Electroencephalogram Evidence for Memory Suppression: A Systematic Review (original) (raw)
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Single-Trial EEG Analysis Predicts Memory Retrieval and Reveals Source-Dependent Differences
Frontiers in Human Neuroscience, 2018
We used pattern classifiers to extract features related to recognition memory retrieval from the temporal information in single-trial electroencephalography (EEG) data during attempted memory retrieval. Two-class classification was conducted on correctly remembered trials with accurate context (or source) judgments vs. correctly rejected trials. The average accuracy for datasets recorded in a single session was 61% while the average accuracy for datasets recorded in two separate sessions was 56%. To further understand the basis of the classifier's performance, two other pattern classifiers were trained on different pairs of behavioral conditions. The first of these was designed to use information related to remembering the item and the second to use information related to remembering the contextual information (or source) about the item. Mollison and Curran (2012) had earlier shown that subjects' familiarity judgments contributed to improved memory of spatial contextual information but not of extrinsic associated color information. These behavioral results were similarly reflected in the event-related potential (ERP) known as the FN400 (an early frontal effect relating to familiarity) which revealed differences between correct and incorrect context memories in the spatial but not color conditions. In our analyses we show that a classifier designed to distinguish between correct and incorrect context memories, more strongly involves early activity (400-500 ms) over the frontal channels for the location distinctions, than for the extrinsic color associations. In contrast, the classifier designed to classify memory for the item (without memory for the context), had more frontal channel involvement for the color associated experiments than for the spatial experiments. Taken together these results argue that location may be bound more tightly with the item than an extrinsic color association. The multivariate classification approach also showed that trial-by-trial variation in EEG corresponding to these ERP components were predictive of subjects' behavioral responses. Additionally, the multivariate classification approach enabled analysis of error conditions that did not have sufficient trials for standard ERP analyses. These results suggested that false alarms were primarily attributable to item memory (as opposed to memory of associated context), as commonly predicted, but with little previous corroborating EEG evidence.
When Remembering Causes Forgetting: Electrophysiological Correlates of Retrieval-Induced Forgetting
Cerebral Cortex, 2006
People tend to forget information that is related to memories they are actively trying to retrieve. On the basis of results from behavioral studies, such retrieval-induced forgetting is held to result from inhibitory control processes that are recruited to attenuate interference caused by competing memory traces. Employing electrophysiological measures of brain activity, the present study examined the neural correlates of these inhibitory processes as they operate. The results demonstrate that sustained prefrontal eventrelated potentials were 1) related to whether or not selective memory retrieval was required during reprocessing of previously studied words and 2) predictive of individual differences in the amount of forgetting observed in an ensuing recall test. The present findings give support to an inhibitory control account of retrievalinduced forgetting and are in accord with the view that prefrontal regions play an important role in the selection and maintenance of relevant memory representations at the expense of those currently irrelevant.
Long term memory has been modeled based on two different types of memory; declarative and non-declarative. Previous studies suggested that declarative memory was associated with high level of emotional arousal. In contrast, non-declarative memory was not. Based on this hypothesis, this paper investigated memory effectiveness using the EEG-based emotional arousal. In the experiment, word recognition test was used as a declarative memory test and word stem completion test as a non-declarative memory test. Four students from IIUM participated in the experiment and their brain signals were recorded to extract EEG-based emotional arousal during the memory tests. The findings from this research showed interesting correlation of the explicit and implicit memory effectiveness. The findings of this research were found to be consistent with suggestions of previous neuroscience and psychology studies, and provided new evidence in analyzing memory effectiveness with emotional arousal.
Electrophysiological Measures of Episodic Memory Control and Memory Retrieval
Clinical Eeg and Neuroscience, 2006
Event-related potentials (ERPs) index processes that occur before, during and after retrieval of information from episodic memory. In this selective review we provide a loose theoretical framework within which retrieval processes operating at these different stages can be considered. We go on to describe how ERPs have been employed in order to index processes operating at each of these stages. These data have contributed to current understanding of the processes that are engaged around the time of episodic memory retrieval, and also illustrate the potential that ERPs have for understanding in detail how memory retrieval processes changes in populations with memory impairments.
Human memory retention and recall processes. A review of EEG and fMRI studies
Neurosciences (Riyadh, Saudi Arabia), 2013
Human memory is an important concept in cognitive psychology and neuroscience. Our brain is actively engaged in functions of learning and memorization. Generally, human memory has been classified into 2 groups: short-term/working memory, and long-term memory. Using different memory paradigms and brain mapping techniques, psychologists and neuroscientists have identified 3 memory processes: encoding, retention, and recall. These processes have been studied using EEG and functional MRI (fMRI) in cognitive and neuroscience research. This study reviews previous research reported for human memory processes, particularly brain behavior in memory retention and recall processes with the use of EEG and fMRI. We discuss issues and challenges related to memory research with EEG and fMRI techniques.
