- Email: [email protected]
Individual differences in psychoticism predict attention for emotional faces
Personality and Individual Differences 48 (2010) 499–501
Contents lists available at ScienceDirect
Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid
Short Communication
Individual differences in psychoticism predict attention for emotional faces Vladimir Miskovic a,*, Louis A. Schmidt a,b,* a b
McMaster Integrative Neuroscience Discovery and Study, McMaster University, Ontario, Canada L8S 4K1 Department of Psychology, Neuroscience and Behaviour, McMaster University, Canada
a r t i c l e
i n f o
Article history: Received 16 July 2009 Received in revised form 22 October 2009 Accepted 29 October 2009 Available online 28 November 2009 Keywords: Psychoticism Attention bias Emotion Personality Facial expressions
a b s t r a c t Psychoticism is a personality trait characterized by disregard for social conventions, coldness, and lack of empathy. We examined whether individual differences in psychoticism predicted attention biases to pictures of happy and angry faces presumed to elicit social approach and social withdrawal behaviors, respectively. Our analyses revealed that high levels of psychoticism were related to reduced attentional capture by angry faces. There were also within-group attention bias differences such that individuals low in psychoticism exhibited cognitive vigilance for both happy and angry faces relative to neutral, while those high in psychoticism did not show preferential processing of emotional expressions. These findings suggest that individual differences in psychoticism are related to alterations in the cognitive processing of socially relevant signals. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction People scoring high on measures of psychoticism exhibit an interpersonal style that is characterized by disregard for social conventions, coldness, and lack of empathy. Psychoticism is likely related to, but not isomorphic with, the concept of psychopathy (Eysenck, 1992). Interestingly, psychopathy and ‘acquired sociopathy’ have been linked to disturbances in the basic processing of emotional expressions (Blair, 2003), involving an inability to attribute and respond to affective states (especially negative ones) in other people. Facial expressions constitute affectively rich signals for higher primates, serving an important function in regulating the social hierarchy. Angry faces are prototypical signals of social threat that may facilitate physiological, cognitive and behavioral resources in order to escape potentially harmful confrontation (Öhman, 1986). Both non-human primate (Rolls, 1992) and human (Esteves, Dimberg, & Öhman, 1994; Hansen & Hansen, 1988) studies have shown that angry faces capture attentional resources relatively quickly and automatically, given their important communicative functions. In non-human primates angry expressions serve as socially corrective signals that can inhibit the behavior of conspecifics (Averill, 1982). Existing evidence indicates that ‘acquired sociopathy’ following brain trauma (Blair & Cipolotti, 2000), antisocial personality disorder (Best, Williams, & Coccaro, 2002) and testosterone administra-
tion (van Honk & Schutter, 2007) are all linked with impaired processing of angry faces. This latter finding is interesting, given the link between psychoticism and testosterone function (Loehlin, Medland, Montgomery, & Martin, 2005; Turakulov, Jorm, Jacomb, Tan, & Easteal, 2004). Furthermore, since psychoticism is also associated with disregard for social violation and others’ approval, it raises the possibility that attention for angry faces may be influenced by normative variation in this personality dimension. In the present study, we attempted to test this hypothesis and extend the literature by moving beyond studies of brain damaged and clinical populations to studies of individual differences in personality (see Reed & Derryberry, 1995 for application to neuroticism and extraversion). We collected measures of psychoticism in a group of non-clinical young adults who then performed a task measuring attention for angry and happy faces. We hypothesized that low levels of psychoticism would be associated with vigilance for angry, relative to neutral, faces while individuals high in psychoticism would fail to exhibit a processing bias for these socially corrective signals. Additional analyses were performed to examine the processing of pro-social emotion (happy faces), given recent evidence that positive emotional stimuli also modulate attention (Brosch, Sander, Pourtios, & Scherer, 2008). 2. Method
* Corresponding authors. Address: Department of Psychology, Neuroscience and Behaviour, McMaster University, Canada (L.A. Schmidt). Tel.: +1 905 525 9140 (V. Miskovic). E-mail addresses: [email protected] (V. Miskovic), [email protected] (L.A. Schmidt). 0191-8869/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2009.10.031
