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Biomedical subjects

A Raine

Publications and source records attributed to A Raine.

At least 55 records · Page 3Linked to original sources

Cognitive-perceptual, interpersonal, and disorganized features of schizotypal personality.

While two factors are currently thought to underlie individual differences in schizotypal personality, three factors may best explain schizotypal traits. This study used confirmatory factor analysis to assess five competing models of schizotypal personality in the general population: null model, one-factor model, simple two-factor model, Kendler two-factor model, and three-factor model. The computer program LISREL was used to analyze Schizotypal Personality Questionnaire subscale scores that reflect the nine traits of schizotypal personality. The scores were obtained from (1) a sample of 822 undergraduates and (2) a replication sample of 102 subjects drawn from the community. Results indicate replicable support for a three-factor model reflecting cognitive-perceptual, interpersonal, and disorganized latent factors. Low intercorrelations between the first two factors and the lack of fit by a one-factor model are partially inconsistent with recent notions that a single vulnerability dimension underlies schizotypal personality. It is argued that future investigations should assess the correlates of all three schizotypal factors in clinical and nonclinical samples in addition to the two more traditional factors. It is hypothesized that three factors of schizophrenic symptomatology observed in recent studies may reflect an exaggeration of three analogous factors found in the general population.

Adolescent↗

The relationship of sweat gland count to electrodermal activity.

This study assessed whether greater skin conductance activity at the distal versus medial site (Scerbo, Freedman, Raine, Dawson, & Venables, 1992) is attributable to a greater number of active (open) sweat glands at the distal site. The number of sweat glands was measured using the Palmar Sweat Index (PSI). Twenty-four subjects were exposed to 10 auditory stimuli. Electrodes were placed on the fore and middle fingers of each hand, using distal sites on one hand and medial sites on the other. The PSI was measured at the medial and distal phalanges adjacent to the electrode placement sites. The distal site contained more open and total sweat glands. Open gland count had the strongest correlations with skin conductance. Multivariate analyses of covariance revealed that site effects for nonspecific and orienting response frequency and trials to habituation were associated with site differences in open glands. Skin conductance measures and the PSI reveal greater electrodermal activity at the distal site. In addition, the number of open glands may be a useful measure related to electrodermal response frequency when polygraph measurement is unavailable.

Acoustic Stimulation↗

Features of borderline personality and violence.

This study tested the hypothesis that borderline personality characterizes extreme violence by assessing features of borderline and schizotypal personality in three groups: Murderers, Violent, and Nonviolent adult offenders. Murderers had higher borderline personality scores than nonviolent offenders (p < .04). A test for linear trend indicated a linear increase in borderline scores with increasing degree of violence across the three groups (p < .02). No group differences were observed for schizotypal personality. Borderline traits associated with extreme violence consisted of unstable, intense relationships and affective instability. Group differences were not an artifact of group differences in age, social class, IQ, or number of previous custodies. It is concluded that borderline personality may predispose toward extreme forms of violence.

Adult↗

Impaired eye tracking in undergraduates with schizotypal personality disorder.

Qualitative ratings of smooth pursuit eye movements were significantly worse for 14 undergraduates with DSM-III-R schizotypal personality disorder than for 18 comparison subjects. The groups did not differ on IQ, indicating that deficits in smooth pursuit eye movements in schizotypal personality disorder are not a function of cognitive deficits.

Female↗

Pre-frontal structural and functional deficits associated with individual differences in schizotypal personality.

This study tests the hypothesis that pre-frontal deficits underlie schizotypal personality in the normal population. Personality measures assessing features of DSM-IIIR schizotypal personality disorder (SPD) were related to left and right pre-frontal brain area assessed by magnetic resonance imaging (MRI), and neuropsychological measures of pre-frontal functioning (Wisconsin Card Sorting Task, WCST) in a group of non-institutionalized, unmedicated normal subjects. High schizotypal scores were significantly associated with reduced pre-frontal area and more WCST perseveration errors; conversely no relationships were observed between these pre-frontal measures and measures of psychosis-proneness unrelated to SPD traits. Pre-frontal structural findings were not found to be mediated by temporal lobe and posterior cortical structural deficits, height, weight, socio-economic status, education level and sex differences, while pre-frontal functional findings were not mediated by non-prefrontal cognitive ability. These findings of pre-frontal structural and functional deficits associated with schizotypal personality provide some initial converging support for a pre-frontal explanation of individual differences in schizotypal personality in the general population.