ERPs and Neural Oscillations during Volitional Suppression of Memory Retrieval
Journal of Cognitive Neuroscience, 2013
■ Although investigations of memory and the dynamics of ERP components and neural oscillations as assessed through EEG have been well utilized, little research into the volitional nature of suppression over memory retrieval have used these methods. Oscillation analyses conducted on the Think/No-Think (TNT) task and volitional suppression of retrieval are of interest to broaden our knowledge of neural oscillations associated not only during successful memory retrieval but also when retrieval is unwanted or suppressed. In the current study, we measured EEG during a TNT task and performed ERP and EEG spectral power band analyses. ERP results replicated other researchersʼ observations of increases in 500-800 msec parietal effects for items where retrieval was instructed to be elaborated compared with being sup-pressed. Furthermore, EEG analyses indicated increased alpha (8-12 Hz) and theta (3-8 Hz) oscillations across parietal electrodes for items that were instructed to be suppressed versus those to be elaborated. Additionally, during the second half of the experiment (after repeated attempts at control), increases in theta oscillations were found across both frontal and parietal electrodes for items that were instructed to be suppressed and that were ultimately forgotten versus those ultimately remembered. Increased alpha power for items that were instructed to be suppressed versus elaborated may indicate reductions of retrieval attempts or lack of retrieval success. Increased theta power for items that were instructed to be suppressed versus elaborated may indicate increased or prolonged cognitive control to monitor retrieval events. ■
Using single-trial EEG to predict and analyze subsequent memory
NeuroImage, 2014
We show that it is possible to successfully predict subsequent memory performance based on single-trial EEG activity before and during item presentation in the study phase. Two-class classification was conducted to predict subsequently remembered vs. forgotten trials based on subjects' responses in the recognition phase. The overall accuracy across 18 subjects was 59.6% by combining pre- and during-stimulus information. The single-trial classification analysis provides a dimensionality reduction method to project the high-dimensional EEG data onto a discriminative space. These projections revealed novel findings in the pre- and during-stimulus periods related to levels of encoding. It was observed that the pre-stimulus information (specifically oscillatory activity between 25 and 35Hz) -300 to 0ms before stimulus presentation and during-stimulus alpha (7-12Hz) information between 1000 and 1400ms after stimulus onset distinguished between recollection and familiarity while the du...
Event-related potential (ERP) studies of memory encoding and retrieval: A selective review
Microscopy Research and Technique, 2000
As event-related brain potential (ERP) researchers have increased the number of recording sites, they have gained further insights into the electrical activity in the neural networks underlying explicit memory. A review of the results of such ERP mapping studies suggests that there is good correspondence between ERP results and those from brain imaging studies that map hemodynamic changes. This concordance is important because the combination of the high temporal resolution of ERPs with the high spatial resolution of hemodynamic imaging methods will provide a greatly increased understanding of the spatio-temporal dynamics of the brain networks that encode and retrieve explicit memories.
arXiv (Cornell University), 2019
Human memory-the learning of new information involves changes at the synaptic level between neurons dedicated for storage of information. Generally, memory is classified as Long-Term Memory and Short-Term Memory. The various types of the memory and their disorder are widely studied using neuroimaging techniques like Electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI). Brain is effectively occupied with the capabilities of learning, retention and recall. The brain regions (pre-frontal cortex, associated hippocampus cortices and their interactions with other lobes) involved in memory recall tasks focuses on understanding the memory retention and recall processes. However, due to highly complicated and dynamic mechanisms of brain, the specific regions where information may reside are not completely explored. In this research paper, recent memory literature using EEG and fMRI studies is reviewed to understand the memory retention and recall processes as well as the various brain regions associated with these processes. A number of stimuli which are reported in previous studies are evaluated and discussed. Furthermore, the challenges which are being faced by researchers in EEG and fMRI methodologies are also presented. Recommendations for the future research related to memory retention and recall are also discussed at the end.
Source-retrieval requirements influence late ERP and EEG memory effects
Brain research, 2007
The present study examined whether event-related potential (ERP) memory effects and measures of ongoing EEG activity (power and phase locking) are sensitive to varying source retrieval requirements in recognition memory. ERP old/new effects were obtained in two distinct source-memory tasks. Functionally related EEG power and phase locking effects were found in the delta and theta frequency range. A late posterior negativity (LPN) was larger for old than new responses irrespective of source accuracy. It was also larger when participants were required to judge how they had previously interacted with a recognized picture as compared to judging its study location. This result is consistent with the view that the LPN reflects processes in the service of reconstructing previous episodes by integrating recognized items with task-relevant contextual attributes, and that LPN amplitude is related to the amount of contextual features available for forming such an integrated representation.