Gustav Kuhn

Look away! Eyes and arrows engage oculomotor responses automatically

The present study investigates how people’s voluntary saccades are influenced by where another person is looking, even when this is counterpredictive of the intended saccade direction. The color of a fixation point instructed participants to make saccades either to the left or right. These saccade directions were either congruent or incongruent with the eye gaze of a centrally presented schematic face. Participants were asked to ignore the eyes, which were congruent only 20% of the time. At short gaze—fixation-cue stimulus onset asynchronies (SOAs; 0 and 100 msec), participants made more directional errors on incongruent than on congruent trials. At a longer SOA (900 msec), the pattern tended to reverse. We demonstrate that a perceived eye gaze results in an automatic saccade following the gaze and that the gaze cue cannot be ignored, even when attending to it is detrimental to the task. Similar results were found for centrally presented arrow cues, suggesting that this interference is not unique to gazes.

Potential social interactions are important to social attention

Social attention, or how spatial attention is allocated to biologically relevant stimuli, has typically been studied using simplistic paradigms that do not provide any opportunity for social interaction. To study social attention in a complex setting that affords social interaction, we measured participants’ looking behavior as they were sitting in a waiting room, either in the presence of a confederate posing as another research participant, or in the presence of a videotape of the same confederate. Thus, the potential for social interaction existed only when the confederate was physically present. Although participants frequently looked at the videotaped confederate, they seldom turned toward or looked at the live confederate. Ratings of participants’ social skills correlated with head turns to the live, but not videotaped, confederate. Our results demonstrate the importance of studying social attention within a social context, and suggest that the mere opportunity for social interaction can alter social attention.

Towards a science of magic

It is argued here that cognitive science currently neglects an important source of insight into the human mind: the effects created by magicians. Over the centuries, magicians have learned how to perform acts that are perceived as defying the laws of nature, and that induce a strong sense of wonder. This article argues that the time has come to examine the scientific bases behind such phenomena, and to create a science of magic linked to relevant areas of cognitive science. Concrete examples are taken from three areas of magic: the ability to control attention, to distort perception, and to influence choice. It is shown how such knowledge can help develop new tools and indicate new avenues of research into human perception and cognition.

There's more to magic than meets the eye

Document S1. Supplemental Experimental ProceduresxDownload (.1 MB ) Document S1. Supplemental Experimental ProceduresMovie 1 Vanishing ball trick pro-illusion conditionxDownload (.75 MB ) Movie 1 Vanishing ball trick pro-illusion conditionMovie 2 Vanishing ball trick anti-illusion conditionxDownload (.85 MB ) Movie 2 Vanishing ball trick anti-illusion condition

Implicit Learning of Nonlocal Musical Rules: Implicitly Learning More Than Chunks.

Dominant theories of implicit learning assume that implicit learning merely involves the learning of chunks of adjacent elements in a sequence. In the experiments presented here, participants implicitly learned a nonlocal rule, thus suggesting that implicit learning can go beyond the learning of chunks. Participants were exposed to a set of musical tunes that were all generated using a diatonic inversion. In the subsequent test phase, participants either classified test tunes as obeying a rule (direct test) or rated their liking for the tunes (indirect test). Both the direct and indirect tests were sensitive to knowledge of chunks. However, only the indirect test was sensitive to knowledge of the inversion rule. Furthermore, the indirect test was overall significantly more sensitive than the direct test, thus suggesting that knowledge of the inversion rule was below an objective threshold of awareness.

You look where I look! Effect of gaze cues on overt and covert attention in misdirection

We designed a magic trick in which misdirection was used to orchestrate observers’ attention in order to prevent them from detecting the to-be-concealed event. By experimentally manipulating the magicians gaze direction we investigated the role that gaze cues have in attentional orienting, independently of any low level features. Participants were significantly less likely to detect the to-be-concealed event if the misdirection was supported by the magicians gaze, thus demonstrating that the gaze plays an important role in orienting peoples attention. Moreover, participants spent less time looking at the critical hand when the magicians gaze was used to misdirect their attention away from the hand. Overall, the magicians face, and in particular the eyes, accounted for a large proportion of the fixations. The eyes were popular when the magician was looking towards the observer; once he looked towards the actions and objects being manipulated, participants typically fixated the gazed-at areas. Using a highly naturalistic paradigm using a dynamic display we demonstrate gaze following that is independent of the low level features of the scene.

