1. Methods Participants & procedures -211 (100 males; mean age = 19.7; SD=1.6) university students completed the study in exchange for academic credits -147 were from Macau, 55 from Mainland China and the remaining 9 were of various other nationalities. -Participants attempted the smile perception task and then completed the SPQ and a demographics questionnaire. Measures Schizotypy Personality Questionnaire (SPQ) -Chinese translated version (8) of the SPQ (9) was used to index the level of schizotypy -Comprises of 3 factors: positive, negative and disorganization -Good psychometric properties in both the original and Chinese versions of the SPQ(8,9). Smile Perception Task -20 video clips of various individuals smiling, as adapted from the BBC Science & Nature Website (10) -Video clips presented one at a time in each consecutive trial via a Flash application -participants indicated if a fake smile was shown by clicking on one of the two designated buttons on screen. -fake smiles and real smiles designated as signal and noise trials of the ‘yes/no’ signal detection task respectively. -The following signal detection measures (11) were calculated: Error rates : False positive (F+) and false negative (F-) F + = 1- H real and F - = 1- H fake. F + : rate at which real smiles were incorrectly identified as fake and vice-versa for F - Sensitivity (d’): d’ = Φ -1 (H fake ) - Φ -1 (F + ). Higher d’ values indicate a greater ability to distinguish between fake and real smiles. Bias (c): c = -0.5[Φ -1 (H fake ) + Φ -1 (F + )]. Lower c values correspond a greater likelihood of identifying a smile as fake regardless of whether it is the correct response. Statistical Analysis -Statistical significance was set at p < 0.05 for all analyses. -Spearman’s Rho (ρ) was used to examine correlations between SPQ variables and error types, as Shapiro-Wilk tests suggest data was not normal -Correlation outcomes were tested with the bonferroni adjusted p value of 0.0064 (0.05/8, assuming 8 unique correlation tests). -As n was sufficiently large (n > 100), regression analyses and T-tests do not require any assumptions of normality (12) -Independent sample T-tests were used to test for gender differences. -Regression analyses were used to evaluate the mediation model, which was further confirmed via bootstrapping analysis Background Schizotypy, Emotion and Smile Perception Schizotypy is a dimensional construct that characterizes the traits associated with schizophrenia-spectrum disorders, observed in a continuum of individuals ranging from the healthy to those afflicted with schizophrenia(1). While extensive research had established the presence of facial emotion perception deficits in schizotypy, the nature and specificity of these deficits remains contentious (2). To understand with greater specificity, the specific perceptual deficits associated with emotional perception in schizotypy, perhaps the study of facial emotion perception can be narrowed down that of smile perception. Given that smile perception is an important component in emotion perception(3), we posit that smile perception is similarly implicated in schizotypy, as well. Hypervigilance Hallucination Hypothesis and Fake smiles The hypervigilance hallucination hypothesis (4) proposed that false-perceptual experiences are essentially false-positive errors in perceiving threats, and we are evolved with a tendency to commit false-positive errors in order to avoid the costly consequences associated with false-negative errors. Such a bias is essentially a combination of a heightened perceptual bias and lowered perceptual sensitivity. While the scope of the hypothesis was originally limited to explaining perceptual disturbances/anomalies in the auditory modality, previous research had showed that it could similarly explain perceptual disturbances/anomalies in the visual modality(5). It appears that this bias exists as a general cognitive mechanism that is associated with eliciting false positive errors across a variety of stimuli, notwithstanding any sensory modalities. Based upon this premise, it is possible that the hypervigilance bias can similarly account for false positive errors associated with deception detection. Deception is another type of threat that is saliently experienced in patients with schizophrenia (6). As such, we posit that schizotypy is associated with a false positive bias in recognizing social stimuli as deceptive; fake smiles are one such stimuli that is often associated with deception (7). The Present Study Taken together, studying smile perception in schizotypy enables us to investigate both the emotional perception deficits and the hypervigilance hallucination hypothesis in schizotypy. We aimed to explore the smile perception deficits in schizotypy, and to test the hypervigilance hallucination hypothesis in schizotypy. Given that the hypervigilance hypothesis was conceptualized via signal detection theory (4), it is best tested via a signal detection paradigm. It also allows us to study the cognitive processes such as perceptual bias and sensitivity that are responsible for the false positive bias. To these ends, a smile perception task was embedded within a signal detection paradigm for the study. The following hypotheses are formulated: 1)The errors rates (false positives and/or false negatives) are associated with Schizotypal Personality Questionnaire (SPQ) scores. 