Perceptual and semantic features in children's use of the animate concept.

Investigated the development of understanding of animate and inanimate items. 52 4–7 yr olds and 15 college students received 3 tasks, including sentence completion, oddity, and sorting tasks. In all conditions, Ss were asked to choose from among animate and inanimate items the 1 which correctly completed the task requirement. Inanimate items in all tasks had 1 perceptual feature in common with the animate item, either movement, making noise, or similarity of size. It was predicted that Ss would select items on the basis of perceptual rather than semantic similarity in those tasks which contained little contextual information. It is concluded that children were aware of the difference between animate and inanimate items in certain conditions, but that perceptual features were often more salient. If contextual restrictions were not evident, the dimension of animateness may have been overlooked in favor of visible, concrete features of the items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual defense revisited.

"In the present study the following hypothesis was submitted to experimental test: Subjects predisposed to use the mechanism of repression in conjunction with a given conflict will, when confronted subliminally with a conflict-relevant stimulus, show defensive behavior directly traceable to the perceptual process itself… ." The results of this study show that "with selective verbal report, familiarity, set, and antecedent conditions all controlled, an avoidance response directly traceable to the perceptual process was obtained." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual orientation and empathy.

Administered an empathy scale and the Embedded Figures Test to 32 male undergraduates to explore the relationship between empathy, as an interpersonal affective variable, and psychological differentiation. As was predicted, empathy was significantly correlated with perceptual orientation (p     

Perceptual asymetries in audition.

Visual feature extraction has been investigated using search experiments. Targets that contain a feature not present in the distractors are easier to detect than if they do not, leading to search asymmetries. If sounds are decomposed into features in the auditory system, there might be asymmetries in analogous tasks. Six experiments investigating this are described. Strong asymmetries were identified, with frequency-modulated targets easier to detect among pure-tone distractors than vice versa and longer sounds easier to select from short distractors than the reverse. It is demonstrated that this asymmetry is not a result of peripheral limitations. In contrast, no asymmetries were observed between high- and low-frequency tones or between short 3-tone sequences differing only in their temporal structure. The results are discussed with reference to models of perceptual grouping and attention, the applicability of analogies between vision and audition, and possible physiological correlates. The paradigm provides a new way in which to investigate auditory feature extraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual repetition blindness effects.

Repetition blindness (RB) may reveal a new limitation on human perceptual processing. Recently, however, researchers have attributed RB to postperceptual processes. The standard rapid serial visual presentation (RSVP) paradigm used in most RB studies is open to such objections. The "single-frame" paradigm introduced by J. C. Johnston and B. L. Hale (1984) allowed investigation of RB with minimal memory demands. Participants made a judgment about whether 1 masked target word was the same or different than a posttarget probe. Confidence ratings permitted use of signal detection methods. In the critical condition for RB, a precue of the posttarget word was provided prior to the target stimulus so that the required judgment amounted to whether the target did or did not repeat the precue word. In control treatments, the precue was an unrelated word or a dummy. Results showed that perceptual sensitivity was significantly reduced in the RB condition relative to baseline control conditions. The data showed that RB can be obtained under conditions in which memory problems are minimal and perceptual sensitivity is assessed independently of biases. RB therefore can be a perceptual phenomenon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual organization and schizotypy.

The preattentive visual information processing of hypothetically psychosis-prone college Ss was evaluated using 3 different paradigms: target detection (n?=?57), visual suffix effect (n?=?57), and configural superiority effect (n?=?68). It was hypothesized that anhedonic Ss would show the same perceptual organization deficits reported in process schizophrenics and that perceptual aberration-magical ideation Ss and depressed Ss would perform similarly to control Ss. In each study, anhedonics performed similarly to each comparison group, even though there was adequate power to detect performance differences if they existed. A framework for understanding the visual information-processing deficits of schizophrenics and high-risk Ss is proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual noise and aging.

Presents evidence pertaining to the hypothesis that aging is characterized by a decrement in the ability to suppress irrelevant stimuli (perceptual noise). Although studies in the various sensory modalities generally support a perceptual noise hypothesis of aging, most of the evidence is marred by serious structural weaknesses. It is concluded that the heuristic value of such a unifying hypothesis seems, however, to justify further investigation aimed at correcting these flaws. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual organization in schizophrenia.

