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Measures of brain activation (e.g., changes in scalp electrical potentials) have become the most popular method for inferring brain function. However, examining brain disruption (e.g., examining behavior after brain injury) can complement activation studies. Activation techniques identify regions involved with a task, whereas disruption techniques are able(More)
Our current understanding of spatial behaviour and parietal lobe function is largely based on the belief that spatial neglect in humans (a lack of awareness of space on the side of the body contralateral to a brain injury) is typically associated with lesions of the posterior parietal lobe. However, in monkeys, this disorder is observed after lesions of the(More)
BACKGROUND In previous studies, the incidence of anosognosia for hemiparesis has varied between 17% and 58% in samples of brain damaged patients with hemiparesis. OBJECTIVE To determine whether this wide variation might be explained by the different criteria used for diagnosing anosognosia. METHODS 128 acute stroke patients with hemiparesis or(More)
Recent technological advances, such as functional imaging techniques, allow neuroscientists to measure and localize brain activity in healthy individuals. These techniques avoid many of the limitations of the traditional method for inferring brain function, which relies on examining patients with brain lesions. This has fueled the zeitgeist that the(More)
The dorsal stream of visual information processing connecting V1 to the parietal cortex is thought to provide a fast control of visually guided reaching. Important for this assumption was the observation that in both the monkey and the human, parietal lesions may provoke disturbance of visually goal-directed hand movements. In the human, severe misreaching(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)
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)
Spatial neglect is usually assessed using cancellation tests or line bisection. A recent comparison of these tests has revealed a double dissociation, in which one neglect patient was impaired in line bisection but not in star cancellation whereas another showed the reverse deficit. This dissociation has prompted the question whether 'neglect' is still a(More)
BACKGROUND AND PURPOSE Hemiparetic stroke patients with disturbed awareness for their motor weakness (anosognosia for hemiparesis/-plegia [AHP]) may exhibit further abnormal attitudes toward or perceptions of the affected limb(s). The present study investigated the clinical relationship and the anatomy of such abnormal attitudes and AHP. METHODS In a new(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)