Jason Tipples

Eye gaze is not unique: automatic orienting in response to uninformative arrows.

Recent studies (Driver et al., 1999; Friesen & Kingstone, 1998; Langton & Bruce, 1999) have argued that the perception of eye gaze may be unique, as compared with other symbolic cues (e.g., arrows), in being able to automatically trigger attentional orienting. In Experiment 1, 17 participants took part in a visuospatial orienting task to investigate whether arrow cues might also trigger automatic orienting. Two arrow cues were presented for 75 msec to the left and right of a fixation asterisk. After an interval of either 25 or 225 msec, the letter O or X appeared. After both time intervals, mean response times were reliably faster when the arrows pointed toward, rather than away from, the location of the target letter. This occurred despite the fact that the participants were informed that the arrows did not predict where the target would appear. In Experiment 2, the same pattern of data was recorded when several adjustments had been made in an attempt to rule out alternative explanations for the cuing effects. Overall, the findings suggest that the eye gaze is not unique in automatically triggering orienting.

The eyebrow frown: a salient social signal.

Seven experiments investigated the finding that threatening schematic faces are detected more quickly than nonthreatening faces. Threatening faces with v-shaped eyebrows (angry and scheming expressions) were detected more quickly than nonthreatening faces with inverted v-shaped eyebrows (happy and sad expressions). In contrast to the hypothesis that these effects were due to perceptual features unrelated to the face, no advantage was found for v-shaped eyebrows presented in a nonfacelike object. Furthermore, the addition of internal facial features (the eyes, or the nose and mouth) was necessary to produce the detection advantage for faces with v-shaped eyebrows. Overall, the results are interpreted as showing that the v-shaped eyebrow configuration affords easy detection, but only when other internal facial features are present.

Fear and fearfulness potentiate automatic orienting to eye gaze

This study examines whether fearful and happy expressions enhance orienting to eye gaze, and the contribution of individual differences in trait fearfulness. Participants carried out a spatial orienting task in which they were presented with neutral, happy, and fearful expressions with eyes gazing either toward or away from a target letter (T or L). The expressions appeared either 300 ms or 700 ms before the onset of the target letter. After both time intervals there was a gaze congruency effect: Response times were faster when the eyes gazed toward (congruent condition) rather than away (incongruent condition) from the location of the target. The congruency effect was larger for fearful faces compared to neutral faces, but not happy faces compared to neutral faces. Furthermore, at a short stimulus onset asynchrony (SOA) between cue and target, the magnitude of the effect of fear on orienting increased with trait fearfulness. The results are discussed in relationship to findings of attentional bias for threat-related stimuli.

Orienting to counterpredictive gaze and arrow cues

In separate experiments, counterpredictive arrow, eye gaze, or abrupt-onset cues were used to test the hypothesis that individual differences in voluntary control influence involuntary orienting. In contrast with previous findings (Friesen, Ristic, & Kingstone, 2004), involuntary orienting effects were found for arrow cues. Furthermore, for both eye gaze and arrow cues, individual differences in voluntary control were associated with involuntary orienting: Involuntary orienting effects were larger for participants who were more effective at using the cue to reorient attention, and also for participants who reported greater ability to control attention. Orienting to abrupt-onset cues was not correlated to individual differences in self-reported attentional control. The findings show that eye gaze and arrow cues instigate similar involuntary and voluntary effects and that involuntary orienting to symbolic cues is linked to individual differences in voluntary control.

Negative emotionality influences the effects of emotion on time perception.

In this study I used a temporal bisection task to test if greater overestimation of time due to negative emotion is moderated by individual differences in negative emotionality. The effects of fearful facial expressions on time perception were also examined. After a training phase, participants estimated the duration of facial expressions (anger, happiness, fearfulness) and a neutral-baseline facial expression. In accordance to the operation of an arousal-based process, the duration of angry expressions was consistently overestimated relative to other expressions and the baseline condition. In support of a role for individual differences in negative emotionality on time perception, temporal bias due to angry and fearful expressions was positively correlated to individual differences in self-reported negative emotionality. The results are discussed in relation both to the literature on attentional bias to facial expressions in anxiety and fearfulness and also, to the hypothesis that angry expressions evoke a fear-specific response.

