A few seconds after being shown an image, an amnesiac is asked to find a match for it within a group of new images. She fails to do it. What is wrong with her? Is it just her memory? Does she also have a perceptual problem? How should we distinguish a purely mnemonic from a deficit that is also perceptual?
“Simple,” you might say. “Do a new experiment. Present the amnesiac simultaneously with the sample and the group of images, and ask her to find the match. If she finds it, the deficit is mnemonic. If she doesn’t, it might also be perceptual.”
Unfortunately, things are not as simple as this. Or so we are told in the new review section, ‘Point/Counterpoint,’ in the latest issue of Neuron, which contains a discussion of mnemonic and perceptual deficits associated to lesions in the Medial Temporal Lobe (MTL)–aficionados will remember H.M. in connection to this kind of lesions. The articles, by W. A. Suzuki at NYU and M. G. Baxter at Oxford, discuss whether there is evidence that lesions in MTL give rise to perceptual deficits, in addition to the well-documented mnemonic deficits. The discussion reviews major experimental work in the field, but also raises conceptual issues about the relations between perception and memory about which philosophers of mind surely have much to say.
Neuron’s new Point/Counterpoint promises to “provide a venue for addressing topical debates and controversies in the field” of neuroscience. The format of ‘Point/Counterpoint’ consists of two review pieces by two leading neuroscientists, each arguing for an opposite conclusion on one hotly debated topic in the field, and a jointly written overview. Philosophers might want to keep an eye on some of these debates. We’ll keep you posted.
By Josefa Toribio, University of Edinburgh
(Vol. 2, March 2007)
Sensory Experience and Intentionalism
By Pierre Le Morvan, The College of New Jersey
(Vol. 3, May 2008)