A report of numerosity task was used in 2 experiments to examine the effect of inherent stimulus organization on the report accuracy of 2 S groups. Ss in each experiment were 10 schizophrenics and 10 drug abusing inpatients (controls). In both experiments, displays containing from zero to 6 lines were presented tachistoscopically. In Exp I, the lines appeared either alone or with noise elements (circles). When the lines appeared alone, schizophrenics and controls performed comparably. Their report accuracy decreased with increases in the number of lines. In the noise condition, the level of performance dropped only for schizophrenics. In Exp II, the stimulus arrays did not contain noise elements. Ss were given the task of reporting all the lines they saw. The perceptual organization of the arrays was manipulated by varying the similarity and proximity of the line elements. The performance of controls deteriorated as the organization of the arrays became more complex; schizophrenics were not affected by the organization. In fact, their average performance was significantly better than that of controls. Results of the 2 experiments are interpreted as evidence that schizophrenics' perceptual deficit lies in a failure to organize information at an early stage in processing. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual closure in schizophrenia.

The concept of closure has been more frequently investigated using normal Ss than psychotic patients. The present study utilizes schizophrenics and compares their performance with a comparable group of hospitalized nonpsychotic Ss. Taylor's (1960) test of closure was used. Tendency to closure tended to be lower for the schizophrenics than for the nonschizophrenics, with schizophrenics on drugs (and, hence, manifesting a greater degree of personality disorganization than the other schizophrenic Ss) showing no tendency towards closure. The results are related to 2 theories of schizophrenia, one which involves a deficit in the energizing or arousal systems in the brain, and the other, an inability to maintain a set in the way normal Ss do. From Psyc Abstracts 36:04:4JQ31S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual concomitants of conceptual reorganization.

Scheerer held that perceptual reorganization occurs as a concomitant of an induced shift in performance on a conceptual sorting test. This study provided an empirical test of Scheerer's claim for a group of mentally retarded Ss. A perceptual test which utilizes the phi phenomenon was administered to 12 retarded Ss who successfully made the shift on the sorting test (the Pass Group) and 12 who did not (the Fail Group). The Pass Group showed evidence of a highly significant perceptual reorganization, whereas no such evidence was found for the Fail Group. These results strongly supported Scheerer's claim, but for a group which he believed incapable of conceptualization and perceptual reorganization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual maps of supermarket locations.

Used multidimensional scaling algorithms to develop perceptual configurations of supermarket locations for 55 consumers. Individual and aggregate perceptual configurations were contrasted to an actual map of supermarket locations, and differences between configurations under 2 multidimensional scaling algorithms were described. Actual and perceived distances to each of the supermarkets were correlated with the frequency of shopping at the respective stores for each consumer. Results indicate that perceptual distances had a more significant relationship to shopping frequency than actual distances. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual organization of two-dimensional patterns.

The perceptual organization of image patterns is considered from 2 standpoints. First, a theoretical framework is presented from which computational models of perceptual organization can be constructed and tested. Second, a specific computational model for perceptual organization of line images is described. In this model, input images are first processed by a dense array of neurons that have properties consistent with recent analyses of single-neuron responses in primary visual cortex. Then, complex image structure is discovered by interleaved pattern-matching and grouping processes constrained by a generalized uniqueness principle. A series of 3-pattern grouping experiments was performed to test a restricted version of the model and to estimate critical parameters. Using the estimated parameters, an extended version of the model was tested by generating predictions for a series of textbook perceptual organization demonstrations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual restoration of obliterated sounds.

When portions of a signal are masked in noisy environments, perceptual restoration can be accomplished through auditory induction (AI). There are 2 classes of AI: (a) temporal induction (TI), which restores contextually appropriate segments of a signal masked at both ears by transient noises; and (b) contralateral induction (CI), which restores a signal masked at one ear when it is heard at the other. TI can prevent fragmentation of steady sounds and can permit comprehension of speech that would otherwise be unintelligible, while CI can prevent mislocalization of a sound source to the side of the unmasked ear. Both classes of AI are subtractive processes requiring that the neural units corresponding to the perceptually restored sound be among those stimulated by the louder interrupting sound. The rules governing AI provide information concerning general principles underlying perceptual organization in hearing. (60 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual localization of surface position.

