Social cognition in schizophrenia: from social stimuli processing to social engagement

Abstract

Social cognition consists of several skills which allow us to interact with other humans. These skills include social stimuli processing, drawing inferences about others' mental states, and engaging in social interactions. In recent years, there has been growing evidence of social cognitive impairments in patients with schizophrenia. Apparently, these impairments are separable from general neurocognitive impairments, such as attention, memory, and executive functioning. Moreover, social cognition seems to be a main determinant of functional outcome and could be used as a guide to elaborate new pharmacological and psychological treatments. However, most of these studies focus on individual mechanisms and observational perspectives; only few of them study schizophrenic patients during interactive situations. We first review evidences of social cognitive impairments both in social stimuli processing and in mental state attribution. We focus on the relationship between these functions and both general cognitive impairments and functional outcome. We next review recent game theory approaches to the study of how social engagement occurs in schizophrenic patients. The advantage of using game theory is that game-oriented tasks can assess social decision making in an interactive everyday situation model. Finally, we review proposed theoretical models used to explain social alterations and their underlying biological mechanisms. Based on interactive studies, we propose a framework which takes into account the dynamic nature of social processes. Thus, understanding social skills as a result of dynamical systems could facilitate the development of both basic research and clinical applications oriented to psychiatric populations.

Keywords: game theory; interactive view; mental state attribution; psychiatry disease; social interaction; social loop.

Figure 1

Brain areas that participate in social processing. A simple classification of brain areas involved in social processing differentiates regions that participate in four related processes. The first is the perception of basic social stimuli, such as biological motions (V5), part of the body (extra-striate body area, EBA), and faces (fusiform face area, FFA). Another process includes emotional and motivational appraisal, where the amygdala (AMY), the anterior insula (AI), the subgenual and perigenual anterior cingulate cortex (ACC), as well as the orbitofrontal cortex (OFC) participate. These cortical structures are in interaction with subcortical structures as the ventral striatum (VS), and the hypothalamus (HTH). These structures in turn interact with other regions which participate in the goal-directed, adaptive behaviors, and the categorization processes, such as the dorsolateral and the medial prefrontal cortex (dlPFC, mPFC) and the ACC. Finally for social attribution, areas like the ventral premotor cortex (vPMC), the superior temporal sulcus (STS), the AI, the posterior cingulate cortex (PCC), and the precuneus (PC) participate in more automatic, bottom-up inferences of other people’s mental states; whereas structures like the mPFC and the temporo-parietal junction (TPJ) are involved in more cognitive theory of mind skills.

Figure 2

Schematic summary of the evidences of social cognitive impairments and their underlying neuro-biological mechanisms in schizophrenic patients. The color circles represent the levels of available evidences from behavioral data (within orange rectangles), and neuroimaging data (within gray rectangle). AMY, amygdala; FFA, fusiform face area; STS, superior temporal sulcus; AI, anterior insula; TPJ, temporo-parietal junction; mPFC, medial prefrontal cortex; dlPFC, dorsolateral prefrontal cortex; OFC, orbitofrontal cortex; ACC, anterior cingulate cortex; PCC, posterior cingulate cortex.

Figure 3

Schematic representation of individual global spaces and the social loop. Each person has a brain system generating global social representations. This system includes areas like the superior temporal sulcus (STS), the medial prefrontal cortex (mPFC), the medial parietal regions (mPR), and the temporo-parietal junction, among others. The global space has a strong relationship and interconnections with other systems (sensory, cognitive, and motor systems) that provide and receive information from them. By mean of these interconnections, the system generates adequate predictions and behaviors that allows the coupling of two, or more, individuals. For similar and complementary proposals see Decety et al. (2007), Hari and Kujala (2009), De Jaegher et al. (2010), Brunet-Gouet et al. (2011).