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Episodic memory formation in unrestricted viewing

Nikolaev, Andrey LU orcid ; Bramao, Ines LU ; Johansson, Roger LU orcid and Johansson, Mikael LU orcid (2023) In NeuroImage 266.
Abstract
The brain systems of episodic memory and oculomotor control are tightly linked, suggesting a crucial role of eye movements in memory. But little is known about the neural mechanisms of memory formation across eye movements in unrestricted viewing behavior. Here, we leverage simultaneous eye tracking and EEG recording to examine episodic memory formation in free viewing. Participants memorized multi-element events while their EEG and eye movements were concurrently recorded. Each event comprised elements from three categories (face, object, place), with two exemplars from each category, in different locations on the screen. A subsequent associative memory test assessed participants’ memory for the between-category associations that... (More)
The brain systems of episodic memory and oculomotor control are tightly linked, suggesting a crucial role of eye movements in memory. But little is known about the neural mechanisms of memory formation across eye movements in unrestricted viewing behavior. Here, we leverage simultaneous eye tracking and EEG recording to examine episodic memory formation in free viewing. Participants memorized multi-element events while their EEG and eye movements were concurrently recorded. Each event comprised elements from three categories (face, object, place), with two exemplars from each category, in different locations on the screen. A subsequent associative memory test assessed participants’ memory for the between-category associations that specified each event. We used a deconvolution approach to overcome the problem of overlapping EEG responses to sequential saccades in free viewing. Brain activity was time-locked to the fixation onsets, and we examined EEG power in the theta and alpha frequency bands, the putative oscillatory correlates of episodic encoding mechanisms. Three modulations of fixation-related EEG predicted high subsequent memory performance: 1) theta increase at fixations after between-category gaze transitions, 2) theta and alpha increase at fixations after within-element gaze transitions, 3) alpha decrease at fixations after between-exemplar gaze transitions. Thus, event encoding with unrestricted viewing behavior was characterized by three neural mechanisms, manifested in fixation-locked theta and alpha EEG activity that rapidly turned on and off during the unfolding eye movement sequences. These three distinct neural mechanisms may be the essential building blocks that subserve the buildup of coherent episodic memories during unrestricted viewing behavior. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
NeuroImage
volume
266
article number
119821
publisher
Elsevier
external identifiers
  • scopus:85144468635
  • pmid:36535321
ISSN
1095-9572
DOI
10.1016/j.neuroimage.2022.119821
project
Learning and remembering: The cognitive neuroscience of memory for real-world events
language
English
LU publication?
yes
id
61ad4ea9-a04f-4790-8e4b-9f00b36287b4
date added to LUP
2022-12-19 10:11:14
date last changed
2023-03-21 03:00:19
@article{61ad4ea9-a04f-4790-8e4b-9f00b36287b4,
  abstract     = {{The brain systems of episodic memory and oculomotor control are tightly linked, suggesting a crucial role of eye movements in memory. But little is known about the neural mechanisms of memory formation across eye movements in unrestricted viewing behavior. Here, we leverage simultaneous eye tracking and EEG recording to examine episodic memory formation in free viewing. Participants memorized multi-element events while their EEG and eye movements were concurrently recorded. Each event comprised elements from three categories (face, object, place), with two exemplars from each category, in different locations on the screen. A subsequent associative memory test assessed participants’ memory for the between-category associations that specified each event. We used a deconvolution approach to overcome the problem of overlapping EEG responses to sequential saccades in free viewing. Brain activity was time-locked to the fixation onsets, and we examined EEG power in the theta and alpha frequency bands, the putative oscillatory correlates of episodic encoding mechanisms. Three modulations of fixation-related EEG predicted high subsequent memory performance: 1) theta increase at fixations after between-category gaze transitions, 2) theta and alpha increase at fixations after within-element gaze transitions, 3) alpha decrease at fixations after between-exemplar gaze transitions. Thus, event encoding with unrestricted viewing behavior was characterized by three neural mechanisms, manifested in fixation-locked theta and alpha EEG activity that rapidly turned on and off during the unfolding eye movement sequences. These three distinct neural mechanisms may be the essential building blocks that subserve the buildup of coherent episodic memories during unrestricted viewing behavior.}},
  author       = {{Nikolaev, Andrey and Bramao, Ines and Johansson, Roger and Johansson, Mikael}},
  issn         = {{1095-9572}},
  language     = {{eng}},
  month        = {{02}},
  publisher    = {{Elsevier}},
  series       = {{NeuroImage}},
  title        = {{Episodic memory formation in unrestricted viewing}},
  url          = {{http://dx.doi.org/10.1016/j.neuroimage.2022.119821}},
  doi          = {{10.1016/j.neuroimage.2022.119821}},
  volume       = {{266}},
  year         = {{2023}},
}