Machinskaia R I, Krupskaia E V, Kurganskaiĭ A V
Fiziol Cheloveka. 2010 Sep-Oct;36(5):29-48.
Adult subjects were asked to recognize a hierarchical visual stimulus (a letter) while their attention was drawn to either the global or local level of the stimulus. Event-related potentials (ERP) and psychophysical indices (reaction time and percentage of correct responses) were measured. An analysis of psychophysical indices showed the global level precedence effect, i.e., the increase in a small letter recognition time when this letter is a part of incongruent stimulus. An analysis of ERP components showed level-related (global vs. local) differences in the timing and topography of the brain organization of perceptual processing and regulatory mechanisms of attention. Visual recognition at the local level was accompanied by (1) stronger activation of the visual associative areas (Pz and T6) at the stage of sensory features analysis (P1 ERP component), (2) involvement mainly of inferior temporal cortices of the right hemisphere (T6) at the stage of sensory categorization (P2 ERP component), and (3) involvement of prefrontal cortex of the right hemisphere at the stage of the selection of the relevant features of the target (N2 ERP component). Visual recognition at the global level was accompanied by (1) pronounced involvement of mechanisms of early sensory selection (N1 ERP component), (2) prevailing activation of parietal cortex of the right hemisphere (P4) at the stage of sensory categorization (P2 ERP component) as well as at the stage of the target stimulus identification (P3 ERP component). It is suggested that perception at the global level of the hierarchical stimulus is related primarily to the analysis of the spatial features of the stimulus in the dorsal visual system whereas the perception at the local level primarily involves an analysis of the object-related features in the ventral visual system.
成年受试者被要求识别一种分层视觉刺激（一个字母），同时将他们的注意力吸引到刺激的整体或局部水平。测量了事件相关电位（ERP）和心理物理学指标（反应时间和正确反应百分比）。对心理物理学指标的分析显示了整体水平优先效应，即当这个小写字母是不一致刺激的一部分时，其识别时间增加。对ERP成分的分析显示，在感知处理和注意力调节机制的大脑组织的时间和地形方面存在与水平相关（整体与局部）的差异。局部水平的视觉识别伴随着：（1）在感觉特征分析阶段（P1 ERP成分）视觉联合区域（Pz和T6）更强的激活；（2）在感觉分类阶段（P2 ERP成分）主要涉及右半球的颞下回（T6）；（3）在选择目标相关特征阶段（N2 ERP成分）涉及右半球的前额叶皮层。整体水平的视觉识别伴随着：（1）早期感觉选择机制（N1 ERP成分）的显著参与；（2）在感觉分类阶段（P2 ERP成分）以及目标刺激识别阶段（P3 ERP成分）右半球顶叶皮层（P4）的主要激活。研究表明，分层刺激的整体水平感知主要与背侧视觉系统中刺激的空间特征分析有关，而局部水平的感知主要涉及腹侧视觉系统中与物体相关特征的分析。
