Gaze-cueing of attention distorts visual space

Résumé 0

"A briefly presented peripheral flash is often mislocalized with a bias toward an attended object. The target mislocalization has been ascribed to the integration of location signals between a target and an attended object, and this results in the mislocalization of the target toward the attended object. It was unclear whether external objects that attract observer’s attention were necessary to cause the target mislocalization. This study aimed at examining whether the target mislocalization occurred when the shift of observers’ attention was induced by gaze cueing, in which observer’s attention is shifted in the direction of other’s gaze. This cueing paradigm requires no external object to attract attention, thus it enabled us to directly examine the necessity of external objects in the target mislocalization. Stimuli consisted of a pictorial face, a target, and a probe. First, the pictorial face was presented, and its gaze was shifted so as to look at either upper-right or upper-left. The target was successively presented for 50 msec. After a temporal interval of 0 or 2000 msec was inserted as a retention interval, the probe was presented below the target. The observers’ task was to judge whether the target had appeared at the left or right side of the probe location. The target was significantly mislocalized in the direction of gaze shift only when the retention interval was 2000 msec. Moreover, reaction time for detecting a target was shorter at the gazed than non-gazed location. These results suggest that the mislocalization does not require external objects attracting attention. Neural signals of target location are possibly averaged with the attention-induced local change in neural signals, and this results in the target mislocalization toward the gazed location."