Biomedical subjects

Scott D Gronlund

Publications and source records attributed to Scott D Gronlund.

4 recordsLinked to original sources

PubMed2006

Aging and visual search: automatic and controlled attentional bias to threat faces.

Using a visual search paradigm, we investigated how age affected attentional bias to emotional facial expressions. In Experiments 1 and 2, participants searched for a discrepant facial expression in a matrix of otherwise homogeneous faces. Both younger and older adults showed a more effective search when the discrepant face was angry rather than happy or neutral. However, when the angry faces served as non-target distractors, younger adults' search was less effective than happy or neutral distractor conditions. In contrast, older adults showed a more efficient search with angry distractors than happy or neutral distractors, indicating that older adults were better able to inhibit angry facial expressions. In Experiment 3, we found that even a top-down search goal could not override the angry face superiority effect in guiding attention. In addition, RT distribution analyses supported that both younger and older adults performed the top-down angry face search qualitatively differently from the top-down happy face search. The current research indicates that threat face processing involves automatic attentional shift and a controlled attentional process. The current results suggest that age only influenced the controlled attentional process.

Adult↗

PubMed2004

Sequential lineups: shift in criterion or decision strategy?

R. C. L. Lindsay and G. L. Wells (1985) argued that a sequential lineup enhanced discriminability because it elicited use of an absolute decision strategy. E. B. Ebbesen and H. D. Flowe (2002) argued that a sequential lineup led witnesses to adopt a more conservative response criterion, thereby affecting bias, not discriminability. Height was encoded as absolute (e.g., 6 ft [1.83 m] tall) or relative (e.g., taller than). If a sequential lineup elicited an absolute decision strategy, the principle of transfer-appropriate processing predicted that performance should be best when height was encoded absolutely. Conversely, if a simultaneous lineup elicited a relative decision strategy, performance should be best when height was encoded relatively. The predicted interaction was observed, providing direct evidence for the decision strategies explanation of what happens when witnesses view a sequential lineup.

Adolescent↗

PubMed2002

A tandem random walk model of the SAT paradigm: response times and accumulation of evidence.

The speed-accuracy trade-off (SAT) paradigm forces participants to trade response speed for information accuracy by presenting them with a response signal at variable times after the onset of processing to which they must give an immediate response (within 300 ms). The processes that underlie the paradigm, especially those affecting response times, are not completely understood. Also, the extent to which the paradigm might affect the evidence accumulation process is still unclear. By testing several different sets of assumptions, we present a random walk model for the SAT paradigm that qualitatively explains both accuracy and response time data. The model uses a tandem random walk, with two possible continuations in a second phase which begins after the response signal. If a boundary is not reached during phase one, the walk transfers the current sum (relative to the size of the boundaries) from phase one to phase two in the form of bias, with drift rate equal to zero. If, however, a boundary is reached in phase one, the second phase starts from zero (no bias) with a strong drift rate towards the previously reached boundary. The model also incorporates a psychological refractory period: a delay in the onset of a second task when two tasks are presented in close succession. The model is consistent with the idea that information about the evidence accumulation rate is not contaminated by the paradigm.

Models, Psychological↗

PubMed2002

Aiding planning in air traffic control: an experimental investigation of the effects of perceptual information integration.

Prior research examined how controllers plan in their traditional environment and identified various information uncertainties as detriments to planning. A planning aid was designed to reduce this uncertainty by perceptually representing important constraints. This included integrating spatial information on the radar screen with discrete information (planned sequences of air traffic). Previous research reported improved planning performance and decreased workload in the planning aid condition. The purpose of this paper was to determine the source of these performance improvements. Analysis of computer interactions using log-linear modeling showed that the planning interface led to less repetitive--but more integrated--information retrieval compared with the traditional planning environment. Ecological interface design principles helped explain how the integrated information retrieval gave rise to the performance improvements. Actual or potential applications of this research include the design and evaluation of interface automation that keeps users in active control by modification of perceptual task characteristics.

Aerospace Medicine↗