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A R Gibson

Publications and source records attributed to A R Gibson.

41 records · Page 3Linked to original sources
PubMed1968

Is orientation-specific color adaptation in human vision due to edge detectors, afterimages, or "dipoles"?

After one looks alternately at red vertical and green horizontal stripes, vertical and horizontal white stripes appear greenish and pink, respectively. This color aftereffect might imply that contour-detecting cells participate in human vision, or might simply be due to afterimages. A procedure that precludes afterimages still yields aftereffects, but sensory units less complex than edge detectors could be responsible.

Afterimage↗
PubMedDate not supplied

Activity of primate magnocellular red nucleus related to hand and finger movements.

Single cells were recorded in the magnocellular red nucleus (RNm) of two cynomolgus monkeys using tungsten microelectrodes. The first monkey was trained to press finger switches and to operate a push-pull device. Comparison of responses while operating the two devices demonstrated a strong distal bias. The finger device elicited large modulations in discharge (greater than or equal to 50 impulses/s) in 75% of the sampled neurons. Most cells fired optimally during thumb switch operation, but also fired vigorously in association with other switch operations. The left motor cortex was removed from the second monkey 18 months prior to microelectrode recording. Cells in the cortically denervated RNm discharged vigorously in association with grouped finger movements that opened and closed the affected right hand. These results coupled with our previous findings suggest that the RNm is preferentially linked to distal limb muscles, and the primary role of the forelimb zone may be to control coordinated hand function including grouped movements of the fingers.

Animals↗