物體為基注意力：辨認作業中的物體內優勢與感覺增強

Object-Based Attention: A Within-Object Benefit and Sensory Enhancement in Discrimination Tasks

過去研究發現，偵測位在相同物體上的目標，比偵測相同距離但位在不同物體的目標，來得快速，顯示了物體效應。本研究探討辨認作業中所觀察到的物體效應是否是物體內優勢或者物體間代價。實驗一採用Egly、Driver及Rafal（1994）的線索典範，並加入無物體基準線，來探討此問題。知覺負荷亦被操弄，亦即低負荷的顏色辨認作業，以及高負荷的顏色／形狀結合辨認作業。實驗結果支持物體內優勢。本研究進一步探討，是否此物體內優勢是感覺增強，還是注意優先所產生。實驗二採用資料有限正確率之方法來測量表徵的品質。結果顯示在低負荷時，注意力以類似的方式分布在有注意到與沒注意到的物體。但在高負荷時，注意力主要分布在注意到的物體，支持感覺增強。本研究之重要意涵也在文中討論。

Object-based attention (OBA) will result if a target appearing at an invalid location on the same object is detected more quickly than a target at an equidistant location on a different object. The current study first asked whether the object effect obtained in the discrimination task was a result of within-object benefit or between-object cost. To answer this, Experiment 1 added an object-absent baseline to the cuing paradigm of Egly, Driver, and Rafal (1994). Perceptual load was manipulated, in which the low-load color and the high-load color/shape conjunction discrimination tasks were adopted. Results favored the within-object benefit hypothesis. The current study further asked whether this within-object benefit was a result of sensory enhancement or attentional prioritization. Experiment 2 adopted the data-limited accuracy measure in order to examine the strength of object representation. In the low-load condition, attention was distributed in a similar manner on the attended and unattended objects. In the high-load condition, attention was allocated within the attended object, favoring the sensory enhancement. The implications of current results are discussed.