Thakral Preston P, Slotnick Scott D
Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX 75235, United States.
Department of Psychology, Boston College, United States.
Behav Brain Res. 2015 Sep 1;290:143-51. doi: 10.1016/j.bbr.2015.04.045. Epub 2015 May 5.
Previous event-related potential (ERP) findings have suggested that during visual item and source memory, nonconscious and conscious sensory (occipital-temporal) activity onsets may be restricted to early (0-800 ms) and late (800-1600 ms) temporal epochs, respectively. In an ERP experiment, we tested this hypothesis by separately assessing whether the onset of conscious sensory activity was restricted to the late epoch during source (location) memory and item (shape) memory. We found that conscious sensory activity had a late (>800 ms) onset during source memory and an early (<200 ms) onset during item memory. In a follow-up fMRI experiment, conscious sensory activity was localized to BA17, BA18, and BA19. Of primary importance, the distinct source memory and item memory ERP onsets contradict the hypothesis that there is a fixed temporal boundary separating nonconscious and conscious processing during all forms of visual conscious retrieval.
先前的事件相关电位（ERP）研究结果表明，在视觉项目和来源记忆过程中，无意识和有意识的感觉（枕颞叶）活动起始可能分别局限于早期（0 - 800毫秒）和晚期（800 - 1600毫秒）时间段。在一项ERP实验中，我们通过分别评估在来源（位置）记忆和项目（形状）记忆过程中，有意识的感觉活动起始是否局限于晚期时间段来检验这一假设。我们发现，有意识的感觉活动在来源记忆过程中起始较晚（>800毫秒），而在项目记忆过程中起始较早（<200毫秒）。在后续的功能磁共振成像（fMRI）实验中，有意识的感觉活动定位在BA17、BA18和BA19区域。至关重要的是，来源记忆和项目记忆中ERP起始的差异与以下假设相矛盾：即在所有形式的视觉有意识检索过程中，存在一个固定的时间界限将无意识和有意识加工区分开来。
