Stimulus configuration and context effects in perceptual organization in schizophrenia.

Two studies assessed perceptual organization in schizophrenia to determine (a) whether inpatient and outpatient groups with poor premorbid schizophrenia have comparable levels of perceptual organization deficit; and (b) whether the deficit could be eliminated by task manipulations. In Study 1, inpatients demonstrated clear evidence of a perceptual organization deficit, whereas outpatients performed similarly to the control groups. In Study 2, a performance pattern that operationally defined a perceptual organization deficit was eliminated by a task manipulation thought to aid in context processing. The perceptual organization deficit is most pronounced in actively symptomatic patients with poor premorbid schizophrenia, and the deficit reflects, in part, deficient top-down influences to basic perceptual processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term visual memory in schizophrenics.

Hypothesized that the deficit of poor premorbid schizophrenics in backward masking is due to interference in short-term visual memory (STVM) because of the tendency to process a pattern mask as if it were a cognitive mask. The hypothesis was tested in a backward-masking picture-recognition paradigm, using data from 32 male psychiatric patients (aged 18–55 yrs) and 14 hospital personnel. The 12 good premorbid schizophrenics, 7 nonschizophrenic psychotics, and normal Ss all showed differential pattern- and cognitive-mask performance. The performances of 13 poor premorbids were equivalent on both mask types. Findings corroborate the hypothesis. It is suggested that integration of stimuli in poor premorbids' sensory storage was intact and that the disruption in processing caused by a pattern mask at 200–300 msec was due to an interference in STVM. It is concluded that the hypothesis of a deficit in perceptual organization best accounts for the apparent disruptions in poor premorbids' STVM. (70 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Meaning dimensions and male-female voice perception in schizophrenics with good and poor premorbid adjustment.

This study explored certain aspects of perceptual distortion in schizophrenia. Among schizophrenics with a good premorbid adjustment, schizophrenics with a poor premorbid adjustment, and normals, auditory perception of spoken material was compared as a function of (a) sex of voice and (b) dimensions of meaning. The Ss listened to successive presentations of a recorded spoken word, mixed with decreasing amounts of masking noise, until their recognition threshold were established. Schizophrenics with poor premorbid adjustment responding to the female voice had significantly higher thresholds than those responding to the male voice. This finding did not occur in schizophrenics with good premorbid adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dot Enumeration Perceptual Organization Task (DEPOT): evidence for a short-term visual memory deficit in schizophrenia

The Dot Enumeration Perceptual Organization Task (DEPOT) evaluates the validity of 2 specific competing cognitive models of early input dysfunction in schizophrenic individuals: a primary Stage 1, sensory store, perceptual organization deficit vs. a Stage 2, short-term visual memory (STVM) deficit. DEPOT was also designed to assess the hypothesis that schizophrenic individuals tend to perform poorly on all cognitive tasks. In DEPOT both number and form judgments are made about the same dot patterns. A response delay manipulation assesses the persistence and operation of STVM. The study included 41 psychotic inpatients (8 with acute and 16 with chronic schizophrenia and 7 with bipolar and 10 with nonbipolar affective disorder) and 38 controls (22 college students and 16 hospital personnel). Although the pattern of results was consistent with neither the Stage 1 deficit nor the general deficit hypotheses, a Stage 2, STVM deficit hypothesis could account parsimoniously for the data.     

Perceptual Organization in Schizophrenia Spectrum Disorders: Empirical Research and Theoretical Implications.

The research into perceptual organization in schizophrenia spectrum disorders has found evidence for and against a perceptual organization deficit and has interpreted the data from within several different theoretical frameworks. A synthesis of this evidence, however, reveals that this body of work has produced reliable evidence for deficits in schizophrenia, as well as for the clinical, stimulus, and task parameters associated with normal and abnormal performance. Recent models of cognition have also advanced understanding of the underlying pathophysiological processes of perceptual organization dysfunction in schizophrenia spectrum disorders. These suggest that deficits in perceptual organization may be one manifestation of a wider disturbance in the integration of contextually related information across space and time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in schizophrenia: Timing or subtypes?

Reviews evidence for sex differences in the epidemiology, symptom expression, and premorbid social competence of schizophrenia. The data present a general picture of poor premorbid competence, early onset, typical schizophrenia in males, and good premorbid competence, late onset, atypical schizophrenia in females. Two main competing models emerge to account for these sex differences: a timing model and a subtype model. Other interpretations, including misdiagnosis of affective disorders as schizophrenia and the overlay of general sex-role styles on psychopathology, are also examined. (2? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Information Processing Deficits in Remitted Schizophrenics.