Magic and fixation: now you don't see it, now you do.

over somatosensory modalities. And the interaction of vision and proprioception has been studied recently in animals and humans (Graziano 1999; Fink et al 1999; Farne et al 2000). Ramachandran and colleagues had the clever insight to appreciate and show that visual input of the reflection of the intact arm seen in a mirror could be used to mobilize previously immobile phantom limbs. Subsequent studies have confirmed the findings of Ramachandran and colleagues (1995) in some phantom-limb patients (Giraux and Sirigu 2003; Hunter et al 2003), and case reports and small studies have shown that therapy similarly using a mirror may be beneficial for some patients with movement deficits of other causes (Altschuler et al 1999; Sathian et al 2000; McCabe et al 2003; Moseley 2004). The effect described here suggests a rather direct effect of vision on motion in healthy subjects, the study of which may be helpful in developing improved rehabilitation methods for patients with motor deficits secondary to neurologic disease. In preparing this paper, I also noticed another paper that demonstrates a different experimental system in which there is an effect of vision via a mirror on proprioception and movement (Franz and Packman 2004).

Misdirection in magic: Implications for the relationship between eye gaze and attention

Magicians use misdirection to manipulate peoples attention in order to prevent their audiences from uncovering their methods. Here we used a prerecorded version of a magic trick to investigate some of the factors that accompany successful misdirection. Prior information about the nature of the trick significantly improved participants’ detection of the method. The informed participants fixated closer to the event in question, suggesting that they were monitoring it more closely once they knew about the trick. The probability of detection was independent of how far the participant was looking from the “secret” event as it happened, but participants who detected the event moved their eyes towards where it took place much earlier than participants who missed it. This result is consistent with the notion that attention is allocated ahead of the current locus of fixation, and we present evidence that attention may be allocated two or more saccade targets ahead of where the participant is fixating.

The Influence of Eye-Gaze and Arrow Pointing Distractor Cues on Voluntary Eye Movements

We investigated Ricciardelli et al.’s (2002) claim, that the tendency for gaze direction to elicit automatic attentional following is unique to biologically significant information. Participants made voluntary saccades to targets on the left or the right of a display, which were either congruent or incongruent with a centrally presented distractor (eye-gaze or arrow). Contrary to Ricciardelli et al., for both distractor types, saccade latencies were slower, and participants made more directional errors, on incongruent than on congruent trials. Moreover, a cost-benefit analysis showed no difference between the two distractor types. However, latencies for erroneous saccades were faster than correctly directed saccades for the eye-gaze distractors, but not for the arrow distractors.

Eye movements affirm: automatic overt gaze and arrow cueing for typical adults and adults with autism spectrum disorder

People with autism spectrum disorder (ASD) show reduced interest towards social aspects of the environment and a lesser tendency to follow other people’s gaze in the real world. However, most studies have shown that people with ASD do respond to eye-gaze cues in experimental paradigms, though it is possible that this behaviour is based on an atypical strategy. We tested this possibility in adults with ASD using a cueing task combined with eye-movement recording. Both eye gaze and arrow pointing distractors resulted in overt cueing effects, both in terms of increased saccadic reaction times, and in proportions of saccades executed to the cued direction instead of to the target, for both participant groups. Our results confirm previous reports that eye gaze cues as well as arrow cues result in automatic orienting of overt attention. Moreover, since there were no group differences between arrow and eye gaze cues, we conclude that overt attentional orienting in ASD, at least in response to centrally presented schematic directional distractors, is typical.