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The internal representation of space involves the integration of different sensory inputs-visual, somatosensory/proprioceptive, vestibular-yielding reference frames which are not based on individual peripheral sensory codes, being organized instead in ego-centred (e.g. head, trunk, arm) and object- or environment-centred coordinates. Lateralized or(More)
Three patients with a right hemisphere lesion and marked left-sided neglect without visual field defects were asked to detect and identify stimuli which were tachistoscopically presented in the left or right visual half-field. Neglect of stimuli presented in the contralesional left visual field, which was observed when the patient's body was in a normal(More)
Two patients with left-sided visual extinction after right parietal damage were each given two 'prior entry' tasks that have recently been used to study attentional biases in normals. The first task presented two unconnected bars, one in each visual field, with the patients asked to judge which appeared sooner. Both patients reported that the right bar(More)
The present study examines which egocentric coordinate system determines the border between the disturbed 'contralateral' and the normal 'ipsilateral' side in patients with hemineglect. Based on the observation of significantly longer reaction times for saccades towards stimuli presented in the left visual field (LVF) in right brain-damaged patients with(More)
Three patients with right-sided lesions and, in two cases, clinically manifest neglect had to compare and to name stimuli presented tachistoscopically either bilateral-simultaneously or unilaterally in the LVF and/or RVF. Whereas there was no difference between unilateral LVF and RVF presentation, "extinction" of the LVF on bilateral stimulation occurred in(More)
Neck-proprioceptive and caloric-vestibular stimulation have been shown to ameliorate the spatial bias exhibited by patients suffering from unilateral visual neglect. These interventions might in principle have their effect by biasing covert attention towards the neglected side. If so, the same interventions should also modulate covert attention in(More)
A series of computerized mazes were masked during presentation allowing only partial view of their structure. Patients suffering from acute or chronic unilateral frontal (medial, lateral) or retrorolandic (temporal, parietal) lesions and non-brain-damaged controls were required to pass through the mazes repeatedly, until they solved them without reaching a(More)
A 57-year-old patient with callosal but not anterior commissure agenesis was investigated with a visual interfield comparison and a naming task. Stimuli were presented tachistoscopically either bilateral-simultaneously or unilaterally in the LVF and/or RVF. The stimuli presented bilaterally differed with respect to their degree of similarity. Whereas the(More)
A computerized maze task was constructed that allowed only partial vision of the maze structure and produced measurements for separate analysis of cognitive processes described as impaired in Parkinson's disease. Eighteen patients suffering from mild Parkinson's disease and 18 individually matched normal controls were investigated. Baseline task response(More)
The eye movement behaviour of a patient suffering from a right basal ganglia infarction with a left-sided hemineglect but without any visual field defects was investigated during reading. The eye movements were registered by means of an i.r. light technique (pupil-corneal reflection method). The main findings were abnormal return sweeps. Whereas in normal(More)