Attention in action and perception: Unitary or separate mechanisms of selectivity?

What is the relation between the two visual stream hypothesis and selective visual attention? In this chapter, we first consider this question at a theoretical level before presenting an example of work from our lab that examines the question: Under what conditions does the emotional content of a visual object influence visually guided action? Previous research has demonstrated that fear can influence perception, both consciously and unconsciously, but it is unclear when fear influences visually guided action. The study tested participants with varying degrees of spiderphobia on two visually guided pointing tasks, while manipulating the emotional valence of the target (positive and negative) and the cognitive load of the participant (single vs dual task). Participants rapidly moved their finger from a home position to a suddenly appearing target image on a touch screen.

Lifespan changes in attention revisited: Everyday visual search.

This study compared visual search under everyday conditions among participants across the life span (healthy participants in 4 groups, with average age of 6 years, 8 years, 22 years, and 75 years, and 1 group averaging 73 years with a history of falling). The task involved opening a door and stepping into a room find 1 of 4 everyday objects (apple, golf ball, coffee can, toy penguin) visible on shelves. The background for this study included 2 well-cited laboratory studies that pointed to different cognitive mechanisms underlying each end of the U-shaped pattern of visual search over the life span (Hommel et al.

Teams on the same wavelength perform better: Inter-brain phase synchronization constitutes a neural substrate for social facilitation.

Working together feels easier with some people than with others. We asked participants to perform a visual search task either alone or with a partner while simultaneously measuring each participant's EEG. Local phase synchronization and inter-brain phase synchronization were generally higher when subjects jointly attended to a visual search task than when they attended to the same task individually.

But is it social? How to tell when groups are more than the sum of their members.

Failure to distinguish between statistical effects and genuine social interaction may lead to unwarranted conclusions about the role of self-differentiation in group function. We offer an introduction to these issues from the perspective of recent research on collaborative cognition.

What's in a Friendship? Partner Visibility Supports Cognitive Collaboration between Friends.

Not all cognitive collaborations are equally effective. We tested whether friendship and communication influenced collaborative efficiency by randomly assigning participants to complete a cognitive task with a friend or non-friend, while visible to their partner or separated by a partition. Collaborative efficiency was indexed by comparing each pair's performance to an optimal individual performance model of the same two people.

When two heads are better than one: Interactive versus independent benefits of collaborative cognition.

Previous research has shown that two heads working together can outperform one working alone, but whether such benefits result from social interaction or from the statistical facilitation of independent responses is not clear. Here we apply Miller's (Cognitive Psychology, 14, 247-279, 1982; Ulrich, Miller & Schröter, Behavior Research Methods, 39(2), 291-302, 2007) race model inequality (RMI) to distinguish between these two possibilities. Pairs of participants completed a visual enumeration task, both as independent individuals and as two members of a team.

Isolating shape from semantics in haptic-visual priming.

The exploration of a familiar object by hand can benefit its identification by eye. What is unclear is how much this multisensory cross-talk reflects shared shape representations versus generic semantic associations. Here, we compare several simultaneous priming conditions to isolate the potential contributions of shape and semantics in haptic-to-visual priming.

Treadmill experience mediates the perceptual-motor aftereffect of treadmill walking.

People have a lifetime of experience in which to calibrate their self-produced locomotion with the resultant optical flow. Contrary to walking across the ground, however, walking on a treadmill produces minimal optical flow, and consequentially, a perceptual-motor aftereffect results. We demonstrate that the magnitude of this perceptual-motor aftereffect-measured by forward drift while attempting to march in-place following treadmill walking-decreases as experience walking on a treadmill is acquired over time.

Person perception informs understanding of cognition during visual search.

Does person perception--the impressions we form from watching others--hold clues to the mental states of people engaged in cognitive tasks? We investigated this with a two-phase method: In Phase 1, participants searched on a computer screen (Experiment 1) or in an office (Experiment 2); in Phase 2, other participants rated the searchers' video-recorded behavior. The results showed that blind raters are sensitive to individual differences in search proficiency and search strategy, as well as to environmental factors affecting search difficulty. Also, different behaviors were linked to search success in each setting: Eye movement frequency predicted successful search on a computer screen; head movement frequency predicted search success in an office.

Looking versus seeing: Strategies alter eye movements during visual search.

Visual search can be made more efficient by adopting a passive cognitive strategy (i.e., letting the target "pop" into mind) rather than by trying to actively guide attention.

Utility of fetal muscle biopsy for diagnosis of nemaline myopathy.

Objectives: To report and discuss prenatal diagnosis of nemaline myopathy (NM) using fetal muscle biopsy.

Methods: A consanguineous couple, with a history of a child with a clinical diagnosis of NM but no molecular genetic confirmation, was referred for prenatal diagnosis in two subsequent pregnancies. Fetal muscle biopsy with ultrasound guidance was undertaken at 22 and 21 weeks, respectively.