2.1. Participants Thirty-eight (10 males, 28 females) undergraduates served as participants (M age = 1931 yr, SD = 126 yr), in exchange for course
500
V. Miskovic, L.A. Schmidt / Personality and Individual Differences 48 (2010) 499–501
credit. All procedures performed were approved by the McMaster University Research Ethics Board, and all participants provided written consent prior to any procedures. 2.2. Procedure Upon arriving to the laboratory, we recorded patterns of resting central and autonomic physiology on a sub-sample of the participants as part of a study on the psychophysiology of personality. All participants filled out several self-report measures, including the Eysenck Personality Questionnaire-Revised Short Form (EPQRS). Participants were then moved to an adjoining room to perform an emotional spatial cueing task. 2.3. Eysenck Personality Questionnaire-Revised Short Form (EPQ-RS) The EPQ-RS is a 48-item questionnaire that is used to measure the personality dimensions of neuroticism, extraversion, and psychoticism. Sample items from the psychoticism scale include: ‘‘Would being in debt worry you?” and ‘‘Do you enjoy co-operating with others?” All of the items are answered either ‘‘Yes” (1) or ‘‘No” (0), and the scores are subsequently summed to derive a total for each of the sub-scales. The EPQ-RS is a psychometrically sound measure with ample test–retest reliability and internal consistency (Eysenck & Eysenck, 1991; Eysenck, Eysenck, & Barrett, 1985). 2.4. Emotional spatial cueing task Participants were seated in a dimly lit, sound attenuated room. All participants were positioned 60 cm from the monitor screen (75 Hz refresh rate). Trials began with a fixation cross in the center of the screen (1000 ms) followed by the onset of a face appearing either to the left or right of fixation (250 ms). Following face onset, the face disappeared and was replaced by a target probe (‘‘”) presented either in the same location previously occupied by the face (valid trials) or in the opposite location (invalid trials). The stimulus onset asynchrony between the cue (face) and the target was 50 ms. Participants had to indicate the target’s location as quickly and accurately as possible. Trials were initiated by participant response or after a specified interval (3000 ms) if no response occurred. The fixation was present throughout the experimental sequence. The inter-trial interval was 1000 ms. Responses were recorded using a keyboard with modified LEFT/RIGHT buttons. The experiment order was as follows: (1) practice block of 24 trials, followed by (2) four blocks of experimental trials (60 trials/block) for a total of 240 trials. Of the 60 trials per block, 45 (75%) were valid (i.e., target probe appearing in the same location as the cue), and 15 (25%) were invalid (i.e., target probe appearing in the location opposite the cue). All trial presentations were random. Angry, happy and neutral faces appeared with equal probability on the left or right. Eight faces (4 female, 4 male) were drawn from the NimStim (Tottenham et al., in press) stimulus set, re-sized and converted to grayscale. The faces subtended an approximately 5° vertical visual angle and the target probe subtended an approximately 1.5° vertical visual angle. Trials with incorrect responses and those with RTs less than 100 ms or more than 1000 ms were excluded from analysis. The experiment was programmed and controlled using EPrime Version 1.0 Software.
indicated no separate engagement/disengagement effects. Accordingly, we computed separate angry and happy attention bias scores (e.g., angry attention bias score = [invalid angry trial RTs – valid angry trial RTs] – [invalid neutral trial RTs – valid neutral trial RTs]). Positive scores indicate attentional vigilance and negative scores indicate attentional avoidance, relative to neutral faces. A score of zero indicates no bias. This method of computing attention bias provides an index similar to the one yielded by traditional dot probe paradigms and is less prone to the motor slowing effects of threat (Mogg, Holmes, Garner, & Bradley, 2008). 2.6. Data loss Participants were excluded due to several reasons: equipment failure and loss of reaction time data (n = 1) and missing measures on the EPQ-RS (n = 1). 3. Results 3.1. Demographic and descriptive statistics Table 1 presents the and descriptive statistics for the EPQ-RS measure. 