Perceptual learning effects demonstrate that the adult visual system retains neural plasticity. If perceptual learning holds any value as a treatment tool for amblyopia, trained improvements in performance must generalize. Here we investigate whether spatial frequency discrimination learning generalizes within task to other spatial frequencies, and across task to contrast sensitivity. Before an...

OBJECTIVE Theta-burst stimulation (TBS) over the primary somatosensory cortex (SI) alters cortical excitability, and in its intermittent form (iTBS) improves tactile spatial acuity. The effects of continuous TBS (cTBS) on tactile acuity remain unknown. The present study examined the influence of cTBS over SI on temporal and spatial tactile acuity on the contralateral hand. METHODS In separate...

Perceptual learning effects demonstrate that the adult visual system retains neural plasticity. If perceptual learning holds any value as a treatment tool for amblyopia, trained improvements in performance must generalise. Here we investigate whether spatial frequency discrimination learning generalises within task to other spatial frequencies, and across task to contrast sensitivity. Before an...

In order to compare regional cerebral activity involved in simultaneous as opposed to successive orientation discrimination, we used positron emission tomography to measure regional cerebral blood flow, in two threefold sets of conditions, in a large number of subjects. The first such triad involved simultaneous orientation discrimination, orientation identification and detection, with all task...

The application of neurobehavioral methods in functional neuroimaging can provide useful information on the neurobiology of schizophrenia. This process can be enhanced by using a standard set of procedures to construct 'neurobehavioral probes' which are suitable for functional imaging and provide reliable measures discriminating patients from healthy controls. While such probes are available fo...

It was shown previously that infants who have neither reached nor crawled discriminate changes in spatial position on the basis of cues other than the projective size of objects displaced in space. It is now shown that binocular vision is not necessary for discrimination and that pictorial cues are not sufficient for discrimination. Parallax variables provide the information used by such infant...

We used Gaussian blurred stimuli to explore the effect of blur on three tasks: (i) 2-line resolution; (ii) line detection; and (iii) spatial interval discrimination, in observers with amblyopia due to anisometropia, strabismus, or both. The results of our experiments can be summarized as follows. (i) 2-Line resolution: in normal foveal vision, thresholds for unblurred stimuli are approx. 0.5 mi...

Possible auditory deficits in neglect were examined by comparing the performance of four right brain-damaged (RBD) patients with left visuospatial neglect, versus four RBD patients without neglect, in three auditory tasks. The first task required speeded discrimination of sound elevation, by moving a central lever up or down according to the vertical position of a peripheral target sound, regar...

This work studies the preattentive discrimination of achromatic textures composed of mixtures of different (Weber) contrasts. These textures differ not at all in local spatial structure, but only in the relative proportions of different contrasts they comprise. It is shown that, like chromatic discrimination, preattentive discrimination of such textures is three-dimensional. The current results...

To address the question of the relationship between the two visual pathways, a ventral stream for object and form vision and a dorsal stream for spatial and motion vision, we measured the spatiotemporal activation patterns in the two pathways responding to an integrated visuospatial task to which form discrimination and spatial location were assigned simultaneously. The two cognitive components...