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Perceptual Organization (perceptual + organization)

Distribution by Scientific Domains

Psychology	50%
Medical Sciences	50%

Selected Abstracts

Perceptual Organization Based on Common Region in Infancy

INFANCY, Issue 2 2007
Ramesh S. Bhatt
We examined whether infants organize information according to the newly proposed principle of common region, which states that elements within a region are grouped together and separated from those of other regions. In Experiment 1, 6- to 7-month-olds exhibited sensitivity to regions by discriminating between the displacement of an element within a region versus across regions. In Experiments 2 (6- to 7-month-olds) and 3 (3- to 4-month-olds), infants who were habituated to 2 elements in each of 2 regions subsequently discriminated between a familiar and novel grouping in familiar and novel regions. Thus, infants as young as 3 to 4 months of age are not only sensitive to regions in visual images, but also use these regions to group elements in accord with the principle of common region. Because common region analysis is critical to such basic visual functions as figure-ground and object segregation, these results suggest that the organizational mechanism that underlies many vital visual functions is already operational by 3 to 4 months of age. [source]

Perceptual organization of motions in pigeons (Columba livia)1

JAPANESE PSYCHOLOGICAL RESEARCH, Issue 3 2004
TOMOKAZU USHITANI
Abstract:, We investigated whether pigeons perceived relative motion of more than one object. We trained pigeons to match a white target dot moving vertically at a constant speed to one color and the same dot moving diagonally to another. In Experiment 1, we presented an additional yellow dot (accompanying dot) moving horizontally near the target. We hypothesized that the pigeons would match the diagonal motion to the color for "vertical motion" and vice versa if they perceived relative motion of the target and the accompanying dot. We reduced the size and the speed of the stimuli by half in Experiment 2 and changed the movement pattern of the target to a sine-function in Experiment 3. In Experiment 4, we presented two accompanying dots. However, the results of Experiments 1 to 4 showed no evidence that pigeons perceived relative motion. In Experiment 5, we substituted a moving frame for accompanying dots. The pigeons tended to respond to the color corresponding to the relative motion. These results suggest that pigeons may organize a set of moving objects as one object moving relative to the other in some stimulus displays in which the second object constitutes an explicit reference frame. [source]

How do nonhuman animals perceptually integrate figural fragments?1

JAPANESE PSYCHOLOGICAL RESEARCH, Issue 3 2004
KAZUO FUJITA
Abstract:, Visual information available from the environment is often fragmented in time and space. Integrating such fragmentary information is essential for animals to recognize meaningful objects surrounding them. It has been well-documented that humans perceptually organize visual inputs. In nonhumans, on the other hand, little has been known about their process of perceptual organization. This paper focuses amodal completion in nonhuman species as one of such processes. So far, several nonhuman species including primates, rodents, and birds have been tested for amodal completion of a variety of stimuli. Positive results have been obtained in most of the species tested. In particular, nonhuman primates have been suggested to share many characteristics of this process with humans; a notable exception is pigeons. They have been shown to fail to complete with a variety of stimuli in a variety of procedures. However, this may be understood as a nature of this species adapted to their ecology. Surprising differences in perception in species that share many cognitive characteristics such as memory, concept formation, figure recognition, and so on, advises us to pay more attention to the correlation of perceptual systems and the way the species live in. [source]

Brain potentials in perception: Picture complexity and emotional arousal

PSYCHOPHYSIOLOGY, Issue 3 2007
Margaret M. Bradley
Event-related potentials (ERPs) were measured while participants viewed affectively arousing and neutral pictures depicting either simple figure,ground compositions or more complex scenes to assess the timing and topography of perceptual and emotional modulation. Emotional pictures elicited a larger late positive potential than neutral pictures in a 400,700-ms window over centro-parietal sensors both for pictures with simple figure,ground composition and for more complex scenes. Picture composition affected ERPs beginning earlier (around 150 ms), with simple figure,ground compositions eliciting less positivity over posterior sensors and less negativity over frontal sensors. Emotionality had little effect on modulation of these early ERPs. These data suggest that the late centro-parietal positive potential primarily reflects motivational relevance, and that earlier posterior (and anterior) components reflect, at least in part, differences in a picture's perceptual organization. [source]

Relationships between ophthalmological and neuropaediatric findings in children adopted from Eastern Europe

ACTA OPHTHALMOLOGICA, Issue 2 2010
Marita Andersson Grönlund
Abstract. Purpose:, This study aimed to evaluate and relate visual function, ocular dimensions and neuropaediatric findings in adoptees from Eastern Europe. Methods:, We studied 72 of 99 children, born during 1990,95 and adopted from Eastern Europe to western Sweden during 1993,97. The children (mean age 7.5 years, range 4.8,10.5 years; 41 boys, 31 girls) were examined after a mean period of 5 years post-adoption by a multidisciplinary team. Correlations between ophthalmological findings and neuropaediatric data were analysed. Results:, Bivariate and regression analyses indicate a significant positive correlation between visual acuity (VA) and perceptual organization (p < 0.001), as well as between strabismus and verbal comprehension (p < 0.02). Fetal alcohol syndrome (FAS) was correlated with low VA (p < 0.02), subnormal stereovision (p < 0.009) and small optic discs (p < 0.02). Small head circumference was related to low VA (p < 0.015) and small optic discs (p < 0.03). Furthermore, small optic discs were related to low birthweight (p < 0.005) and preterm birth (p < 0.01). Large optic cups were correlated with poorer perceptual organization (p < 0.02). Conclusions:, In this group of adoptees from Eastern Europe, ophthalmological findings were correlated to neuropaediatric findings, especially those arising from prenatal adverse events resulting in growth deficiency and central nervous system damage. Therefore, it is important and valuable with an ophthalmological examination in children adopted from Eastern Europe. [source]