Recovery of 3D volume from 2-tone images of novel objects

Moore, Cassandra; Cavanagh, Patrick

doi:10.1016/s0010-0277(98)00014-6

Cited by 113 publications

(109 citation statements)

References 32 publications

(46 reference statements)

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…In combination with the fact that sensory stimulation is identical before and after template exposure, the perceptual change of the two-tone image in this experimental design thus provides an ideal index of the impact of knowledge on perception. This notion is supported by previous psychophysical and neuroimaging literature, which indicates that disambiguation of two-tone images is due to top-down influences from high-level processes onto low-level visual function (3,(23)(24)(25)(26). In particular, two-tone image perception recruits memory processes and object knowledge associated with cortical areas such as precuneus and dorsolateral prefrontal cortex; these processes activate stored, high-level visual representations of the template images and feed back information to lower-level areas to shape perceptual processing, even as early as the primary visual cortex V1.…”

Section: Resultssupporting

confidence: 79%

See 1 more Smart Citation

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Teufel

Subramaniam

Dobler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

231

240

View full text Add to dashboard Cite

Many neuropsychiatric illnesses are associated with psychosis, i.e., hallucinations (perceptions in the absence of causative stimuli) and delusions (irrational, often bizarre beliefs). Current models of brain function view perception as a combination of two distinct sources of information: bottom-up sensory input and top-down influences from prior knowledge. This framework may explain hallucinations and delusions. Here, we characterized the balance between visual bottom-up and top-down processing in people with early psychosis (study 1) and in psychosis-prone, healthy individuals (study 2) to elucidate the mechanisms that might contribute to the emergence of psychotic experiences. Through a specialized mental-health service, we identified unmedicated individuals who experience early psychotic symptoms but fall below the threshold for a categorical diagnosis. We observed that, in early psychosis, there was a shift in information processing favoring prior knowledge over incoming sensory evidence. In the complementary study, we capitalized on subtle variations in perception and belief in the general population that exhibit graded similarity with psychotic experiences (schizotypy). We observed that the degree of psychosis proneness in healthy individuals, and, specifically, the presence of subtle perceptual alterations, is also associated with stronger reliance on prior knowledge. Although, in the current experimental studies, this shift conferred a performance benefit, under most natural viewing situations, it may provoke anomalous perceptual experiences. Overall, we show that early psychosis and psychosis proneness both entail a basic shift in visual information processing, favoring prior knowledge over incoming sensory evidence. The studies provide complementary insights to a mechanism by which psychotic symptoms may emerge.visual perception | psychosis | top-down processing | predictive coding | schizophrenia

show abstract

Section: Resultssupporting

confidence: 79%

“…To quantify top-down processing, we used two-tone images as stimuli (3,(23)(24)(25)(26). Without appropriate knowledge, these images appear to depict meaningless 2D black-and-white patches (Fig.…”

Section: Resultsmentioning

confidence: 99%

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Teufel

Subramaniam

Dobler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

231

240

View full text Add to dashboard Cite

show abstract

“…It has often been posited that to derive a rapid and accurate representation of the distal stimulus, the visual system must invoke top-down mechanisms. These may operate, for example, to allow stored knowledge of objects' shapes to guide figure-ground segregation (Peterson, 1994) and recovery of 3-D shape (Moore & Cavanagh, 1998), or they may guide attention toward behaviorally relevant information within a familiar scene (Chun & Jiang, 1998. Alternatively, these mechanisms may be manifest as heuristic assumptions about the nature of the visual world that, though not infallible, are likely to be correct and can therefore provide computational shortcuts to facilitate veridical reconstruction of distal stimulus properties (e.g., Aks & Enns, 1992;Enns & Rensink, 1991;Ramachandran, 1988).…”

Section: Discussionmentioning

confidence: 99%

Sequential priming of 3-D perceptual organization

McCarley

2001

Perception & Psychophysics

View full text Add to dashboard Cite

In four experiments, the effects of sequential priming on the perceptual organization of complex three-dimensional (3-D) displays were examined. Observers were asked to view stereoscopic arrays and to search an embedded subset of items for an odd-colored target while 3-D orientation of the stimuli was varied randomly between trials. Search times decreased reliably when 3-D stimulus orientation was unchanged on consecutive trials, indicating substantial sequential priming by 3-D stimulus layout. The priming was nonsensory and was independent of priming by additional stimulus characteristics. Finally, priming by 3-D layout was unaffected by observers' foreknowledge of display orientation. Results indicate that perceptual organization of 3-D stimuli is guided by a short-term trace of 3-D spatial relationships between stimuli.

show abstract

“…Although we have argued in favor of independent processing of parts and their relations, this does not mean that these two sources of information cannot interact. Bottom-up representation of the parts can certainly be aided in a top-down interactive fashion from preexisting representation of objects, and this feedback can facilitate processing of local elements or parts and assist in the recovery of the local components under degraded conditions (Moore & Cavanagh, 1998;Weisstein & Harris, 1974;Wheeler, 1970). In addition, object processing can be affected by structural properties that go beyond the combination of local parts; for instance, emergent features such as "goodness" of parts can be determined reliably on the basis of interrelationships of parts of the object (Palmer, 1977(Palmer, , 1978.…”

Section: Relationship To Other Researchmentioning

confidence: 99%

Independent representation of parts and the relations between them: Evidence from integrative agnosia.

Behrmann

Peterson

Moscovitch

et al. 2006

Journal of Experimental Psychology: Human Perception and Perfor

View full text Add to dashboard Cite

Whether objects are represented as a collection of parts whose relations are coded independently remains a topic of ongoing discussion among theorists in the domain of shape perception. S.M., an individual with integrative agnosia, and neurologically intact ("normal") individuals learned initially to identify 4 target objects constructed of 2 simple volumetric parts. At test, the targets were mixed with distractors, some of which could be discriminated from the targets on the basis of a mismatching part, whereas the rest could be discriminated only on the basis of the altered spatial arrangements of parts. S.M. learned to identify the target objects, although at a rate slower than that of the normal participants. At test, he correctly rejected distractors on the basis of mismatching parts but was profoundly impaired at rejecting distractors made of the same local components but with mismatching spatial arrangements. These results suggest that encoding the spatial arrangements of parts of an object requires a mechanism that is different from that required for encoding the shape of individual parts, with the former selectively compromised in integrative agnosia.

show abstract

Recovery of 3D volume from 2-tone images of novel objects

Cited by 113 publications

References 32 publications

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Sequential priming of 3-D perceptual organization

Independent representation of parts and the relations between them: Evidence from integrative agnosia.

Contact Info

Product

Resources

About