VISUAL-MOTION SENSATION YIELDED BY NON-VISUALLY DRIVEN ATTENTION

When a visual stimulus (the ''cue'') is presented and followed by a li ne, the line is perceived to grow rapidly from the cued side even when it is presented physically simultaneously (the ''line-motion effect'' ), We now report that the same line motion can be observed when the cu e is presented in a non-visual modality, such as auditory or somatosen sory. A beep sound was presented either from the left or the right spe aker as an auditory cue, or an electric pulse was applied to a finger put on the left or the right side of a CRT display as a somatosensory cue, A line probe was then presented between the two possible cue posi tions, Both the auditory and the somatosensory cues led to line motion , thus the line motion could not be interpreted as a variation of with in-modality effects, such as visual apparent motion, When the cue lead time was manipulated, the obtained time courses of the effects were s imilar across the three cue modalities (Experiment 1), The minor diffe rences could be explained simply in Germs of latency of detection, acc ording to results of another experiment (Experiment 2), Finally, the l ine-motion task was compared with a task of temporal order judgment, w here two targets were presented simultaneously at the cued and the unc ued sides, and the subject was asked to judge which of the targets had appeared first, As a result, similar dependencies on cue lead time we re obtained between the two tasks within subjects (Experiment 3), Thus , the non-visual cue seems to facilitate ''prior entry'' of a visual s timulus nearby in the spatial representation, much the same way as a v isual cue does. These effects should be attributed to modality non-spe cific spatial attention, i,e,, a ''gradient'' of information processin g efficiency across various locations. (C) 1997 Elsevier Science Ltd.