This study investigated early stages of information processing in schizophrenia as assessed by a backward-masking paradigm. Ten remitted process schizophrenics and 10 matched normal controls were tested. Subjects were matched for both age and intelligence. All schizophrenics met the criteria of an early onset, poor premorbid adjustment, evidence of formal thought disorder (e.g., language disturbance) and had previously exhibited hallucinations or delusions. Stimuli were tachistoscopically exposed under two masking conditions, two stimulus durations, and five masking latencies (stimulus onset asynchronies) over four 200-trial sessions, for a total of 800 trials. A two-alternative forced-choice recognition of a T or A served as the dependent measure. Results indicated that whereas schizophrenics were more impaired than normals under both masking conditions, they were particularly impaired under the pattern mask condition. These results add support to the growing evidence of an early information processing disturbance in schizophrenia that is trait dependent and is not an artifact of nonspecific pathological disturbance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

John M. Neale.

Announces John M. Neale as a recipient of the 1974 Early Career Award, and presents his biography and list of scientific publications. For his investigations of information processing and the role of perceptual factors in process and reactive schizophrenia. His series of investigations of adult schizophrenia, including studies on size estimation, preference for visual complexity, span of apprehension, reaction time, premorbid adjustment, two-flash threshold, and the assessment of paranoid systems, are characterized by their careful execution and varied methodologies. The results of these investigations, done in collaboration with Rue Cromwell, helped to clarify the variations in size estimation characteristic of process and reactive schizophrenics, indicated the importance of anticipatory reaction time responses in discriminating schizophrenic from normal performance, and suggested the role of full versus partial report in span of apprehension tasks. Currently, he is vigorously pursuing a program of research on children at risk for schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical anhedonia and schizophrenia.

Assessed the relation of anhedonia to schizophrenia using 69 schizophrenics and 54 psychiatric control outpatients from 3 mental health centers. In addition to indexes of schizophrenia, each S was given the Physical Anhedonia Scale, a measure of premorbidity, and a vocabulary test. Measures of chronicity and education were also included. ANOVAs indicated no significant differences in anhedonia among 4 diagnostic groups: paranoid schizophrenics, nonparanoid schizophrenics, unipolar affective psychiatric control Ss, and other psychiatric control Ss. Intercorrelations showed that anhedonia was negatively related to premorbid social status, years of education and vocabulary, but it was not significantly related to hospitalization. Data do not support the hypothesis that anhedonia is a consistent sign of schizophrenia but are compatible with the notion that anhedonia is the consequence of such liabilities as psychiatric disturbance, poor premorbid status, low educational level, and low verbal ability. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical correlates of anhedonia and perceptual aberration in first-episode patients with schizophrenia and affective disorder.

Examined the association between scales measuring physical anhedonia, social anhedonia, and perceptual aberration and premorbid functioning, clinical state, and current level of adjustment in 91 psychotic Ss. The patients were examined at the onset of their 1st psychotic episode and again 18 mo later. For patients with schizophrenia, anhedonia was significantly related to premorbid functioning. No association was found between the scales and clinical state or level of adjustment at intake or follow-up. In affective disorder patients, no correlation was found between premorbid functioning (a stable characteristic) and scale scores, but moderately large correlations emerged between the scales and clinical state and level of adjustment at both assessment times. These results suggest that schizophrenic and affective disorder patients endorse items on these scales for different reasons. The authors hypothesize that for patients with schizophrenia the scales assess enduring personality characteristics, whereas for the affective disordered patients they assess clinical condition at the time of testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Premorbid adjustment and the recovery of mothering function in acute schizophrenic women.

42 female acute, 1st-admission schizophrenics treated briefly in a community mental health center were followed from day of admission to 1 yr postdischarge. Mothers in the sample, divided on the basis of premorbid adjustment (n = 19 good premorbids; n = 8 poor premorbids) were studied regarding the changing patterns of child care shown over the 1-yr period. Results indicate that poor premorbid mothers were younger than good premorbids at the time of their 1st psychotic episode and had at least 1 infant child. The children of good premorbids were largely in middle childhood. Data are discussed in terms of the implications of early release programs for schizophrenia on the ultimate mental health of the offspring and on the whole area of "high-risk" studies. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An investigation of semantic space in patients with schizophrenia

