Influence of Phenomenal Time on Perceived Space

Abstract

It is known from work by Helson and King that the apparent spatial distance between stimuli presented in succession depends on the time interval between those stimuli ("tau effect"). It is also known that the apparent time (i.e., the interval of time perceived between stimuli presented in succession) depends on the spatial distance between the stimuli defining the time interval (called "kappa effect" by Cohen, Hansel, and Sylvester). For the "kappa effect," apparent time between lights and stimuli on the skin of the forearm undergoes modification depending on the apparent spatial distance, as presented in Suto's work beginning in the early 1940s. The present work is complementary to Suto's. Its purpose is to test whether apparent spatial distance depends on the objective or subjective (apparent, phenomenal) time interval. To achieve this, our crucial (third) experiment was preceded by two exploratory experiments: the first to verify the illusion in which a subdivided interval appears longer than an empty interval of the same length (Oppel-Kundt temporal illusion); the second to verify the presence of the "tau effect" with simultaneous tactual and auditory stimuli for time intervals between 1500 and 2500 msec. In the third experiment subjects received successive tactual stimuli defining two spatial distance and two time intervals. They also received auditory stimuli that produced the Oppel-Kundt illusion by making the time intervals phenomenally different. The results fill a small experimental gap by showing it is subjective (phenomenal) and not objective (physical) time that influences perceived spatial distances.

“Cutaneous Rabbit” Hops Toward a Light: Unimodal and Cross-Modal Causality on the Skin

“…A visual flash, however, has both temporal and spatial information, which should elicit cross-modal correspondence between tactile and visual senses in terms of time and space. We hypothesized that a simple flash could modulate the CRE depending on its location of presentation, similar to reports of the tau and kappa effects (Suto, 1952; Russo and Dellantonio, 1989). The expected results should be important when we consider the mechanism of the CRE, as well as causality perception in the outer world.…”

“…This suggests that although a flash might not relocate a tactile stimulus, a flash could modulate illusorily located tactile sensation, as visual influences on the tau and kappa effects have been reported (Suto, 1952; Russo and Dellantonio, 1989). Cross-modal causality plays a key role in governing the integration of sensory information, depending on its ecological plausibility (Schutz and Kubovy, 2009).…”

“…Indeed, the tactile tau and kappa effects are also susceptible to cross-modal (visual or auditory) influences (Suto, 1952; Russo and Dellantonio, 1989); other combinations are also possible (e.g., the audiovisual tau effect: Kawabe et al, 2008), indicating the incorporation between unimodal and cross-modal causality perception. Conversely, one previous study has suggested that the CRE is not affected by concurrent auditory temporal information (Flach and Haggard, 2006).…”

The cutaneous rabbit revisited.

“…The reverse effect is known as the S or kappa effect, in which the ratio of the two spatial intervals influences the perceived ratio of two temporal intervals (for overview, see Jones & Huang, 1982). The tactile tau effect and tactile kappa effects are both susceptible to cross-modal influences (Russo & Dellantonio, 1989; Suto, 1952), suggesting that they arise subsequent to primary sensory representation. This suggestion is further supported by the fact that tactile kappa effects can be obtained for sequences of stimuli that cross the body midline (Suto, 1952).…”

The Oppel-Kundt Illusion is Effective in Modulating Horizontal Space Representation in Humans

“…The magnitude of the illusory effect is a function of multiple properties of the stimuli, such as texture and illusory gradient (Giora & Gori, 2010;Wackermann & Kastner, 2010). Interestingly, the principles underlying the illusion are also effective within sensory modalities other than vision, such as haptic (e.g., haptic line bisection; Suzuki & Arashida, 1992) audition (e.g., estimation of time intervals; Russo & Dellantonio, 1989). Additionally, the illusion is effective also across modalities.…”