Attentional Modulation of a Figural Aftereffect

Evidence is reported that indicates that adaptation of the Schroder staircase is affected by attention. In previous work it has been shown that if subjects adapt to an unambiguous staircase, responses to an ambiguous test figure are biased towards the opposing perspective. In the current work, subjects adapted to superimposed upright and inverted Schroder staircases. Both staircases were centered on a common fixation point and were of different sizes and colors. Attention to each staircase was controlled by asking subjects to detect color changes in the line segments that defined one or the other staircase. Responses to an ambiguous test figure depended on which of the adapting staircases was attended.

16 PF Correlates of Perceptual Reactance

College students ( n = 24 males, 36 females) volunteered to take the kinesthetic figural aftereffect task and the 16 PF in a survey of state versus trait personality correlates of perceptual reactance. A reliable emergence of the trait component of perceptual reactance over trials was noted. Perceptual reducers were outgoing, affected by feelings, happy-go-lucky, practical, and undisciplined, while augmenters were reserved, stable, sober, imaginative, and controlled. Findings tend to support the trait model of perceptual reactance, with interference from a state component.

Perceived Exertion and Stimulus Intensity Modulation

Perceptual augmentation and reduction were considered contrasting styles of Stimulus Intensity Modulation. Differences in perceived exertion between augmenters and reducers were determined for three cycle ergometer work loads. Subjects were 20 males having similar physiological characteristics. Stimulus Intensity Modulation was determined by kinesthetic figural aftereffect. Augmenters rated their perceptions of physical exertion to be more intense than reducers at 450, 750 and 1050 kpm/min. Differences in physiological responses between augmenters and reducers were not significant at the three work loads. Style of Stimulus Intensity Modulation appeared differentially to influence perceived exertion at the work levels studied.

Anchor Effects and Figural Aftereffects: A Comparative Psychophysical Investigation

Perceptual contrast effect was studied from two points of view, as a special anchor effect and as a special figural aftereffect. Two experiments were conducted to investigate the influence of stimulus onset asynchrony on contrast and assimilation effects, induced and measured by different psychophysical methods. Stimuli were circular beams of light projected on screens (Delboef type of illusion). When anchor and series stimuli were shown and the latter were judged by means of a rating scale, stimulus onset asychrony had no substantial influence on the contrast effect (Exp. I). When the constant method was applied, however, the asynchrony altered the shape of the contrast effect considerably (Exp. II).

Kinesthetic Figural Aftereffects in Acute Schizophrenia: A Style of Processing Stimuli?

The Kinesthetic Figural Aftereffect test was administered to 106 psychiatric inpatients to assess styles of stimulus processing in schizophrenia. Three conditions were used: (1) standard stimulus conditions at the acute phase; (2) standard conditions, 7 wk. later, to evaluate stability over time; (3) reversed stimulus conditions to assess kinesthetic figural aftereffect generality under different stimulus conditions. Results indicated that: (1) schizophrenics reduced stimuli, but differences between patient groups were not significant. (2) Kinesthetic figural aftereffect stability over time was shown by nonschizophrenics ( p < .01) but not by schizophrenic and borderline patients. (3) All diagnostic groups reversed kinesthetic figural aftereffect responses under reversed stimulus conditions, e.g., former “augmenters” tended to reduce more under augmenting conditions, suggesting the importance of the specific stimulus conditions. (4) Acute schizophrenics showed a stimulus-governed style. (5) The results raise questions about kinesthetic figural aftereffects as a measure of response style.

Untersuchungen zur Lokalisierung von Wahrnehmungsprozessen: Figurale Nachwirkungen bei binokularen Wettstreit-Bedingungen

Figural aftereffects were measured under binocular-rivalry conditions, the suppressed part of the binocular-rivalry situation being used as an inspection figure. The results show that figural aftereffects are reduced in a partly suppressed configuration and disappear completely when the inspection figure is fully suppressed. This indicates that the figural aftereffect process is localized at a higher level in the visual system than area 17.