Latency of evoked neuromagnetic M100 reflects perceptual and acoustic stimulus attributes

The latency of components of the auditory evoked neuromagnetic field has been shown to reflect, or encode, stimulus attributes. In particular, the M100 component, occurring approximately 100 ms post stimulus onset has a latency that depends on stimulus pitch, spectral complexity and presentation level. This study used magnetoencephalography to record neuromagnetic fields evoked by presentation of two-tone complexes consisting of various proportions of 100 Hz and 1 kHz energy. These are perceived categorically, as evidenced by classification and reaction time measurements. It is found that the M100 latency also varies categorically, that is, characterized by two plateau regions with a sharp interface. Thus, we find that not only does the M100 latency reflect acoustic attributes of a stimulus, but also such perceptual characteristics.     

Levels of selection and capacity limits.

Examined the effects of word relevancy (word in relevant or irrelevant location) and display load (1–4 words) on physical, semantic, and controlled processing of nontargets in visual target-detection tasks administered to 300 undergraduates in 8 experiments. Interwoven with the detection task was a test-word identification task that was used to measure priming potency of nontargets. Physical and semantic levels of processing were measured in terms of identity and semantic priming, respectively. Nontarget primes were repeated as test words in identity priming. Nontarget primes were semantic associates of test words in semantic priming. Controlled processing of nontargets was measured in terms of recognition memory on a subsequent test. All measures increased with word relevancy and decreased with display load. The priming effects remained intact even when word presentation was speeded up and controlled processing was sharply curtailed. Data indicate that all levels of processing are selective and capacity limited. (60 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A paradoxical exposure-duration effect in the Stroop task: Temporal segregation between stimulus attributes facilitates selection.

In comparison with the situation in which target and distractor are presented until response, Stroop interference substantially decreases when the target color is removed from the display 150–160 ms after stimulus onset (W. La Heij, N. A. Kaptein, A. C. Kalff, & L. de Lange, 1995; 0. Neumann, 1986). Six experiments showed that this paradoxical exposure-duration effect is robust, that it is not due to the target's exposure duration per se, and that it is not due to an increased spatial selectivity of input selection. The present findings support and extend earlier observations that changes in the display during stimulus exposure affect attentional selection. The findings are tentatively interpreted in terms of (a) reduced duration of input selection or (b) facilitation of attribute selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between coping styles and perceptual asymmetry.

This study examined the relationship between coping styles and hemispheric asymmetry, on the basis of prior evidence of reduced posterior right hemisphere (RH) activity in depression, and the relationship between ruminative coping and depression. Two samples of undergraduates (N=170) completed chimeric faces tasks and 2 measures of coping styles, the self-report Responses Styles Questionnaire and a behavioral choice task. In women but not in men, self-reported rumination was associated with a decreased RH bias on the emotion-based chimeric task. In both genders, choosing to engage in an emotional task was associated with increased RH involvement. Results indicate that although brooding and dwelling on the negative may be associated with decreased RH involvement, openness to emotion may be associated with increased RH involvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extending the simultaneous-sequential paradigm to measure perceptual capacity for features and words.

In perception, divided attention refers to conditions in which multiple stimuli are relevant to an observer. To measure the effect of divided attention in terms of perceptual capacity, we introduce an extension of the simultaneous-sequential paradigm. The extension makes predictions for fixed-capacity models as well as for unlimited-capacity models. We apply this paradigm to two example tasks, contrast discrimination and word categorization, and find dramatically different effects of divided attention. Contrast discrimination has unlimited capacity, consistent with independent, parallel processing. Word categorization has a nearly fixed capacity, consistent with either serial processing or fixed-capacity, parallel processing. We argue that these measures of perceptual capacity rely on relatively few assumptions compared to most alternative measures. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relationship between perceptual style and reactivity to motion.