3.2. Correlational and regression analyses Table 2 summarizes the Pearson correlations between EPQ-RS scores and attention bias, including an overall mean RT score (collapsing across all expressions). As predicted, psychoticism was significantly inversely related to bias toward angry faces. There were no other significant personality and attention correlations, except a trend for neuroticism and slower overall RTs, consistent with neurotics being more cognitively distractible (Eysenck & Graydon, 1989). To test the prediction that individuals high in psychoticism would exhibit reduced attention bias toward angry faces, we performed a linear regression using centered psychoticism scores (Aiken & West, 1991) to predict angry attention bias. Psychoticism accounted for approximately 17% of the variability in attention for angry faces [F(1, 34) = 7.83, p = .009, b = .44, Adj. R2 = .17]. This effect remained significant after controlling for gender (p = .03). There were no significant effects when predicting attention for happy faces (p’s > .23). 3.3. Within-group analyses Using psychoticism to predict mean bias scores does not provide conclusive evidence of a personality based difference in attentional processing. Therefore, we next compared angry and happy bias against a score of zero (no bias) to show meaningful cognitive effects. We created high (n = 16) and low (n = 20) groups using a median split (see Table 1)1. Separate within-group analyses, revealed that the low psychoticism group, as expected, showed significant attentional vigilance, both toward angry [M = 21.00 ms, SEM = 10.87 ms; t(18) = 1.93, one-tailed p = .04] and happy [M = 17.78 ms, SEM = 9.45 ms; t(18) = 1.88, one-tailed p = .04] faces relative to neutral ones. The high psychoticism group did not show significant non-zero bias scores (angry bias M = 8.46 ms,
2.5. Reaction time (RT) data reduction The emotional spatial cueing task was a modified version of the exogenous cueing paradigm (Posner, Inhoff, Friedrich, & Cohen, 1987) used to compute separate attention engagement and disengagement scores. Inspection of a Q–Q plot for overall mean RT indicated normal distribution. Exhaustive preliminary analyses
1 The groups did not differ on overall mean RT for the attention task or in selfreported attentional control ability (Derryberry & Reed, 2002), arguing against general cognitive differences independent of emotional modulation. There was also no significant difference in mean percentage accuracy between the high (M = 96%, SD = 1.6%) and low (M = 95.9%, SD = 1.0%) psychoticism individuals (p = .83) and no significant correlations between psychoticism and accuracy scores for angry, happy or neutral faces, specifically (r’s < 0.16, p’s > .30).
V. Miskovic, L.A. Schmidt / Personality and Individual Differences 48 (2010) 499–501 Table 1 Descriptive statistics for the EPQ-RS measure.
Acknowledgements
Personality measures
Mean
Median
SD
Range (0–12)
Psychoticism Neuroticism Extraversion
5.42 4.97 8.61
6 5 9.5
2.42 3.61 2.36
9 12 10
Table 2 Pearson zero-order correlations among the EPQ-RS personality measures and attention performance. Positive bias scores indicate attentional vigilance and negative bias scores indicate attentional avoidance, relative to neutral expressions. Reaction time scores (in ms) EPQ-RS measure Psychoticism Neuroticism Extraversion
Angry bias .44* .09 .13
501
Happy bias
Overall RT
.21 .13 .20
.25 .32+ .09
Note: *p = .01; +p = .06.
SEM = 9.71 ms; happy bias M = 4.00 ms, SEM = 10.79 ms, one-tailed p’s > .20), indicating that emotional faces failed to modulate attention for these individuals. 4. Discussion We examined whether individual differences in psychoticism predicted attentional processing of emotional expressions. As predicted, individuals high in psychoticism displayed reduced attention toward pictures of angry faces. There were also withingroup attention differences such that individuals low in psychoticism showed vigilance toward angry and happy compared to neutral faces. This is consistent with previous findings showing that signals of threat (Esteves et al., 1994) and biologically relevant positive stimuli (Brosch et al., 2008) have preferential access to attentional resources. Individuals high in psychoticism did not show such attention biases. Our findings suggest that some of the characteristics associated with psychoticism, such as disregard for social conventions, coldness, and lack of empathy may be due, in part, to cognitive hypovigilance for salient social signals, especially socially corrective signals such as angry faces. This notion is consistent with recent evidence linking the personality dimension of psychoticism to diminished threat sensitivity (Perkins & Corr, 2006) and a more extensive literature linking psychopathy to threat hyporesponsivity (see Bijtteiber, Beck, Claes, & Vandereycken, 2009). While the constructs of psychoticism, psychopathy and ‘acquired sociopathy’ index different psychological processes, all of these phenomena may share in common, a disregard for social expectations and deficits in responding appropriately to others’ affective states. Future studies should examine how individual differences in psychoticism influence attentional processing of other negative affect states (e.g., fear, disgust) as well as examining biologically based measures of ‘on-line’ attentional processing, such as evoked brain potentials during the presentation of affective faces.
