Codispoti Maurizio, Ferrari Vera, Junghöfer Markus, Schupp Harald T
Department of Psychology, University of Bologna, Italy.
Neuroimage. 2006 Aug 15;32(2):583-91. doi: 10.1016/j.neuroimage.2006.04.180. Epub 2006 Jun 5.
The present study examined cortical indicators of selective attention underlying categorization based on target features in natural scenes. The primary focus was to determine the neural sources associated with the processing of target stimuli containing animals compared to non-target control stimuli. Neural source estimation techniques [current source density (CSD) and L2-minimum norm estimate (L2-MNE)] were used to determine the sources of the potential fields measured from 58 sensor sites. Assuring an excellent signal-to-noise ratio, the categorization task consisted of 2400 trials. Replicating previous findings, target and non-target ERP activity diverged sharply around 150 ms after stimulus onset and the early differential ERP activity appeared as positive deflection over fronto-central sensor sites and as negative deflection over temporo-occipital regions. Both source estimation techniques (CSD and L2-MNE) suggested primary sources of the early differential ERP activity in posterior, visual-associative brain regions and, although less pronounced, revealed the contribution of additional anterior sources. These findings suggest that selective attention to category-relevant features reflects the interactions between prefrontal and inferior temporal cortex during visual processing of natural scenes.
本研究考察了基于自然场景中目标特征进行分类时选择性注意的皮层指标。主要重点是确定与包含动物的目标刺激处理相关的神经源，并与非目标对照刺激进行比较。使用神经源估计技术[电流源密度（CSD）和L2最小范数估计（L2-MNE）]来确定从58个传感器位点测量的电位场的来源。为确保良好的信噪比，分类任务包括2400次试验。重复先前的研究结果，目标和非目标ERP活动在刺激开始后约150毫秒左右急剧分离，早期差异ERP活动在额中央传感器位点表现为正偏转，在颞枕区域表现为负偏转。两种源估计技术（CSD和L2-MNE）均表明早期差异ERP活动的主要来源位于后部视觉联合脑区，并且虽然不太明显，但也揭示了额外前部来源的贡献。这些发现表明，对类别相关特征的选择性注意反映了自然场景视觉处理过程中前额叶和颞下回之间的相互作用。
