The motivation and pleasure dimension of negative symptoms: Neural substrates and behavioral outputs

Abstract

A range of emotional and motivation impairments have long been clinically documented in people with schizophrenia, and there has been a resurgence of interest in understanding the psychological and neural mechanisms of the so-called “negative symptoms” in schizophrenia, given their lack of treatment responsiveness and their role in constraining function and life satisfaction in this illness. Negative symptoms comprise two domains, with the first covering diminished motivation and pleasure across a range of life domains and the second covering diminished verbal and non-verbal expression and communicative output. In this review, we focus on four aspects of the motivation/pleasure domain, providing a brief review of the behavioral and neural underpinnings of this domain. First, we cover liking or in-the-moment pleasure: immediate responses to pleasurable stimuli. Second, we cover anticipatory pleasure or wanting, which involves prediction of a forthcoming enjoyable outcome (reward) and feeling pleasure in anticipation of that outcome. Third, we address motivation, which comprises effort computation, which involves figuring out how much effort is needed to achieve a desired outcome, planning, and behavioral response. Finally, we cover the maintenance emotional states and behavioral responses. Throughout, we consider the behavioral manifestations and brain representations of these four aspects of motivation/pleasure deficits in schizophrenia. We conclude with directions for future research as well as implications for treatment.

Understanding and treating amotivation in people with psychosis: An experimental study of the role of guided imagery

“…We have summarised this body of research in a single anticipatory deficit model of ANS (Figure 1). The model is consistent with neurophysiological studies, suggesting changes in the neural pathways mediating 'wanting', while 'hedonic' neural pathways, and consummatory pleasure (the immediate experiential pleasure of a primary reinforcer) are unaffected (Barch and Dowd, 2010;Kring and Barch, 2014). This consensus suggests focusing interventions on the difference between what is anticipated, and what is likely to be experienced, addressing both anticipatory cognitions and affective pre-experience.…”

“…The anticipatory deficit in ANS can be conceptualised as the absence of a required bridge between present stasis and future action: in neurophysiological terms, the dopaminergic fronto-striatal pathways through which goal-directed behaviours are hypothesised to be formulated, enacted, and evaluated (Kring and Barch, 2014). If a person is not able to anticipate that a proposed action will bring pleasure or success (i.e.…”

Reward-dependent modulation of working memory is associated with negative symptoms in schizophrenia

“…One factor is referred to as diminished expression, comprising blunted affect and alogia. The other factor is referred to as diminished motivation and pleasure, or apathy, and comprises asociality, anhedonia and avolition (Kring and Barch, 2014;Strauss et al, 2012). This distinction might allow a more differentiated approach in the search of underlying pathophysiological mechanisms (Blanchard and Cohen, 2006;Foussias and Remington, 2010;Liemburg et al, 2013;Messinger et al, 2011).…”

Altered reward anticipation: Potential explanation for weight gain in schizophrenia?

“…Functional MRI experiments probing reward anticipation in the ventral striatum with MID tasks reveal decreased striatal activation in drug-naïve and unmedicated schizophrenia patients Hägele et al, 2015;Juckel et al, 2006b) as well as in participants at high clinical risk for psychosis (Juckel et al, 2012;Wotruba et al, 2014). The degree of reduced reward anticipation is linked to symptom severity (Juckel et al, 2006a;Kring and Barch, 2014;Nielsen et al, 2012) and altered dopamine activity, as suggested by the observation that treatment with atypical antipsychotics partially normalizes ventral striatal dysfunction in schizophrenia (Nielsen et al, 2012;Walter et al, 2009). …”