Accession Number : AD0001008


Title :   SPREAD OF EVOKED CORTICAL POTENTIALS


Descriptive Note : Joint proj. rept.


Corporate Author : EMORY UNIV ATLANTA GA SCHOOL OF MEDICINE


Personal Author(s) : MICKLE, WALTER A ; ADES, HARLOW W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/001008.pdf


Report Date : 14 Oct 1952


Pagination or Media Count : 36


Abstract : The lateral surfaces of the cerebral cortex in 11 cats were exposed. Measurements of the latency and sign of the action potentials in the auditory cortex which were evoked by click stimulation demonstrated a regularity of pattern of events. For 6 msec, no evoked activity was detected. Then an island of positive potential appeared in the anterior suprasylvian gyrus and, at subsequent msec intervals, wider areas showed this potential change. At about 9 msec most of the ectosylvian gyri developed a negative potential. This was interrupted 1 or 2 msec later by a change toward positivity in a few spots near the middle of the auditory area. Bipolar recording demonstrated similar patterns. The expanding wave traveled distances up to 10 mm radially from the origin at rates up to 1.5 m/sec. Extirpation of the focus had no effect, but shallow cuts on the cortex tangential to the advancing wave front interrupted the positive component, but not the negative in the middle ectosylvian gyri.


Descriptors :   *PATTERNS , RECORDING SYSTEMS , HEARING , ISLANDS , BIPOLAR SYSTEMS , CEREBRAL CORTEX


Subject Categories : Cybernetics


Distribution Statement : APPROVED FOR PUBLIC RELEASE