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)     

Functional mapping of human memory using PET: Comparisons of conceptual and perceptual tasks.

Tested whether different neurological regions subserved the conceptual and perceptual memory components by using positron emission tomography (PET). Regional cerebral blood flow (RCBF) of 14 Ss (mean age 25 yrs) during 2 conceptual tasks of semantic cued recall and semantic association was compared to a control condition in which Ss made semantic associations to nonstudied words. RCBF during 2 perceptual tasks of word fragment cued recall and word fragment completion was also compared to a word fragment nonstudied control condition. There were clear dissociations in RCBF that reflected differences in brain regions subserving the 2 types of memory processes. Conceptual processing produced more activation in the left frontal and temporal cortex and the lateral aspect of the bilateral inferior parietal lobule. Perceptual memory processing activated the right frontal and temporal cortex and the bilateral posterior areas. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrophysiological evidence for a postperceptual locus of suppression during the attentional blink

When an observer detects a target in a rapid stream of visual stimuli, there is a brief period of time during which the detection of subsequent targets is impaired. In this study, event-related potentials (ERPs) were recorded from normal adult observers to determine whether this "attentional blink" reflects a suppression of perceptual processes or an impairment in postperceptual processes. No suppression was observed during the attentional blink interval for ERP components corresponding to sensory processing (the P1 and N1 components) or semantic analysis (the N400 component). However, complete suppression was observed for an ERP component that has been hypothesized to reflect the updating of working memory (the P3 component). Results indicate that the attentional blink reflects an impairment in a postperceptual stage of processing.     

Perceptual asymmetry in psychosis-prone college students: Evidence for left-hemisphere overactivation.

The hypothesis that psychosis-prone students demonstrate a pattern of exaggerated perceptual asymmetry across both left- and right-hemisphere dichotic-listening tasks (consonant-vowel [CV] and tonal contour discrimination) was investigated. Ss who scored high on the Perceptual Aberration or Magical Ideation scale or both (n?=?20) demonstrated a significantly exaggerated right-ear advantage on a CV task in relation to normal control Ss (n?=?27) but showed a reduced left-ear advantage on a tone task. The hypothesis of exaggerated functional lateralization across hemispheres in the psychosis-prone Ss was not supported, but the results are consistent with a hypothesis of left hemisphere overactivation in this sample. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A dual-task analysis of resource allocation in dysthymia and anhedonia.

Research has shown dysthymic individuals to be hyporesponsive at various stages of information processing, yet it is not clear whether dysthymics are deficient in the amount of available attentional resources for information processing or, instead, in the allocation of those resources. To distinguish between these possibilities, dysthymics were compared to anhedonic and normal control Ss during the performance of memory tasks, under conditions of varying task priority and difficulty. Although there were no performance differences, dysthymics and anhedonics exhibited a consistently smaller P300 component of the event-related potential. Furthermore, P300 results indicated that dysthymics and anhedonics responded differently from controls to variations in task demands. Thus, although evidence was obtained for group differences in both resource capacity and resource allocation strategy, the overall pattern of results is interpreted as favoring the latter. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event-related potential measures of information processing during general anesthesia

To investigate the incidence and manner of auditory information processing during a state of presumed unconsciousness event-related brain potentials (ERPs) were studied in 41 patients undergoing cardiac surgery with propofol/alfentanil anesthesia. The ERPs were recorded during auditory oddball tasks administered before and within several periods of the operation. Mean nasopharyngeal temperature and anesthetic concentrations were determined for each intraoperative ERP recording epoch. During anesthesia ERP waves could still be observed up to 500 ms after stimulus onset indicating that auditory information processing was not suppressed completely by the administered anesthetic agents. Relative to the preoperative recordings, the P1-N1-P2 complex was delayed and more positive going during anesthesia. Comparable changes in ERP morphology have been observed during Stage II-IV sleep, suggesting parallels in the mechanisms underlying early auditory processing in both states of reduced arousal level, possibly related to a selective reduction of a non-specific activity. N1 and P2 peak amplitudes were found to be larger for the deviant tones compared to the standard tones. These amplitude differences most likely reflect automatic detection of stimulus deviance, although it cannot be excluded entirely that they were due to differences in refractoriness. Anesthetic concentrations and nasopharyngeal temperature were found to be of minor significance for ERP control. It is suggested that ERPs could serve as intraoperative reference measures, providing the earliest evidence for auditory processing. This characteristic is important for validation of signals and techniques that are proposed to improve conventional monitoring of anesthesia with respect to detecting unintended awareness.     

