Neuromagnetic Investigations of Cortical Regions Underlying Short-Term Memory
Final rept. 1 Jul 1991-30 Jun 1992
NEW YORK UNIV NY
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Spontaneous neuronal activity of the brain within the alpha frequency bandwidth is found to be suppressed in visual cortex when comparing a rotated, and possibly inverted object with an object previously seen to determine whether they are identical. Moreover, the pattern of suppression adjusts to task demands. Thus, visual cortex participates in the processes of mental imagery. A mathematical solution for the magnetic inverse problem has been developed to determine the locations of alpha suppression within the brain based on magnetic field measurements of the magnetic field power across the scalp. Behavioral studies of a persons loss of memory for the loudness of a tone can be characterized by a decaying exponential dependence on time. The characteristic lifetime is found to match to within 0.2 sec the individuals lifetime for the decay of the neuronal activation trace in primary determined neuromagnetically.
- Medicine and Medical Research