Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Department of Psychology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
J Clin Exp Neuropsychol. 2022 Apr;44(3):210-225. doi: 10.1080/13803395.2022.2101620. Epub 2022 Jul 25.
Temporal order memory is a core cognitive function that underlies much of our behavior. The ability to bind together information within and across events, and to reconstruct that sequence of information, critically relies upon the hippocampal relational memory system. Recent work has suggested traumatic brain injury (TBI) may particularly impact hippocampally mediated relational memory. However, it is currently unclear whether such deficits extend to temporal order memory, and whether deficits only arise at large memory loads. The present study assessed temporal order memory in individuals with chronic, moderate-severe TBI across multiple set sizes.
Individuals with TBI and Neurotypical Comparison participants studied sequences of three to nine objects, one a time. At test, all items were re-presented in pseudorandom order, and participants indicated the temporal position (i.e., first, second, etc.) in which each object had appeared. Critically, we assessed both the frequency and the magnitude of errors (i.e., how far from its studied position was an item remembered).
Individuals with TBI were not impaired for the smallest set size, but showed significant impairments at 5+ items. Group differences in the error frequency did not increase further with larger set sizes, but group differences in error magnitude did increase with larger memory loads. Individuals with TBI showed spared performance for the first object of each list (primacy) but were impaired on the last object (recency), though error frequency was better for last compared to middle items.
Our findings demonstrate that TBI results in impaired temporal order memory for lists as small as five items, and that impairments are exacerbated with increasing memory loads. Assessments that test only small set sizes may be insufficient to detect these deficits. Further, these data highlight the importance of additional, sensitive measures in the assessment of cognitive impairments in TBI.
时间顺序记忆是一种核心认知功能，它构成了我们行为的基础。将信息在事件内和跨事件结合起来，并重建该信息序列的能力，严重依赖于海马体关系记忆系统。最近的研究表明，创伤性脑损伤（TBI）可能特别影响海马介导的关系记忆。然而，目前尚不清楚这些缺陷是否会扩展到时间顺序记忆，以及是否只有在大的记忆负荷下才会出现缺陷。本研究评估了慢性、中重度 TBI 个体在多个集合大小下的时间顺序记忆。
TBI 个体和神经典型对照组参与者学习三到九个物体的序列，一个一个地学习。在测试中，所有项目以伪随机顺序重新呈现，参与者指出每个项目出现的时间位置（即第一、第二等）。重要的是，我们评估了错误的频率和幅度（即，一个项目被记住的位置与其学习位置相差多远）。
TBI 个体在最小集合大小上没有受损，但在 5 个以上的项目上表现出显著的受损。随着集合大小的增加，组间错误频率的差异没有进一步增加，但组间错误幅度的差异随着记忆负荷的增加而增加。TBI 个体对每个列表的第一个项目（首因）表现出良好的表现，但对最后一个项目（近因）表现出受损，尽管最后一个项目的错误频率比中间项目好。
我们的发现表明，TBI 导致列表的时间顺序记忆受损，即使列表只有五个项目，并且随着记忆负荷的增加，这些损伤会加剧。仅测试小集合大小的评估可能不足以检测到这些缺陷。此外，这些数据强调了在 TBI 认知障碍评估中使用额外、敏感的测量方法的重要性。
