period? could be extended well into adult life, which has significant implications for our understanding of cortical plasticity.

Backlink

Thanks to Brain facts and figures

Nature discuss neuromarketing:

A more skeptic view of neuromarketing is that cognitive scientists, many of whom watched from the sidelines as their molecular colleagues got rich, are now jumping on the commercial bandwagon. According to this view, neuromarketing is little more than a new fad, exploited by scientists and marketing consultants to blind corporate clients with science

No one would do that, would they? Would they…?

Geoffrey Sampson doesn’t believe in the language instinct. I remember reading his book Educating Eve in my final year at university and being splendidly, incoherantly, annoyed by his views on the nature-nurture debate. My girlfriend at the time had been set the book as part of her linguistics course and I singularly failed to express to her just how wrong-headed Sampson’s arguments were – how he completely failed to engage with the whole point of Pinker’s book., for one thing.

Of course I was fresh from reading things like Rethinking Innateness and had all the zeal of the new convert. I can’t remember the details of Sampson’s argument, and now I think i’d like to re-read it to check if i still feel the same way, and maybe to recapture that feeling of annoyance. Maybe my appreciation of it will have changed, I certainly think my appreciation of the language innateness debate has changed – i’ve had the luck to read Terance Deacon’s The Symbolic Species for a start, and that’s a book which should stretch anyone’s appreciation of language and brain evolution.

This is a screenshot of me playing with the BrainVoyager BrainTutor. BrainVoyager make fMRI analysis and visualisation software, and they’re kind enough to offer this interactive guide to different cortical regions for free.

Pictures can’t describe how much fun it is to play with, adding and removing the different hemispheres, labels, views, rotating the whole head, etc. It’s a shame they don’t have more areas programmed in at the moment (it’s just the lobes the gyri and sulci – but there’s a promising ‘forthcoming’ button for Brodmann areas).