Andrzej Michalski

The ocular following reflex in cats deprived of pattern vision from birth

An investigation of vertical ocular following reflexes evoked from retinal sites of different horizontal eccentricity was carried out on visually deprived cats. The recording was performed in pretrigeminal preparations where horizontal eye movements are absent. A light slit or a black stick (1 degrees X 4 degrees) were moved with 10 degrees/sec speed for 2 sec along the vertical meridian or parallelly up to 40 degrees in the nasal or temporal hemifield. As in previously described normally reared cats, the following reflexes were evoked from the whole area, but the pursuit movements had longer latency and lower velocity at the periphery than in the center of the retina. However, irrespectively of the place of stimulation, the latency of the pursuit movements was longer, their velocity lower and the course less regular than in normally reared cats. It therefore follows that in visually deprived cats the ocular following reflex is impaired.

ERP Responses to Smile-Provoking Pictures

Abstract: The aim of the present study was to search for event-related potential (ERP) correlates of processing pictures commonly described as “funny” but not preceded by the apparent “context-setting” phase. Three pairs of stimuli were used: (1) famous cartoon characters and images of household objects, (2) pictures reminiscent of a recently seen joke and similar pictures that did not produce such associations, (3) funny caricatures and drawings of neutral human faces. ERP differences in each pair were analyzed in two experiments. In the first experiment, both stimuli were targets in an “oddball” procedure, presented among the more frequent green disks. In the second experiment, they were both nontargets whereas the green disks were task-relevant. Both experiments and all pairs of stimuli produced similar results. ERPs for funny pictures were consistently more positive within the broad latency windows, resembling the effects of emotional arousal. Negative deflections, typical for incongruity processing, ...