It's Time to Relabel the Brain

Another day, another study finds that 'visual' cortex is activated by something other than information from the eyes:

A research team from the Hebrew University of Jerusalem recently demonstrated that the same part of the visual cortex activated in sighted individuals when reading is also activated in blind patients who use sounds to “read”. The specific area of the brain in question is a patch of left ventral visual cortex located lateral to the mid-portion of the left fusiform gyrus, referred to as the “visual word form area” (VWFA). Significant prior research has shown the VWFA to be specialized for the visual representation of letters, in addition to demonstrating a selective preference for letters over other visual stimuli. The Israeli-based research team showed that eight subjects, blind from birth, specifically and selectively activated the VWFA during the processing of letter “soundscapes” using a visual-to-auditory sensory substitution device (SSD) (see www.seeingwithsound.com for description of device).

There's lots of research like this. People are excited by mirror neurons because they are cells in motor cortex that are activated by both motor activity and perception of that motor activity. It's incredible, people cry - cells in a part of the brain that we said 30 years ago does one thing seem to also do another thing. How could this be??

I would like to propose a simple hypothesis to explain these incredible results and that is that we have been labeling the brain incorrectly for a long time. The data telling us this has been around for a long time too and continues to roll in, but for some reason we still think the old labels are important enough to hold onto. It's time to let go.

I'm going to go out on a limb and say it's a bit more complicated than this

Mirror Neurons, or, What's the Matter with Neuroscience?

One of the problems I face as I try to figure out what the brain is up to, if not representing, is that I can't rely on the neuroscience literature to back me up. The problem is that, while there has been a lot of data collected over the years, very little of it has been collected within an ecological framework. Neuroscientists are looking for how the brain represents information, not how it perceives it; they're looking to see where perception and action are integrated in the brain, not how the brain-body-environment system produces stable, functional behaviour. This matters because there's no such thing as theory-free observations - all data comes from this experiment rather than that experiment, and even simply reporting a result is laden with theoretical assumptions, even when these aren't explicitly identified. So until I can find a neuroscientist interested in collecting a little data (and I would love to hear from any such person!) I'm limited to laying out the consequences of taking the ecological route and critiquing what's out there already. 

The worst offenders, in terms of theory-laden data disguised as 'merely the observed facts', are mirror neurons. They are, I think, the text book example of what's the matter with neuroscience, and I thought it was about time to talk about them a little. For those interested, the most recent exposition of what mirror neurons are and do can be found in a recent (and currently open access) issue of Perspectives on Psychological Science: there's a brief introduction (Glenberg, 2011a), a detailed Q&A paper (Gallese et al, 2011) by five main figures in the field, and a summary (Glenberg, 2011b).(Update: recent meta analysis finds mirror type activity all over the brain, including the cerebellum!)