University of Stirling

About: University of Stirling is a education organization based out in Stirling, Stirling, United Kingdom. It is known for research contribution in the topics: Population & Polyunsaturated fatty acid. The organization has 7722 authors who have published 20549 publications receiving 732940 citations. The organization is also known as: Stirling University.

Reflexive visual orienting in response to the social attention of others

Abstract: Four experiments investigate the hypothesis that cues to the direction of another's social attention produce a reflexive orienting of an observer's visual attention. Participants were asked to make a simple detection response to a target letter which could appear at one of four locations on a visual display. Before the presentation of the target, one of these possible locations was cued by the orientation of a digitized head stimulus, which appeared at fixation in the centre of the display. Uninformative and to-be-ignored cueing stimuli produced faster target detection latencies at cued relative to uncued locations, but only when the cues appeared 100 msec before the onset of the target (Experiments 1 and 2). The effect was uninfluenced by the introduction of a to-be-attended and relatively informative cue (Experiment 3), but was disrupted by the inversion of the head cues (Experiment 4). It is argued that these findings are consistent with the operation of a reflexive, stimulus-driven or exogenous orient...

Face Recognition in Poor-Quality Video: Evidence From Security Surveillance:

Abstract: Security surveillance systems often produce poor-quality video, and this may be problematic in gathering forensic evidence. We examined the ability of subjects to identify target people captured by a commercially available video security device. In Experiment 1, sub- jects personally familiar with the targets performed very well at iden- tifying them, but subjects unfamiliar with the targets performed very poorly. Police officers with experience in forensic identification per- formed as poorly as other subjects unfamiliar with the targets. In Experiment 2, we asked how familiar subjects can perform so well. Using the same video device, we edited clips to obscure the head, body, or gait of the targets. Obscuring body or gait produced a small decrement in recognition performance. Obscuring the targets' heads had a dramatic effect on subjects' ability to recognize the targets. These results imply that subjects recognized the targets' faces, even in these poor-quality images.

Noise and determinism in synchronized sheep dynamics

Abstract: A major debate in ecology concerns the relative importance of intrinsic factors and extrinsic environmental variations in determining population size fluctuations1,2,3,4,5,6. Spatial correlation of fluctuations in different populations caused by synchronous environmental shocks2,7,8 is a powerful tool for quantifying the impact of environmental variations on population dynamics8,9. However, interpretation of synchrony is often complicated by migration between populations8,10. Here we address this issue by using time series from sheep populations on two islands in the St Kilda archipelago11,12,13. Fluctuations in the sizes of the two populations are remarkably synchronized over a 40-year period. A nonlinear time-series model shows that a high and frequent degree of environmental correlation is required to achieve this level of synchrony. The model indicates that if there were less environmental correlation, population dynamics would be much less synchronous than is observed. This is because of a threshold effect that is dependent on population size; the threshold magnifies random differences between populations. A refined model showsthat part of the required environmental synchronicity can be accounted for by large-scale weather variations. These results underline the importance of understanding the interaction between intrinsic and extrinsic influences on population dynamics14.