Required high effort increases subsequent persistence and reduces cheating.

Two experiments examined the effect of the degree of effort required in preliminary tasks on the persistence and cheating in subsequent tasks. Undergraduates (N?=?276) were administered mathematics problems and perceptual identifications requiring high effort for one group and low effort for another group. A control group received neither of these tasks. All Ss then received an anagram task in which success depended on persistence with no opportunity to cheat (Exp I) or success was improbable and depended on cheating (Exp II). In Exp I, increasing the degree of effort required in the preliminary tasks increased the number of anagrams subsequently solved and increased the duration spent on unsolved anagrams. In Exp II, requiring high effort in the preliminary tasks decreased how often Ss falsified their performances. Results suggest that honesty may be increased by generalized effects of rewarded high efforts. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social deficits in hypothetically psychosis-prone college women.

Identified hypothetically psychosis-prone female college students (aged 17–20 yrs) by scales of Physical Anhedonia (n?=?25), Perceptual Aberration (n?=?32), and Nonconformity (n?=?26) and compared them with 27 controls on a role-playing task calling for social skill in interpersonal situations. All 3 groups of experimental Ss exceeded controls on social inappropriateness of response. The anhedonic Ss were significantly more avoidant and more odd than were controls. The perceptual aberration Ss were more odd and more hostile, and the nonconformity Ss were more hostile than were controls. Nevertheless, the experimental Ss were not inferior to controls on overall skill level. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Equivalence of body image disturbances in anorexia and bulimia nervosa.

A silhouette method, the Body Image Assessment, was used to measure self-evaluation of current and ideal body size in 3 groups: Ss with anorexia nervosa (n?=?37), Ss with bulimia nervosa (n?=?59), and normal control Ss (n?=?95). Current and ideal body size measures were contrasted across the 3 groups using body mass index as a covariate to control for the Ss' actual body size. Both eating disorder groups judged current body size to be larger and ideal body size to be thinner relative to control Ss. When actual body size was not statistically controlled, Ss with anorexia nervosa judged current body size to be thinner than did control Ss and Ss with bulimia nervosa. Data illustrate the importance of controlling for actual body size when investigating the self-evaluation of body size. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Body weight and bulimia as discriminators of psychological characteristics among anorexic, bulimic, and obese women.

Bulimic women from underweight (n?=?20), normal-weight (n?=?31), and overweight (n?=?22) categories were compared with restrictor anorexics (n?=?20), normal controls (n?=?31), and obese Ss (n?=?22). Ss' mean age was 21.13 yrs. Each S was administered the Minnesota Multiphasic Personality Inventory (MMPI), Rotter's Internal–External Locus of Control scale, the Rosenberg Self-Esteem Scale (M. Rosenberg, 1965), and the Semantic Differential scale. Bulimic women in all 3 weight categories exhibited greater psychopathology, more external locus of control, lower self-esteem, and lower sense of personal effectiveness than nonbulimic women at similar weight levels. The highest psychopathology, lowest self-esteem, and most external locus of control were found among the underweight bulimic women. Significant differences between bulimic women of different weight levels suggest the need for some modification of treatment approaches depending on the bulimic woman's weight level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A longitudinal study of the performance of hypertensive and normotensive subjects on the Wechsler Adult Intelligence Scale.

