Consciousness and the Social Brain
briefly, drawing attention to one location. Then a target dot flashes briefly. The person must press a button as soon as the target appears. When the cue draws attention away from the location of the target, the person responds slowly. When the cue draws attention toward the location of the target, the person responds quickly. In this way, visual attention can be demonstrated. (B) In the social attention version, the cue that draws attention is not a square around a location but a picture of a face that looks toward one side or the other.
In this task, you are not told to follow the gaze of the face. You are given no instructions at all about the eyes on that face. But you evidently can’t help shifting your attention in the direction that the face is looking. This finding was initially interpreted as evidence for a special mechanism in the human brain that monitors the gaze of others and aligns attention between people. Where you see someone else looking, your own attention automatically follows.
It is only fair to report a body of work that, on the whole, has ambiguous findings. Other scientists tried to replicate this effect of gaze in the Posner task. 13 – 15 The results were mixed. Gaze direction was not unique. A simple arrow at the center of the screen pointing to the right or left, or a dot stepping to the right or left, had a similar ability to direct people’s attention. Eyes looking to the right or left were not special. Some have argued that a gaze cue may be more potent in drawing attention than a nongaze cue, 16 but by and large the evidence suggests that any cue will draw attention.
These results represent a failure to find any special effect of gaze monitoring. A person’s attention does, indeed, tend to automatically follow the direction of someone else’s gaze. But it also automatically follows any number of other cues and pointers. The results using the Posner task have tended to put a damper on the hypothesis of a special mechanism for social attention.
I believe that the pessimism is unwarranted. The limit of the Posner task, and also its strength, is that it can generalize across different kinds of cues. If a red square suddenly turns green, it will draw attention to its region of space. If a stationary square suddenly jiggles, that jiggle will also draw attention to its region of space.Clearly, color and motion are not the same thing. They are processed by different circuitry in the visual system. Nobody would argue on the basis of the Posner task that the brain utterly lacks separate, specialized mechanisms for color and motion. Yet in the Posner task, color and motion function in a similar way. They cannot easily be disentangled. The task is therefore not the right tool to distinguish one perceptual mechanism from another. The fact that a pair of eyes moving to the left or right draws attention but that an arrow pointing to the left or right also draws attention just as well says little or nothing about the brain’s specialized mechanism for processing eyes. These particular studies neither refute nor support the hypothesis of social attention.
I’ve described these complexities and mixed results for the sake of accuracy and completeness. The literature does contain some controversy. I do not wish to simplify or ignore the inconvenient details. However, taken together, the evidence on gaze and the brain point toward a particular conclusion. The human brain (and the monkey brain) seems to be equipped with specialized machinery that monitors the gaze of others.
Does the Attention Schema Theory Equate Awareness with an Eye Tracker?
In talking about the attention schema theory with colleagues and friends, I encounter scientific interest, enthusiasm, and inevitably some disagreement. The counterarguments tend to cluster into a few common forms. Throughout this book I address these common counterarguments. Here I would like to address what is probably the most common criticism of the attention schema theory.
According to the theory, awareness is a reconstructed model of attention. We often know where someone is attending by observing where someone’s eyes are pointing. Therefore the theory (accordingto this criticism) equates awareness with eye tracking. But how can awareness be explained as an eye tracker? A simple machine, available on the market for the past few decades, uses infrared light bounced off of the cornea to track eye position. Point the device at a person and it can
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