1.The Assessment of Eyewitness Memory Using Electroencephalogram: Application of Machine Learning Algorithm
Keunsoo HAM ; Ki Pyeong KIM ; Hojin JEONG ; Seong Ho YOO
Korean Journal of Legal Medicine 2018;42(2):62-70
This study was conducted to investigate whether memory accuracy can be assessed by analyzing electrophysiological responses (i.e., electroencephalography [EEG]) for retrieval cues related to the witnessed scene. Specifically, we examined the different patterns of EEG signals recorded during witnessed (target) and unwitnessed (lure) stimuli using event-related potential (ERP) analysis. Moreover, using multivariate pattern analysis, we also assessed how accurately single-trial EEG signals can classify target and lure stimuli. Participants watched a staged-crime video (theft crime), and the EEG signals evoked by the objects shown in the video were analyzed (n=56). Compared to the target stimulus, the lure stimulus elicited larger negative ERPs in frontal brain regions 300 to 500 milliseconds after the retrieval cue was presented. Furthermore, the EEG signals observed 450 to 500 milliseconds after the retrieval cue was presented showed the best classification performance related to eyewitness memory, with the mean classification accuracy being 56%. These results suggest that the knowledge and techniques of cognitive neuroscience can be used to estimate eyewitness memory accuracy.
Brain
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Classification
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Cognitive Neuroscience
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Cues
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Electroencephalography
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Evoked Potentials
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Machine Learning
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Memory
2.Increased Ventrolateral Prefrontal Cortex Activation during Accurate Eyewitness Memory Retrieval: An Exploratory Functional Near-Infrared Spectroscopy Study
Keunsoo HAM ; Ki Pyoung KIM ; Hojin JEONG ; Seong Ho YOO
Korean Journal of Legal Medicine 2018;42(4):146-152
We investigated the neural correlates of accurate eyewitness memory retrieval using functional near-infrared spectroscopy. We analyzed oxygenated hemoglobin (HbO₂) concentration in the prefrontal cortex during eyewitness memory retrieval task and examined regional HbO₂ differences between observed objects (target) and unobserved objects (lure). We found that target objects elicited increased activation in the bilateral ventrolateral prefrontal cortex, which is known for monitoring retrieval processing via bottom-up attentional processing. Our results suggest bottom-up attentional mechanisms could be different during accurate eyewitness memory retrieval. These findings indicate that investigating retrieval mechanisms using functional nearinfrared spectroscopy might be useful for establishing an accurate eyewitness recognition model.
Cognitive Neuroscience
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Memory
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Oxygen
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Prefrontal Cortex
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Spectroscopy, Near-Infrared
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Spectrum Analysis