AbstractsPsychology

Many conflicting reports have been given in the literature concerning the effect of various factors on the rate of reversal of figure and ground in reversible perspective. Flugel (7, 8) suggested that changes in eye movement increased the number of reversals. He thought that fixation on one part of the figure could lead to S’s interpretation of this part as being "nearer” the observer and that changes in perspective were induced by changing the fixation point. Donahue (5) found that there was a rhythm in the reversals but the shift in the fixation point was not in rhythm with the reversal. He suggested that "…the shifting appearance is due to central factors and that the eye movements depend upon the shifting appearance rather than vice versa…" (5, p. 616). The contention that eye movement caused the figures to fluctuate met a more vigorous blast from a later study. Higginson (13, p. 311), commented that "…the theory of eye-movements as constituting a determining factor…has not one single fact to serve as a scientific foundation." One investigator attempting to find an explanation for the phenomena of reversible Figure (5) doubted that a person's rate of reversals remained stable from one day to the next. Guilford and Braly's study (11) attacked this question of reliability. They found that the rate of reversal was fairly constant for the same individual from day to day. The reversals were especially consistent for the same individual throughout an hour of observation. The range of fluctuation rates among the various subjects was found to be quite high. Guilford and Braly inferred from this that the rate of fluctuation was a valid measure of some individual trait that is relatively constant. However, they could not find anything to which the rate of reversal was related. Additional attempts have made to ferret out factors to which the rate of reversal are related. Many investigators have studied the relationship between the rate of reversals and biological functionings. Two investigators (23, 3) found a relation between the rate of reversal and the fluctuation found in vaso-motor changes. McDougall (19) performed an experiment in which he produced fatigue in his subjects. Fatigue appeared to lengthen the time between reversals. It was inferred from this that fatigue raises the resistance in the nervous paths and this results in slow reversals. McDougall (18) elaborated on his theory that raising the resistance in the nervous paths resulted in slow reversals. He contended that traits of personality are related to the speed of the nervous impulses in the nervous system. On the basis of this assumption an attempt was made to discriminate between an "introverted" and an "extroverted" personality by administering reversible figure tests. Other research workers (16, 12, 11, 1, 21) have found 'supporting and conflicting evidence that "organic” and "functional" cases may be discriminated from "normals" in terms of their performance on reversing figures. Hunt states (16, p. 992) that “…although these few studies give no…