Disentangling the interaction of sex differences and hemispheric specialization for face processing - Evidence from ERPs.

Recent studies on face processing and its hemispheric lateralization suggest that inconsistencies in earlier findings might be partially explained by sex differences, as findings from event-related potential studies indicated a more asymmetric functioning of the visual cortex during face encoding in men, whereas women seemed to display a more bilateral activation pattern. The aim of this study was to further investigate the role of sex differences in hemispheric specialization during face recognition. Fifty-four healthy participants (27 females and 27 males) engaged in a familiarity decision task in which famous and unfamiliar faces were presented in a lateralized tachistoscopic fashion with unilateral und bilateral presentation modes and measurement of event-related potentials and behavioral responses. Results showed a clear N170 component for males and females in all experimental conditions. No hemispheric differences of the N170 were observed in the bilateral condition and both groups showed larger right-hemispheric than left-hemispheric N170 amplitudes in the left visual field condition. In the right visual field condition, however, only female participants showed significantly larger left-hemispheric compared to right-hemispheric N170 amplitudes, whereas male participants did not show such a modulation. The effect corresponds to a greater responsivity of left-hemispheric processes underlying the N170 component in female participants. Further analyses revealed N170 differences in the left and right hemisphere for females only, when stimuli were presented unilaterally. In contrast, this modulation of N170 amplitudes was only observed in the left hemisphere in males. The results suggest a stronger hemispheric lateralization in men than in women during face processing.

Prison Climate and Its Role in Reducing Dynamic Risk Factors During Offender Treatment.

Although several offender treatment experts have suggested that therapeutic relationships play an important role in offender treatment, empirical finding supporting those arguments are scarce. The present study has therefore examined the relationship between prison climate, treatment motivation, and their influence on changes in risk factors in N = 215 inmates and detainees in four correctional facilities in Berlin, Germany. The inmates' perception of prison climate significantly correlated with their attitudes towards treatment. More positive climate in terms of therapeutic hold and more positive treatment attitude in terms of trust in therapy were also the best predictors of stronger decreases in dynamic risk factors measured by the Level of Service Inventory-Revised (LSI-R). Our results support the importance of treatment relationship factors within the course of offender rehabilitation.

Emotional context restores cortical prediction error responses in schizophrenia.

The mismatch negativity (MMN) deficit in schizophrenia is a consistently replicated finding and is considered a potential biomarker. From the cognitive neuroscience perspective, MMN represents a cortical correlate of the prediction error, a fundamental computational operator that may be at the core of various cognitive and clinical deficits observed in schizophrenia. The impact of emotion on cognitive processes in schizophrenia is insufficiently understood, and its impact on basic operators of cortical computation is largely unknown. In the visual domain, the facial expression mismatch negativity (EMMN) offers an opportunity to investigate basic computational operators in purely cognitive and in emotional contexts. In this study, we asked whether emotional context enhances cortical prediction error responses in patients with schizophrenia, as is the case in normal subjects. Therefore, seventeen patients with schizophrenia and eighteen controls completed a visual sequence oddball task, which allows for directly comparing MMN components evoked by deviants with high, intermediate and low emotional engagement. Interestingly, patients with schizophrenia showed pronounced deficits in response to neutral stimuli, but almost normal responses to emotional stimuli. The dissociation between impaired MMN and normal EMMN suggests that emotional context not only enhances, but restores cortical prediction error responses in patients with schizophrenia to near-normal levels. Our results show that emotional processing in schizophrenia is not necessarily defect; more likely, emotional processing heterogeneously impacts on cognition in schizophrenia. In fact, this study suggests that emotional context may even compensate for cognitive deficits in schizophrenia that are, in a different sensory domain, discussed as biomarkers.

Face identity is encoded in the duration of N170 adaptation.

Previous studies assessing the involvement of the face-sensitive N170 component of the event-related potential (ERP) in the processing of face identity have shown controversial results when assessing N170 amplitude in repetition suppression (RS) designs. On the other hand, N170 adaptation is robustly associated with the inter-stimulus interval (ISI) between immediate face repetitions. Interestingly, interactions of face identity and ISI could provide valuable information on early encoding of face identity, but have not been investigated so far. We employed a repetition suppression paradigm using identical and non-identical repetitions as well as parametrically varied ISIs between 500 msec and 2,000 msec in 27 healthy subjects to investigate N170 adaptation effects. Both face identity and varying ISIs significantly influenced N170 adaptation effects, albeit with small effects sizes. Most importantly, however, face identity and ISIs strongly interacted with rapid N170 amplitude recovery in non-identical trials, but sustained N170 adaptation in identical trials. We excluded low-level sensory contributions to the N170 adaptation effect by analyzing the P1 component and by running an additional experiment employing different stimulus sizes. This specific result strongly argues in favor of neuronal sensitivity to face identity, which is primarily mirrored in the N170 temporal decay function that essentially differentiates identical and non-identical face trials. In general, taking advantage of the temporal dimension of adaptation processes, i.e., their decay over time, provides additional dissections of neuronal function into feature-specific selectivity versus non-selectivity.

Differential effects of early life stress on hippocampus and amygdala volume as a function of emotional abilities.

Early life stress (ELS) is known to have considerable influence on brain development and affective functioning. Previous studies in clinical populations have shown that hippocampus and amygdala, two central structures of limbic emotion processing circuits, are predominantly affected by early stress exposure. Given the inconsistent findings on ELS-related effects in healthy populations and the associations of ELS and affective functioning, the question arises which additional emotion-relevant variables need to be considered to better understand the effects of ELS. We, therefore, investigated the volume of hippocampus and amygdala in 25 high alexithymic (h-ALEX) and 25 low alexithymic (l-ALEX) individuals, which were matched with regard to ELS, but significantly differed in their degree of emotional functioning. Volumetric analyses were performed using FSL-FIRST, a method to automatically segment subcortical structures on T1-weighted magnetic resonance images. Alexithymia was assessed using the Toronto Alexithymia Scale and Bermond-Vorst Alexithymia Questionnaire. ELS was assessed by Childhood Trauma Questionnaire (CTQ) and Early Trauma Inventory. Our data showed that ELS was negatively associated with right hippocampus volume in h-ALEX individuals, while there was no such association in the l-ALEX group. Furthermore, ELS was positively associated with left amygdala volume in l-ALEX individuals, but not in individuals with high levels of alexithymia. The present study emphasizes a substantial relationship between intrapersonal factors, such as alexithymia and neural alterations related to the experience of ELS. Longitudinal study designs are necessary to pursue the question of how emotional abilities interact with individual adaptations to early stress exposure on the neural level.