Perception and the Experimental Arousal of the Symbolic Processes
The most direct method for arousing representational processes that would be congruent with subsequent perceptual input is the repeated presenta-
tion of the same stimulus. This is involved in the traditional procedure for determining visual recognition thresholds by the method of limits, but repetition and exposure duration are confounded in such studies. Haber (1966, 1967) discussed several studies in which he and his associates presented the same stimulus repeatedly at the same tachistoscopic exposure speed for a given group of subjects. Subjects were asked to report only letters that they recognized clearly, rather than total words, a procedure that Haber views as a superior index of perception as phenomenal experience because it is less affected by guessing strategies than is the method of reporting whole words. The results of these studies indicated that the clarity of letters increased markedly over repeated presentations, even when few or none of the letters could be seen on the initial exposure, demonstrating the "growth" of a percept as a function of repetition.