Faculty Collaboration Database

Psychophysics of electrical stimulation of striate cortex in macaques. J Neurophysiol 2005 Nov;94(5):3430-42

Date

08/05/2005

Pubmed ID

16079195

DOI

10.1152/jn.00406.2005

Scopus ID

2-s2.0-27144553795 (requires institutional sign-in at Scopus site)   60 Citations

Abstract

Macaques indicated their detection of onset or alteration of 0.2-ms pulses applied in various configurations through electrodes implanted in striate cortex. When microelectrodes were introduced and left in place, the threshold for detection of 100-Hz pulses nearly doubled within 24 h. However, for chronically implanted platinum-alloy macroelectrodes detection thresholds usually remained stable for many months, independently of location within striate cortex or its immediately subjacent white matter. Thresholds were unaffected by the visual conditions, such as light versus darkness, or movement of the eyes; but in one animal blind after acute glaucoma thresholds for loci in striate cortex were permanently decreased by about 50%. Learning to respond to electrical stimulation of the optic tract produced no tendency to respond to such stimulation of striate cortex. Onset of stimulation at a given locus could be detected even in the face of continuous supraliminal stimulation at four surrounding loci on a 3-mm radius. The surround stimulation did alter the threshold of the central locus, but such stimuli could not summate if they were subliminal by some 10%. Cessation of stimulation that had been continuing for 1 min to 1 h could be detected if it were being applied at a level 20-75% above that needed for detection of stimulus onset. Continuous stimulation had a pronounced "priming" effect, in that modulation of frequency or intensity of such stimulation by as little as 5% could be detected (e.g., 20 microA in a background of 500 microA, or <2-ms interpulse interval with pulses at 50 Hz). Using pulses inserted in various phase relations to ongoing pulses at 2-5 Hz, it could be determined that stimulus pulses were surrounded by a strong facilitatory period for about 30 ms, which was then replaced by refractoriness. Given the congruence of macaque and human visual anatomy and psychophysics, these results further encourage efforts to develop a cortical prosthesis for the blind.

Author List

Bartlett JR, DeYoe EA, Doty RW, Lee BB, Lewine JD, Negrão N, Overman WH Jr

Author

Edgar A. DeYoe PhD Adjunct Professor in the Radiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Behavior, Animal
Deep Brain Stimulation
Differential Threshold
Electric Stimulation
Evoked Potentials
Long-Term Potentiation
Macaca nemestrina
Male
Psychomotor Performance
Psychophysics
Refractory Period, Electrophysiological
Refractory Period, Psychological
Visual Cortex