Adult↗

An evaluation of structural and functional prefrontal deficits in schizophrenia: MRI and neuropsychological measures.

Magnetic resonance imaging was used to assess prefrontal brain structure in 17 schizophrenic, 18 psychiatric control, and 19 normal control subjects of comparable age, social background, and educational status, while three neuropsychological measures were used to assess prefrontal functioning. Schizophrenic patients had significantly smaller prefrontal areas than both psychiatric control and normal control subjects in all three planes. When posterior brain area and temporal lobe were entered into statistical analysis as covariates, they did not explain the prefrontal deficits. Schizophrenic patients made more perseveration errors on the Wisconsin Card Sorting Task and had fewer correct responses on the Spatial Delayed Response Task than normal control subjects. Schizophrenic patients performed more poorly than psychiatric control subjects on the Block Design Test. No group differences were found on three other nonfrontal tasks. These data lend some support to the role of prefrontal deficits in the development of schizophrenia.

Adult↗

Sex differences in schizotypal personality in a nonclinical population.

This study tests the hypothesis that normal women will score higher on the more "positive" features of schizotypal personality and normal men will score higher on more "negative" schizotypal features. Two samples (n = 393, 394) were administered the Schizotypal Personality Questionnaire, which contains subscales corresponding to the 9 schizotypal personality traits outlined in the Diagnostic and Statistical Manual of Mental Disorders (rev. 3rd ed.; American Psychiatric Association, 1987). Women scored significantly higher on the positive subscales of Ideas of Reference and Odd Beliefs/Magical Thinking, and men scored significantly higher on the negative subscales of No Close Friends and Constricted Affect. These findings replicated from one sample to another. These results are broadly consistent with previous findings on schizotypal personality and schizophrenia. It is hypothesized that sex differences in schizophrenic symptomatology may in part reflect an exaggeration of normal sex differences in the general population.

Adult↗

Mixed handedness and features of schizotypal personality in a nonclinical sample.

Using a nonclinical, noncollege sample, this study set out to confirm and extend previous findings of a relationship between the cognitive-perceptual features of schizotypal personality and mixed handedness using the Schizotypal Personality Questionnaire (SPQ). Based on previous findings of relationships between nondextrality and thought disorder in schizophrenia, it was predicted that the odd speech subscale of the SPQ would have the strongest relationship with mixed handedness. Mixed-handed adults did have significantly higher scores than right-handed and left-handed adults on the cognitive-perceptual factor and its subscale of odd speech. Similar trends were also observed for the cognitive-perceptual subscales of suspiciousness, eccentric behavior, and unusual perceptual experiences. These results support and extend previous findings, and are broadly consistent with the association between thought disorder and nondextrality in schizophrenia.

Adolescent↗

A major effect of recording site on measurement of electrodermal activity.

Although the medial phalanx has been recommended as the preferred site for recording skin conductance activity, a review of articles published in Psychophysiology indicates that a large minority (34%) of studies employ the distal phalanx. Informal observations also suggest that the distal site may be more reactive than the medial site. This study formally tests this observation by recording skin conductance from both medial and distal phalanges. Twenty-four right-handed subjects (12 male, 12 female) were exposed to a series of 10 orienting and defensive stimuli. Electrodes were placed on the fore and middle fingers of each hand, with distal sites used on one hand and medial sites on the other for each subject. Skin conductance amplitudes were 3.5 times larger at distal than medial sites (p less than .002), while skin conductance levels were 2.08 times larger at distal sites (p less than .0005). A significant Site X Stimulus interaction (p less than .025) indicated that the distal site was more sensitive to habituation over trials and to increases in skin conductance amplitudes with increasing stimulus intensity than the medial site. On the basis of these findings it is recommended that distal sites be used in preference to medial sites in the recording of skin conductance activity.

