Dynamic Touch by Hand and Head During Walking: Protective Behavior for the Head?

We investigated perception of the extent of an object held in the hand or attached to the head during walking. Participants wielded an occluded, weighted rod by hand and by head and reported the perceived location of the rod end (relative to a virtual vertical line) while walking and while standing. There was an unexpected effect of body part on perceived location of the rod end. In particular, participants stood or walked so that the rod end was farther away from the vertical line when wielding with the head than wielding with the hand. It is possible that differences between the tasks and the relative costs of a collision influenced the locomotory behavior in each condition.     

Infants’ scanning of dynamic faces during the first year

This research investigated infants’ scanning of a talking, socially engaging face. Three- to four-month-olds looked equally at the mouth and eyes whereas 9-month-olds attended more to the eyes than mouth. These findings shed light on information infants’ seek from dynamic face stimuli.     

Can holistic processing be learned for inverted faces?

The origin of "special" processing for upright faces has been a matter of ongoing debate. If it is due to generic expertise, as opposed to having some innate component, holistic processing should be learnable for stimuli other than upright faces. Here we assess inverted faces. We trained subjects to discriminate identical twins using up to 1100 exposures to each twin in different poses and images. In the upright orientation, twin discrimination was supported by holistic processing. Removal of a single face feature had no effect on performance, and a composite effect (Young, A. W., Hellawell, D., & Hay, D.C. (1987). Configurational information in face perception. Perception 16 (6), 747-759) was obtained. In the inverted orientation, however, above chance identification ability relied on (a) image specific learning, or (b) tiny local feature differences not noticed in the upright faces. The failure to learn holistic processing for inverted faces indicates that, in contrast to the situation for objects (Tarr, M.J., & Pinker, S. (1989). Mental rotation and orientation-dependence in shape recognition. Cognitive Psychology 21 (2), 233-282), orientation specificity of face processing is highly stable against practice.     

Vigilance for threat: effects of anxiety and defensiveness

Eysenck’s (1997) theory that attentional biases for threat vary as an interactive function of trait anxiety and defensiveness was tested using a visual probe task. Two stimulus exposure conditions were used to explore a secondary issue concerning attentional allocation over time. Results indicated that, among high trait anxious participants, only those with low levels of defensiveness showed vigilance for threatening faces presented for 500 ms. They also showed an attentional preference for neutral faces, relative to happy faces, irrespective of exposure condition. This pattern was reversed in high trait anxious participants with high levels of defensiveness, who showed an attentional bias towards happy faces (relative to neutral faces) under both exposure conditions. The findings are discussed in relation to their implications for (a) the significance of measures of defensiveness for the conceptualization of high trait anxious individuals, and (b) the status of anxiety-related biases at different stages of information processing.     

A multi-attribute extension of the secretary problem: Theory and experiments

We present a generalization of a class of sequential search problems with ordinal ranks, referred to as “secretary” problems, in which applicants are characterized by multiple attributes. We then present a procedure for numerically computing the optimal search policy and test it in two experiments with incentive-compatible payoffs. With payoffs dependent on the absolute ranks of the attributes, we test the optimal search model with both symmetric (Experiment 1) and asymmetric (Experiment 2) search problems. In both experiments we find that, relative to the optimal search policy, subjects stop the search too early. Our results show that this bias is largely driven by a propensity to stop prematurely on applicants of intermediate (relative) quality.     

Infants' ability to match dynamic phonetic and gender information in the face and voice.

Six experiments tested young infants' sensitivity to vowel and gender information in dynamic faces and voices. Infants were presented with side-by-side displays of two faces articulating the vowels /a/ or /i/ in synchrony. The heard voice matched the gender of one face in some studies and the vowel of one face in other studies and, in some studies, vowel and gender were placed in conflict. Infants of age 4.5 months showed no evidence of matching face and voice on the basis of gender, but were able to ignore irrelevant gender information and match on the basis of the vowel. Robust evidence of the ability to match on the basis of gender was not evident until 8 months of age. This set of findings suggests that, when identical stimuli are used, gender matching does not emerge until a later age than does phonetic matching. Results are discussed in relation to key theories of intermodal development.     

Subjectively different emotional schematic faces not automatically discriminated from the brain’s bioelectrical responses

The present study investigates how the brain automatically discriminates emotional schematic faces, as indicated by the mismatch responses, and how reliable these brain responses are. Thirty-three healthy volunteers participated in the vMMN EEG experiment with four experimental sets differing from each other by the type of standard (object with scrambled face features) and the type of deviants (Angry, Happy and Neutral schematic faces) presented. Conscious subjective evaluations of valence, arousal and attention catching of the same stimuli showed clear differentiation of emotional expressions. Deviant faces elicited rather similar vMMN at frontal and occipital sites. Bayesian analyses suggest that vMMN does not differ between angry and happy faces. Neutral faces, however, did not yield statistically significant vMMN at occipital leads. Pearson’s correlation and intra-class correlation analyses showed that the brain’s reactions to the stimuli were highly stable within individuals across the experimental sets, whereas the mismatch responses were much more variable.