Impaired emotion regulation in schizophrenia: evidence from event-related potentials.

BACKGROUND: Although several aspects of emotion seem to be intact in schizophrenia, there is emerging evidence that patients show an impaired ability to adaptively regulate their emotions. This event-related potential (ERP) study examined whether schizophrenia is associated with impaired neural responses to appraisal frames, that is when negative stimuli are presented in a less negative context. METHOD: Thirty-one schizophrenia out-patients and 27 healthy controls completed a validated picture-viewing task with three conditions: (1) neutral pictures preceded by neutral descriptions ('Neutral'), (2) unpleasant pictures preceded by negative descriptions ('Preappraised negative'), and (3) unpleasant pictures preceded by more neutral descriptions ('Preappraised neutral'). Analyses focused on the late positive potential (LPP), an index of facilitated attention to emotional stimuli that is reduced following cognitive emotion regulation strategies, during four time windows from 300 to 2000 ms post-picture onset. RESULTS: Replicating prior studies, controls showed smaller LPP in Preappraised neutral and Neutral versus Preappraised negative conditions throughout the 300-2000-ms time period. By contrast, patients showed (a) larger LPP in Preappraised neutral and Preappraised negative versus Neutral conditions in the initial period (300-600 ms) and (b) an atypical pattern of larger LPP to Preappraised neutral versus Preappraised negative and Neutral conditions in the 600-1500-ms epochs. CONCLUSIONS: Modulation of neural responses by a cognitive emotion regulation strategy seems to be impaired in schizophrenia during the first 2 s after exposure to unpleasant stimuli.

Event-related potential examination of facial affect processing in bipolar disorder and schizophrenia.

BACKGROUND: Patients with bipolar disorder exhibit consistent deficits in facial affect identification at both behavioral and neural levels. However, little is known about which stages of facial affect processing are dysfunctional. METHOD: Event-related potentials (ERPs), including amplitude and latency, were used to evaluate two stages of facial affect processing: N170 to examine structural encoding of facial features and N250 to examine decoding of facial features in 57 bipolar disorder patients, 30 schizophrenia patients and 30 healthy controls. Three conditions were administered: participants were asked to identify the emotion of a face, the gender of a face, or whether a building was one or two stories tall. RESULTS: Schizophrenia patients' emotion identification accuracy was lower than that of bipolar patients and healthy controls. N170 amplitude was significantly smaller in schizophrenia patients compared to bipolar patients and healthy controls, which did not differ from each other. Both patient groups had significantly longer N170 latency compared to healthy controls. For N250, both patient groups showed significantly smaller amplitudes compared with controls, but did not differ from each other. Bipolar patients showed longer N250 latency than healthy controls; patient groups did not differ from each other. CONCLUSIONS: Bipolar disorder patients have relatively intact structural encoding of faces (N170) but are impaired when decoding facial features for complex judgments about faces (N250 latency and amplitude), such as identifying emotion or gender.

Impaired neural response to internal but not external feedback in schizophrenia.

BACKGROUND: Accurate monitoring and integration of both internal and external feedback is crucial for guiding current and future behavior. These aspects of performance monitoring are commonly indexed by two event-related potential (ERP) components: error-related negativity (ERN) and feedback negativity (FN). The ERN indexes internal response monitoring and is sensitive to the commission of erroneous versus correct responses, and the FN indexes external feedback monitoring of positive versus negative outcomes. Although individuals with schizophrenia consistently demonstrate a diminished ERN, the integrity of the FN has received minimal consideration. METHOD: The current research sought to clarify the scope of feedback processing impairments in schizophrenia in two studies: study 1 examined the ERN elicited in a flanker task in 16 out-patients and 14 healthy controls; study 2 examined the FN on a simple monetary gambling task in expanded samples of 35 out-patients and 33 healthy controls. RESULTS: Study 1 replicated prior reports of an impaired ERN in schizophrenia. By contrast, patients and controls demonstrated comparable FN differentiation between reward and non-reward feedback in study 2. CONCLUSIONS: The differential pattern across tasks suggests that basic sensitivity to external feedback indicating reward versus non-reward is intact in schizophrenia, at least under the relatively simple task conditions used in this study. Further efforts to specify intact and impaired reward-processing subcomponents in schizophrenia may help to shed light on the diminished motivation and goal-seeking behavior that are commonly seen in this disorder.

Visual masking by object substitution in schizophrenia.