Adult↗

Third ventricle enlargement and lower heart rate levels in a high-risk sample.

Heart rate activity and computed tomographic measures of structural brain abnormalities were evaluated in 32 individuals with a genetic risk for schizophrenia (offspring of schizophrenic mothers). Heart rate activity was assessed in 1962 when the subjects were a mean age of 15.1 years. Diagnostic and computed tomography assessments were conducted in 1980. Compared to individuals with normal third ventricles, individuals with enlarged third ventricles evidenced significantly lower heart rate levels overall and significantly lower heart rate during rest and during the periods preceding conditioning and test for conditioning stimulus trials. These effects were independent of age, psychiatric diagnosis, and abnormalities in other brain regions. Difficulties in interpretation posed by the index of brain abnormality employed and by the 18-year time interval between the heart rate and computed tomography assessments are discussed. Together with prior evidence of a relationship between third ventricle enlargement and reduced electrodermal responsiveness in the same subjects, these findings provide a preliminary indication that enlargement of the third ventricle may involve damage to diencephalic structures involved in autonomic nervous system activity.

Adolescent↗

The SPQ: a scale for the assessment of schizotypal personality based on DSM-III-R criteria.

Existing self-report measures of schizotypal personality assess only one to three of the nine traits of schizotypal personality disorder. This study describes the development of the Schizotypal Personality Questionnaire (SPQ), a self-report scale modeled on DSM-III-R criteria for schizotypal personality disorder and containing subscales for all nine schizotypal traits. Two samples of normal subjects (n = 302 and n = 195) were used to test replicability of findings. The SPQ was found to have high sampling validity, high internal reliability (0.91), test-retest reliability (0.82), convergent validity (0.59 to 0.81), discriminant validity, and criterion validity (0.63, 0.68), findings which were replicated across samples. Fifty-five percent of subjects scoring in the top 10 percent of SPQ scores had a clinical diagnosis of schizotypal personality disorder. Thus, the SPQ may be useful in screening for schizotypal personality disorder in the general population and also in researching the correlates of individual schizotypal traits.

Affective Symptoms↗

Neuroanatomical correlates of skin conductance orienting in normal humans: a magnetic resonance imaging study.

Although little is known about the neuroanatomical basis of skin conductance orienting in intact normal humans, the limited literature on animals and humans with neurological and clinical disorders implicate prefrontal, temporal/amygdala, and pons brain areas in mediating skin conductance orienting. This study relates area of these structures using magnetic resonance imaging techniques to skin conductance orienting responses in 17 normal humans in order to test hypotheses that larger area of these excitatory structures will be associated with more orienting responses. Left and right hand skin conductance orienting was significantly associated with left and right prefrontal area (r = .44-.60), area of the pons (r = .43-.54), and left but not right temporal/amygdala area (r = .47-.53). No relationships were observed with areas thought to be unrelated to skin conductance activity (cerebellum, nonfrontal cortical area), medial prefrontal cortex, or the third ventricle. This appears to be the first study relating brain structure to skin conductance orienting in intact normal humans. Although preliminary at the present time, these results implicate prefrontal, pons, and temporal/amygdala areas in the mediation of skin conductance orienting in normal humans.

Adult↗

Are lateral eye-movements a valid index of functional hemispheric asymmetries?

Lateral eye-movements (LEMs) to verbal and spatial questions are frequently used as an index of asymmetries in hemisphere activation and the concept of 'hemisphericity'. There have, however, been few attempts to validate LEMs using independent cognitive measures of hemisphere function. This study relates laterality indices of LEMs recorded in the dark using infrared recording techniques, and elicited by verbal and spatial questions, to other measures of left and right hemisphere functioning (verbal and non-verbal dichotic listening, block design, digit span) in 43 subjects. LEM laterality indices were unrelated to these validation measures. It is concluded that although appropriate question type-LEM relationships may reflect transient asymmetries in hemispheric activation, they are not a valid index of stable individual differences in hemisphere utilization.