This research was supported by a doctoral scholarship from the Natural Sciences and Engineering Research Council of Canada (NSERC) awarded to Vladimir Miskovic under the direction of Louis Schmidt and Grants from NSERC and the Social Science and Humanities Research Council of Canada (SSHRC) awarded to Louis Schmidt. We wish to thank Sue McKee for her help with data collection. References Aiken, L. S., & West, S. G. (1991). Multiple regression: Testing and interpreting interactions. Thousand Oaks, CA: Sage Publications, Inc. Averill, J. R. (1982). Anger and aggression: An essay on emotion. New York: SpringerVerlag. Best, M., Williams, J. M., & Coccaro, E. F. (2002). Evidence for a dysfunctional prefrontal circuit in patients with an impulsive aggressive disorder. Proceedings of the National Academy of Sciences, USA, 99, 8448–8453. Bijtteiber, P., Beck, I., Claes, L., & Vandereycken, W. (2009). Gray’s reinforcement sensitivity theory as a framework for research on personality–psychopathology associations. Clinical Psychology Review, 29, 421–430. Blair, R. J. R. (2003). Facial expressions, their communicatory functions and neurocognitive substrates. Philosophical Transactions: Biological Sciences, 358, 561–572. Blair, R. J. R., & Cipolotti, L. (2000). Impaired social reversal: A case of ‘acquired sociopathy’. Brain, 123, 1122–1141. Brosch, T., Sander, D., Pourtios, G., & Scherer, K. R. (2008). Beyond fear: Rapid spatial orienting toward positive emotional stimuli. Psychological Science, 19, 362–370. Derryberry, D., & Reed, M. A. (2002). Anxiety-related attentional biases and their regulation by attentional control. Journal of Abnormal Psychology, 111, 225–236. Esteves, F., Dimberg, U., & Öhman, A. (1994). Automatically elicited fear: Conditioned skin conductance responses to masked facial expressions. Cognition and Emotion, 8, 393–413. Eysenck, H. J. (1992). The definition and measurement of psychoticism. Personality and Individual Differences, 13, 757–785. Eysenck, H. J., & Eysenck, S. B. G. (1991). Eysenck personality scales (EPS Adult). London: Hodder and Stoughton. Eysenck, S. B. G., Eysenck, H. J., & Barrett, P. (1985). A revised version of the psychoticism scale. Personality and Individual Differences, 6, 21–29. Eysenck, M. W., & Graydon, J. (1989). Susceptibility to distraction as a function of personality. Personality and Individual Differences, 10, 681–687. Hansen, C. H., & Hansen, R. D. (1988). Finding the face in the crowd: An anger superiority effect. Journal of Personality and Social Psychology, 54, 917–924. Loehlin, J. C., Medland, S. E., Montgomery, G. W., & Martin, N. G. (2005). Eysenck’s psychoticism and the X-linked androgen receptor gene CAG polymorphism in additional Australian samples. Personality and Individual Differences, 39, 661–667. Mogg, K., Holmes, A., Garner, M., & Bradley, B. P. (2008). Effects of threat cues on attentional shifting, disengagement and response slowing in anxious individuals. Behaviour Research and Therapy, 46, 656–667. Öhman, A. (1986). Face the beast and fear the face: Animal and social fears as prototypes for evolutionary analyses of emotion. Psychophysiology, 23, 123–145. Perkins, A. M., & Corr, P. J. (2006). Reactions to threat and personality: Psychometric differentiation of intensity and direction dimensions of human defensive behavior. Behavioural Brain Research, 169, 21–28. Posner, M. I., Inhoff, A. W., Friedrich, F. J., & Cohen, A. (1987). Isolating attentional systems: A cognitive-anatomical analysis. Psychobiology, 15, 107–121. Reed, M. A., & Derryberry, D. (1995). Temperament and attention to positive and negative trait information. Personality and Individual Differences, 18, 135–147. Rolls, E. (1992). Neurophysiological mechanisms underlying face processing within and beyond the temporal cortical area. Philosophical Transactions of the Royal Society of London, B, 335, 11–21. Tottenham, N., Tanaka, J., Leon, A. C., McCarry, T., Nurse, M., Hare, T. A., et al. (in press). The NimStim set of facial expressions: Judgments from untrained research participants. Psychiatry Research. Turakulov, R., Jorm, A. F., Jacomb, P. A., Tan, X., & Easteal, S. (2004). Association of dopamine-b-hydroxylase and androgen receptor gene polymorphism with Eysenck’s P and other personality traits. Personality and Individual Differences, 37, 191–202. van Honk, J., & Schutter, D. J. L. G. (2007). Testosterone reduces conscious detection of signals serving social correction. Psychological Science, 18, 663–667.
