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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 frontal(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)
We recorded eye movements to and away from visual stimuli from a patient with left-sided neglect following a right frontal infarct in order to determine (a) whether and to what extent his neglect was due to sensory inattention and directional motor neglect and (b) whether he had difficulty suppressing inappropriate eye movements to visual stimuli ("release"(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)
A 43 year-old man with presumed progressive multifocal leukoencephalopathy developed difficulty recognizing objects and faces in the presence of adequate visual acuity and visual fields. His copying and matching of line drawings was intact, suggesting that his agnosia was associative. However, he had difficulty perceiving overlapping forms and drawings of(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 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)
Patients with unilateral (left-sided) spatial neglect following right-hemisphere stroke were tested for the effects of visual stimulation on performance of a line-bisection task. As predicted from research on brain mechanisms of spatial orientation and attention, dynamic visual stimuli presented on the left side substantially reduced neglect in the task. In(More)
Hungry or sated adult female (N = 29) and male subjects (N = 28), classified according to whether they had eaten or not within 2 h, rated four concentrations of sucrose in a lime drink for their sweetness intensity and pleasantness. Subjects also rated their attitude towards sweets in general (self-reported sweet tooth). Female subjects rated the solutions(More)