scholarly journals The genomic underpinnings of oscillatory biomarkers supporting successful memory encoding in humans

2019 ◽  
Author(s):  
Stefano Berto ◽  
Miles Fontenot ◽  
Sarah Seger ◽  
Fatma Ayhan ◽  
Emre Caglayan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Memory Performance ◽  
Temporal Cortex ◽  
Memory Task ◽  
Memory Formation ◽  
Inhibitory Neurons ◽  
Patient Specific ◽  
Memory Encoding ◽  
Brain Oscillations ◽  
Resected Tissue

AbstractIn humans, brain oscillations are thought to support critical features of memory formation such as coordination of activity across regions, consolidation, and temporal ordering of events. However, understanding the molecular mechanisms underlining this activity in humans remains a major challenge. Here, we measured memory-sensitive oscillations using direct intracranial electroencephalography recordings from the temporal cortex of patients performing an episodic memory task. By then employing transcriptomics on the resected tissue from the same patients, we linked gene expression with brain oscillations, identifying genes correlated with oscillatory signatures of memory formation across six frequency bands. A co-expression analysis isolated biomarker-specific modules associated with neuropsychiatric disorders as well as ion channel activity. Using single-nuclei transcriptomic data from this resected tissue, we further revealed that biomarker-specific modules are enriched for both excitatory and inhibitory neurons. This unprecedented dataset of patient-specific brain oscillations coupled to genomics unlocks new insights into the genetic mechanisms that support memory encoding. By linking brain expression of these genes to oscillatory patterns, our data help overcome limitations of phenotypic methods to uncover genetic links to memory performance.

scholarly journals Aberrant prefrontal beta oscillations predict episodic memory encoding deficits in schizophrenia

2016 ◽  
Author(s):  
Federica Meconi ◽  
Sarah Anderl-Straub ◽  
Heidelore Raum ◽  
Michael Landgrebe ◽  
Berthold Langguth ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Verbal Memory ◽  
Semantic Processing ◽  
Memory Performance ◽  
Oscillatory Activity ◽  
Healthy Controls ◽  
Memory Encoding ◽  
Brain Oscillations ◽  
Beta Power ◽  
Pattern Similarity

AbstractVerbal episodic memory is one of the core cognitive functions affected in patients suffering from schizophrenia (SZ). Although this verbal memory impairment in SZ is a well-known finding, our understanding about its underlying neurophysiological mechanisms is rather scarce. Here we address this issue by recording brain oscillations during a memory task in a sample of healthy controls and patients suffering from SZ. Brain oscillations represent spectral fingerprints of specific neurocognitive operations and are therefore a promising tool to identify neurocognitive mechanisms that are affected by SZ. Healthy controls showed a prominent suppression of left prefrontal beta oscillatory activity during successful memory formation, which replicates several previous oscillatory memory studies. In contrast, patients failed to exhibit such left prefrontal beta power suppression. Utilizing a new topographical pattern similarity approach, we further demonstrate that the degree of similarity between a patient's beta power decrease to that of the controls reliably predicted memory performance. This relationship between beta power decreases and memory was such that the patients' memory performance improved as they showed a more similar topographical beta desynchronization pattern compared to that of healthy controls. These findings suggest that left prefrontal beta power suppression (or lack thereof) during memory encoding is a possible biomarker for the observed encoding impairments in SZ in verbal memory. This lack of left prefrontal beta power decreases might indicate a specific semantic processing deficit of verbal material in patients with schizophrenia.

Oscillatory Theta Activity during Memory Formation and Its Impact on Overnight Consolidation: A Missing Link?

2015 ◽  
Vol 27 (8) ◽  
pp. 1648-1658 ◽  
Author(s):  
Dominik P. J. Heib ◽  
Kerstin Hoedlmoser ◽  
Peter Anderer ◽  
Georg Gruber ◽  
Josef Zeitlhofer ◽  
...  
Keyword(s):  
Memory Performance ◽  
Memory Task ◽  
Memory Formation ◽  
Theta Activity ◽  
Sleep Spindles ◽  
Sleep Spindle ◽  
Control Task ◽  
Spindle Activity ◽  
Before And After ◽  
Neuronal Processes

