You are in: Home » Research at the Unit » Emotion research
Social attention perception
What you lookin' at?
Human's show a remarkable ability to perceive another person's focus of attention from their eye gaze, body orientation, or head orientation. This is referred to as "social attention perception". In a series of experiments we have used adaptation to study the visual mechanisms underlying this ability.
Adaptation refers to a change in perception following prolonged exposure to a particular stimulus and has been primarily associated with the study of low-level visual cues, such as colour, line orientation, or motion direction. However, recent research has shown that high-level visual objects, including faces are also susceptible to adaptation.
In the case of adaptation to line orientation, adapting to line oriented 30o to the right of vertical causes a line oriented 10o to the right of vertical to perceived as oriented away from the adapting stimulus. We addressed whether a similar phenomenon applied to gaze and other social attention cues.
Eye Gaze
I Thought You Were Looking at Me: Direction-Specific Aftereffects in Gaze Perception
Jenkins, R., Beaver, J. D., & Calder, A. J. (2006). I thought you were looking at me: Direction-specific aftereffects in gaze perception. Psychological Science, 17, 506-513.
Gaze direction is an important social signal in humans and other primates. In this study, we used an 'adaptation' paradigm to investigate the functional organization of gaze perception in humans. Prolonged exposure (adaptation) to consistent leftward or rightward gaze produced a powerful illusion that virtually eliminated observers' perception of gaze in the adapted direction—gaze in the adapted direction was seen as pointing straight ahead, while gaze to the opposite side was unimpaired (Figure 1). The effect held across changes in size or head orientation or the adapting and test images suggesting that our findings do not reflect adaptation to low-level visual properties. Our findings provide evidence that humans have distinct populations of neurons that are selectively responsive to particular directions of seen gaze.
Figure 1: Follwing adaptation to Left (dotted line) and Right (dashed line) gazing eyes, participants' perceive left and right gazing eyes as "straight ahead" respectively.
Visual Representation of Eye Gaze is Coded by a Non-Opponent Multichannel System
Calder, A. J., Jenkins, R., Cassel, A., & Clifford, C. W. G. (2008). Visual representation of eye gaze is coded by a nonopponent multichannel system. Journal of Experimental Psychology: General, 137(2), 244-261.
The gaze adaptation effect is consistent with either of two representational frameworks—a multichannel system comprising separate channels for distinct gaze directions (e.g., left, direct, and right), or an opponent coding system in which all gaze directions are coded by just two channels, one coding left gaze the other right, with direct gaze represented as a neutral point reflecting equal activation of both left and right pools. In two experiments we used adaptation procedures to investigate which of these models provides the optimal account. For multichannel coding adaptating to an alternating sequence of left and right gaze would predict a broadening of the range in which gaze is seen as direct whereas adapting to direct gaze would result in a narowing of this range. Opponent coding does not predict these opposite effects. Both experiments supported multichannel coding (Figure 2). Previous research has shown that facial identity is coded by an opponent-coding system, hence our results also demonstrate that gaze is coded by a distinct representational framework to facial identity.
Figure 2: Following adaptation to A) alternating left and right gaze participants show a widening of the acceptable range to call eye gaze "straight ahead" and therefore make more 'direct' responses. B) Following adaptation to direct facing eyegaze participants show a narrowing of the acceptable range to call stimuli facing "direct" and therefore make less 'direct' responses. Only multichannel coding predicts these opppsite adaptation effects hence our results reveal that the visual representation of eye gaze is coded my a multichannel system.
Separate Coding of Different Gaze Directions in the Superior Temporal Sulcus and Inferior Parietal Lobule
Calder, A. J., Beaver, J. D., Winston, J. S., Dolan, R. J., Jenkins, R., Eger, E., & Henson, R.N.A. (2007). Separate coding of different gaze directions in the superior temporal sulcus and inferior parietal lobule. Current Biology, 17, 20-25.
Human functional imaging has demonstrated posterior superior temporal sulcus (STS) activation in gaze processing, particularly in coding the intentions conveyed by gaze, but to date has provided no evidence of separate coding of different gaze directions. This may be because neurons coding different gaze directions are interspersed. We therefore used fMRI adaptation, which is considered to offer superior resolution, to investigate whether the human anterior STS contains representations of different gaze directions, as suggested by non-human primate research. Subjects viewed probe faces gazing left, directly ahead, or right. Adapting (i.e. prolonged exposure) to leftward gaze produced a reduction in brain activation to left relative to right (and direct) gaze probes in the anterior STS and inferior parietal cortex; rightward gaze adaptation produced a corresponding reduction to right gaze probes (Figure 3). Consistent with these findings, averted gaze in the adapted direction was misidentified as direct. Our study provides the first human evidence of dissociable neural systems for left and right gaze.
Figure 3: Three different views of the brain (Sagittal, Coronal, and Transverse) through A) the Anterior STS and B) Inferior Patietal Lobule. C shows mean event-related response to each of the three types of probe faces (10° left, direct, and 10° right) as a function of the direction of gaze adaptation (left and right) for the maximally activated voxel in the right anterior STS (RSTS; 57, 9, −27). LL = left adaptation-left gaze probe; LD = left adaptation-direct gaze probe, and so on. For the preadaptation data (right graphs), L = left probe, D = direct probe, and R = right probe.
Other cues to social attention?
About Turn: The Visual Representation of Human Body Orientation Revealed by Adaptation
Lawson, R. P., Clifford, C. W. G., & Calder, A. J. (in press). About turn: The visual representation of human body orientation revealed by adaptation. Psychological Science.
Body orientation also provides an important cue, particularly when viewing at a distance. In a separate series of experiments we showed that perception of left and right oriented bodies could also be selectively adapted. In addition we showed that the visual representation of body orientation is also best accounted for by a multichannel system, with separate channels coding different body directions (e.g., left, direct, right).
