Eye Movements during Vigilance

Abstract

This study concerns eye movements recorded during a vigilance situation. Evidence was obtained on where people looked when they were watching for signals, which were 0.5-sec. pauses in the motion of a slowly revolving pointer. The following results were obtained: (1) Detection probability for two dials was approximately half the detection rate for one dial. (2) Analysis of eye-movement records showed that in the one-dial situation every missed signal was fixated without being recognized. (3) In the two-dial condition, signals were not only either fixated or unfixated, but some were fixated for part of their duration. Approximately one-third of the signals fell into each fixation category. (4) In contrast to the one-dial condition, the largest proportion of unreported signals for two dials were not fixated at all. Nearly as many unreported signals were partially fixated. About one-quarter of the unreported signals were fixated for their full duration. (5) Individual Ss differed with respect to the time they paused on one dial before shifting to the other. Those who shifted more frequently detected more signals.

REINFORCEMENT OF EYE MOVEMENT WITH CONCURRENT SCHEDULES1

“…Since line of sight is involved in the selection of components of spatial stimulus configurations, the conditioning of eye movements plays an important role in choice selection. For instance, Schroeder and Holland (1968a) and Mackworth et al (1964) showed that, in a vigilance situation, the speed of shifting fixations was related to the number of signals detected regardless of signal rate. Schroeder (1969) has shown that, in a simple discrete-trial discrim- --I--ination task, subjects learn to ignore redundant stimuli according to their relevance to the critical stimulus.…”

“…Mackworth and Morandi (1967) showed that subjects, when gazing at photographs, look mostly at the informative elements of the pictures. Mackworth, Kaplan, and Metlay (1964) and Schroeder and Holland (1968a) showed that eye-movement rates are correlated with signal rates on vigilance tasks. Recent experiments with monkeys (Berger, 1968) and with humans (Schroeder and Holland, 1968b) This situation is analogous to concurrent schedules in more usual operant conditioning situations (e.g., Catania, 1966 Catania, 1963). A COD is some specified delay between a switch from one key and the next available reinforcement on the other key.…”

Parafoveal vision impairments and their influence on reading performance and self-evaluated reading abilities

“…This remarkable result can be explained by attentional influences. First, stimuli can be missed even though the eyes are focused on the corresponding target location [12,22]. More important, diminished alertness may have caused slower fixation shifts (back to the fixation point when the patient noticed the deviation) as well as larger variations of gaze positions.…”

“…Supposing that vision-related QoL is multidimensional, the NEI-VFQ consists of 39 rating items in 12 subscales: (1) general health (two items); (2) general vision (two items); (3) ocular pain (two items); (4) difficulties with near-vision activities (six items); (5) difficulties with distance vision activities (six items); (6) limitations in social functioning due to vision (three items); (7) mental health symptoms due to vision problems (five items); (8) role difficulties due to vision problems (four items); (9) dependency on others due to vision problems (four items); (10) driving problems (three items); (11) color vision problems (one item) and (12) peripheral vision problems (one item). By averaging the vision-related dimensions except general health, a composite score was generated that ranges from 0 ("worst possible functioning") to 100 ("best possible functioning").…”

Clinical Assessment of Complex Visual Dysfunction

“…Bálint's patients' visual fields were easily fatigable, resembling a pathological enhancement of the effects of fatigue noted with prolonged monitoring of visual displays by normal observers performing in experiments of vigilance or sustained attention. [142][143][144] The patient failed to detect objects in the periphery, more so on the left, due to constriction of the attention field, as in the hemineglect syndrome.…”