Biomedical subjects

Bradley S Gibson

Publications and source records attributed to Bradley S Gibson.

5 recordsLinked to original sources

PubMed2006

Visual attention and the semantics of space: beyond central and peripheral cues.

The distinction between central and peripheral cues has played an important role in understanding the functional nature of visual attention for the past 30 years. In the present article, we propose a new taxonomy that is based on linguistic categories of spatial relations. Within this framework, spatial cues are categorized as either "projective" or "deictic." Using an empirical diagnostic, we demonstrate that the word cues above, below, left, and right express projective spatial relations, whereas arrow cues, eye-gaze cues, and abrupt-onset cues express deictic spatial relations. Thus, the projective-versus-deictic distinction crosscuts the more traditional central-versus-peripheral distinction. The theoretical utility of this new distinction is discussed in the context of recent evidence suggesting that a variety of central cues can elicit reflexive orienting.

Attention↗

PubMed2005

Variation in cue duration reveals top-down modulation of involuntary orienting to uninformative symbolic cues.

This article reports three experiments in which the effects of cue duration on involuntary orienting to uninformative symbolic cues (arrows presented at fixation) were investigated. Experiment 1 showed that symbolic cues had less effect on involuntary orienting when they were presented for only 25 msec than when they were presented for 200 msec across a range of stimulus onset asynchronies. Experiment 2 suggested that the effect of cue duration on involuntary orienting was due primarily to top-down strategic factors, rather than to bottom-up stimulus factors, and Experiment 3 suggested that these strategic factors may involve differences in how the cue is processed. Altogether, the present findings are important because they emphasize the distinction between cue processing and the putative involuntary orienting that results from such processing in the symbolic-cuing paradigm. In so doing, the present results help resolve discrepant findings that have been reported across previous studies.

Attention↗

PubMed2005

Linguistically mediated visual search: the critical role of speech rate.

Recent studies have shown that the presentation of concurrent linguistic context can lead to highly efficient performance in a standard conjunction search task by the induction of an incremental search strategy (Spivey, Tyler, Eberhard, & Tanenhaus, 2001). However, these findings were obtained under anomalously slow speech rate conditions. Accordingly, in the present study, the effects of concurrent linguistic context on visual search performance were compared when speech was recorded at both a normal rate and a slow rate. The findings provided clear evidence that the visual search benefit afforded by concurrent linguistic context was contingent on speech rate, with normal speech producing a smaller benefit. Overall, these findings have important implications for understanding how linguistic and visual processes interact in real time and suggest a disparity in the temporal resolution of speech comprehension and visual search processes.

Fixation, Ocular↗

PubMed2004

Using hazard functions to assess changes in processing capacity in an attentional cuing paradigm.

Processing capacity--defined as the relative ability to perform mental work in a unit of time--is a critical construct in cognitive psychology and is central to theories of visual attention. The unambiguous use of the construct, experimentally and theoretically, has been hindered by both conceptual confusions and the use of measures that are at best only coarsely mapped to the construct. However, more than 25 years ago, J. T. Townsend and F. G. Ashby (1978) suggested that the hazard function on the response time (RT) distribution offered a number of conceptual advantages as a measure of capacity. The present study suggests that a set of statistical techniques, well-known outside the cognitive and perceptual literatures, offers the ability to perform hypothesis tests on RT-distribution hazard functions. These techniques are introduced, and their use is illustrated in application to data from the contingent attentional capture paradigm.

Attention↗

PubMed1991

Directing spatial attention within an object: altering the functional equivalence of shape descriptions.

Three experiments extended the demonstrated effects of spatial attention to a new area, the perceptual organization of objects. We manipulated observers' fixation location, their spatial attention location, and their intentions to hold one alternative of a Necker cube that had been altered in one region to favor one of the alternative interpretations (the biased region) and measured reports about the perceived organization of the cube over 30-s trials. Regardless of fixation location, responses showed obligatory effects of the bias only when observers attended to the biased region of the cube and not when they attended to the unbiased region of the cube, even when the biased region lay between fixation and the attended unbiased region. On the basis of these experiments, we argue that spatial attention operates through mechanisms of facilitation and inhibition to determine the functional nature of the structural description of an object.

Adult↗