Adaptation effects and reversible figures: a comment on Horlitz and O'Leary

Horlitz and O'Leary have provided further evidence for the important role of such top-down processes as attention and familiarity on reported reversals of ambiguous figures. As such, these results are consistent with the claims of several other investigators who have argued that any theory of phenomenal reversal that is based solely on passive neural processes is likely to be incomplete. However, Horlitz and O'Leary make the additional claims (1) that the several reports of adaptation effects in the literature are readily reinterpreted within an information-access framework and (2) that their own empirical work demonstrates a basic failure of neural-adaptation effects with reversible figures. It is proposed here that these claims must be viewed with caution. First, Horlitz and O'Leary's explanation for the discrepancy of their results from those of ostensibly similar experimental procedures in the reversible-figure literature is not the only, or the most likely, possibility. A plausible alternative model that posits critical procedural differences (specifically, duration of adaptation) across studies has been offered, and supporting empirical work for this latter suggestion has been presented. Second, the empirical efforts of Horlitz and O'Leary, while providing further evidence for top-down processes, do not eliminate the likely role of adaptation effects with reversible figures. There is strong reason to believe that the viewing conditions selected by these researchers may not have been sufficient to produce appreciable adaptation. Moreover, there is excellent reason to believe that both bottom-up and top-down processes moderate reported reversals of these figures.(ABSTRACT TRUNCATED AT 250 WORDS)