Contents lists available at ScienceDirect
Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid
Short Communication
Individual differences in psychoticism predict attention for emotional faces Vladimir Miskovic a,*, Louis A. Schmidt a,b,* a b
McMaster Integrative Neuroscience Discovery and Study, McMaster University, Ontario, Canada L8S 4K1 Department of Psychology, Neuroscience and Behaviour, McMaster University, Canada
a r t i c l e
i n f o
Article history: Received 16 July 2009 Received in revised form 22 October 2009 Accepted 29 October 2009 Available online 28 November 2009 Keywords: Psychoticism Attention bias Emotion Personality Facial expressions
a b s t r a c t Psychoticism is a personality trait characterized by disregard for social conventions, coldness, and lack of empathy. We examined whether individual differences in psychoticism predicted attention biases to pictures of happy and angry faces presumed to elicit social approach and social withdrawal behaviors, respectively. Our analyses revealed that high levels of psychoticism were related to reduced attentional capture by angry faces. There were also within-group attention bias differences such that individuals low in psychoticism exhibited cognitive vigilance for both happy and angry faces relative to neutral, while those high in psychoticism did not show preferential processing of emotional expressions. These findings suggest that individual differences in psychoticism are related to alterations in the cognitive processing of socially relevant signals. Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction People scoring high on measures of psychoticism exhibit an interpersonal style that is characterized by disregard for social conventions, coldness, and lack of empathy. Psychoticism is likely related to, but not isomorphic with, the concept of psychopathy (Eysenck, 1992). Interestingly, psychopathy and ‘acquired sociopathy’ have been linked to disturbances in the basic processing of emotional expressions (Blair, 2003), involving an inability to attribute and respond to affective states (especially negative ones) in other people. Facial expressions constitute affectively rich signals for higher primates, serving an important function in regulating the social hierarchy. Angry faces are prototypical signals of social threat that may facilitate physiological, cognitive and behavioral resources in order to escape potentially harmful confrontation (Öhman, 1986). Both non-human primate (Rolls, 1992) and human (Esteves, Dimberg, & Öhman, 1994; Hansen & Hansen, 1988) studies have shown that angry faces capture attentional resources relatively quickly and automatically, given their important communicative functions. In non-human primates angry expressions serve as socially corrective signals that can inhibit the behavior of conspecifics (Averill, 1982). Existing evidence indicates that ‘acquired sociopathy’ following brain trauma (Blair & Cipolotti, 2000), antisocial personality disorder (Best, Williams, & Coccaro, 2002) and testosterone administra-
tion (van Honk & Schutter, 2007) are all linked with impaired processing of angry faces. This latter finding is interesting, given the link between psychoticism and testosterone function (Loehlin, Medland, Montgomery, & Martin, 2005; Turakulov, Jorm, Jacomb, Tan, & Easteal, 2004). Furthermore, since psychoticism is also associated with disregard for social violation and others’ approval, it raises the possibility that attention for angry faces may be influenced by normative variation in this personality dimension. In the present study, we attempted to test this hypothesis and extend the literature by moving beyond studies of brain damaged and clinical populations to studies of individual differences in personality (see Reed & Derryberry, 1995 for application to neuroticism and extraversion). We collected measures of psychoticism in a group of non-clinical young adults who then performed a task measuring attention for angry and happy faces. We hypothesized that low levels of psychoticism would be associated with vigilance for angry, relative to neutral, faces while individuals high in psychoticism would fail to exhibit a processing bias for these socially corrective signals. Additional analyses were performed to examine the processing of pro-social emotion (happy faces), given recent evidence that positive emotional stimuli also modulate attention (Brosch, Sander, Pourtios, & Scherer, 2008). 2. Method
* Corresponding authors. Address: Department of Psychology, Neuroscience and Behaviour, McMaster University, Canada (L.A. Schmidt). Tel.: +1 905 525 9140 (V. Miskovic). E-mail addresses: [email protected] (V. Miskovic), [email protected] (L.A. Schmidt). 0191-8869/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2009.10.031
2.1. Participants Thirty-eight (10 males, 28 females) undergraduates served as participants (M age = 1931 yr, SD = 126 yr), in exchange for course