2) False positive errors (perceiving a real smile as fake) are associated with SPQ scores; higher false positive rate should correspond to higher SPQ scores 3) Perceptual bias and/or sensitivity mediate the relationship between SPQ scores and false positive errors in smile perception (see figure on the right). Results -Males (m = 6.69, SD = 3.78) are significantly higher on the SPQ disorganization factor than females (m = 5.58, SD = 3.54), t(209) = 2.21, p =0.03. -SPQ Total scores and all 3 SPQ factors significantly correlated to F + but not F- -c and d’ completely mediated the relationship between SPQ Total and F + SPQ total scores predict both c,d’ and F +. after the addition of c and d’ to the regression equation, the ß of SPQ total decreased to 0, Further confirmed by bootstrapping analysis via 2000 bootstrapped samples (see below). Schizotypy (SPQ) Perceptual Sensitivity (d’) False Positive Errors in Smile Perception (F + ) Perceptual Bias (c) ρ correlations between SPQ variables and error rates Variable F+F+ F-F- ρpρp SPQ Total0.230.001*-0.020.803 SPQ Pos0.200.004*0.010.875 SPQ Neg0.210.002*-0.030.705 SPQ Disorg0.220.001*-0.020.757 Note.* p < 0.05 after Bonferroni correction. Predictors of False Positive Error Rate Variable F+F+ Model 1 β Model 2 β95% CI Constant0.21*0.50*[0.46, 0.53] SPQ Total0.004*0.000[0.00, 0.01] c -0.31*[-0.33, -0.28] d’d’ -0.16*[-018, -0.15] R2R2 0.090.85 F (df = 210)21.06*377.40* ∆R2∆R2 0.75 ∆F∆F 504.80* Note.* p <0.001. Bootstrapping Analysis EffectSEp Total Effect0.00450.001<0.001 Direct Effect0.00050.00040.27 Indirect Effect0.0040.0001<0.05 Smile Perception Task : an example trial time Discussion Strong support for the hypervigilance hallucination hypothesis in schizotypy.  Schizotypy associated with F+ ; real smiles were perceived as fake but not vice-versa.  Cognitive processes (c and d’) associated with the hypervigilance hallucination hypothesis were implicated in schizotypy  these processes accounted for the relationship between schizotypy and false positive errors in smile recognition Smile perception errors may account for some of the previously documented emotion perception deficits in schizotypy F+ bias in recognizing threatening/deceptive social cues as possible socio-cognitive marker of schizotypy  Supplement/aid conventional assessments in the early detection of schizophrenia In showing that F+ occur commonly in the healthy population and are even thought to be adaptive in certain situations (i.e. protect against deception), the hypervigilance hallucination hypothesis minimizes the deviance and maladaptation commonly associated with psychopathology.)  Implication in public/patient education to reduce stigma and fostering insight in patients References: 1. 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The effect of lying on intentional versus unintentional facial expressions. Eur Rev Appl Psychol. 2008;58(2):65–73. 8. Chen WJ, Hsiao CK, Lin CC. Schizotypy in community samples: the three-factor structure and correlation with sustained attention. J Abnorm Psychol.1997;106(4):649–54. 9. Raine A. The SPQ: a scale for the assessment of schizotypal personality based on DSM-III-R criteria. Schizophr Bull.17(4):555–64. 10. British Broadcasting Corporation. Spot the fake smile. 2013 [cited 2013 Sep 24]. Available from: http://www.bbc.co.uk/science/humanbody/mind/surveys/smiles/ 11. Macmillan NA. Signal detection theory as data analysis method and psychological decision model. In: Keren G, Lewis C, editors. A handbook for data analysis in the behavioral sciences Methodological issues pp Erlbaum. Hillsdale, NJ: Erlbaum; 1993. p. 21–57. 12. Lumley T, Diehr P, Emerson S, Chen L. The importance of the normality assumption in large public health data sets. Annu Rev Public Health. 2002;23:151–69. http://www.bbc.co.uk/science/humanbody/mind/surveys/smiles/ Acknowledgements: The authors thank Lei Man Wai, Caren and Yang Fuming, Deci for their assistance in this study. This research was supported by a grant from the University of Macau (MYRG106(Y1-L2)-FSH11-CMZ) – which is gratefully acknowledged. Beware of the Smiling Poker Face: The Hypervigilant Detection of Fake Smiles in Schizotypy Presenting author: Gerard Junhong Yu, Department of Psychology, University of Macau, Macau Co-authors: Allan B.I. Bernardo and Charles M. Zaroff, Department of Psychology, University of Macau, Macau Poster presented at the 26th Association for Psychological Science Annual Convention, May 22-25, 2014, San Francisco, CA, USA