The relationship between the perceptual-style dimension of field dependence-independence, as measured by the rod-and-frame test (RFT) and the group Hidden Figures Test, and motion disturbance, as evidenced by a version of the Brief Vestibular Disorientation Test (BVDT) was investigated in 83 naval aviation students. Significant correlations were found between RFT scores and BVDT scores. Field dependence was significantly associated with disturbance by the motion stimulus of the test. Apparent contradictions of the present findings with those involving simulator sickness are discussed. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A dissociation between perceptual explicit and implicit memory processes

Patient M.S., who underwent right-occipital lobe resection to treat intractable epilepsy, has intact recall and recognition memory for words, but impaired repetition priming in word identification and visual stem-completion tasks. This mirror dissociation to amnesia suggests that explicit recognition and visuoperceptual repetition priming are mediated by distinct neural systems. In prior studies, however, M.S.' recognition memory was tested only with tasks that drew upon his intact verbal knowledge. The present study examined M.S.' recognition memory for nonverbal perceptual information, namely, the modality and font of word presentation and line patterns. M.S.' recognition memory was intact, providing further evidence that perceptual explicit and implicit memory processes are subserved by functionally and neurally independent memory systems.     

Contribution of age, genes, and environment to the relationship between perceptual speed and cognitive ability.

The aim of this study was to examine genetic influences on cognitive ability in adulthood in the context of the relationship between perceptual speed and cognitive aging. Quantitative genetic analysis of data from the Swedish Adoption Twin Study of Aging allowed for estimation of the contribution of age, genetic, and environmental effects to the variance in a latent cognitive factor and to the covariance between the cognitive factor and perceptual speed. The sample included 292 pairs of monozygotic and dizygotic twins, both reared together and reared apart, ranging in age from 40 to 84 years. Analysis of components of total variance in the cognitive factor indicated that 90% of the age-related variance in the cognitive factor was shared with perceptual speed and 70% of the genetic variance in the cognitive factor was shared with perceptual speed. The correlation between the speed and cognitive factors was primarily genetically mediated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between overinclusive thinking, perceptual rigidity, and the discrimination learning of new concepts.

Compared 19 newly admitted psychiatric inpatients who showed overinclusive thinking on the Payne Object Classification Test with 24 patients matched for age, IQ, and abstraction ability who were not overinclusive. In a concept-attainment experiment, contrary to prediction, overinclusive Ss did not learn overinclusive concepts. There were no significant differences between the groups. However, overinclusive Ss, as predicted, showed an abnormal lack of "Einstellung" rigidity as measured by a flexibility score from the Brengelmann Picture Recognition Test. The overinclusion score of the object classification test correlated highly (.90) with this flexibility score. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between self-esteem and sensory (perceptual) constancy.

This study explored the relationship between self-esteem and sensory constancy, as measured by the perception of shape. 85 preadolescent males, representing 5 types of self-esteem, were individually asked to match a geometric shape with 1 of a graded series of rectangles. The procedure was intended to elicit judgments in accord with sensory rather than phenomenal constancy. These judgments were obtained under stress and nonstress orientations. The results, indicating that persons high in their estimates of personal worth are better able to attain sensory constancy, were limited to the stress condition. It is hypothesized that persons high in self-esteem can adapt more appropriately to instructions and adopt an analytic attitude excluding distracting stimuli. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing capacity under perceptual and cognitive load: A closer look at load theory.

Variations in perceptual and cognitive demands (load) play a major role in determining the efficiency of selective attention. According to load theory (Lavie, Hirst, Fockert, & Viding, 2004) these factors (a) improve or hamper selectivity by altering the way resources (e.g., processing capacity) are allocated, and (b) tap resources rather than data limitations (Norman & Bobrow, 1975). Here we provide an extensive and rigorous set of tests of these assumptions. Predictions regarding changes in processing capacity are tested using the hazard function of the response time (RT) distribution (Townsend & Ashby, 1978; Wenger & Gibson, 2004). The assumption that load taps resource rather than data limitations is examined using measures of sensitivity and bias drawn from signal detection theory (Swets, 1964). All analyses were performed at two levels: the individual and the aggregate. Hypotheses regarding changes in processing capacity were confirmed at the level of the aggregate. Hypotheses regarding resource and data limitations were not completely supported at either level of analysis. And in all of the analyses, we observed substantial individual differences. In sum, the results suggest a need to expand the theoretical vocabulary of load theory, rather than a need to discard it. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Correspondence between neuropsychological and functional ratings of perceptual neglect.

