AN INVESTIGATION OF VELOCITY SYNTHESIS

C ohen , R. L. An investigation of velocity synthesis. Scand. J. Psychol ., 1962, 3 , 97–111.—A short series of experiments has shown that it is possible to divide up the distribution of scores obtained from a group of subjects performing on the velocity synthesis apparatus mainly on the basis of (1) instructions and (2) eye behaviour. It was further found that the difference in scores dependent on differences in eye behaviour could be traced to the effect of the Aubert-Fleischl Paradox. An alternative to the gestalt model was suggested, viz. a signal/interference model.     

ADAPTATION EFFECTS AND AFTER EFFECTS OF MOVING PATTERNS VIEWED IN THE PERIPHERY OF THE VISUAL FIELD

Different patterns of figures moving behind a window were viewed by subjects while fixating a point 8.5–11° visual angle NW of the display. With prolonged viewing and small figures, the motion appeared to stop completely. With moving figures which stretched the whole way across the field, perpendicular to the direction of motion, a pulsating or wave motion was experienced. A reduction in the number of moving figures was also reported with all the patterns. When the stimulus motion was stopped, the expected after effect of motion in the opposite direction was usually experienced, although in many cases the stopping of the stimulus motion led to an immediate disappearance of the stimulus figures.     

Learning spatial sequences in unilateral neglect

Brain-damaged patients with unilateral spatial neglect ignore aspects of the world located on the side opposite their lesion. In the present study we examined the performance of unilateral neglect patients (UN) on an SRT task in which a hybrid repeating sequence (21313) was used. We analyzed the patients' performance for each location separately as a function of the target's location in the trial preceding the response. The UN patients were severely limited in their learning of the sequence when compared to normal controls. In particular, they appeared to learn unique associations (21 and 13) but not ambiguous ones (31 and 32). We discuss two possible explanations for this phenomenon. The first is that UN patients show a deficit similar to that of normal subjects in dual task situations. The second is that the learning deficit is unique to spatial processing impairments of UN patients and is not directly related to research with normal population. We outline future research that may distinguish between these two explanations.