| 摘要: | 摘 要 在心理學的研究中已經有許多的實驗支持突現刺激( abrupt onset ) 可以快速且自動的吸引我們的注意力 ( Jonides, 1981; Yantis, 1984; Muller & Rabbitt, 1989 )。Theeuwes等人(1998,1999)更發現，突現刺激的出現不只可以吸引注意力更會吸引我們的眼睛直接轉移過去。注意力和眼球運動間的關係一直以來都被研究者們所關心。在過去的文獻中對於兩者間的關係主要有兩派不同的論點，一派是認為注意力和眼球運動間有密切的連結關係，伴隨有眼動的情形下可以增加對於目標物的辨識程度( Kowler et al., 1995；Hoffman & Subramanian, 1995；)；以及Sheliga, Riggio and Rizzolatti, (1987,1994,1995)所提出的注意力前運動理論(premotor theory of attention)認為注意力和眼動系統同屬於一個神經機制，注意力的存在是為隨後所要執行的眼動做準備。另一派則認為注意力和眼動系統彼此間是可以分開獨立運作的（Posner, 1980; Posner and Dehaene, 1994; Hunt and Kingstone, 2003）。因此，本論文即是利用突現刺激可以同時吸引注意力和眼球運動的特性，來探查注意力和眼動間的關係。實驗中更操弄突現刺激在不同的時間點出現（SOA: 0,100,200,300ms），藉此觀察注意力和眼動系統間在時間向度上分離的可能性。 實驗結果發現，隨著突現刺激出現時間的早或晚，對於眼球運動有不同的影響效果。當突現刺激出現的時間較早時（SOA= 0,100ms），影響的可能是視知覺處理階段，使得眼動潛伏時間延長；而當突現刺激出現的時間較晚時（SOA= 200,300ms），影響的是可能是動作反應的階段，使得眼動軌跡彎曲度變大、眼球運動落點不準確。隨著突現刺激出現時間點的不同，會對注意力選擇和眼動系統產生兩種不同且互相獨立的干擾效果。因此我們認為視覺注意力和眼球運動系統彼此間在時間向度上是可以分離的。Abstract It is well-known that an abrupt onset distracter can capture attention and eye movements automatically (Theeuwes et al. 1998). A long-standing debate in the attentional research is the relationship between covert attention and saccadic eye movements. The premotor theory of attention proposes that visual attention and saccade programming are closely interlinked (Sheliga et al. 1995). However, Juan et al. (2004) recently challenged this prevailed theory by showing that the allocation of visual attention can be dissociated with saccade programming in time. In this study, following the same logic of Juan et al., the onset time of the abrupt onset in a visual search task is manipulated attempting to probe the functional dissociability of the oculomotor and the attentional systems in human. The data revealed that the effect on the saccade latency and that on the saccade execution (e.g. curvature, saccade endpoints.) seem to have independent temporal function of the onset time of the AO. In the earlier AO onset time points (SOA: 0,100ms), within the pro-saccade paradigm, the AO can delay saccade latency (F（1,9）=25.224, P<0.01), but cannot influence the saccade curvature (F（1, 9）=0.066, P=0.803 >0.05). In contrast, when an AO was presented in the later time points (SOA: 200, 300 ms), the trajectories of saccades curve away from the abrupt onset location but the saccade latencies were not affected (F（1,9）=2.566, P>0.05). Our data indicate that the saccade latency and the curvature are both affected by the presence of abrupt onset. But there is a little difference in the AO time function. In the early time (SOA= 0,100ms), the abrupt onset of colored-singleton can delay saccade latency but don’t affect the saccade curvature. When a color-singleton abrupt onset presented in the latter time (SOA= 200,300ms), the trajectories of saccades curve away from the abrupt onset location. We dissociate the attetntional selection and the saccade generation. The pattern of the result may indicate that visual attention (measured by the saccade latency) and saccade execution (measured by the saccade curvature) can be dissociated in a temporal domain. |