Performance on the Wechsler Adult Intelligence Scale (WAIS) was followed over 2 5- to 6-year intervals for essential hypertensive Ss (EH; n?=?22) free from medical complications and for normotensive Ss (N; n?=?20). EH were treated with adrenergic beta-blocking drugs, diuretics, or both. Mean age was 46 years (SD?=?12.6 years), initially (Time 1). Results were unaltered by adjustment for initial age. N improved modestly on the Verbal scale, from Time 1 to Time 2 only. EH neither improved nor declined on the Verbal scale. Scores remained unchanged for both EH and N Ss for the Performance scale. Overall, and at Times 2 and 3, Verbal scores were lower for the EH group. It was concluded that neither decline nor improvement in cognitive function over time are necessary outcomes of modest, carefully treated, uncomplicated hypertension in the middle years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional information processing: Modulation of fear in normal and dysthymic subjects.

The role of emotion and its associated psychophysiology have received little systematic attention in studies of psychopathology. In the present study, dysthymic and control subjects with high or low fear levels were compared on a task involving anticipation of pleasant and unpleasant slides to evaluate whether dysthymic subjects would demonstrate differential affective processing. Dysthymic subjects were found to differ from controls in several psychophysiological measures, though not in ratings of the slides or in behavioral performance. Although dysthymic subjects showed normal or heightened initial reactions to emotionally significant warning stimuli, results suggest that they withdrew and ceased affective processing as the actual emotional stimulus approached. Response mobilization processes supporting normal overt behavior appear to be intact, but aspects of the orienting response may be dysfunctional in dysthymia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming after severe closed head trauma: Automatic and attentional processes.

The 2-process theory of semantic priming (J. H. Neely, 1977; M. I. Posner and C. R. Snyder, 1975) was used to determine the maintenance of automatic processes after severe closed head injury (CHI) and to determine whether processes that demand attention suffer a deficit. Ss with severe CHI (N?=?18,?>?2 yrs postinjury) and 18 matched control Ss completed a lexical decision task in which a category prime was followed by a target. Automatic and attentional priming were determined by orthogonally varying prime–target relatedness, expectancy, and stimulus onset asynchrony. Although the CHI Ss had slower reaction times (RTs) overall, there were no significant group differences in the magnitude of either the automatic or attentional component of semantic priming. The present results indicate the integrity of semantic processes and normal semantic priming in long-term patients with severe CHI. The results are discussed in relation to an attentional resource hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Familial prevalence and coaggregation of schizotypy indicators: A multitrait family study.

Schizophrenic probands (n?=?17), their 1st-degree relatives (n?=?61), and medically and psychiatrically screened normal control Ss (n?=?18) were studied with structured interviews for Diagnostic and Statistical Manual of Mental Disorders (DSM-III) Axis I disorders and schizotypal personality disorder, questionnaire measures of schizotypy, measures of smooth-pursuit eye movement dysfunction, and attention dysfunction. Schizophrenic Ss scored abnormally on essentially all measures. Relatives differed significantly from control Ss on most measures. Correlational analyses indicate that many characteristics tested in these measures run together in families. The data are consistent with the hypothesis that a single vulnerability dimension or typology, presumably in part genetically transmitted, may account for phenotypically distinct abnormalities. These traits, taken together, may have joint usefulness for identifying persons with a predisposition to schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Illusion of control: Invulnerability to negative affect and depressive symptoms after laboratory and natural stressors.

Examined whether individual differences in susceptibility to the illusion of control predicted differential vulnerability to depressive responses after a laboratory failure and naturally occurring life stressors. The illusion of control decreased the likelihood that Ss (N?=?145) would (1) show immediate negative mood reactions to the lab failure, (2) become discouraged after naturally occurring negative life events, and (3) experience increases in depressive symptoms a month later given the occurrence of a high number of negative life events. In addition, the stress-moderating effect of the illusion of control on later depressive symptoms appeared to be mediated in part by its effect on reducing the discouragement Ss experienced from the occurrence of negative life events. These findings provide support for the hopelessness theory of depression and for the optimistic illusion–mental health link. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parkinson's dementia and Alzheimer's dementia: an evoked potential comparison

