Top-down modulation of the perception of other people in schizophrenia and autism

Abstract

Accurately and efficiently perceiving social cues such as body movements and facial expressions is important in social interaction. Accurate social perception of this kind does not solely rely on "bottom-up" visual processing but is also subject to modulation by "top-down" signals. For example, if instructed to look for signs of happiness rather than fear, participants are more likely to categorize facial expressions as happy-this prior expectation biases subsequent perception. Top-down modulation is also important in our reactions to others. For example, top-down control over imitation plays an important role in the development of smooth and harmonious social interactions. This paper highlights the importance of top-down modulation in our perception of, and reactions to, others. We discuss evidence that top-down modulation of social perception and imitation is atypical in Autism Spectrum Conditions and in schizophrenia, and we consider the effect this may have on the development of social interactions for individuals with these developmental disorders.

Keywords: attention; autism; expectation; modulation; priming; schizophrenia; social perception; top-down.

Figure 1

Stimuli employed by Bird et al. (2006). Four images (two face images and two house images) were presented on each trial; images were arranged in a diamond shape with images from the same category (faces or houses) in the same dimension. For instance here faces are presented in the vertical dimension and houses in the horizontal dimension. Figure is reproduced, with permission, from Bird et al. (2006).

Figure 2

Results from Cook and Bird (2011a). Control participants primed with pro-social attitudes imitated significantly more than those primed with non-social attitudes. However, this social modulation of imitation was not observed for individuals with ASC: those primed with pro-social attitudes imitated to the same extent as those primed with non-social attitudes. “^*” indicates p < 0.05.

Figure 3

Scatter plot showing the significant correlation in the ASC group between imitation-inhibition (interference score) and reaction times in the mentalising task (ToM, Theory of Mind condition). Figure is reproduced, with permission, from Spengler et al. (2010a).

Figure 4

Abnormal connectivity in the brain in ASC. Compared to control participants individuals with ASC showed a significantly increased effect of dPFC on IFG and reduced effect of IPL on IFG. STS, superior temporal sulcus; IPL, inferior parietal lobule; IFG, inferior frontal gyrus; dPFC, dorsal prefrontal cortex. Figure is reproduced, with permission, from Shih et al. (2010).

Figure 5

Abnormal connectivity in the brain in schizophrenia. Lateral views of the left hemisphere of the brain. The red lines connect areas that exhibited greater frontotemporal electroencephalogram coherence during talking than during listening for normal controls and patients with schizophrenia. The thickness of the line indicates the probability level for the t-tests that compared the findings. The thicker the line, the larger the difference between the two coherences. In the controls, coherence during talking was greater than during listening for all 20 of the electrode pairs. In the patients, coherences during talking were greater for only two of the pairs (one in each hemisphere). NS, not significant. Data from Ford et al. (2002). Figure and caption is reproduced, with permission from Fletcher and Frith (2009).