Asymmetric interference between sex and emotion in face perception

Previous research with speeded-response interference tasks modeled on the Garner paradigm has demonstrated that task-irrelevant variations in either emotional expression or facial speech do not interfere with identity judgments, but irrelevant variations in identity do interfere with expression and facial speech judgments. Sex, like identity, is a relatively invariant aspect of faces. Drawing on a recent model of face processing according to which invariant and changeable aspects of faces are represented in separate neurological systems, we predicted asymmetric interference between sex and emotion classification. The results of Experiment 1, in which the Garner paradigm was employed, confirmed this prediction: Emotion classifications were influenced by the sex of the faces, but sex classifications remained relatively unaffected by facial expression. A second experiment, in which the difficulty of the tasks was equated, corroborated these findings, indicating that differences in processing speed cannot account for the asymmetric relationship between facial emotion and sex processing. A third experiment revealed the same pattern of asymmetric interference through the use of a variant of the Simon paradigm. To the extent that Garner interference and Simon interference indicate interactions at perceptual and response-selection stages of processing, respectively, a challenge for face processing models is to show how the same asymmetric pattern of interference could occur at these different stages. The implications of these findings for the functional independence of the different components of face processing are discussed.

When Time Stands Still: Fear-Specific Modulation of Temporal Bias Due to Threat

The current study was designed to test the fear-specific nature of temporal bias due to threat. A temporal bisection procedure was used in which participants (N = 46) were initially trained to recognize short (400 ms) and long (1,600 ms) standard durations. In the test phase, participants were asked to judge whether the duration of computer-generated faces drawn to appear threatening, fearful, and neutral, was closer to either the short or long duration they had learnt earlier. Past research was replicated-the durations of the arousing facial expressions were overestimated relative to a low arousal (neutral) expression. Overestimation for threat was positively correlated with individual differences in fearfulness, trait anxiety, and distress. Multiple regression analyses were carried out to test the hypothesis was that individual differences in anxiety and fearfulness but not other traits would uniquely predict temporal overestimation due to threat. The results showed that fearfulness but not other traits (trait anxiety, anger, distress, activity, and sociability) was a unique and strong (partial r = .47) predictor of increased overestimation for both threatening and fearful expressions. The findings support the hypothesis that threat-related expressions activate a fear-specific system (Öhman & Mineka, 2001) or fear representations (Beck & Clark, 1997) in fearful individuals.

Working memory involved in predicting future outcomes based on past experiences

Deficits in working memory have been shown to contribute to poor performance on the Iowa Gambling Task [IGT: Bechara, A., & Martin, E.M. (2004). Impaired decision making related to working memory deficits in individuals with substance addictions. Neuropsychology, 18, 152-162]. Similarly, a secondary memory load task has been shown to impair task performance [Hinson, J., Jameson, T. & Whitney, P. (2002). Somatic markers, working memory, and decision making. Cognitive, Affective, & Behavioural Neuroscience, 2, 341-353]. In the present study, we investigate whether the latter findings were due to increased random responding [Franco-Watkins, A. M., Pashler, H., & Rickard, T. C. (2006). Does working memory load lead to greater impulsivity? Commentary on Hinson, Jameson, and Whitneys (2003). Journal of Experimental Psychology: Learning, Memory & Cognition, 32, 443-447]. Participants were tested under Low Working Memory (LWM; n=18) or High Working Memory (HWM; n=17) conditions while performing the Reversed IGT in which punishment was immediate and reward delayed [Bechara, A., Dolan, S., & Hindes, A. (2002). Decision making and addiction (part II): Myopia for the future or hypersensitivity to reward? Neuropsychologia, 40, 1690-1705]. In support of a role for working memory in emotional decision making, compared to the LWM condition, participants in the HWM condition made significantly greater number of disadvantageous selections than that predicted by chance. Performance by the HWM group could not be fully explained by random responding.

Orienting to eye gaze and face processing.

The author conducted 7 experiments to examine possible interactions between orienting to eye gaze and specific forms of face processing. Participants classified a letter following either an upright or inverted face with averted, uninformative eye gaze. Eye gaze orienting effects were recorded for upright and inverted faces, irrespective of whether the faces were simple, schematic faces or more realistic faces. In contrast, inversion affected orienting to targets appearing along the vertical axis. Switching the contrast between the iris and sclera reversed orienting to eye gaze. Lifting the eyelid to expose more of the iris-sclera contrast led to a potentiation of orienting to eye gaze. Raising the eyebrow alone without the eyelid did not affect orienting. The findings suggest that local perceptual information is critical for orienting to eye gaze and that the effect can occur with a degree of independence from certain types of face processing.

Increased gaze following for fearful faces. It depends on what you’re looking for!

An oculomotor visual search task was used to investigate how participants follow the gaze of a non-predictive and task irrelevant distractor gaze, and the way in which this gaze following is influenced by the emotional expression (fearful vs. happy) as well as participants’ goal. Previous research has suggested that fearful emotions should result in stronger cueing effects than happy faces. Our results demonstrated that the degree to which the emotional expression influenced this gaze following varied as a function of the search target. When searching for a threatening target, participants were more likely to look in the direction of eye gaze on a fearful compared to a happy face. However, when searching for a pleasant target, this stronger cueing effect for fearful faces disappeared. Therefore, gaze following is influenced by contextual factors such as the emotional expression, as well as the participant’s goal.