Auditory endogenous event-related potentials (ERPs) and flash visual evoked potentials (VEPs) were recorded in 26 elderly patients with idiopathic Parkinson's disease (PD), 14 with dementia and 12 non-demented, 16 elderly patients with Alzheimer dementia (AD) and 15 cognitively intact controls. ERP P3 and flash-VEP N2, P2 and delta (P2-P1) latency measures were significantly increased in the demented PD group compared with controls. The ERP P3 latency was also significantly delayed in the AD group compared with controls, but the differences in the flash-VEP measures from controls were not significant. No significant differences were noted between the PD groups, except for a significantly shorter flash-VEP N1 latency in the demented PD group; this was also the only significant evoked potential difference between the AD and PD dementia groups, which were otherwise electrophysiologically similar.     

PLATO DCS, an interactive computer system for personal counseling: Further development and evaluation.

Two newly developed solutions components are described as additional resources for users of the PLATO computer-based Dilemma Counseling System (PLATO DCS). The specific and structural dilemma solutions components contain 69 representative life-choice problems and over 400 specific and general solutions that assist users in solving their psychological dilemmas. Computer-based dilemma counseling was examined empirically by assessing self-reported problem improvement in 2 groups of undergraduate students treated on PLATO DCS (n?=?48) or in a no-contact control group (n?=?62). Ss who used PLATO DCS showed significantly greater improvement in their problems than the control group 1 wk after treatment. This difference tended to persist 1 mo after treatment. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual organization in Alzhiemer's disease.

The ability of 16 AD patients and 16 age-matched control Ss to discriminate degraded forms was compared. Also examined were the effects of aging on perceptual organization by comparison of performance of normal Ss ranging in age from 20 to 86 years. Ss discriminated 2 forms, a circle and a square, each composed of randomly distributed dots concurrently embedded in visual noise. By means of a forced-choice procedure, the threshold signal-to-noise ratios at 4 levels of figure degradation were obtained, each presented at 3 durations. Performance by the normal Ss did not vary with age for long-duration stimuli, but did decline with age for briefly presented stimuli. Relative to age-matched control Ss, AD patients had significantly elevated thresholds at all form densities. Disruption of visual processing at the level of perceptual organization is likely a contributing factor to impairment of high-order visual function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The duality of selection: Excitatory and inhibitory processes in auditory selective attention.

Behavioral and event-related potential (ERP) measurements were made in an auditory selective-attention paradigm, both before and after a series of inhibition or discrimination training sessions. The presence of distractors caused poor perceptual sensitivity, weak P3 responses, conservative responding, and slow reaction times relative to baseline. Distraction prompted a frontal enhancement of ERP components occurring 100-250 ms after the onset of attended signals (N1, P2, and N2). Training ameliorated behavioral interference from distraction. Participants receiving inhibition training acquired improved inhibitory processing of distractors, an effect that peaked 200 ms after distractor onset, In a proposed model, distinct excitatory and inhibitory mechanisms work interactively to maintain sensitivity to environmental change in the fare of disruption from the contextual integration of irrelevant events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cerebral asymmetry and hypnosis: A signal-detection analysis of divided visual field stimulation.

Examined brightness discriminations in a divided-field paradigm with a signal-detection procedure in 3 sessions, the 2nd with hypnosis. Practiced, hypnotically susceptible Ss were subdivided into high (n?=?6) and medium (n?=?5) susceptible groups on the basis of a susceptibility scale monitored throughout the hypnosis session. High-susceptible Ss showed increases in d′ in the left visual field (right hemisphere) with hypnosis, whereas medium-susceptible Ss showed bilateral enhancements. Beta remained invariant in both groups across 3 sessions but was higher in the left visual field. Results provide evidence of altered brain function with hypnosis and an association of focal right hemispheric changes with high susceptibility and, through the invariance of β, fail to support the attribution of perceptual changes to attitudinal, nonstate factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)