Friendly fire and the proportion of friends to foes

Losses of inhibitory control may be partly responsible for some friendly fire incidents. The Sustained Attention to Response Task (SART; Robertson, Manly, Andrade, Baddeley, & Yiend, 1997) may provide an appropriate empirical model for this. The current investigation aimed to provide an ecologically valid application of the SART to a small arms simulation and examine the effect of different proportions of enemy to friendly confederates. Seven university students engaged in a small arms simulation where they cleared a building floor using a near-infrared emitter gun, tasked with firing at confederates representing enemies and withholding fire to confederates representing friends. All participants completed three conditions which were differentiated by the proportion of enemies to friends present. As hypothesized, participants failed to withhold responses more often when the proportion of foes was higher, suggesting that a prepotent motor response routine had developed. This effect appeared to be disproportionately more substantial in the high foe condition relative to the others. Participants also subjectively reported higher levels of on-task focus as foe proportions increased, suggesting that they found this more mentally demanding. Future research could examine closer the nature of the performance reductions associated with high proportions of foes, as it appears that this is more complex than a simple linear relationship

Go-stimuli proportion influences response strategy in a sustained attention to response task

The sustained attention to response task (SART) usefulness as a measure of sustained attention has been questioned. The SART may instead be a better measure of other psychological processes and could prove useful in understanding some real-world behaviours. Thirty participants completed four Go/No-Go response tasks much like the SART, with Go-stimuli proportions of .50, .65, .80 and .95. As Go-stimuli proportion increased, reaction times decreased while both commission errors and self-reported task-related thoughts increased. Performance measures were associated with task-related thoughts but not taskunrelated thoughts. Instead of faster reaction times and increased commission errors being due to absentmindedness or perceptual decoupling from the task, the results suggested participants made use of two competing response strategies, in line with a response strategy or response inhibition perspective of SART performance. Interestingly, performance measures changed in a nonlinear manner, despite the linear Go proportion increase. A threshold may exist where the prepotent motor response becomes more pronounced, leading to the disproportionate increase in response speed and commission errors. This research has implications for researchers looking to employ the SAR

Negative stimuli may improve visuospatial working memory

The impact of negative affect on working memory performance is unclear. Visuospatial and verbal working memory are critical in many settings, but may be impaired during exposure to negative stimuli. In Experiment 1, the impact of task-irrelevant negative picture stimuli on verbal compared to visuospatial working memory performance was investigated. Unexpectedly, visuospatial memory performance was superior for trials containing negative stimuli than trials with neutral stimuli. The impact of negative picture stimuli on visuospatial working memory was further examined in Experiment 2. Performance was again superior for negative stimuli relative to neutral stimuli. While much previous research has reported that negative affect is disruptive of visuospatial working memory, the improved performance found here is consistent with other research particularly where negative or arousing stimuli are thought to increase the pool of available processing resources or effort. Implications for contexts where working memory demands occur alongside distressing stimuli are discussed, as well as future research suggestions

The effects of a transition between local and global processing on vigilance performance

Sixty participants performed a sustained attention task in which they were required to perform either global or local feature discrimination. Two groups required just one type of discrimination, while the remaining two groups started on one type of discrimination before transitioning to the other type halfway through. A transition resulted in worse performance when compared to no transition. It was also found that the local discrimination group showed improved performance over time compared to the global discrimination group. Functional near-infrared spectroscopy (fNIRS) was used to measure blood oxygenation during the task and was used as an index of cerebral hemodynamic activity. Total oxygenation was found to increasemore in global discrimination tasks. It was also found that the left prefrontal cortex showed little change in nontransition tasks while in transition tasks it followed the same trend as the right prefrontal cortex. Combined with performance data, it suggests that an increased utilization of bilateral resources may in some cases improve performance over time