Recovery of motion perception after surgery

For a while now I’ve been revisiting an article by Nawrot, Rizzo, Rockland and Howard III in Vision Research (“A transient deficit of motion perception in human“). I’m fascinated because it is a very well-documented case of functional recovery after surgery for epilepsy. I’m also intrigued by what the authors don’t ask about or comment on (how was the recovery mediated?), and by the implications of this case for understanding neural modularity (or equipotentiality, the complementary idea). These latter two discussions will be held over for another post.

The authors describe patient SF, a 19 year old female with intractable epilepsy in the posterior portion of the temporal lobe, at the occipital lobe junction, in the right hemisphere. They discuss the difficulty in finding a human homologue to motion area MT in the macaque, which takes part in many kinds of motion computation and which provides input to and receives input from other areas, even ones not particularly associated with motion processing. For example, there is connectivity between area V4, commonly associated with the processing of color, and MT in the macaque. Fans of the binding problem understand why connections between MT and V4 are potentially important.

SF was tested extensively prior to topectomy (the removal of tissue corresponding to epileptic foci). The area removed was the lightly-shaded area in the below figure – the small, numbered darker areas were removed for microscopic examination. White matter and surrounding vasculature was generally spared in the operation.

Long term memory for pictures

My wife bought a vintagey shirt the other day. It’s long-sleeved, white, with colored letters on the front to the effect of “Tickle Me, Hug Me” etc., and a picture of Elmo below. I’ve searched the web in vain for a picture…and finally found one!

Then late last night, I discovered one of the tags from the purchase on her dresser, and I stopped immediately in my tracks. It looked like a plastic pillow inflated version of this:

I said to myself – that’s just like the logo of Love, American Style!

The vividness with which the logo and bits and pieces of the show (that damn title song) burst into my mind was impressive. I was 10 years old in 1973 (the show ended in January, 1974 – I had to look that up), trying to catch a bit of what my older sisters were watching. I knew it was risqué entertainment!

This experience reminded me of a recently published article by Mitchell (November, 2006, “Nonconscious Priming After 17 Years: Invulnerable Implicit Memory?“ in Psychological Science).

The supremacy of vision, elephant-style

My Psychology of Language class was having their third “Critical Issues Discussion” the other day – this one was entitled “Is language uniquely human?” Early in the term I gave them a basic guide, a number of things to look up to get them started; read specific chapters in Pinker’s The Language Instinct and Carroll’s The Psychology of Language, read up on communication abilities by dolphins, parrots, apes, and other species. One specific mention I made was to discuss mirror self-recognition and what “success” in the task might mean about the conceptual abilities of the organism. I hoped, as I wrote the little how-to guide to jumpstart them early in the term, that they would find the discussion interesting.

Then, well after they received the guide from me, news of mirror self recognition in an Asian elephant appeared, which was discussed in about a billion places.