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.     

Gender Differences in Self-Serving Attributions About Sexual Experiences1

Two studies investigated sex differences in attributions about sexual experiences. Subjects were asked to provide causal explanations for satisfying and unsatisfying past experiences. Men were expected to display a greater self-serving bias than women. This hypothesis was supported for unsatisfying but not for satisfying experiences. In both experiments, males were found to blame their partners more for unsatisfying experiences than females. Males used self-serving attributions, assigning more responsibility to the partner than to themselves (Experiment I), whereas women displayed self-derogatory attributions, attributing negative outcomes more to themselves than to their partners (Experiment II). Furthermore, self-derogatory attribution patterns were correlated with unsatisfactory sexual histories in women but not in men. Implications for the treatment of sexual dysfunctions via reattribution training are discussed.     

Equating the brightness of brief visual stimuli of unequal durations

The brightness of brief displays whose durations do not exceed a critical period of integration is known to covary with stimulus duration (Bloch’s law). There are cases in which the interdependence of duration and brightness introduces an unwanted confounding that must be avoided. Three methods for equating the brightness of brief stimuli displayed under computer control are described and evaluated, and an example of the outcome obtained with the most efficient procedure is reported.     

On the relationship between stimulus intensity and duration of visible persistence

Stimulus intensity and duration of visible persistence have been found to vary directly in some studies but inversely in others. Hawkins and Shulman (1979) have proposed that this inconsistency can be resolved by separating the studies that employed a decrement-threshold measure of persistence (Type I measure) from those that measured the total duration of persistence (Type II measure). They suggested that Type I measures yield an inverse relationship, whereas Type II measures yield a direct relationship between intensity and persistence. Hawkins and Shulman's model is incomplete in ways that are easily remedied. However, the model is totally contradicted by the experimental evidence. A new resolution of the inconsistent results is proposed in terms of retinal afterimages.     

Minority influence and social categorization

In this article, a theoretical distinction is proposed between representative outgroup minorities (representative of a minority category in the society, e.g. gays) and dissident outgroup minorities (defined as a minority subgroup within a larger outgroup category). Two studies are reported comparing the social influence of dissident outgroup minorities with that of ingroup minorities (belonging to the subject's own social category). It was predicted that a position advocated by a dissident outgroup minority would be more readily accepted than that of an ingroup minority, but that the ingroup minority would be more likely to elicit the generation of new, alternative solutions. A first experiment in which subjects were either exposed to an ingroup minority, an outgroup minority, or no influence source confirmed these predictions. In a second experiment, subjects were either exposed to a majority or to a minority source either belonging to the subject's own social category or to the outgroup. The results indicate that the position of an ingroup majority was readily accepted whereas the otherwise identical message of an outgroup majority was rejected; neither ingroup nor outgroup majority stimulated the development of alternative proposals. Again, in line with Nemeth' (1986a) theory, the position of an ingroup minority was rejected but stimulated the generation of new, alternative proposals. The differential role of social category membership in minority and majority influence and the applicability of Nemeth' (1986a) theory to the attitude change area are discussed.