Abstract
In general, a stimulus to which an organism responds has several aspects. If the organism's behavior would be changed by independent variation or elimination of only one aspect of the stimulus, it is possible to say that the organism attends to that aspect. This controlling relation between a response and a particular aspect of stimulus is called “attention” [cf. SKINNER (6)]. All of those aspects in the stimulus, however, does not necesarily control the organism equally.
Many experimental studies on attention in discrimination learning have been reported. In almost all of them, method of research is to divide the stimulus with some aspects into several physical parameters and to vary each of them independently. But it is supposed that the stimulus brings about different control over the behavior, depending on whether a simple stimulus (in which only a single aspect is included) or a compound stimulus (in which two aspects are included) is presented.
In the present experiment, differences between these two stimulus situations (simple stimulus situation and compound stimulus situation) are studied on the same subjects.
Pigeons were trained to respond to a stimulus that contains two aspects in itself and were tested on attention in extinction trials. In the experiment of REYNOLDS, one single aspect became a cue to discriminate the stimulus. In the present experiment, however, it was found that both of two aspects worked effectively and the irrelevant cue also had a noticeable effect.
