Voluntary control and the dynamics of perceptual bi-stability

• Published in: Vision research (Oxford) 2005, Vol.45 (1), p.41-55
• Main Authors: van Ee, R., van Dam, L.C.J., Brouwer, G.J.
• Format: Article
• Language: English
• Subjects: Binocular rivalry; Biological and medical sciences; Effort of will; Fundamental and applied biological sciences. Psychology; Humans; Necker cube; Perception; Perceptual bi-stability; Perceptual reversals; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychophysics; Random Allocation; Slant rivalry; Vision; Vision, Binocular - physiology; Visual awareness; Visual Perception - physiology; Voluntary control
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/j.visres.2004.07.030

Voluntary control and conscious perception seem to be related: when we are confronted with ambiguous images we are in some cases and to some extent able to voluntarily select a percept. However, to date voluntary control has not been used in neurophysiological studies on the correlates of conscious perception, presumably because the dynamic of perceptual reversals was not suitable. We exposed the visual system to four ambiguous stimuli that instigate bi-stable perception: slant rivalry, orthogonal grating rivalry, house-face rivalry, and Necker cube rivalry. In the preceding companion paper [van Ee, R. (2005). Dynamics of perceptual bi-stability for stereoscopic slant rivalry and a comparison with grating, house-face, and Necker cube rivalry. Vision Research] we focussed on the temporal dynamics of the perceptual reversals. Here we examined the role of voluntary control in the dynamics of perceptual reversals. We asked subjects to attempt to hold percepts and to speed-up the perceptual reversals. The investigations across the four stimuli revealed qualitative similarities concerning the influence of voluntary control on the temporal dynamics of perceptual reversals. We also found differences. In comparison to the other rivalry stimuli, slant rivalry exhibits: (1) relatively long percept durations; (2) a relatively clear role of voluntary control in modifying the percept durations. We advocate that these aspects, alongside with its metrical (quantitative) aspects, potentially make slant rivalry an interesting tool in studying the neural underpinnings of visual awareness.