Interictal epileptiform discharges (IEDs) can impair memory. The properties of IEDs most detrimental to memory, however, are undefined. We studied the impact of temporal and spatial characteristics of IEDs on list learning. Subjects completed a memory task during intracranial EEG recordings including hippocampal depth and temporal neocortical subdural electrodes. Subjects viewed a series of objects, and after a distracting task, recalled the objects from the list. The impacts of IED presence, duration, and propagation to neocortex during encoding of individual stimuli were assessed. The effects of IED total number and duration during maintenance and recall periods on delayed recall performance were also determined. The influence of IEDs during recall was further investigated by comparing the likelihood of IEDs preceding correctly recalled items vs. periods of no verbal response. Across 6 subjects, we analyzed 28 hippocampal and 139 lateral temporal contacts. Recall performance was poor, with a median of 17.2% correct responses (range 10.4–21.9%). Interictal epileptiform discharges during encoding, maintenance, and recall did not significantly impact task performance, and there was no significant difference between the likelihood of IEDs during correct recall vs. periods of no response. No significant effects of discharge duration during encoding, maintenance, or recall were observed. Interictal epileptiform discharges with spread to lateral temporal cortex during encoding did not adversely impact recall. A post hoc analysis refining model assumptions indicated a negative impact of IED count during the maintenance period, but otherwise confirmed the above results. Our findings suggest no major effect of hippocampal IEDs on list learning, but study limitations, such as baseline hippocampal dysfunction, should be considered. The impact of IEDs during the maintenance period may be a focus of future research.

发作间期癫痫样放电 (IED) 会损害记忆力。然而，对记忆最有害的 IED 的特性是未定义的。我们研究了 IED 的时间和空间特征对列表学习的影响。受试者在颅内脑电图记录期间完成了一项记忆任务，包括海马深度和颞叶新皮质硬膜下电极。受试者观看了一系列物体，并在完成一项分散注意力的任务后，从列表中回忆起这些物体。评估了在编码单个刺激期间 IED 的存在、持续时间和对新皮质的传播的影响。还确定了维护和召回期间简易爆炸装置总数和持续时间对延迟召回性能的影响。通过比较 IED 在正确召回项目之前的可能性与 IED 在召回期间的影响，进一步研究了 IED 在召回期间的影响。没有口头回应的时期。在 6 名受试者中，我们分析了 28 个海马和 139 个横向颞叶接触。召回性能很差，正确响应的中位数为 17.2%（范围 10.4-21.9%）。编码、维持和回忆期间的发作间期癫痫样放电不会显着影响任务绩效，并且在正确回忆期间与无反应期间 IED 的可能性之间没有显着差异。在编码、维护或召回期间未观察到放电持续时间的显着影响。在编码期间扩散到外侧颞叶皮层的发作间期癫痫样放电不会对回忆产生不利影响。事后分析精炼模型假设表明 IED 计数在维护期间有负面影响，但在其他方面证实了上述结果。我们的研究结果表明海马 IED 对列表学习没有重大影响，但应考虑研究限制，例如基线海马功能障碍。简易爆炸装置在维修期间的影响可能是未来研究的重点。