Two forms of persistence in visual information processing

Iconic memory, which was initially regarded as a unitary phenomenon, has since been subdivided into several components. In the present work we examined the joint effects of two such components (visible persistence and the visual analog representation) on performance in a partial report task. The display consisted of 15 alphabetic characters arranged around the perimeter of an imaginary circle on the face of an oscilloscope. The observer named the character singled out by a bar-probe. Two factors were varied: exposure duration of the array (10, 50, 100, 150, 200, 300, 400 or 500 ms) and duration of blank period (interstimulus interval, ISI) between the termination of the array and the onset of the probe (0, 50, 100, 150, or 200 ms). Performance was progressively impaired as both exposure duration and ISI were increased. The results were explained in terms of a probabilistic combinatorial model in which the timecourses of visible persistence and of the visual analog representation are regarded as time-locked to the onset and to the end of stimulation, respectively. The impairing effect of exposure duration was attributed to the relatively high spatial demands of the task that could be met optimally by information in visible persistence (which declines as a function of exposure duration), but less adequately by information in the visual analog representation. A second experiment, employing a task with lesser spatial demands, confirmed this interpretation.     

Effects of observing competitive and violent versions of a sport

Males were randomly assigned to view either (1) a film clip featuring hockey fights or (2) a film of nonaggressive hockey action or (3) a no-film control condition after having first been angered or treated politely by an experimental confederate. The dependent variable was represented by a measure of aggressive mood and a behavioral measure of retaliatory aggression. Analyses revealed that both angered and nonangered subjects exhibited an increase in aggressive mood following exposure to the fight film. However, the analysis involving retaliatory aggression against the confederate yielded an anger x film interaction. While angered subjects were more aggressive than nonangered, only angered subjects retaliated against the confederate after viewing the fight film. The results were discussed in terms of Berkowitz’s (1974) aggressive cue theory. A version of this paper was presented at the meeting of the North American Society for the Sociology of Sport, Edmonton, Canada, November 1987.