Perception
-
Sound-induced flash illusion (SiFI) refers to the illusion that the number of visual flashes is equal to the number of auditory sounds when the visual flashes are accompanied by an unequal number of auditory sounds presented within 100 ms. The effect of repetition suppression (RS), an adaptive effect caused by stimulus repetition, upon the SiFI has not been investigated. Based on the classic SiFI paradigm, the present study investigated whether RS would affect the SiFI differently by adding preceding stimuli in visual and auditory modalities prior to the appearance of audiovisual stimuli. ⋯ However, the visual RS had no effect on the size of the fission and fusion illusions. The present study suggested that RS could affect the SiFI, indicating that the RS effect in different modalities would differentially affect the magnitude of the SiFI. In the process of multisensory integration, the visual and auditory modalities had asymmetrical RS effects.
-
Previous research has shown that interpersonal synchrony is associated with a number of prosocial effects. We investigated the respective roles of behavioural synchrony and perceived task demands on perceptions of cohesion by performing two experiments in which participants viewed pairs of point-light figures engaging in four coordinated behaviours. Behaviours were seen twice, once in perfect in-phase synchrony and once with synchrony manipulated (phase shift: 180° in Experiment 1 and 45°, 90°, 270°, and 315° in Experiment 2). ⋯ Results indicate that in-phase synchrony is associated with higher levels of perceived cohesion and that perceived exertion is a good predictor of cohesion ratings. Two interactions suggest that the effect is not purely perceptual and that participants observing coordinated movement also make inferences about the intentions of those observed. Results are discussed and future directions suggested.
-
Our brain continually integrates bottom-up sensory signals to create a coherent experience of the body. This bodily experience is also constrained by top-down knowledge of body appearance. ⋯ Here, we explore top-down limits on body ownership with the invisible finger stretching illusion, in which synchronous visuotactile stimulation applied to the real fingers and an area of empty space elicits the illusion of owning elongating fingers. The results demonstrate that it is possible to experience stretchy fingers like Mr Fantastic without visual stimuli of a fake hand, even if we do not actually feel invisible like The Invisible Man.
-
The study investigates the impact of age and gender on (1) experimental pressure pain detection thresholds (PPDT) and pressure pain tolerance thresholds (PPTolT) and (2) participants' self-reports of pain intensity and unpleasantness at suprathreshold and subthreshold levels. ⋯ A mismatch in pain sensitivity, tolerance, and pain self-reports was observed. Findings suggest that pain experiences in the elderly differ from the experiences in the young on multiple dimensions: sensory, affective, and cognitive. Findings may also indicate that the elderly appraise pain experiences using different psychological strategies.
-
Ambiguous figures attract observers because perception alternates between different interpretations while the sensory information stays unchanged. Understanding the underlying processes is difficult because the precise time instant of this endogenous reversal event needs to be known but is difficult to measure. Presenting ambiguous figures discontinuously and using stimulus onset as estimation of the reversal event increased temporal resolution and provided a series of well-confirmed EEG signatures. ⋯ We interpret our results as follows: ambiguity conflicts take place during processing of stimulus elements in early visual areas roughly 130 ms after stimulus onset. The disambiguation of these elements and their assembly to object 'gestalts' result from an interplay between early visual and object-specific brain areas in a temporal window between 130 and 260 ms after stimulus onset. In the particular case of Boring's old/young woman the processes of element disambiguation and gestalt construction are already finished at 170 ms and, thus, 90 ms earlier than in the case of ambiguous geometric figures (eg Necker cube or Schroeder staircase) or of binocular rivalrous gratings.