Time allocation in human vigilance

Three human subjects detected unpredictable signals by pressing either of two telegraph keys. The relative frequencies with which detections occurred for the two alternatives were varied. The procedure included a changeover delay and response cost for letting go of a key. All subjects matched the relative time spent holding each key to the relative number of detections for that key, in conformity with the matching law. One subject's performance, which at first deviated from the relation, came into conformity with it when response cost was increased. Another subject's performance approximated matching more closely when the changeover delay was increased. The results confirm and extend the notions that choice consists in time allocation and that all behavior can be measured on the common scale of time.     

Hemisphere function and vigilance

A vigilance task in which successive signals were presented to one or other hemiretina, and therefore to one or other cerebral hemisphere, revealed no differences between the hemispheres in terms of detections, although detections declined overall during the experimental period. False positive responses also declined, but consistently more arose from the left hemisphere. There was also a difference in the detection of signals received through the nasal and temporal hemiretinae, the temporal hemiretina showing superiority in detection rate throughout the experiment. This finding may provide a new and more economical approach to the tunnel vision phenomenon.     

The multiple vigilance test

The multiple vigilance test is a 30-min signal detection task designed to assess performance. Sixty target and 180 nontarget stimuli are presented with random interstimulus intervals ranging from 4 to 11 sec. Subjects respond by pressing the spacebar (or microswitch in an alternate version of the program) when they see the masking pattern transformed into the target. This vigilance test is used in conjunction with measures of physiological sleepiness (Multiple Sleep Latency Test) and subjective sleepiness (Stanford Sleepiness Scale). This behavioral information concerning manifest sleepiness provides a more complete picture of a subject’s state of alertness. The assessment of vigilance during long, monotonous, nonstimulating tasks is clinically important in patients with disorders of sleep and arousal.     

An examiner-induced visual vigilance apparatus

A film/record instrument is described that could measure attending behavior, distractibility, hyperkinetic movement, and selected aspects of visual perception by recording the subject's response to significant visual stimuli.     

Test anxiety and visual vigilance

Twenty male and 20 female subjects, previously classified as high or low in test anxiety, participated in an experiment on visual vigilance under conditions designed either to enhance or minimize feelings of being tested. Detection rate declined across the 36 min of the task among subjects high in test anxiety who believed that they were being tested and in subjects low in test anxiety who did not. False detection rates revealed no significant differences among conditions. Analysis of sensitivity to signals according to statistical decision theory revealed low sensitivity in both the high-anxiety test and low-anxiety/no-test conditions than in the other two. Analysis of decisional criteria showed that subjects in the high-anxiety test condition were more conservative in setting a criterion than subjects in the other three conditions. No sex differences were found. The results are discussed in terms of an elaboration of Sarason's (1978) model of test anxiety.     

Sense mode and coupling in a vigilance task

Usarmymedical Research Laboratory, Fort Knox, Kentucky This investigation examined the performance of 36 Ss on three 90-min vigilance tasks. As time on task increased, there was a significant decrease in number of detections and false responses and a corresponding significant increase in response latency. The consistent rank order relationship between stimulus conditions suggests that there were uniform trends among these conventional response measures. There was a significant decline in sensitivity (d′) lor the closely coupled tasks, regardless of the sense mode involved. However, d′ remained fairly stable for the loosely coupled visual task. The significant increase in criterion values(β) suggest that Ss adopt a more conservative mode of responding with increasing time on task. Further, these data indicate that a lack of control of coupling effects, rather than sense mode specificity, may have confounded the interpretation of prior research on visualand auditory tasks.     

A vigilance model for latent learning

The author proposes a heuristic model for latent learning. It is concluded that to regard academic learning as qualitatively different from other forms of learning is to deny evolutionary continuity. Academic learning is not a unitary process governed by a single set of parameters. In addition, it is observed that the problem of student motivation may very well turn out to be purely academic. The instructional technique for a captive audience of a class may be so structured as to make the direction of attention irresistible, the performance of a response, when needed, compelling, and the acquisition of knowledge inevitable. Vigilance is an instance of innate foundation. Its most striking characteristics are its universality in the animal world, its ready evocation by a wide range of stimuli, and its apparent behavioral and physiological manifestations. The last two are the natural resources for objective investigation, and the first may well be the basis of broad and valid generalizations.     

Chewing gum moderates the vigilance decrement

We examine the impact of chewing gum on a Bakan‐type vigilance task that requires the continual updating of short‐term order memory. Forty participants completed a 30‐min auditory Bakan‐task either with, or without, the requirement to chew gum. Self‐rated measures of mood were taken both pre‐ and post‐task. As expected, the vigilance task produced a time‐dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in post‐task self‐rated alertness scores. The declines in both performance and subjective alertness were attenuated in the chewing‐gum group. In particular, correct RTs were significantly shorter following the chewing of gum in the latter stages of the task. Additionally, the gradients of decline for target detection and incline for correct RTs were both attenuated for the chewing‐gum group. These findings are consistent with the data of Tucha and Simpson (2011), Appetite, 56, 299–301, who showed beneficial effects of chewing gum in the latter stages of a 30 min visual attention task, and extend their data to a task that necessitates the continuous updating of order memory. It is noteworthy that our data contradict the claim (Kozlov, Hughes, & Jones, 2012, Q. J. Exp. Psychology, 65, 501–513) that chewing gum negatively impacts short‐term memory task performance.