Remarks on Colquhoun's: “ The Effect of ‘ unwanted ’ Signals on Performance in a Vigilance Task ”

Abstract

Colquhoun's 1961 experiment is interpreted as emphasizing the discrimination phase of a complex task in which the detection of a signal is followed by the discrimination of one of its features. His conclusion that signal probability determines vigilance performance is supported by research from this laboratory with a simple detection task. In our research the probability is redefined as the ratio of signals to attention-eliciting stimuli, and the latter stimuli must be presented at high rates (15 or more times per minute). His results with the complex task suggest an effect of signal probability on search and scanning patterns during prolonged visual work.