Sleep has been shown to promote memory consolidation driven by certain oscillatory patterns, such as sleep spindles. However, sleep does not consolidate all newly encoded information uniformly but rather “selects” certain memories for consolidation. It is assumed that such selection depends on salience tags attached to the new memories before sleep. However, little is known about the underlying neuronal processes reflecting presleep memory tagging. The current study sought to address the question of whether event-related changes in spectral theta power (theta ERSP) during presleep memory formation could reflect memory tagging that influences subsequent consolidation during sleep. Twenty-four participants memorized 160 word pairs before sleep; in a separate laboratory visit, they performed a nonlearning control task. Memory performance was tested twice, directly before and after 8 hr of sleep. Results indicate that participants who improved their memory performance overnight displayed stronger theta ERSP during the memory task in comparison with the control task. They also displayed stronger memory task-related increases in fast sleep spindle activity. Furthermore, presleep theta activity was directly linked to fast sleep spindle activity, indicating that processes during memory formation might indeed reflect memory tagging that influences subsequent consolidation during sleep. Interestingly, our results further indicate that the suggested relation between sleep spindles and overnight performance change is not as direct as once believed. Rather, it appears to be mediated by processes beginning during presleep memory formation. We conclude that theta ERSP during presleep memory formation reflects cortico-hippocampal interactions that lead to a better long-term accessibility by tagging memories for sleep spindle-related reprocessing.

scholarly journals Impaired Desynchronization of Beta Activity Underlies Memory Deficits in People with Parkinson’s Disease

2019 ◽  
Author(s):  
Hayley J. MacDonald ◽  
John-Stuart Brittain ◽  
Bernhard Spitzer ◽  
Simon Hanslmayr ◽  
Ned Jenkinson
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Brain Activity ◽  
Memory Performance ◽  
Memory Formation ◽  
Motor Deficits ◽  
Beta Activity ◽  
Memory Encoding ◽  
Concomitant Reduction ◽  
Non Motor Symptoms

AbstractThere is a pressing need to better understand the mechanisms underpinning the increasingly recognised non-motor deficits in Parkinson’s disease. Brain activity during Parkinson’s disease is excessively synchronized within the beta range (12–30Hz). However, relatively little is known about how the abnormal beta rhythms impact on non-motor symptoms. In healthy adults, beta desynchronization is necessary for successful episodic memory formation. We investigated whether there was a direct relationship between decreased beta modulation and memory formation in Parkinson’s disease. Electroencephalography recordings were made during an established memory-encoding paradigm. Parkinson’s participants showed impaired memory strength (P = 0.023) and reduced beta desynchronization (P = 0.014) relative to controls. Longer disease duration was correlated with a larger reduction in beta desynchronization, and a concomitant reduction in memory performance. These novel results extend the notion that pathological beta activity is causally implicated in the motor and (lesser appreciated) non-motor deficits inherent to Parkinson’s disease.

scholarly journals Noradrenergic projections from the locus coeruleus to the amygdala constrain auditory fear memory reconsolidation

2020 ◽  
Author(s):  
Josue Haubrich ◽  
Matteo Bernabo ◽  
Karim Nader
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Locus Coeruleus ◽  
Molecular Mechanisms ◽  
Fear Memory ◽  
Memory Formation ◽  
Memory Reconsolidation ◽  
Memory Encoding ◽  
Memory Strength ◽  
The Brain

ABSTRACTMemory reconsolidation is a fundamental plasticity process in the brain that allows established memories to be changed or erased. However, certain boundary conditions limit the parameters under which memories can be made plastic. Strong memories do not destabilize, for instance, although why they are resilient is mostly unknown. Here, we extend the understanding of the mechanisms implicated in reconsolidation-resistant memories by investigating the hypothesis that specific modulatory signals shape memory formation into a state that lacks lability. We find that the activation of the noradrenaline-locus coeruleus system (NOR-LC) during strong fear memory encoding increases molecular mechanisms of stability at the expense of lability in the amygdala. Preventing the NOR-LC from modulating strong fear encoding results in the formation of memories that can undergo reconsolidation within the amygdala and thus are vulnerable to post-reactivation interference. Thus, the memory strength boundary condition on reconsolidation is set at the time of encoding by the action of the NOR-LC.

scholarly journals Signal complexity of human intracranial EEG tracks successful associative memory formation across individuals

2017 ◽  
Author(s):  
Timothy C. Sheehan ◽  
Vishnu Sreekumar ◽  
Sara K. Inati ◽  
Kareem A. Zaghloul
Keyword(s):  
Verbal Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Low Frequency ◽  
Human Memory ◽  
Memory Formation ◽  
Intracranial Eeg ◽  
Neural Signal ◽  
Signal Complexity ◽  
Successful Recall