500
V. Miskovic, L.A. Schmidt / Personality and Individual Differences 48 (2010) 499–501
credit. All procedures performed were approved by the McMaster University Research Ethics Board, and all participants provided written consent prior to any procedures. 2.2. Procedure Upon arriving to the laboratory, we recorded patterns of resting central and autonomic physiology on a sub-sample of the participants as part of a study on the psychophysiology of personality. All participants filled out several self-report measures, including the Eysenck Personality Questionnaire-Revised Short Form (EPQRS). Participants were then moved to an adjoining room to perform an emotional spatial cueing task. 2.3. Eysenck Personality Questionnaire-Revised Short Form (EPQ-RS) The EPQ-RS is a 48-item questionnaire that is used to measure the personality dimensions of neuroticism, extraversion, and psychoticism. Sample items from the psychoticism scale include: ‘‘Would being in debt worry you?” and ‘‘Do you enjoy co-operating with others?” All of the items are answered either ‘‘Yes” (1) or ‘‘No” (0), and the scores are subsequently summed to derive a total for each of the sub-scales. The EPQ-RS is a psychometrically sound measure with ample test–retest reliability and internal consistency (Eysenck & Eysenck, 1991; Eysenck, Eysenck, & Barrett, 1985). 2.4. Emotional spatial cueing task Participants were seated in a dimly lit, sound attenuated room. All participants were positioned 60 cm from the monitor screen (75 Hz refresh rate). Trials began with a fixation cross in the center of the screen (1000 ms) followed by the onset of a face appearing either to the left or right of fixation (250 ms). Following face onset, the face disappeared and was replaced by a target probe (‘‘”) presented either in the same location previously occupied by the face (valid trials) or in the opposite location (invalid trials). The stimulus onset asynchrony between the cue (face) and the target was 50 ms. Participants had to indicate the target’s location as quickly and accurately as possible. Trials were initiated by participant response or after a specified interval (3000 ms) if no response occurred. The fixation was present throughout the experimental sequence. The inter-trial interval was 1000 ms. Responses were recorded using a keyboard with modified LEFT/RIGHT buttons. The experiment order was as follows: (1) practice block of 24 trials, followed by (2) four blocks of experimental trials (60 trials/block) for a total of 240 trials. Of the 60 trials per block, 45 (75%) were valid (i.e., target probe appearing in the same location as the cue), and 15 (25%) were invalid (i.e., target probe appearing in the location opposite the cue). All trial presentations were random. Angry, happy and neutral faces appeared with equal probability on the left or right. Eight faces (4 female, 4 male) were drawn from the NimStim (Tottenham et al., in press) stimulus set, re-sized and converted to grayscale. The faces subtended an approximately 5° vertical visual angle and the target probe subtended an approximately 1.5° vertical visual angle. Trials with incorrect responses and those with RTs less than 100 ms or more than 1000 ms were excluded from analysis. The experiment was programmed and controlled using EPrime Version 1.0 Software.
indicated no separate engagement/disengagement effects. Accordingly, we computed separate angry and happy attention bias scores (e.g., angry attention bias score = [invalid angry trial RTs – valid angry trial RTs] – [invalid neutral trial RTs – valid neutral trial RTs]). Positive scores indicate attentional vigilance and negative scores indicate attentional avoidance, relative to neutral faces. A score of zero indicates no bias. This method of computing attention bias provides an index similar to the one yielded by traditional dot probe paradigms and is less prone to the motor slowing effects of threat (Mogg, Holmes, Garner, & Bradley, 2008). 2.6. Data loss Participants were excluded due to several reasons: equipment failure and loss of reaction time data (n = 1) and missing measures on the EPQ-RS (n = 1). 3. Results 3.1. Demographic and descriptive statistics Table 1 presents the and descriptive statistics for the EPQ-RS measure. 3.2. Correlational and regression analyses Table 2 summarizes the Pearson correlations between EPQ-RS scores and attention bias, including an overall mean RT score (collapsing across all expressions). As predicted, psychoticism was significantly inversely related to bias toward angry faces. There were no other significant personality and attention correlations, except a trend for neuroticism and slower overall RTs, consistent with neurotics being more cognitively distractible (Eysenck & Graydon, 1989). To test the prediction that individuals high in psychoticism would exhibit reduced attention bias toward angry faces, we performed a linear regression using centered psychoticism scores (Aiken & West, 1991) to predict angry attention bias. Psychoticism accounted for approximately 17% of the variability in attention for angry faces [F(1, 34) = 7.83, p = .009, b = .44, Adj. R2 = .17]. This effect remained significant after controlling for gender (p = .03). There were no significant effects when predicting attention for happy faces (p’s > .23). 