Stimulus Intensity and Attention in Relation to Learning Theory

Three experiments are described which test the hypothesis that the more intense of two stimuli will, ceteris paribus, be more likely to receive attention. It is assumed that an objective behavioural manifestation of attention to a given stimulus is a preference for responding to it rather than to another which is present at the same time.

In all three experiments, successions of pairs of visual stimuli interspersed with single stimuli were presented to the subject, and he was instructed to respond to either (by pressing its corresponding morsekey), but not both, in the case of the pairs. The first two experiments reveal significant tendencies to respond to the larger and the brighter stimulus respectively. In the third experiment, there was a tendency, but a statistically insignificant one, to respond to a constant rather than to a flickering stimulus.

It is shown that the attraction of attention by a more intense stimulus follows from Hull's system with the addition of his new variable, “stimulus-intensity dynamism (V),” and it is suggested that it may thus be possible to add attention to the phenomena that can be integrated with an objective behaviour theory.