Charles M Butter

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BUTTER, C. M. Perseveration in extinction and in discrimination reversal tasks /bllowing selective frontal ablations in Macaca mulatta. PHYSIOL. BEHAV. 4 (2) 163--171, 1969.--In order to determine whether the perseverative syndrome exhibited by monkeys with frontal lobe lesions can be fractionated by partial frontal lesions, monkeys with dorsolateral(More)
In Experiment 1, 11 of 13 stroke patients with left-sided neglect benefitted from monocular patching in at least one (of five) tests of neglect. This beneficial effect in most cases was limited to the period when the patch was worn. In Experiment 2, another group of stroke patients (n = 18) with left-sided neglect were tested in a line-bisection task with(More)
Simple reaction times to lateralized visual (Experiment 1) or auditory (Experiment 2) targets were studied in normal subjects. The targets were preceded by a visual or auditory cue located on the same (valid cue), or opposite (invalid cue) side as the subsequent target, or on both sides (neutral cue), with one of four cue target intervals. The validity of(More)
Patients with stable, homonymous hemianopia due to unilateral occipital infarcts and control subjects performed a task in which they judged whether or not an arrow was pointing at one of the dots in a pattern of dots they had recently seen in free vision, but was no longer visible. This task, as shown in prior studies as well as in the present one, involves(More)
Blindfolded subjects estimated with either hand the center of rods positioned in either left or right hemispace. In one condition, they also performed a concurrent verbal task. Bias and variability of bisection settings were the dependent variables. Bisections performed in left hemispace were biased to the left of true center, more so when the left hand was(More)
Normal subjects performed simple reaction time responses to lateralized visual target stimuli (Experiment 1) and lateralized tactile target stimuli (Experiment 2). In each experiment, the lateralized targets were preceded at one of four intervals by a visual or tactile cue located on the same (valid cue), or opposite (invalid cue) side, or on both sides(More)
Rhesus monkeys were trained to fixate a central stimulus and to detect and localize a 50 msec light flash presented 6-80 degrees on either side of the central stimulus. Following large lesions of the superior colliculus, they showed persistent deficits in localizing flashes presented 43-80 degrees from the fixation stimulus. However, they were not(More)
In order to investigate whether pulvinar lesions produce behavioral impairments similar to those that follow superior colliculus lesions, monkeys were tested on a visual search task before and after receiving radiofrequency lesions of either the superior colliculus or pulvinar. The animals searched for a small target pattern within an array of varying(More)
We utilized the methods of comparative psychology and of ethology to assess the effects of frontal lesions on species-specific aversive and aggressive behaviors in rhesus monkeys. Removal of orbital frontal (OF) cortex enhanced aversive reactions and reduced aggressive reactions in several threatening situations, including a social colony. The deficit in(More)