An Automobile's Tail Lights: Sacrificing Safety for Playful Design?

OBJECTIVE: The counterintuitive "Union Jack"-inspired turn signals on versions of BMW's Mini vehicles was investigated to reveal potential impacts on human performance. BACKGROUND: When some Mini drivers indicate a change in direction, they do so with an oppositely oriented arrow. This conflict, between the task-irrelevant spatial shape and task-relevant location of the signal, mimics a "converse" spatial-Stroop effect that, in combination with the ubiquitous use of arrows on road signs, may be confusing. METHOD: Participants (n = 30) responded-via right and left keypresses-to the directions of road signs and turn signals in both pure and mixed blocks. Reaction times and accuracies were recorded to determine performance in each condition (compatible, neutral, incompatible). RESULTS: Performance suffered when the location and direction of the stimuli did not correspond. When responding to turn signals the cost to performance was especially salient in mixed blocks. Thus, when driving on roads where the meanings of arrows on road signs is important, turn signals pointing in a direction opposite from the directional intention indicated by the signals' location are likely to be confusing. CONCLUSION: The design of some Mini's "Union Jack" style taillights opposes well-established principles of cognitive functioning, caused confusion in our laboratory study and therefore may be a safety hazard-a possibility that ought to be explored in more realistic (e.g., driving simulator) situations. APPLICATION: BMW designers should consider universally adopting the neutral, "horizontal line," illumination style that is currently available in the aftermarket.

Effects of fatigue on attention and vigilance as measured with a modified attention network test.

As part of a larger study on the effects of fatigue on various attentional and behavioural measures, we had participants complete a modified version of Luna et al.'s (J Neurosci Methods 306:77-87, Luna et al., J Neurosci Methods 306:77-87, 2018) ANTI-Vea task (mANTI-Vea) at the beginning and end (pre/post) of each of two 8-h testing sessions. Between these administrations of the mANTI-Vea our participants spent ~ 6 h performing an intervening task. Our intent in this project was two-fold: first, to replicate the pattern of effects reported in Luna et al.'s original presentation of the ANTI-Vea; second, to assay the impact of fatigue on vigilance and attention by observing shifts in mANTI-Vea performance as a function of time on task and before versus after the intervening task. With time-on-task (the mANTI-Vea is divided into six sub-blocks) we observed that participants became increasingly conservative in their biases to respond towards infrequent targets, showed a decline in sensitivity, and lapsed in responding in the psychomotor vigilance task with greater frequency. In the pre/post comparison, we observed an increase in the proportion of lapses, but not in participants' response biases. Attentional network scores were found to be somewhat insensitive to our fatigue manipulations; the effect of time-on-task was only significant for orienting scores on RT, and our pre/post comparison was only significant for RT derived executive functioning scores.