BACKGROUND: Schizophrenia patients demonstrate impairment on visual backward masking, a measure of early visual processing. Most visual masking paradigms involve two distinct processes, an early fast-acting component associated with object formation and a later component that acts through object substitution. So far, masking paradigms used in schizophrenia research have been unable to separate these two processes. METHOD: We administered three visual processing paradigms (location masking with forward and backward masking, four-dot backward masking and a cuing task) to 136 patients with schizophrenia or schizoaffective disorder and 79 healthy controls. A psychophysical procedure was used to match subjects on identification of an unmasked target prior to location masking. Location masking interrupts object formation, four-dot masking task works through masking by object substitution and the cuing task measures iconic decay. RESULTS: Patients showed impairment on location masking after being matched for input threshold, similar to previous reports. After correcting for age, patients showed lower performance on four-dot masking than controls, but the groups did not differ on the cuing task. CONCLUSIONS: Patients with schizophrenia showed lower performance when masking was specific to object substitution. The difference in object substitution masking was not due to a difference in rate of iconic decay, which was comparable in the two groups. These results suggest that, despite normal iconic decay rates, individuals with schizophrenia show impairment in a paradigm of masking by object substitution that did not also involve disruption of object formation.

Disturbances in the spontaneous attribution of social meaning in schizophrenia.

BACKGROUND: Schizophrenia patients show disturbances on a range of tasks that assess mentalizing or 'Theory of Mind' (ToM). However, these tasks are often developmentally inappropriate, make large demands on verbal abilities and explicit problem-solving skills, and involve after-the-fact reflection as opposed to spontaneous mentalizing. METHOD: To address these limitations, 55 clinically stable schizophrenia out-patients and 44 healthy controls completed a validated Animations Task designed to assess spontaneous attributions of social meaning to ambiguous abstract visual stimuli. In this paradigm, 12 animations depict two geometric shapes 'interacting' with each other in three conditions: (1) ToM interactions that elicit attributions of mental states to the agents, (2) Goal-Directed (GD) interactions that elicit attributions of simple actions, and (3) Random scenes in which no interaction occurs. Verbal descriptions of each animation are rated for the degree of Intentionality attributed to the agents and for accuracy. RESULTS: Patients had lower Intentionality ratings than controls for ToM and GD scenes but the groups did not significantly differ for Random scenes. The descriptions of the patients less closely matched the situations intended by the developers of the task. Within the schizophrenia group, performance on the Animations Task showed minimal associations with clinical symptoms. CONCLUSIONS: Patients demonstrated disturbances in the spontaneous attribution of mental states to abstract visual stimuli that normally evoke such attributions. Hence, in addition to previously established impairment on mentalizing tasks that require logical inferences about others' mental states, individuals with schizophrenia show disturbances in implicit aspects of mentalizing.

Automatic and controlled attentional processes in startle eyeblink modification: effects of habituation of the prepulse.

The effect of prehabituation of the prepulse on startle eyeblink modification was studied in two experiments. In Experiment 1, college student participants were either prehabituated or nonhabituated to a tone that served as a prepulse in a startle modification passive attention paradigm. Neither short lead interval (60 and 120 ms) prepulse inhibition (PPI) nor long lead interval (2,000 ms) prepulse facilitation (PPF) was affected by the prehabituation procedure. In Experiment 2, participants were presented with an active attention paradigm in which one of two tone prepulses was attended while the other was ignored. One group was prehabituated to the prepulses and the other was not. Unlike the results with the passive paradigm in Experiment 1, prehabituation did significantly diminish attentional modulation of PPI and PPF. These results are consistent with the hypothesis that passive PPI and PPF are primarily automatic processes, whereas attentional modulation involves controlled cognitive processing.

Discrete and continuous prepulses have differential effects on startle prepulse inhibition and skin conductance orienting.

The effectiveness of different types of auditory prepulses in eliciting skin conductance orienting and in producing prepulse inhibition (PPI) of the acoustic startle eyeblink was studied in two experiments. A discrete white noise prepulse produced greater PPI than either a continuous white noise, a discrete tone, or a continuous tone. The discrete white noise advantage was not due to similarity in bandwidth to the startle pulse or to a refractory effect of the prepulse. Moreover, a dissociation between PPI and skin conductance orienting was seen in both experiments. PPI using auditory prepulses appears to be dependent primarily on the acoustic characteristics of the transient portion of the prepulse, whereas skin conductance orienting is more dependent on the sustained portions of the stimulus.