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P Mustillo

Publications and source records attributed to P Mustillo.

7 recordsLinked to original sources
PubMed1988

Anisotropies in global stereoscopic orientation discrimination.

Human orientation discrimination of long rectangular targets formed from dynamic random-element stereograms was assessed at four orientations (horizontal, vertical, left, and right oblique) as a function of width, disparity direction and magnitude using a temporal two-alternative, forced-choice paradigm. The results revealed the presence of an oblique effect in cyclopean orientation discrimination. In addition, observers discriminated targets with crossed disparity better than targets with uncrossed disparity, and had lower discrimination thresholds when the targets were oriented horizontally than vertically. These results demonstrate the existence of the oblique effect in the hypercyclopean domain comparable in magnitude to that present in the luminance domain.

Depth Perception↗
PubMed1984

Monitoring demyelination in multiple sclerosis with multi-flash campimetry.

Multi-flash campimetry is a computer-implemented psychophysical technique that allows a rapid and extensive assessment of visual flicker sensitivity. Multi-flash field maps generated from the data typically reveal the presence of 'islands' of degraded temporal resolution in multiple sclerosis (MS) patients, but not in normal control observers. These distinct 'islands' presumably reflect the influence of demyelination as well as a variety of other possible transient factors, such as edema and inflammation of the optic nerve. The question addressed in the present study concerned a means of distinguishing among such influences. The strategy employed was to test MS patients more than once over a period of several months. Under the assumption that there is little or no significant remyelination in the central nervous system, it was argued that 'islands' that remain present over time should be those that principally reflect demyelination. Transient changes that appear in the fields of MS patients probably reflect the influence of other mediating factors. Examples of multi-flash field maps are presented to illustrate this point and to serve as an initial assessment of the reliability of the technique. It is concluded that multi-flash campimetry may prove to be an effective aid in documenting the degree of progressive visual involvement in MS, and provide a means of monitoring the clinical course of demyelination in the visual system.

Adult↗
PubMed1984

Auditory deficits in multiple sclerosis: a review.

This article reviews available clinical and psychophysical data concerning the effects of multiple sclerosis (MS) on basic auditory processes. On the basis of the data, it is suggested that the presence of auditory deficits should be sought in MS patients. This is especially important in light of recent psychophysical evidence suggesting that subtle auditory problems present in affected individuals may not always be detectable via conventional clinical testing. These data also provide an alternate means of interpreting various aspects of impaired auditory functioning in MS patients, and aid in generating new hypotheses regarding the possible consequences of demyelination on normal auditory perception. Finally, new ways of testing such hypotheses are proposed, and possible directions for future research are suggested.

Auditory Perception↗
PubMedDate not supplied

Multi-flash campimetry in multiple sclerosis.

Data are reported from the initial stage of development of a psychophysical technique that allows temporal resolution to be sampled in 120 retinal locations per eye in half an hour. This computer generated test consists of systematically increasing the off period of a small spot of light, temporally modulated at 5 Hz, until the light is perceived as flickering. Visual field plots based on the data from control observers reveal good temporal resolution in the central visual field with a fall-off in resolving power in peripheral regions. Data from multiple sclerosis patients are characterized by "islands" of poor temporal resolution that presumably reflect demyelination along the optic nerve.

Adult↗