Memory Deficit in Patients With Temporal Lobe Epilepsy: Evidence From Eye Tracking Technology

Abstract

Objective: To explore quantitative measurements of the visual attention and neuroelectrophysiological relevance of memory deficits in temporal lobe epilepsy (TLE) by eye tracking and electroencephalography (EEG).Methods: Thirty-four TLE patients and twenty-eight healthy controls were invited to complete neurobehavioral assessments, cognitive oculomotor tasks, and 24-h video EEG (VEEG) recordings using an automated computer-based memory assessment platform with an eye tracker. Visit counts, visit time, and time of first fixation on areas of interest (AOIs) were recorded and analyzed in combination with interictal epileptic discharge (IED) characteristics from the bilateral temporal lobes.Results: The TLE patients had significantly worse Wechsler Digit Span scores [F(1, 58) = 7.49, p = 0.008]. In the Short-Term Memory Game with eye tracking, TLE patients took a longer time to find the memorized items [F(1, 57) = 17.30, p < 0.001]. They had longer first fixation [F(1, 57) = 4.06, p = 0.049] and more visit counts [F(1, 57) = 7.58, p = 0.008] on the target during the recall. Furthermore, the performance of the patients in the Digit Span task was negatively correlated with the total number of IEDs [r(28) = −0.463, p = 0.013] and the number of spikes per sleep cycle [r(28) = −0.420, p = 0.026].Conclusion: Eye tracking appears to be a quantitative, objective measure of memory evaluation, demonstrating memory retrieval deficits but preserved visual attention in TLE patients. Nocturnal temporal lobe IEDs are closely associated with memory performance, which might be the electrophysiological mechanism for memory impairment in TLE.

Memory characteristics in mesial temporal lobe epilepsy: Insights from an eye tracking memory game and neuropsychological assessments

“…The automated computer-based memory assessment platform was adapted from Li et al as reported in our previous study, 24 The subjects were asked to acknowledge the memory target(s) by clicking a mouse. They were prompted for a response and after their response was recorded, feedback was provided and they clicked the left mouse button to continue to the next trial.…”

Recognition memory deficits detected through eye‐tracking in well‐controlled children with self‐limited epilepsy with centrotemporal spikes

“…[21][22][23] Based on these, we can unfold the pattern of memory encoding and recognition, and elucidate the underlying mechanism of memory deficits in the diseases. 22,24 The visual paired comparison (VPC) task has been validated as a widely scalable discriminant digital cognitive assessment, especially in recognition memory. 20,25 In this task, subjects are familiarized with two identical images followed by the presentation of the familiar image coupled with a novel one.…”

“…Memory has been shown to guide eye movements, which might enhance the efficiency of visual exploration by directing attention toward informative regions 21–23 . Based on these, we can unfold the pattern of memory encoding and recognition, and elucidate the underlying mechanism of memory deficits in the diseases 22,24 . The visual paired comparison (VPC) task has been validated as a widely scalable discriminant digital cognitive assessment, especially in recognition memory 20,25 .…”

Interictal discharges delay target‐directed eye movements and impair attentional set‐shifting in children with epilepsy

“…19,23 Eye movements are closely associated with attentional behavior in the normative state [24][25][26] and demonstrate marked abnormalities in people with epilepsy. [27][28][29][30][31] The strong associations between eye movements and attentional behavior provide a compelling rationale to apply eye tracking as an adjunct in the neuropsychological assessment of children with epilepsy. 31,32 Furthermore, because eye movements can be tracked on a moment-to-moment basis, they may inform understanding of ephemeral processes, such as TCI.…”

“…Eye movements are closely associated with attentional behavior in the normative state 24–26 and demonstrate marked abnormalities in people with epilepsy 27–31 . The strong associations between eye movements and attentional behavior provide a compelling rationale to apply eye tracking as an adjunct in the neuropsychological assessment of children with epilepsy 31,32 .…”