Biomedical subjects

Jay Pratt

Publications and source records attributed to Jay Pratt.

42 records · Page 3Linked to original sources

PubMed2003

Inhibition of return spreads across 3-D space.

Focusing attention to a location in 3-D space operates much the same as in 2-D space. Attending a location in 2-D space is followed by a selective inhibitory aftereffect known as inhibition of return (IOR). Here, we report the results of two 3-D reflexive cuing studies in which depth was defined by binocular disparity. As has been shown before, attentional cuing was specific for x-y-z locations. However, the present results show that IOR is not depth specific. After a specific location in x-y-z is cued, IOR occurs for the depth plane in front of and behind the cued location. The finding that IOR spreads across depth planes may be related to how inhibited locations are encoded in the superior colliculus. We argue that the functional role of a depth-blind IOR is to bias attention against going back to any part of a previously attended object.

Attention↗

PubMed2002

Endogenous saccades are preceded by shifts of visual attention: evidence from cross-saccadic priming effects.

The present study examines whether endogenous saccades are preceded by shifts of attention. Three experiments are reported in which participants were required to execute a saccadic eye movement to a certain location and to subsequently identify the orientation of a target triangle. Prior to the execution of the saccade a prime was presented, which was compatible or incompatible with the target. A priming effect (faster responses in the compatible condition than in the incompatible condition) occurred only when the prime was presented at the saccade destination, and this effect was larger when the prime was presented during oculomotor programming than when it was presented prior to oculomotor programming. The results indicate that an endogenous shift of attention precedes endogenous saccades, providing further support for theories of visual selection that assume a tight coupling between attention and saccades.

Adult↗

PubMed2002

Examining the role of the fixation cue in inhibition of return.

To clarify the role of the fixation cue in inhibition of return (IOR), the present study compared four conditions: fixation cue immediately after the peripheral cue, in the middle of the stimulus-onset asynchrony (SOA), immediately before the onset of the target, or no fixation cue. With a 200-ms SOA, less IOR was found when the fixation cue was either absent or occurred immediately after the peripheral cue. No differences between the four conditions were found with 400-ms and 800-ms SOAs. These findings suggest that there is a brief period of time in which attention cannot be withdrawn from the peripherally cued location. Once attention has been withdrawn from the peripherally cued location, IOR can be found at short SOAs.

Cues↗

PubMed2002

Visual orienting in college athletes: explorations of athlete type and gender.

Covert orienting was measured in 50 college athletes and 51 nonathletes of both genders. Visual environments of the sports were both static (swimming, track) and dynamic (soccer, volleyball). Participants made speeded responses in a task measuring vigilance, alerting, automatic orienting, voluntary orienting, modulation of automatic orienting, and modulation of inhibition of return. Gender differences werefound in the overall response times of nonathletes and in the alerting measures for all participants. However, all participants were similar in their automatic orienting. Sport-specific effects were seen in voluntary orienting and in the modulation of automatic orienting. These gender and sports-related findings are interpreted in light of the experience athletes have in the dynamic control of spatial attention.

Adult↗

PubMed2002

Examining the activity-distribution model of visual attention with exogenous cues and targets.

LaBerge and his co-workers (e.g., LaBerge & Brown, 1986, 1989; LaBerge, Carlson, Williams, & Bunney, 1997) used an experimental method consisting of three rapid successive displays, each requiring a difficult letter discrimination, to show that visual attention is best accounted for with an activity-distribution model rather than a moving-spotlight model. The present study sought to further this line of investigation by inserting exogenous cues and targets, often used in studies that have found support for the moving-spotlight model, into the basic method used by LeBerge and colleagues. The results from three experiments were consistent with the activity-distribution model and not with the moving-spotlight model.

Adult↗

PubMed2002

Determining whether attentional control settings are inclusive or exclusive.

The aim of the present study was to determine whether attentional control settings operate with an inclusive rule (orient attention to stimuli that share a task-relevant feature with the target) or an exclusive rule (do not orient attention to stimuli that do not share a task-relevant feature with the target). All three experiments used a variation of the Folk and Remington (e.g., Folk, Remington, & Johnston, 1992) paradigm. In Experiment 1, cuing effects were found for combination cues (cues containing an onset feature and a color feature) with both onset and color targets. Experiment 2, using a delay between cue and target, revealed inhibition of return (IOR) for combination cues with onset and color targets. Unexpectedly, IOR was also found for onset cues with color targets, and this finding was confirmed in Experiment 3. These findings indicate that attentional control settings use an inclusive rule. Moreover, the presence of IOR with onset cues and color targets suggests that onset cues may automatically capture attention, but attention control settings allow for rapid disengagement when the onset cue does not contain a task-relevant feature.

Attention↗