3.3. Within-group analyses Using psychoticism to predict mean bias scores does not provide conclusive evidence of a personality based difference in attentional processing. Therefore, we next compared angry and happy bias against a score of zero (no bias) to show meaningful cognitive effects. We created high (n = 16) and low (n = 20) groups using a median split (see Table 1)1. Separate within-group analyses, revealed that the low psychoticism group, as expected, showed significant attentional vigilance, both toward angry [M = 21.00 ms, SEM = 10.87 ms; t(18) = 1.93, one-tailed p = .04] and happy [M = 17.78 ms, SEM = 9.45 ms; t(18) = 1.88, one-tailed p = .04] faces relative to neutral ones. The high psychoticism group did not show significant non-zero bias scores (angry bias M = 8.46 ms,
2.5. Reaction time (RT) data reduction The emotional spatial cueing task was a modified version of the exogenous cueing paradigm (Posner, Inhoff, Friedrich, & Cohen, 1987) used to compute separate attention engagement and disengagement scores. Inspection of a Q–Q plot for overall mean RT indicated normal distribution. Exhaustive preliminary analyses
1 The groups did not differ on overall mean RT for the attention task or in selfreported attentional control ability (Derryberry & Reed, 2002), arguing against general cognitive differences independent of emotional modulation. There was also no significant difference in mean percentage accuracy between the high (M = 96%, SD = 1.6%) and low (M = 95.9%, SD = 1.0%) psychoticism individuals (p = .83) and no significant correlations between psychoticism and accuracy scores for angry, happy or neutral faces, specifically (r’s < 0.16, p’s > .30).
V. Miskovic, L.A. Schmidt / Personality and Individual Differences 48 (2010) 499–501 Table 1 Descriptive statistics for the EPQ-RS measure.
Acknowledgements
Personality measures
Mean
Median
SD
Range (0–12)
Psychoticism Neuroticism Extraversion
5.42 4.97 8.61
6 5 9.5
2.42 3.61 2.36
9 12 10
Table 2 Pearson zero-order correlations among the EPQ-RS personality measures and attention performance. Positive bias scores indicate attentional vigilance and negative bias scores indicate attentional avoidance, relative to neutral expressions. Reaction time scores (in ms) EPQ-RS measure Psychoticism Neuroticism Extraversion
Angry bias .44* .09 .13
501
Happy bias
Overall RT
.21 .13 .20
.25 .32+ .09
Note: *p = .01; +p = .06.
SEM = 9.71 ms; happy bias M = 4.00 ms, SEM = 10.79 ms, one-tailed p’s > .20), indicating that emotional faces failed to modulate attention for these individuals. 4. Discussion We examined whether individual differences in psychoticism predicted attentional processing of emotional expressions. As predicted, individuals high in psychoticism displayed reduced attention toward pictures of angry faces. There were also withingroup attention differences such that individuals low in psychoticism showed vigilance toward angry and happy compared to neutral faces. This is consistent with previous findings showing that signals of threat (Esteves et al., 1994) and biologically relevant positive stimuli (Brosch et al., 2008) have preferential access to attentional resources. Individuals high in psychoticism did not show such attention biases. Our findings suggest that some of the characteristics associated with psychoticism, such as disregard for social conventions, coldness, and lack of empathy may be due, in part, to cognitive hypovigilance for salient social signals, especially socially corrective signals such as angry faces. This notion is consistent with recent evidence linking the personality dimension of psychoticism to diminished threat sensitivity (Perkins & Corr, 2006) and a more extensive literature linking psychopathy to threat hyporesponsivity (see Bijtteiber, Beck, Claes, & Vandereycken, 2009). While the constructs of psychoticism, psychopathy and ‘acquired sociopathy’ index different psychological processes, all of these phenomena may share in common, a disregard for social expectations and deficits in responding appropriately to others’ affective states. Future studies should examine how individual differences in psychoticism influence attentional processing of other negative affect states (e.g., fear, disgust) as well as examining biologically based measures of ‘on-line’ attentional processing, such as evoked brain potentials during the presentation of affective faces.
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