Adolescent↗

Verbal short-term memory span in speech-disordered children: implications for articulatory coding in short-term memory.

One influential explanation of the development of verbal short-term memory in children argues that short-term memory capacity is a direct function of speech rate. This theory predicts that children with pathologically slow speech will show reduced verbal short-term memory capacity and will show less evidence of speech-base coding on verbal memory tasks. To test this prediction, verbal short-term memory span was assessed using a task that did not require a verbal response in 37 speech-disordered children and 37 age- and sex-matched controls (age range 4-15 years). The speech-disordered group had a significantly lower short-term memory capacity, a smaller word length effect, and reduced speech-motor activity during rehearsal periods. Covariance analyses revealed that these differences were not a function of general intellectual or motor speed differences between the groups, and that speech rate as a covariate abolished group differences in short-term memory. These results suggest that speech rate may be a causal determinant of verbal short-term memory capacity.

Adolescent↗

Relationships between central and autonomic measures of arousal at age 15 years and criminality at age 24 years.

Previous studies have indicated that criminality is in part genetically determined, but it is not clear how this predisposition manifests itself at a biological level. This prospective study tests the hypothesis that a psychophysiological predisposition to criminality partly manifests itself through autonomic and central nervous system underarousal. Psychophysiological measures, taken at the age of 15 years, were related to criminality status that was assessed at the age of 24 years. Criminals had a significantly lower resting heart rate, skin conductance activity, and more slow-frequency electroencephalographic activity than noncriminals. Differences were not mediated by social, demographic, and academic factors. These results constitute the first clear evidence that implicates underarousal in all three response systems (electrodermal, cardiovascular, and cortical) in the development of criminality. Although arousal variables correctly classified 74.7% of all subjects, psychophysiological factors alone cannot fully account for criminal behavior and do not negate the potential role of social variables in predicting criminal behavior.

Adolescent↗

Structural and functional characteristics of the corpus callosum in schizophrenics, psychiatric controls, and normal controls. A magnetic resonance imaging and neuropsychological evaluation.

In 1986 Nasrallah and colleagues found that increased thickness of the corpus callosum may be specific to right-handed female schizophrenics. Male and female right-handed schizophrenics were compared with normal and psychiatric controls of comparable age, sex, education, and social class on measures of callosal thickness from a midsagittal magnetic resonance imaging cut and neuropsychological tests of interhemispheric transfer. The sex difference in anterior and posterior callosal thickness in normal controls was reversed in schizophrenics, with the corpus callosum being thicker in female schizophrenics and thinner in male schizophrenics. Similar findings were also observed in the psychiatric control group. These structural differences were not paralleled by evidence of impaired interhemispheric transfer on neuropsychological tasks. These results support the finding of sex-dependent callosal abnormalities in schizophrenia but indicate that these abnormalities may not be specific to this illness.

Adult↗

Reward dominance and passive avoidance learning in adolescent psychopaths.

This study tests predictions that adolescent psychopaths are hyperresponsive to rewards (Quay, 1988) and deficient in passive avoidance learning (Newman & Kosson, 1986). Forty male adolescent juvenile offenders were divided into psychopaths and nonpsychopaths using cluster analysis. Subjects were administered a passive avoidance learning task which required learning when to respond to cards associated with either reward or punishment. Results showed a greater responsivity to reward in psychopaths, with no group differences in passive avoidance errors. Results lend support to the view that psychopaths tend to focus on the prospect of reward under conditions of mixed incentives and, when sufficiently motivated, are capable of improved performance. Together with findings of recent psychophysiological studies, these results suggest that adolescent psychopaths may have latent abilities which could have treatment implications.

Adolescent↗