Automatic focusing of attention on object size and shape

Résumé 0

"In two experiments we investigated the automatic adjusting of theattentional focus to simple geometric shapes. The participants performed avisual search task with four stimuli (the target and three distractors)presented always around the fixation point, inside an outlined frame notrelated to the search task. A cue informed the subject only about thepossible size and shape of the frame, not about the target. The results of thefirst experiment showed faster target detection in the valid cue trials,suggesting that attention was captured automatically by the cue shape. In thesecond experiment, we introduced a flanker stimulus (compatible orincompatible with the target) in order to determine if attentional resourcesspread homogenously inside and outside the frame. The results showed thatperformance depended both on cue validity and frame orientation. The flankereffect was dependent on compatibility and flanker position (vertical orhorizontal meridian). The results of both experiments suggest that the formof an irrelevant object can capture attention despite participants’ intentionand the results of the second experiment suggest that the attentionalresources are more concentrated along the horizontal meridian."