Biomedical subjects
Publications and source records attributed to L S Cohene.
Holding and Orenstein (1984) purport to have demonstrated evidence that is contrary to a theory of iconic memory; however, the conclusions of these authors are called into question for methodological reasons.
Pairs of complementary dot-pattern stimuli whereby each stimulus pair forms a bigram were used in an iconic memory paradigm. The variables of stimulus duration, interstimulus interval, dot density, and letter field were all shown to affect recognition performance of 15 naive college students.
The study examined visual recognition of bigrams, each formed from a pair of "random" dot patterns, as a function of stimulus offset asynchrony and duration. The results replicate and extend those of an earlier study by showing that the effect of backward masking in vision, where the mask is actually a part of the preceding composite target, is limited to about 250 to 300 msec. This time interval is suggested as that required to complete the processing of that composite target. The results may be understood in terms of an interruption hypothesis, with selective attention and/or discontinuity detectors as mechanisms possibly involved in the masking process.