In 2 experiments, observers were required to identify corresponding points on an object viewed from multiple orientations. On each trial, a surface was presented initially with a single target location marked by a small dot. Following a brief blank interval, the same surface was presented again at a different orientation. The observer was required to position an adjustable probe dot in this 2nd display to match the location of the target in the 1st view. Under optimal conditions, the variance in their settings over multiple trials was just a few minutes of arc, though these errors varied significantly with the structural complexity of the depicted surface. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Skewed symmetry: A nonaccidental property used to perceive visual forms.

Mathematically, skewed symmetry is a nonaccidental property because it can be interpreted as bilateral symmetry in depth viewed from a nonorthogonal angle. To find out whether this is a useful property in the perception of visual forms, 4 experiments were designed in which the Ss had to determine whether 2 symmetric or random patterns were the same regardless of possible affine transformations between them. The results provided mixed evidence: Although there was always a large symmetry advantage, skewed symmetry was only perceived as bilateral symmetry in depth for dot patterns with higher order types of symmetry (Exp 1), when the dots were connected to form closed polygons (Exp 2 and 4), or when they were surrounded by a frame to enhance their planarity (Exp 3). In other cases, Ss relied on local groupings on the basis of proximity or curvilinearity, which are qualitatively affine invariant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual and cognitive spatial learning.

Ss were taught novel mappings between visual space and motor space with either a variant on a prism adaptation paradigm (Exps 1 and 2) or a nonperceptual cognitive task (Exps 3 and 4). First, discrimination training specified that one visual location required a new pointing response but another location did not. This led to unusual generalization unlike typical generalization decrement. Second, training at 9 locations specified that 1 location required a new response but that the remaining 8 did not. This simple isolation mapping was unlearnable and instead a flat function fit through all of space. In contrast, for the cognitive paradigm, not only was isolation of one region of space easily learned, it was the preferred pattern of generalization. Implications for perceptual learning, as well as the qualitative distinctions between perceptual and cognitive learning, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual selectivity in hallucinatory schizophrenics.

Constructed a manual for categorizing themes present in hallucinations using 10 males and 7 females from 49 actively hallucinating Ss. The authors agreed on the major theme for 30 of 32 remaining Ss, indicating significant interjudge reliability (p     

Perceptual biases in psychosis-prone individuals.

College students screened for psychosis-proneness using the Chapman scales were compared on 4 free-vision tasks that typically yield left-spatial-field biases. The tasks included 2 chimeric face tests, consisting of happy/neutral faces and male/female faces, and 2 nonface tasks, consisting of pairs of dot-filled or gradient-filled rectangles. Participants endorsing perceptual aberration items, magical ideation items, or both (n?=?98) and control participants (n?=?112) were left-biased on all tasks but gradients and were most biased on emotion faces; in contrast, i.e., social anhedonia participants (n?=?40) displayed very little or no left-field biases. For all groups, task intercorrelations were greatest between the 2 face tasks and between the 2 nonface tasks. These findings suggest patterns of atypical perceptual asymmetry in psychosis-prone individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual load alters visual excitability.

Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load should affect simultaneous, but not sequential, stimulus presentations, the visual excitability account makes the novel prediction that load should affect detection sensitivity for both simultaneous and sequential presentations. Participants fixated a stimulus stream, responding to targets defined by either a color (low load) or color and orientation conjunctions (high load). Additionally, detection sensitivity was measured for a peripheral critical stimulus (CS) presented occasionally. Increasing load at fixation reduced sensitivity to the peripheral CSs; this effect was similar regardless of whether CSs were presented simultaneously with central stimuli or during the (otherwise empty) interval between them. Controls ruled out explanations of the results in terms of strategic task prioritization. These findings support a cortical excitability account for perceptual load, challenging stimulus competition accounts. (PsycINFO Database Record (c) 2011 APA, all rights reserved)