Examined perceptual neglect in 59 stroke patients (mean age 61.9 yrs) as described by neuropsychological assessment (NP) and by occupational therapists' (OT) functional assessment. Results indicate that NP and OT raters agreed on the presence of neglect in the majority (73–80%) of cases, depending on the scale definitons used. In the remaining cases, most discrepancies existed between ratings of no vs mild neglect. At times, neuropsychological assessment both over- and underestimated the degree of neglect cited by OT raters as functional perceptual impairment due to sources of possible error or bias. The need for and value of efforts to describe the neuropsychological impairments associated with observed functional deficits are highlighted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the relation between perceptual priming and recognition memory.

Two experiments evaluated the hypothesis that perceptual fluency is used to infer prior occurrence. Subjects heard (Experiment 1) or saw (Experiment 2) a list of words and then were presented in the same modality with both these and other words twice in succession: first in a more or less impoverished fashion, and then in clear fashion. For the first of these two presentations, the subjects tried to identify the word; for the second, they gave a recognition judgment. As predicted by the perceptual fluency hypothesis, and as has been found in previous research, the recognition judgments were more positive for identified words than for unidentified words. However, degree of impoverishment, by which apparent perceptual fluency was brought under experimental control, did not affect the recognition judgments. The perceptual fluency hypothesis was therefore not supported, and the observed relation between identification and recognition was attributed to an item selection effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality, perceptual defense, and stereoscopic perception.

Stereoscopic perception was investigated using an experimental design similar to those employed in tachistoscopic studies of perceptual defense. "In the first experiment, some of the variables involved in stereoscopic suppression were investigated, while the second experiment demonstrated the differences in the stereoscopic perception of normals and schizophrenics." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anhedonia, perceptual aberration, and the Rorschach.

26 college students who scored deviantly high on a scale of physical anhedonia and 27 who scored high on a scale of perceptual aberration were compared with 26 normal control Ss on the Rorschach scored for the delta index of thought disorder and the alpha index of deviancy. The anhedonic Ss and perceptual aberration Ss gave more schizophrenic-like Rorschach responses than the control Ss. This finding indicates the importance of follow-up studies to determine whether Ss who score deviantly high on these scales are at high risk for schizophrenia and/or other psychosis. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thought disorder, perceptual aberrations, and schizotypy.

Empirical links between schizophrenia and schizotypic psychopathology were examined. The Perceptual Aberration Scale (PerAb; L. J. Chapman, J. O. Chapman, & M. L. Raulin; see record 1979-23733-001) was used to identify putative schizotypic individuals and a contrast group of nonschizotypic controls. The Thought Disorder Index (TDI; M. J. Coleman et al.; see record 1994-15942-001) was used to quantify and classify thought disorder in these individuals. High PerAb participants, selected for having an increased number of self-reported perceptual and body image aberrations, showed an elevation in the amount and frequency of thought disorder as well as an increased number of idiosyncratic verbalizations. This supports the hypothesis that psychometrically identified schizotypic individuals display thought disorder similar to that shown by schizophrenic patients and some of their 1st-degree relatives, suggesting that there is a relation between schizotypic psychopathology, as tapped by the PerAb scale, and clinical schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivation, model attributes, and prosocial behavior.

Examined the personality and situational effects that influence prosocial behavior. 112 safety- and esteem-oriented (as measured by a sentence-completion test) undergraduates were exposed to an emergency situation wherein the experimenter was ostensibly injured by an "explosion." Results indicate that there were significant situational and personality determinants of helping and imitative behavior. Overall, there was more help when Ss were interacting with an active vs a passive model. Esteem-oriented Ss were more likely to initiate helping behavior and were more strongly influenced by high-competence models. In contrast, safety-oriented Ss helped less overall and were more influenced by high-status models. Results are discussed in terms of a Person?×?Situation paradigm of prosocial behaviors. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)