Effect of external target presence on visual adaptation with active and passive movement.

Acceleration information for prism adaptation need not be reafferent: A comment on McCarter and Mikaelian (1978)

“…In obtaining the present data, both active and passive movement were used with a confined-movement exposure condition. It was expected that both movement procedures would be effective in producing aftereffects as they had been in Melamed et al (1973). The contention here is that the importance of informational feedback from acceleration is not in its potential usage as reafference, as McCarter and Mikaelian indicate, but, rather, that a manipulation designed to keep movement confined to the visual field serves two interdependent purposes.…”

“…It always can be argued, however, that it is the attentional requirements of active movement that distinguishes it from passive movement (Melamed, Halay, & Gildow, 1973). Active movement in the Held paradigm necessitates focusing attention on both visual and proprioceptive information concerning momentary arm position.…”

“…Secondly, the decelerating, stopping, and renewed accelerating at the end of each excursion provide an enhanced opportunity for the subject to detect differences between the visual and proprioceptive location of the limb. The manner in which the subject's hand was confined to the field of view in the following procedure was designed to emphasize the subject's need to attend to arm location in much the same manner as the number calling task operated in Melamed et al (1973).…”

Components of displacement adaptation in acquisition and decay as a function of hand and hall exposure

“…The subjects were instructed not to look at their hands or feet, and the narrow field of view (approximately 20°) virtually precluded sight of any part of the body. During hand exposure, subjects watched one of their hands, with a slide attached to forefinger and mounted on a track in a Held and Gottlieb (1958) type of apparatus (illustrated in Melamed, Halay, & Gildow, 1973), while they moved the arm in a lateral motion within the visual field. A metronome timed this back-and-forth slide movement, each cycle requiring 6.0 sec for completion.…”

Further evidence for dissociating decay and readaptation in prism adaptation

“…The procedure yielded the same results as were obtained for the active readaptation group in the present experiment (i.e., no reduction in aftereffects from the first to the second posttest periods). The data for the active readaptation group in the present study perhaps further emphasize and expand on the issue of the attentional requirements of the various adaptation-induction procedures previously DISSOCIATING DECAYAND READAPTATION 75 raised by Melamed, Halay, and Gildow (1973) and Melamed, Wallace, and Seyfried (1979). Both Melamed et al (1973) and Melamed, Wallace, and Seyfried (1979) showed that manipulations that increase the likelihood of the subjects' attending to arm location in a Held-type adaptation procedure increase the magnitude of adaptation observed.…”