A Meta-Analysis of Cognitive Deficits in Adults with a Diagnosis of Schizophrenia

This review identified 1275 studies examining cognitive deficits in people with schizophrenia, published between 1990 and 2003. Data from 113 studies (4365 patients and 3429 controls) were combined in a meta-analysis carried out on the five cognitive domains of IQ, memory, language, executive function, and attention. Studies were excluded where they lacked a suitable control group or failed to present complete information. In all five cognitive domains, analysis indicated a consistent trend for patients to perform more poorly than healthy controls, with significant heterogeneity across studies. Sources of heterogeneity were analyzed and a need to ensure more appropriate composition of patient and control groups and to adopt a more refined and methodologically correct, hypothesis-driven approach was identified.     

Thermal sensitivity in Tourette syndrome: preliminary report

The effects of heat on tic symptoms were studied in a sample of 78 adults with Tourette syndrome. 62 men and 16 women completed a survey concerning the type, onset, and course of their tics. 10 adult male subjects also participated in a thermal challenge during which ambient temperature was raised from 22 degrees C to 35 degrees C following a control period. Of the 78, 24% or 19 reported increased tics upon exposure to heat. Compared to the remaining 59 subjects, there were no differences in sex distribution, current age, or overall course of illness. In the thermal challenge, there was general increase in tics that was correlated with sweat rate (r = .55, p = .001). This effect was prominent in 5 of 10 subjects (rs = .29 to .63). There were no mean differences in current age, age of onset, or current severity of symptoms between the five subjects of each group. Tic symptoms in a subgroup of patients with Tourette syndrome may be sensitive to heat. Abnormal heat regulation is not a likely explanation for the observed increase in tics. The increase may be due to normal heat-loss mechanisms through dopaminergic pathways.     

Differential effects of psychopathy and antisocial personality disorder symptoms on cognitive and fear processing in female offenders

Psychopathy and antisocial personality disorder (APD) have long been considered important risk factors for criminal behavior and incarceration. However, little is known about the psychobiological underpinnings that give rise to the disinhibited behavior of female offenders. Using an instructed fear-conditioning paradigm and a sample of incarcerated female offenders, we manipulated attentional focus and cognitive load to characterize and differentiate between the dysfunctional cognitive and affective processes associated with these syndromes. We used fear-potentiated startle (FPS) and event-related potentials as measures of affective and cognitive processing, respectively. After controlling for APD symptoms, psychopathic women displayed greater FPS while attending directly to threat-relevant stimuli and displayed less FPS while performing a demanding task that directed attention to threat-irrelevant information. Conversely, controlling for psychopathy, women with high APD symptoms displayed less overall FPS, especially when instructed to focus on threat-relevant stimuli. However, as the demands on cognitive resources increased, they displayed greater FPS. For both psychopathy and APD, analysis of the event-related potentials qualified these findings and further specified the abnormal cognitive processes associated with these two syndromes. Overall, simultaneous analysis of psychopathy and APD revealed distinct patterns of cognitive processing and fear reactivity.     

Response perseveration in psychopathic women.

Recent attempts to validate the Psychopathy Checklist-Revised (PCL-R) as a measure of psychopathy in female offenders have been limited by a failure to examine laboratory correlates of the syndrome. We assessed 112 incarcerated women by using the PCL-R and examined their performance on a card perseveration task that has been used to demonstrate response perseveration in psychopathic men. Contrary to prediction, psychopathic women did not perseverate responding when the PCL-R was used either dimensionally or categorically. The authors discuss the implications of the results for the PCL-R and for female psychopathy more generally.     

Theory of mind and joint action in Parkinson’s disease

It has been suggested that the Theory of Mind (ToM) may rely on more basic processes of social cognition, such as action control (e.g., joint action), even if little is known about this relationship. The relationship between ToM and joint action can be studied in patients with Parkinson’s disease (PD), because they are characterized not only by a deficit in ToM (and in its cognitive and affective subcomponents) but also by a deficit in the inhibition of competing responses. Sixty PD patients and 60 matched healthy controls (HCs) performed a go/no-go Flanker task in both joint and individual conditions. Cognitive (Advanced Test or AT) and affective (Emotion Attribution Task or EAT) ToM also were measured. Thirty-five PD patients and matched HCs also performed the standard Flanker task, as a control measure. In patients, only individuals with high AT scores exhibited a joint Flanker effect, whereas in HCs the joint effect was found irrespectively of AT score. Patients with low EAT scores showed a greater interference effect than patients with high scores, whereas the opposite pattern was found for HCs. In regression analysis AT and EAT scores predicted the Flanker effect in the joint condition only. In the standard task, both groups showed a Flanker effect. The role of different fronto-striatal circuits, especially in PD patients, could explain the different involvement of cognitive and affective ToM in joint tasks. The Flanker effect is discussed considering the referential coding account and the attention-focus account as possible candidates to explain joint action effects.     

Emotion among women with psychopathy during picture perception

Emotional reactions in women with psychopathy were examined in a mixed-picture paradigm using psychophysiological measures. Startle probes were presented at 2.0 or 4.5 s following onset of a 6-s picture presentation. At 2.0 s, nonpsychopaths exhibited the typical pattern of eyeblink reflex magnitude: unpleasant > neutral > pleasant. Psychopaths with high general levels of anxiety also exhibited this pattern. Psychopaths with lower anxiety exhibited attenuated reflex magnitudes during unpleasant pictures. Similarly, when focusing on psychopathy components, only individuals expressing high antisocial behavior and high emotional detachment exhibited smaller reflex magnitudes during unpleasant pictures. At 4.5 s, all groups exhibited normal, potentiated reflex magnitudes during unpleasant pictures. Group differences were not observed for other measures.