AbstractMemory performance is highly variable between individuals. Most studies examining human memory, however, have largely focused on the neural correlates of successful memory formation within individuals, rather than the differences between them. As such, what gives rise to this variability is poorly understood. Here, we examined intracranial EEG (iEEG) recordings captured from 43 participants (23 male) implanted with subdural electrodes for seizure monitoring as they performed a paired-associates verbal memory task. We identified three separate but related signatures of neural activity that tracked differences in successful memory formation across individuals. High performing individuals consistently exhibited less broadband power, flatter power spectral density (PSD) slopes, and greater complexity in their iEEG signals. Furthermore, within individuals across three separate time scales ranging from seconds to days, successful recall was positively associated with these same metrics. Our data therefore suggest that memory ability across individuals can be indexed by increased neural signal complexity.Significance StatementWe show that participants whose intracranial EEG exhibits less low frequency power, flatter power spectrums, and greater sample entropy overall are better able to memorize associations, and that the same metrics track fluctuations in memory performance across time within individuals. These metrics together signify greater neural signal complexity which may index the brain’s ability to flexibly engage with information and generate separable memory representations. Critically, the current set of results provide a unique window into the neural markers of individual differences in memory performance which have hitherto been underexplored.

scholarly journals A selective benefit of transient, but not sustained, reward to memory formation

2021 ◽  
Author(s):  
Avery S. Gholston ◽  
Kimberly Sarah Chiew
Keyword(s):  
Temporal Dynamics ◽  
Memory Performance ◽  
Response Speed ◽  
Memory Formation ◽  
Task Engagement ◽  
Item Memory ◽  
Mixed Block ◽  
Memory Encoding ◽  
Behavioral Experiments ◽  
Context Memory

Reward benefits to memory formation have been robustly linked to dopaminergic activity. Despite established characterization of dopaminergic mechanisms as operating at multiple timescales, potentially supporting distinct functional outcomes, the temporal dynamics by which reward might modulate memory encoding are just beginning to be investigated. In the present study, we leveraged a mixed block/event experimental design to disentangle transient and sustained reward influences on task engagement and subsequent recognition memory in an adapted monetary-incentive encoding (MIE) paradigm. Across three behavioral experiments, transient and sustained reward modulation of item and context memory was probed, at both 24-hour and ~10-minute retention intervals, to investigate the importance of overnight consolidation. In general, we observed that transient reward was associated with enhanced item memory encoding, while sustained reward modulated task engagement at encoding (specifically, increasing response speed) but did not confer a benefit to subsequent memory performance. Notably, reward benefits to item memory performance were somewhat inconsistent across the three experiments, and in contrast to predictions, we did not observe reward modulation of context memory performance or amplification of reward effects by overnight consolidation. Taken together, the observed pattern of behavior suggests potentially distinct roles for transient and sustained reward in memory encoding and cognitive performance and suggests that further investigation of the temporal dynamics of dopaminergic contributions to memory formation will advance understanding of motivated memory.

scholarly journals Whole-brain connectivity during encoding: age-related differences and associations with cognitive and brain structural decline

2021 ◽  
Author(s):  
Elettra Capogna ◽  
Markus H Sneve ◽  
Liisa Raud ◽  
Line Folvik ◽  
Hedda Ness ◽  
...  
Keyword(s):  
Brain Connectivity ◽  
Memory Performance ◽  
Temporal Cortex ◽  
Structural Data ◽  
Older Age ◽  
Memory Encoding ◽  
Cognitive Changes ◽  
Whole Brain ◽  
Age Related ◽  
Connectivity Patterns

There is a limited understanding of age differences in functional connectivity during memory encoding. In the present study, a sample of cognitively healthy adult participants (n=488), a subsample of whom had longitudinal cognitive and brain structural data spanning 8 years back, underwent fMRI while performing an associative memory encoding task. We investigated 1) age changes in whole-brain connectivity during memory encoding; whether 2) encoding connectivity patterns overlap with the activity signatures of specific cognitive processes and whether 3) connectivity changes associated with memory encoding related to longitudinal brain structural and cognitive changes. Age was associated with decreased intranetwork connectivity and increased connectivity during encoding. Task-connectivity between mediotemporal and posterior parietal regions — which overlapped with areas involved in mental imagery — was related to better memory performance only in older age. The connectivity patterns supporting memory performance in older age reflected preservation of thickness of the medial temporal cortex. These investigations collectively indicate that functional patterns of connectivity should be interpreted in accordance with a maintenance rather than a compensation account.

