John R. Binford

Variation in performance on auditory and visual monitoring tasks as a function of signal and stimulus frequencies

Observers were required to detect double jumps of a diffuse light spot jumping in a circular pattern and more intense noise pulses in a pulse train. Seven groups performed at different combinations of stimulus and signal frequencies, higher signal frequency/stimulus frequency ratios, and lower stimulus frequencies. Stimulus frequency was a more potent determiner of performance than signal frequency, and performance was not invariant within a given signal frequency/stimulus frequency ratio. Correlations of dependent measures were also examined.-Results are discussed with reference to various theories of vigilance behavior.

VIGILANCE FOR AUDITORY INTENSITY CHANGES AS A FUNCTION OF PRELIMINARY FEEDBACK AND CONFIDENCE LEVEL.

Forty-eight subjects were asked to respond to occasional increments in a pulse train with ratings of certainty of signal occurrence for 20 min. Half (F) subjects were given feedback; half (NF) were not. In a second session all responded during an 80 min period with a simple response. In another, half responded with certainty ratings; half responded with a simple response. Finally, those who had responded with ratings responded simply and those who had employed a simple response made ratings. It was found that F subjects made fewer false responses and tended to make fewer detections in earlier sessions. In later sessions false responses were reduced for all. The usual progressive false response and detection reductions and latency increases were noted; when subjects employed ratings reductions in certainty were noted within sessions. It was concluded that the data support the detection theory model for vigilance for this type of task.

Some Factors Influencing the Effective Auditory Intensive Difference Limen

Observers were required to detect changes in intensity in signals of two types: (1) a continuous Gaussian noise to which increments were added randomly and infrequently; (2) a sequence of pulses, 0.5‐sec duration occurring periodically at 2.5‐sec intervals to which increments were added infrequently and randomly. For each of the types of task, several levels of discrimination difficulty were employed. It was found that the changes in intensity of the steady noise were more readily detected than comparable changes in intensity of pulses. At intermediate difficulty levels, the number of detections of increases in the steady signal declined with time on task; and, at intermediate and high difficulty levels, the number of detections of louder pulses declined with time. Progressive increases in response latency were also noted in some of these conditions, and there was a general tendency for false detections to decline with time on task. Possible explanations for the differential discriminations of changes in ...

Nonstationarity in paired-associate learning as indicated by a second guess procedure

Abstract Recent models for simple learning based on an all-or-none concept of the learning process have received extensive experimental support. Analyses of the results of tests of such models have centered upon stationarity considerations, and analyses of behavior prior to the last error have, under some circumstances, supported the stationarity implied by such models. In the following study a second guess method was employed in which subjects were asked, whenever they made an erroneous response, to make a second choice; under these conditions a simple all-or-none model implies stationarity. The results of the study are not consistent with a simple all-or-none model and alternative models are suggested which may go further in accounting for the results obtained.

MONITORING READILY DETECTED AUDITORY SIGNALS AND DETECTION OF OBSCURE VISUAL SIGNALS.

Twenty-four Ss were required to detect infrequently and randomly occurring visual and auditory signals under six different schedules. In four of the sessions there were 40 visual signals and, respectively, 0, 20, 40, or 80 auditory signals. In two sessions there were 20 visual signals and 20 or 60 auditory signals. Auditory signals (increments in a steady noise background) were relatively easy to detect; visual signals (double jumps of a moving clock hand) were relatively difficult to detect. Missed detections of visual signals increased with time on task for each condition. Latency of response to visual signals increased progressively for all conditions except the one with no auditory signals (control condition). Latency was least for this control condition but decreased monotonically with number of auditory signals in other conditions. Visual missed responses were intermediate in frequency for the control conditions and apparently decreased monotonically as a function of the ratio of auditory to visual signals in the other conditions. Latency was higher for conditions with more visual signals, but no such simple relationship is apparent for missed detections.

Repetition and associative learning

A modification of the Rock type experiment was executed with the expectation that the modifications would produce results at odds with those obtained by Rock. Controls for item selection effects were introduced, and Ss were not discarded for failure to meet criterion. Somewhat different methods of data analysis indicate that Ss learn less rapidly with error replacement (the Rock procedure) than do Ss learning under normal conditions, i.e., with repetition.