Effect of hypnotic age regression on the magnitude of the Ponzo illusion: A replication.

Abstract

A 1969 study by Parrish, Lundy, and Leibowitz which investigated the effect of hypnotic age regression on the magnitude of the Ponzo and Poggendorff illusions was partially replicated. In the present study, the Ponzo illusion was presented to eight college students under three conditions (waking, regressed to age 9, and regressed to age 5). Results indicated no significant difference in the magnitude of the illusion across the three conditions. These findings were in contradiction to those cited by Parrish et al., whose age-regressed 5s responded to the illusion in a manner typical of young children. It was concluded that hypnotic age regression does not affect the magnitude of the Ponzo illusion, and it was suggested that age regression is a questionable tool for investigating developmental aspects of perception.

What, if anything, is regressed about hypnotic age regression? A review of the empirical literature.

“…Task-motivated control subjects were not able to match this performance. Four subsequent attempts have failed, however, to replicate these findings; in these four studies, regressed subjects' performance on the Ponzo illusion conformed to a familiar pattern-different from children and similar to motivated control subjects (Asher, Barber, & Spanos, 1972;Perry & Chisholm, 1973;Porter, Woodward. Bisbee, & Fenker, 1972).…”

“…Another tack pursued by recent investigators has been to probe the perceptual processes of hypnotically age-regressed subjects to determine whether there is a return of childlike perceptual faculties. The first important study in this tradition (Parrish et al, 1969) (Asher, Barber, & Spanos, 1972;Perry & Chisholm, 1973;Porter, Woodward. Bisbee, & Fenker, 1972).…”

Hypnotically induced limb anesthesia and adaptation to displacing prisms: A failure to confirm.

“…Dramatic findings are reported periodically in the hypnosis literature, but, unfortunately, they often prove difficult to confirm in independent laboratories. (For instances of such replication failure, see Ascher, Barber, & Spanos, 1972;Porter, Woodward, Bisbee, & Fenker, 1972;Spanos, Ansari, & Stam, 1979;Stam, Radtke-Bodorik, & Spanos, 1980). Attempts to confirm are particularly important when the dramatic results appear to run counter to most of the available evidence.…”