scholarly journals Prediction of Successful Memory Encoding Based on Lateral Temporal Cortical Gamma Power

2021 ◽  
Vol 15 ◽  
Author(s):  
Soyeon Jun ◽  
June Sic Kim ◽  
Chun Kee Chung
Keyword(s):  
Verbal Memory ◽  
Memory Performance ◽  
Recognition Task ◽  
Memory Formation ◽  
Gamma Activity ◽  
Support Vector ◽  
Svm Classifier ◽  
Memory Encoding ◽  
Gamma Frequency ◽  
Gamma Power

Prediction of successful memory encoding is important for learning. High-frequency activity (HFA), such as gamma frequency activity (30–150 Hz) of cortical oscillations, is induced during memory tasks and is thought to reflect underlying neuronal processes. Previous studies have demonstrated that medio-temporal electrophysiological characteristics are related to memory formation, but the effects of neocortical neural activity remain underexplored. The main aim of the present study was to evaluate the ability of gamma activity in human electrocorticography (ECoG) signals to differentiate memory processes into remembered and forgotten memories. A support vector machine (SVM) was employed, and ECoG recordings were collected from six subjects during verbal memory recognition task performance. Two-class classification using an SVM was performed to predict subsequently remembered vs. forgotten trials based on individually selected frequencies (low gamma, 30–60 Hz; high gamma, 60–150 Hz) at time points during pre- and during stimulus intervals. The SVM classifier distinguished memory performance between remembered and forgotten trials with a mean maximum accuracy of 87.5% using temporal cortical gamma activity during the 0- to 1-s interval. Our results support the functional relevance of ECoG for memory formation and suggest that lateral temporal cortical HFA may be utilized for memory prediction.

scholarly journals Noradrenergic projections from the locus coeruleus to the amygdala constrain fear memory reconsolidation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Josué Haubrich ◽  
Matteo Bernabo ◽  
Karim Nader
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Locus Coeruleus ◽  
Molecular Mechanisms ◽  
Fear Memory ◽  
Memory Formation ◽  
Memory Reconsolidation ◽  
Memory Encoding ◽  
Memory Strength ◽  
The Brain

Memory reconsolidation is a fundamental plasticity process in the brain that allows established memories to be changed or erased. However, certain boundary conditions limit the parameters under which memories can be made plastic. Strong memories do not destabilize, for instance, although why they are resilient is mostly unknown. Here, we investigated the hypothesis that specific modulatory signals shape memory formation into a state that is reconsolidation-resistant. We find that the activation of the noradrenaline-locus coeruleus system (NOR-LC) during strong fear memory encoding increases molecular mechanisms of stability at the expense of lability in the amygdala of rats. Preventing the NOR-LC from modulating strong fear encoding results in the formation of memories that can undergo reconsolidation within the amygdala and thus are vulnerable to post-reactivation interference. Thus, the memory strength boundary condition on reconsolidation is set at the time of encoding by the action of the NOR-LC.

The Relationship Between Interoception and Metacognition

2016 ◽  
Vol 30 (2) ◽  
pp. 76-86 ◽  
Author(s):  
Judith Meessen ◽  
Verena Mainz ◽  
Siegfried Gauggel ◽  
Eftychia Volz-Sidiropoulou ◽  
Stefan Sütterlin ◽  
...  
Keyword(s):  
Memory Performance ◽  
Memory Task ◽  
Demographic Characteristics ◽  
Metacognitive Awareness ◽  
Interoceptive Awareness ◽  
Future Research ◽  
Heartbeat Perception ◽  
Interoceptive Accuracy ◽  
The Relationship

Abstract. Recently, Garfinkel and Critchley (2013) proposed to distinguish between three facets of interoception: interoceptive sensibility, interoceptive accuracy, and interoceptive awareness. This pilot study investigated how these facets interrelate to each other and whether interoceptive awareness is related to the metacognitive awareness of memory performance. A sample of 24 healthy students completed a heartbeat perception task (HPT) and a memory task. Judgments of confidence were requested for each task. Participants filled in questionnaires assessing interoceptive sensibility, depression, anxiety, and socio-demographic characteristics. The three facets of interoception were found to be uncorrelated and interoceptive awareness was not related to metacognitive awareness of memory performance. Whereas memory performance was significantly related to metamemory awareness, interoceptive accuracy (HPT) and interoceptive awareness were not correlated. Results suggest that future research on interoception should assess all facets of interoception in order to capture the multifaceted quality of the construct.

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