in recent onset schizophrenia
Christian H. Röder
Sieds Dieleman
Harald Mohr
Anje Sterrenburg
Nico J.M. van Beveren
David E.J. Linden
Quarterly Journal of Experimental Psychology, 2014 Jun 25:1-35. [Epub ahead of print]
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Abstract
Patients with schizophrenia show deficits in core cognitive functi- ons as well as in social cognition. The aim of the present study was to test whether deficits in social cognition influence non-social, “cold”, cognition. Thirty-five patients with recent-onset schizophrenia (SC) and thirty heal- thy controls (HC) performed a Simon task with social and simple geo- metric stimuli. We investigated whether the Simon effect, the slowing of reaction times produced by stimulus incongruities in the task irrelevant spatial domain, differs between patients and healthy participants as a function of the social nature of the cues. The Simon-effect was generated by a schematic drawing of human eyes (social cues) or rectangles (non- social cues). Overall, patients had longer reaction times than HC. In the eye-like condition, the Simon-effect was significantly stronger for HC than SC. In HC the Simon-effect was significantly stronger in the eye-like compared to the rectangle condition. In patients, the Simon effect did not differ significantly between both conditions. Thus, the influence of social cues was greatly reduced in the patient group. Current psychopathology or antipsychotic treatment did not influence results. The present study supports earlier findings of altered processing of schematic social cues in patients with schizophrenia, especially when gaze is task-irrelevant.
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Introduction
Schizophrenia is a psychiatric illness, which is characterised by “positive” symptoms such as delusions, hallucinations and disorganization on the one hand and “negative” symptoms such as lack of drive, reduc- tion in hedonic experience and social withdrawal on the other. In addition, many patients suffer from cognitive deficits such as impairments in se- lective attention (Krieger et al., 2005), perception (Sergi & Green, 2003), speed of processing (Bechard-Evans, Iyer, Lepage, Joober, & Malla, 2010), and working memory (Haenschel et al., 2007). More recently, deficits in social cognition, for example emotional processing, social perception, at- tributional bias and theory of mind, have become a focus of schizophrenia research (Green & Horan, 2010). Brothers (Brothers, 2002) defined social cognition as ‘‘the processing of any information which culminates in the accurate perception of the dispositions and intentions of other individu- als”. It is an on-going debate to what extent general cognitive abilities and social cognition overlap. In healthy subjects Ziv, Leiser and Levine (2011) identified two independent factors for core cognition and social cognition and found that deficits in social cognition could not be entirely attributed to deficits in executive functioning. Similarly, social cognition deficits in patients with schizophrenia only partially explained by deficits in core cog- nitive functions (Brune, 2005; Ziv et al., 2011). Although performance on general cognitive tests explained a high percentage of variance in social cognitive tasks in patients with schizophrenia (Sergi et al., 2007; Vauth, Rusch, Wirtz, & Corrigan, 2004), a model with two separate factors fitted the data better, than a model with a combined factor for both domains (Sergi et al., 2007). More recently, van Hooren et al. (2008) concluded that core cognition and social cognition are two separate domains in pa- tients with schizophrenia. They further suggest, that the concept of social cognition as a coherent domain is problematic, as the different domains of social cognition comprise various independent cognitive mechanisms (van Hooren et al., 2008). Furthermore, a recent meta-analysis found only small to moderate correlations between social cognitive domains and the non-social cognitive domains of the MATRICS (Ventura, Wood, & Hel- lemann, 2013).
Previous studies have mainly focused on potential influences of ge- neral cognitive abilities on social cognition. Whether altered social cogni- tion in turn influences “cold” cognition in schizophrenia is largely unknown (Bustillo et al., 1997). Gaze is the quintessential social cue (Shepherd, 2010), which may inform about other individuals’ intentions. The position of body, head and the orientation of eyes can direct spatial attention or social gaze. The importance of eye gaze compared to head or body posi- tion is emphasized by the hierarchical organization of the brain areas sub- serving these functions. Neurons coding for eye gaze can inhibit neurons coding for averted head position, and information about head position can inhibit neurons coding for averted body position (Perrett, Hietanen, Oram, & Benson, 1992).
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Several studies found that the perception of gaze deviation (Fran- ck et al., 1998; Franck et al., 2002; Hooker & Park, 2005; Tso, Mui, Tay- lor, & Deldin, 2012) is similar in patients with schizophrenia and healthy controls for gaze that is averted to the left or right. However, patients with schizophrenia have the tendency to interpret slightly averted gaze as di- rected to them (Hooker & Park, 2005) and to perceive gaze as directed to them earlier than healthy controls when gaze is rotated in a stepwise fa- shion towards the observer (Tso et al., 2012). Patients who have a stron- ger tendency to perceive gaze as directed to them were more impaired in socio-emotional functioning (Tso et al., 2012).
Gaze cueing describes the effect of the gaze of another person on spatial attention (Driver et al., 1999).Gaze cueing is already present in three month old or even younger infants (Hoehl et al., 2009), and can also be evoked by schematic pictures of eye-like objects. It has been shown in multiple studies (for an overview see (Tipper, 2010)) that this effect is measurable by faster reaction times to stimuli presented in the attended space compared to stimuli presented in the unattended space, even when gaze is not predictive (Frischen & Tipper, 2004). These results and the fast occurrence of the cue effects (within 200 ms of gaze shift) indicate an au- tomatic, reflexive and stimulus-driven (exogenous) orienting of attention, which is impossible to suppress.
Gaze cues can be effective in guiding or disrupting attention (Tip- per, 2010), but only few studies have studied this process in patients with schizophrenia (Akiyama et al., 2008a; Langdon, Corner, McLaren, Coltheart, & Ward, 2006; Magnee, Kahn, Cahn, & Kemner, 2011) with diverging results. Langdon et al. (2006) and Magnee et al. (2011), found no differences between patients with schizophrenia and healthy controls: patients had even better cueing effects at very short stimulus-onset- asynchrony (SOA) of 100 ms than healthy controls (Langdon et al., 2006). In contrast, chronic patients with schizophrenia profited less from gaze cueing with schematic eyes than healthy controls (Akiyama et al., 2008b), while both groups show similar results when arrows are used as spatial cues (Magnee et al., 2011). The biggest differences between patients with schizophrenia and healthy controls were observed when abstract symbols were used to cue spatial attention (Akiyama et al., 2008b). However all three studies used different stimuli, which may account for the diverging results. Langdon et al. (2006) presented faces, which were either turned to the left or right, thus gaze in a narrow sense was not examined. Mag- nee et al. (2011) presented frontal faces with deviated and neutral gaze. Akiyama et al. (2008b) used two different stimuli categories, one of which one resembled eyes. Stimuli were derived from an earlier study exami- ning spatial coding of the Simon effect (Zorzi, Mapelli, Rusconi, & Umilta, 2003).
Effects of gaze shift have been further examined in patients with schizophrenia using the inhibition of return (IOR)-paradigm (Carter, Ro- bertson, Chaderjian, O’Shora-Celaya, & Nordahl, 1994; Gouzoulis-May- frank et al., 2007; Nestor, Klein, Pomplun, Niznikiewicz, & McCarley,