Elimination of visual field effects by use of a single report technique: Evidence for order-of-report artifact.

Abstract

When Ss are asked to recall verbal materials tachistoscopically presented simultaneously in both visual fields, recall is typically better for items in the left visual field. Some Es have interpreted this finding as indicating a perceptual mechanism that necessitates scanning the memory trace in a left-to-right order, with fading of the elements in the right field while those in the left are being scanned. An alternative explanation is that since Ss tend to report the items in a left-to-right order, there is fading of the memory trace for the right-hand elements during the relatively slow task of reporting the earlier items. To differentiate between the 2 theories, 25 right-handed 15-22 yr. old students reported only 1 item, as indicated by tactile vibration of 1 of their fingers immediately after presentation of the visual materials. Using this technique, no left-right field differences were found. Exp. II, with 6 right-handed undergraduates, examined the effect of varying the interval between presentation of items and occurrence of the signal indicating the letter to be recalled. Even with intervals of 2000 msec., no left-right differences were found. (17 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)