There has been increasing interest in the semantic cognitive system in schizophrenia. Recent findings suggest a possible breakdown of semantic information processing in this disorder. The current study attempts to further examine semantic organization in schizophrenia. Twenty-eight chronic, early-onset schizophrenic patients and 32 controls were matched for premorbid intelligence and compared in their ability to spontaneously cluster exemplars from a specific category during a fluency task. Using multidimensional scaling and clustering techniques, 11 exemplars occurring most frequently in both groups were chosen for examination of their relative "proximity" during word generation. Patients with schizophrenia showed a less stable two-dimensional organization of exemplars and were less likely to group exemplars into subordinate clusters than were normals. These results suggest that semantic networks are disorganized in these patients. These findings may have some implications for the debate over the origin of "thought disorder" in schizophrenia.     

Perceptual anomalies in schizophrenia co-occur with selective impairments in the gamma frequency component of midlatency auditory ERPs.

This study aimed to establish concordance between phenomenological and psychophysiological indices of sensory gating disturbance in schizophrenia. Perceptually normal and deviant subgroups of schizophrenia (SZ) and healthy comparison (HC) participants were empirically determined on the basis of self-rated Sensory Gating Inventory scores. Contrasts by diagnosis and subgroup classification were conducted on event-related brain potential (ERP) response attenuation to paired auditory stimuli, measured in time (P50 ERP) and frequency (low frequency, 1-20 Hz; gamma band, 20-50 Hz) domains. The SZ sample evidenced significantly less low-frequency response attenuation than did HC but comparable P50 and gamma responses. The low-frequency response, however, appeared insensitive to variation in perceptual experience between SZ subgroups. Conversely, smaller P50 amplitude and weaker gamma response attenuation distinguished deviant SZ (n=17) from normal SZ (n=9) and normal HC (n=29) subgroups. Perceptually normal SZ and normal HC subgroups were statistically equivalent across all comparisons. These findings support hypotheses relating perceptual disturbance in schizophrenia to an early sensory input dysfunction, which is thought to involve gamma-mediated thalamocortical integration of sensory stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grasping behavior in schizophrenia suggests selective impairment in the dorsal visual pathway.

This study frames anomalous functional brain organization in schizophrenia (SCZ) within an evolutionary model of brain development, the dual trends theory (DTT). The DTT argues that neural architecture develops along 2 separate pathways: the dorsal archicortical trend and the ventral paleocortical trend. The DTT dovetails with visual system organization, which is also composed of 2 independent pathways: a dorsal stream dedicated to visuomotor action and a ventral stream dedicated to perceptual processing. The present study examined the integrity of these pathways using a size-contrast visual illusion. Prior research has shown that, normally, perceptual estimations of object size are susceptible to visual illusions, whereas goal-directed actions are resistant. The authors hypothesized that, unlike control participants, SCZ patients' actions would be susceptible to the illusion, reflecting dorsal stream dysfunction. Here, 42 SCZ patients and 42 healthy controls grasped and estimated the size of target blocks in control and illusion conditions. During estimation, both groups were equally perturbed by the illusion; however, grasping movements of patients alone were influenced by the illusion. These results suggest disrupted dorsal brain circuitry in SCZ but relatively intact ventral circuitry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Premorbid anomalies and risk of schizophrenia and depressive disorders in a birth cohort exposed to prenatal rubella.

In a birth cohort prenatally exposed to rubella, we assessed whether prospectively documented premorbid neuromotor dysfunction, mannerisms, deviant behaviors, and temperament during childhood and adolescence were impaired in cases who developed depressive disorder (DD) relative to rubella-exposed controls and cases who developed schizophrenia spectrum psychosis (SSP). Premorbid neuromotor dysfunction and mannerisms were not increased among DD cases compared to controls or SSP cases. With regard to temperament, approachability was greater in DD cases than in controls and SSP cases. There were numerical increases in the proportions of DD cases with premorbid deviant behaviors compared to controls, but the findings fell short of statistical significance; the proportion of subjects with deviant behaviors in DD cases was similar to that found for SSP. These results indicate that premorbid neuromotor dysfunction and mannerisms may be specific to SSP among major psychiatric disorders in this cohort, and suggest that premorbid deviant behaviors are increased in both DD and SSP. Greater premorbid approachability may be associated with an increased risk of adult DD. Implications of these findings for school psychology are furnished. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of gender differences in the reduction of etiologic heterogeneity in schizophrenia

