Department of Psychology, Georgia Institute of Technology, Atlanta, GA 30318
Department of Psychology, Georgia Institute of Technology, Atlanta, GA 30318.
eNeuro. 2021 Jan 28;8(1). doi: 10.1523/ENEURO.0387-20.2020. Print 2021 Jan-Feb.
Episodic memories are multidimensional, including simple and complex features. How we successful encode and recover these features in time, whether these temporal dynamics are preserved across age, even under conditions of reduced memory performance, and the role of attention on these temporal dynamics is unknown. In the current study, we applied time-resolved multivariate decoding to oscillatory electroencephalography (EEG) in an adult lifespan sample to investigate the temporal order of successful encoding and recognition of simple and complex perceptual context features. At encoding, participants studied pictures of black and white objects presented with both color (low-level/simple) and scene (high-level/complex) context features and subsequently made context memory decisions for both features. Attentional demands were manipulated by having participants attend to the relationship between the object and either the color or scene while ignoring the other context feature. Consistent with hierarchical visual perception models, simple visual features (color) were successfully encoded earlier than were complex features (scenes). These features were successfully recognized in the reverse temporal order. Importantly, these temporal dynamics were both dependent on whether these context features were in the focus of one's attention, and preserved across age, despite age-related context memory impairments. These novel results support the idea that episodic memories are encoded and retrieved successively, likely dependent on the input and output pathways of the medial temporal lobe (MTL), and attentional influences that bias activity within these pathways across age.
情景记忆是多维的，包括简单和复杂的特征。我们如何成功地在时间内对这些特征进行编码和恢复，这些时间动态是否在跨年龄、甚至在记忆表现下降的情况下得到保留，以及注意力对这些时间动态的作用是未知的。在当前的研究中，我们应用时分辨解码对成年人的全生命周期样本中的脑电（EEG）进行了研究，以调查简单和复杂感知情景特征的成功编码和识别的时间顺序。在编码时，参与者研究了呈现颜色（低水平/简单）和场景（高水平/复杂）上下文特征的黑白物体的图片，然后对两种特征都进行了上下文记忆决策。通过让参与者关注对象与颜色或场景之间的关系，同时忽略其他上下文特征，来操纵注意力需求。与分层视觉感知模型一致，简单的视觉特征（颜色）比复杂特征（场景）更早成功编码。这些特征以相反的时间顺序被成功识别。重要的是，这些时间动态既取决于这些上下文特征是否是注意力的焦点，又取决于跨年龄的保留，尽管与年龄相关的上下文记忆损伤。这些新的结果支持了这样一种观点，即情景记忆是依次进行编码和检索的，可能取决于内侧颞叶（MTL）的输入和输出途径，以及注意力对这些途径内活动的偏向作用，这些作用在跨年龄过程中得到了保留。
