Biomedical subjects

S Gono

Publications and source records attributed to S Gono.

4 recordsLinked to original sources

PubMed1996

Ineffective leftward search in line bisection and mechanisms of left unilateral spatial neglect.

We examined the eye-fixation pattern of a patient with severe left unilateral spatial neglect who showed leftward searches of various extent in more than half of line bisection trials. Because of complete left homonymous hemianopia, he perceived only the segment of the line between its right endpoint and the point of the leftmost fixation. In the trials with leftward searches, he frequently placed the subjective midpoint on the right part of the perceived segment. In the trials without leftward searches, he placed it near the left extreme point of the perceived segment. For all these bisections, the subjective midpoint was constantly placed far to the right of the true midpoint of the line irrespective of the length perceived. We consider that in severe left unilateral spatial neglect, rightward attentional bias is the predominant factor that determines where to place the subjective midpoint. Transient attentional shift to the left may produce leftward searches, but it does not induce effective processing of line bisection.

Aged↗

PubMed1994

Improvement of left unilateral spatial neglect in a line extension task.

Patients with left unilateral spatial neglect following lesions that mainly involved the right parietal lobe performed a line extension task, extending a horizontal line leftward to double its original length. We examined line extension performances in the left and right hemispaces, as well as in the midline, to assess whether spatial conditions affected these performances. Whatever the severity of neglect found in the line bisection test, the line extension performances of the patients were almost accurate and comparable with those of normal controls across the three spatial conditions. The neglect patients executed movements in or toward the contralesional space as the task oriented their attention sufficiently to the left. The results suggest that the motor component, ie, directional hypokinesia, has little part in left unilateral spatial neglect due to right parietal lesions.

Adult↗

PubMed1993

Clock-drawing test and unilateral spatial neglect.

We investigated the ability of 25 patients with left unilateral spatial neglect to make a clock face by putting numbers inside a printed circle. Impairment seen in this clock-drawing test did not parallel neglect severity as judged by results of the line-cancellation and line-bisection tests, as well as the copying of a daisy. The score for clock drawing correlated highly with the verbal WAIS score. Most neglect patients with a verbal IQ of 87 or more could draw a clock face fairly well and used planning in placing the numbers 12, 3, 6, and 9 before the others. In clock drawing, verbal intelligence may compensate for left unilateral spatial neglect. We therefore recommend use of the line-cancellation and line-bisection tests, as well as the copying test, but do not recommend use of the clock-drawing test in the diagnosis of left unilateral spatial neglect.

Aged↗

PubMed1990

Improvement of unilateral spatial neglect with numbering.

We examined 8 patients with moderate to severe left unilateral spatial neglect by means of a series of line cancellation tasks. We asked the patients to cross out lines in the 1st trial, to number lines in the 2nd trial, and again to cross out lines in the 3rd trial. In the 2nd trial with numbering, all the patients showed improvement of left unilateral spatial neglect. Numbering involved the successive use of increasing numbers. This process seemed to motivate the patients to continue searching for another line, even at the point when they would be satisfied that they had completed the task if they used simple crossing-out. Insufficient motivation for visuospatial searching may play an important role in unilateral spatial neglect observed in cancellation tasks.

Aged↗