Awareness and Integration: Understanding the Challenges of Inferring Multisensory Integration Outside of Awareness

<p>Multisensory integration describes the cognitive processes by which information from various perceptual domains is combined to create coherent percepts. For consciously aware perception, multisensory integration can be inferred when information in one perceptual domain influences subjective experience in another. Yet the relationship between integration and awareness is not well understood. One current question is whether multisensory integration can occur in the absence of perceptual awareness. Because there is subjective experience for unconscious perception, researchers have had to develop novel tasks to infer integration indirectly. For instance, Palmer and Ramsey (2012) presented auditory recordings of spoken syllables alongside videos of faces speaking either the same or different syllables, while masking the videos to prevent visual awareness. The conjunction of matching voices and faces predicted the location of a subsequent Gabor grating (target) on each trial. Participants indicated the location/orientation of the target more accurately when it appeared in the cued location (80% chance), thus the authors inferred that auditory and visual speech events were integrated in the absence of visual awareness. In this thesis, I investigated whether these findings generalise to the integration of auditory and visual expressions of emotion. In Experiment 1, I presented spatially informative cues in which congruent facial and vocal emotional expressions predicted the target location, with and without visual masking. I found no evidence of spatial cueing in either awareness condition. To investigate the lack of spatial cueing, in Experiment 2, I repeated the task with aware participants only, and had half of those participants explicitly report the emotional prosody. A significant spatial-cueing effect was found only when participants reported emotional prosody, suggesting that audiovisual congruence can cue spatial attention during aware perception. It remains unclear whether audiovisual congruence can cue spatial attention without awareness, and whether such effects genuinely imply multisensory integration.</p>

Awareness and Integration: Understanding the Challenges of Inferring Multisensory Integration Outside of Awareness

<p>Multisensory integration describes the cognitive processes by which information from various perceptual domains is combined to create coherent percepts. For consciously aware perception, multisensory integration can be inferred when information in one perceptual domain influences subjective experience in another. Yet the relationship between integration and awareness is not well understood. One current question is whether multisensory integration can occur in the absence of perceptual awareness. Because there is subjective experience for unconscious perception, researchers have had to develop novel tasks to infer integration indirectly. For instance, Palmer and Ramsey (2012) presented auditory recordings of spoken syllables alongside videos of faces speaking either the same or different syllables, while masking the videos to prevent visual awareness. The conjunction of matching voices and faces predicted the location of a subsequent Gabor grating (target) on each trial. Participants indicated the location/orientation of the target more accurately when it appeared in the cued location (80% chance), thus the authors inferred that auditory and visual speech events were integrated in the absence of visual awareness. In this thesis, I investigated whether these findings generalise to the integration of auditory and visual expressions of emotion. In Experiment 1, I presented spatially informative cues in which congruent facial and vocal emotional expressions predicted the target location, with and without visual masking. I found no evidence of spatial cueing in either awareness condition. To investigate the lack of spatial cueing, in Experiment 2, I repeated the task with aware participants only, and had half of those participants explicitly report the emotional prosody. A significant spatial-cueing effect was found only when participants reported emotional prosody, suggesting that audiovisual congruence can cue spatial attention during aware perception. It remains unclear whether audiovisual congruence can cue spatial attention without awareness, and whether such effects genuinely imply multisensory integration.</p>

The Perceptual Awareness Scale—recent controversies and debates

Accurate insight into subjective experience is crucial for the science of consciousness. The Perceptual Awareness Scale (PAS) was created in 2004 as a method for obtaining precise introspective reports for participants in research projects, and since then, the scale has become increasingly popular. This does not mean, of course, that no critiques have been voiced. Here, we briefly recapitulate our main thoughts on the intended PAS usage and the findings of the first decade, and we update this with the latest empirical and theoretical developments. We focus specifically on findings with relevance to whether consciousness is gradual or all-or-none phenomenon, to what should be considered conscious/unconscious, and to whether PAS is preferable to alternative measures of awareness. We respond in detail to some recent, selected articles.

Form and Function in Information for Visual Perception

Visual perception involves spatially and temporally coordinated variations in diverse physical systems: environmental surfaces and symbols, optical images, electro-chemical activity in neural networks, muscles, and bodily movements—each with a distinctly different material structure and energy. The fundamental problem in the theory of perception is to characterize the information that enables both perceptual awareness and real-time dynamic coordination of these diverse physical systems. Gibson's psychophysical and ecological conception of this problem differed from that of mainstream science both then and now. The present article aims to incorporate Gibson's ideas within a general conception of information for visual perception. We emphasize the essential role of spatiotemporal form, in contrast with symbolic information. We consider contemporary understanding of surface structure, optical images, and optic flow. Finally, we consider recent evidence about capacity limitations on the rate of visual perception and implications for the ecology of vision.