The perception of doubly curved surfaces from anisotropic textures
Article Abstract:
Most existing computational models of the visual perception of three-dimensional shape from texture are based on assumed constraints about how texture is distributed on visible surfaces. The research described in the present article was designed to investigate how violations of these assumptions influence human perception. Observers were presented with images of smoothly curved surfaces depicted with different types of texture, whose distribution of surface markings could be both anisotropic and inhomogeneous. Observers judged the pattern of ordinal depth on each object by marking local maxima and minima along designated scan lines. They also judged the apparent magnitudes of relative depth between designated probe points on the surface. The results revealed a high degree of accuracy and reliability in all conditions, except for a systematic underestimation of the overall magnitude of surface relief. These findings suggest that human perception of three-dimensional shape from texture is much more robust than would be reasonable to expect based on current computational models of this phenomenon.
Publication Name: Psychological Science
Subject: Psychology and mental health
ISSN: 0956-7976
Year: 2004
User Contributions:
Comment about this article or add new information about this topic:
Read my lips
Article Abstract:
It is well known that the right side of the mouth moves more than the left during speech, but little is known about how this asymmetry affects lipreading. We investigated asymmetries in the visual expression and perception of speech using the McGurk effect-an illusion in which incongruent lip movements cause listeners to misreport sounds. Thirty right-handed participants watched film clips in which the left, the right, or neither side of the mouth was covered. The McGurk effect was attenuated when the right side of the mouth was covered, demonstrating that this side is more important to lipreading than is the left side of the mouth. Mirror-reversed images tested whether the asymmetry was the result of an observer bias toward the left hemispace. The McGurk effect was stronger in the normal than in the mirror orientation when the mouth was fully visible. Thus, observers attend more to what they think is the right side of the speaker's mouth. Asymmetries in mouth movements may reflect the gestural origins of language, which are also right lateralized.
Publication Name: Psychological Science
Subject: Psychology and mental health
ISSN: 0956-7976
Year: 2004
User Contributions:
Comment about this article or add new information about this topic:
Visual sensing without seeing
Article Abstract:
Author Abstract: It has often been assumed that when we use vision to become aware of an object or event in our surroundings, this must be accompanied by a corresponding visual experience (i.e., seeing). The studies reported here show that this assumption is incorrect. When observers view a sequence of displays alternating between an image of a scene and the same image changed in some way, they often feel (or sense) the change even though they have no visual experience of it. The subjective difference between sensing and seeing is mirrored in several behavioral differences, suggesting that these are two distinct modes of conscious visual perception.
Publication Name: Psychological Science
Subject: Psychology and mental health
ISSN: 0956-7976
Year: 2004
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Recognition of faces of ingroup and outgroup children and adults. Categorization by schema relations and perceptual similarity in 5-year-olds and adults: A study in vision and in audition
- Abstracts: The activation of inappropriate analyses in garden-path sentences: Evidence from structural priming. Planning causes and consequences in discourse
- Abstracts: The influence of puberty, family processes, and leisure activities on the timing of first sexual experience. Brief report: parent's life events and substance use among German Adolescent girls, testing a family mediation model
- Abstracts: When is schematic participant information encoded? Evidence from eye-monitoring. The time-course of prediction in incremental sentence processing: evidence from anticipatory eye movements
- Abstracts: Use of the mutual exclusivity assumption by young word learners. Spatial updating of environments described in texts