Recent research has shown a resurgence of interest in the study of gender differences in schizophrenia. Accumulated evidence suggests that, compared with women, men have a higher incidence of schizophrenia, earlier age of onset, poorer course and medication response, poorer premorbid social and intellectual functioning, fewer affective symptoms, lower family morbid risk of schizophrenia and affective disorders, more evidence of obstetric complications in their mothers, and greater structural brain abnormalities. The roles of estrogen, neurodevelopment, and family history of affective disorder are evaluated as co-contributors to the observed gender differences in schizophrenia. Particular emphasis is given to evaluating the hypothesis that men are more prone to a hypothesized poor-prognosis, neurodevelopmental subtype of schizophrenia, for which early environmental brain insults play an important etiologic role, whereas women may be more prone to a hypothesized good-prognosis, affective subtype that is genetically related to the affective disorders. This hypothesis is evaluated in terms of (a) its ability to account for gender differences in schizophrenia, (b) its ability to link differences in clinical presentation to proposed differences in etiology; and (c) its potential to generate testable predictions for future schizophrenia research.     

Verbal fluency deficits in patients with schizophrenia: Semantic fluency is differentially impaired as compared with phonologic fluency.

Patients with schizophrenia show deficits in phonologic (ability to name words that begin with a specific letter, e.g., F) and semantic (ability to name members of a category, e.g., "animals" fluency.) Whereas the former deficit has been presumed to reflect a dysfunction of the frontal lobe, the latter has been linked to frontal and temporoparietal brain areas. These 2 verbal fluency measures were studied in a sample of 27 schizophrenia patients and 24 normal controls who were matched on age and a putative measure of premorbid intellectual ability. A 2-min production task of switching between letters and between categories measured demand for flexibility. On switching and nonswitching tasks controls produced more words during semantic versus phonologic fluency. Conversely, schizophrenia patients produced more words for letters than for categories, suggesting dysfunction of the frontal and temporoparietal areas of the brain. Furthermore, the greater impairment of semantic fluency may be related to a breakdown of semantic information processing beyond "executive" search and retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual aberrations impair mental own-body transformations.

Dysfunctional self and bodily processing have been reported from the schizophrenia spectrum. Here, the authors tested 72 students (40 women) to determine whether performance in a mental own-body transformation task relates to self-rated frequency of spontaneously experienced schizotypal body schema alterations (perceptual aberration). Participants provided speeded left-right decisions concerning the body of a visually depicted human figure (front view vs. back view). For men, reaction times to disembodied perspectives increased with increasing scores on a validated perceptual aberration scale. This finding constitutes behavioral evidence for the clinically postulated association between aberrant bodily experiences during everyday life and aberrant processing in a mental own-body transformation task arguably reflecting mild dysfunction at the temporo-parietal junction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proprioception and schizophrenia: a replication study with nonschizophrenic patient controls

In 3 experiments, weight discrimination, arm flexion discrimination, and a test of kinesthetic figural aftereffects were used to evaluate the proprioceptive functioning of 40 schizophrenic patients, 30 nonschizophrenic (psychotic and nonpsychotic) patients, and 10 normals. The additional variables of premorbid functioning and paranoia were also examined. Previous findings of a subtle proprioceptive deficit for schizophrenics in comparison with normals were replicated for nonparanoid schizophrenics of a weight-discrimination procedure and poor premorbid schizophrenics on an arm-flexion task. The kinesthetic-figural-aftereffects schizophrenic deficit previously reported by the author and E. Ebner (see record 1974-23243-001) was not replicated. Deficits in proprioception also were found for all nonschizophrenic patient groups on the weight-discrimination procedure and for poor premorbid nonschizophrenic psychotics and neurotics on the arm-flexion task. It is concluded that a deficit in proprioception is not unique to schizophrenia but appears to be related to chronicity and severity of pathology in both schizophrenic and nonschizophrenic hospitalized patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing clinically relevant perceptual organization with multidimensional scaling techniques.

Multidimensional scaling (MDS) techniques provide a promising measurement strategy for characterizing individual differences in cognitive processing, which many clinical theories associate with the development, maintenance, and treatment of psychopathology. The authors describe the use of deterministic and probabilistic MDS techniques for investigating numerous aspects of perceptual organization, such as dimensional attention, perceptual correlation, within-attribute organization, and perceptual variability. Additionally, they discuss how formal quantitative models can be used, in conjunction with MDS-derived representations of individual differences in perceptual organization, to test theories about the role of cognitive processing in clinically relevant phenomena. They include applied examples from their work in the areas of eating disorders and sexual coercion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)