Sarah Saperia

Investigating consummatory and anticipatory pleasure across motivation deficits in schizophrenia and healthy controls

Anhedonia has traditionally been considered a characteristic feature of schizophrenia, but the true nature of this deficit remains elusive. This study sought to investigate consummatory and anticipatory pleasure as it relates to motivation deficits. Eighty-four outpatients with schizophrenia and 81 healthy controls were administered the Temporal Experience of Pleasure Scale (TEPS), as well as a battery of clinical and cognitive assessments. Multivariate analyses of variance were used to examine the experience of pleasure as a function of diagnosis, and across levels of motivation deficits (i.e. low vs. moderate. vs. high) in schizophrenia. Hierarchical regression analyses were also conducted to evaluate the predictive value of amotivation in relation to the TEPS. There were no significant differences between schizophrenia and healthy control groups for either consummatory or anticipatory pleasure. Within the schizophrenia patients, only those with high levels of amotivation were significantly impaired in consummatory and anticipatory pleasure compared to low and moderate groups, and compared to healthy controls. Further, our results revealed that amotivation significantly predicts both consummatory and anticipatory pleasure, with no independent contribution of group. Utilizing study samples with a wide range of motivation deficits and incorporating objective paradigms may provide a more comprehensive understanding of hedonic deficits.

F219. NOVEL OBJECTIVE ASSESSMENT OF ACTIVITY ENGAGEMENT IN SCHIZOPHRENIA USING WIRELESS MOTION CAPTURE

Abstract Background Amotivation and reduced engagement in goal-directed activities are prominent features of schizophrenia. Previous investigations of patients’ engagement in activities have largely relied on accounts of daily living activities rather than objective task-based measures. The current study used wireless motion capture in an open-field setting to evaluate activity preference when individuals are provided an explicit choice between an active engagement option versus a passive engagement option. Methods Twenty stable adult outpatients with schizophrenia and twenty matched healthy controls completed the Activity Preference Task, in which participants play a physical motion-based video game (active engagement) or watch a film (passive engagement) for fifteen minutes. No incentive was associated with either activity, and participants could engage in either activity at any time. Duration of engagement on the active option and number of switches between activity options were computed as the primary task outcome measures using objective motion data. Participants’ behaviour during active engagement was further quantified by computation of physical intensity (average hand speed) and persistence (tendency for sustained continuous engagement). Clinical assessments of positive and negative symptoms, apathy, cognition, depression, medication side-effects, motor ability, and community functioning were also administered. Results Schizophrenia participants’ duration, intensity, and persistence of active engagement were correlated with apathy (|ρ|=0.72–0.79, p<0.01) and community functioning (ρ=0.50–0.67, p<0.05). Although no significant group differences were detected in the individual comparisons of task measures, exploratory cluster analysis based on the two primary task measures identified three clusters of individuals with distinct profiles of engagement intensity (F(2,36)=9.141, p<0.001) and persistence (F(2,36)=13.954, p<0.001), and clinical apathy (F(2,37)=4.183, p=0.023). Further, there were significant diagnostic group by cluster assignment interaction effects for engagement intensity (F(2,33)=4.551, p=0.018) and apathy (F(2,34)=3.445, p=0.043) that highlighted substantial behavioural heterogeneity specific to schizophrenia; these interaction effects appeared to be driven primarily by a subgroup of patients who exhibited reduced engagement and increased apathy compared to individuals in other clusters as well as within-cluster healthy control counterparts. Discussion The Activity Preference Task provides a means of quantifying activity engagement in schizophrenia, which may be particularly valuable given the lack of objective assessments that measure non-incentivized, intrinsically motivated behaviours. Our initial findings suggest that patients with schizophrenia as a group are equally inclined as healthy individuals towards actively engaging activities when presented an explicit choice, but provision of such opportunities may be insufficient for amotivated patients to initiate and maintain engagement in functional behaviours.

An Examination of the Multi-Faceted Motivation System in Healthy Young Adults

Background: Amotivation is a prevalent symptom in schizophrenia (SZ) and depression (MDD), and is linked to poor functional outcomes in affected individuals. Conceptualizations of motivation have outlined a multi-faceted construct comprised of reward responsiveness, reward expectancy, reward valuation, effort valuation, and action selection/preference-based decision making. To date, findings from studies utilizing variable-centered approaches to examining isolated facets of motivation in SZ and MDD have been inconsistent. Thus, the present study adopted a person-centered approach, and comprehensively examined the reward system in a non-clinical sample in an attempt to explore potential subtypes of motivation impairments, while minimizing the effects of illness-related confounds. Methods: Ninety-six healthy undergraduate students were evaluated for amotivation, schizotypal traits, depressive symptoms, and cognition, and administered objective computerized tasks to measure the different facets of motivation. Cluster analysis was performed to explore subgroups of individuals based on similar motivation task performance. Additionally, correlational analyses were conducted in order to examine inter-relationships between motivation facets, and relations between clinical measures and facets of motivation. Results: Cluster analysis identified two subgroups of individuals with differential motivation performance profiles. Correlational analyses revealed that reward responsiveness was associated with amotivation, depressive symptoms, and negative schizotypy. Further, significant inter-correlations were found between reward responsiveness and reward expectancy, as well as between reward valuation and effort valuation. Conclusions: Our results mark important steps forward in understanding motivation in a non-clinical sample, and guide future dimensional and comprehensive analyses of the multi-faceted reward system. It remains to be seen whether these patterns of results will be similar in clinical populations such as SZ and MDD.