scholarly journals Alpha/beta power decreases during episodic memory formation predict the magnitude of alpha/beta power decreases during subsequent retrieval

2020 ◽  
Author(s):  
Benjamin J. Griffiths ◽  
María Carmen Martín-Buro ◽  
Bernhard P. Staresina ◽  
Simon Hanslmayr ◽  
Tobias Staudigl
Keyword(s):  
Episodic Memory ◽  
Memory Retrieval ◽  
Spectral Power ◽  
Learning Task ◽  
Neural Representation ◽  
Parameter Estimates ◽  
Beta Activity ◽  
Amount Of Information ◽  
Beta Power ◽  
Alpha Beta

AbstractEpisodic memory retrieval is characterised by the vivid reinstatement of information about a personally-experienced event. Growing evidence suggests that the reinstatement of such information is supported by reductions in the spectral power of alpha/beta activity. Given that the amount of information that can be recalled depends on the amount of information that was originally encoded, information-based accounts of alpha/beta activity would suggest that retrieval-related alpha/beta power decreases similarly depend upon decreases in alpha/beta power during encoding. To test this hypothesis, seventeen human participants completed a sequence-learning task while undergoing concurrent MEG recordings. Regression-based analyses were then used to estimate how alpha/beta power decreases during encoding predicted alpha/beta power decreases during retrieval, on a trial-by-trial basis. When subjecting these parameter estimates to group-level analysis, we find evidence to suggest that retrieval-related alpha/beta (7-15Hz) power decreases fluctuate as a function of encoding-related alpha/beta power decreases. These results suggest that retrieval-related alpha/beta power decreases are contingent on the decrease in alpha/beta power that arose during encoding. Subsequent analysis uncovered no evidence to suggest that these alpha/beta power decreases reflect stimulus identity, indicating that the contingency between encoding- and retrieval-related alpha/beta power reflects the reinstatement of a neurophysiological operation, rather than neural representation, during episodic memory retrieval.

scholarly journals Directional coupling of slow and fast hippocampal gamma with neocortical alpha/beta oscillations in human episodic memory

2019 ◽  
Vol 116 (43) ◽  
pp. 21834-21842 ◽  
Author(s):  
Benjamin J. Griffiths ◽  
George Parish ◽  
Frederic Roux ◽  
Sebastian Michelmann ◽  
Mircea van der Plas ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Memory Retrieval ◽  
Memory Formation ◽  
Beta Power ◽  
Wide Range ◽  
Alpha Beta ◽  
Episodic Memories ◽  
Hippocampal Theta ◽  
Multisensory Information ◽  
Flow Of Information

Episodic memories hinge upon our ability to process a wide range of multisensory information and bind this information into a coherent, memorable representation. On a neural level, these 2 processes are thought to be supported by neocortical alpha/beta desynchronization and hippocampal theta/gamma synchronization, respectively. Intuitively, these 2 processes should couple to successfully create and retrieve episodic memories, yet this hypothesis has not been tested empirically. We address this by analyzing human intracranial electroencephalogram data recorded during 2 associative memory tasks. We find that neocortical alpha/beta (8 to 20 Hz) power decreases reliably precede and predict hippocampal “fast” gamma (60 to 80 Hz) power increases during episodic memory formation; during episodic memory retrieval, however, hippocampal “slow” gamma (40 to 50 Hz) power increases reliably precede and predict later neocortical alpha/beta power decreases. We speculate that this coupling reflects the flow of information from the neocortex to the hippocampus during memory formation, and hippocampal pattern completion inducing information reinstatement in the neocortex during memory retrieval.

scholarly journals Directional coupling of slow and fast hippocampal gamma with neocortical alpha/beta oscillations in human episodic memory

2018 ◽  
Author(s):  
Benjamin J. Griffiths ◽  
George Parish ◽  
Frederic Roux ◽  
Sebastian Michelmann ◽  
Mircea van der Plas ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Memory Retrieval ◽  
Division Of Labour ◽  
Memory Formation ◽  
Beta Power ◽  
Wide Range ◽  
Directional Coupling ◽  
Alpha Beta ◽  
Episodic Memories ◽  
Flow Of Information

AbstractEpisodic memories hinge upon our ability to process a wide range of multisensory information and bind this information into a coherent, memorable representation. On a neural level, these two processes are thought to be supported by neocortical alpha/beta desynchronisation and hippocampal theta/gamma synchronisation, respectively. Intuitively, these two processes should couple to successfully create and retrieve episodic memories, yet this hypothesis has not been tested empirically. We address this by analysing human intracranial EEG data recorded during two associative memory tasks. We find that neocortical alpha/beta (8-20Hz) power decreases reliably precede and predict hippocampal “fast” gamma (60-80Hz) power increases during episodic memory formation; during episodic memory retrieval however, hippocampal “slow” gamma (40-50Hz) power increases reliably precede and predict later neocortical alpha/beta power decreases. We speculate that this coupling reflects the flow of information from neocortex to hippocampus during memory formation, and hippocampal pattern completion inducing information reinstatement in the neocortex during memory retrieval.Significance StatementEpisodic memories detail our personally-experienced past. The formation and retrieval of these memories has long been thought to be supported by a division of labour between the neocortex and the hippocampus, where the former processes event-related information and the latter binds this information together. However, it remains unclear how the two regions interact. We uncover directional coupling between these regions, with power decreases in the neocortex that precede and predict power increases in the hippocampus during memory formation. Fascinatingly, this process reverses during memory retrieval, with hippocampal power increases preceding and predicting neocortical power decreases. These results suggest a bidirectional flow of information between the neocortex and hippocampus is fundamental to the formation and retrieval of episodic memories.

scholarly journals Alpha/beta power decreases during episodic memory formation predict the magnitude of alpha/beta power decreases during subsequent retrieval

2021 ◽  
Vol 153 ◽  
pp. 107755
Author(s):  
Benjamin J. Griffiths ◽  
María Carmen Martín-Buro ◽  
Bernhard P. Staresina ◽  
Simon Hanslmayr ◽  
Tobias Staudigl
Keyword(s):  
Episodic Memory ◽  
Memory Formation ◽  
Beta Power ◽  
Alpha Beta

scholarly journals Alpha/beta power decreases track the fidelity of stimulus-specific information

2019 ◽  
Author(s):  
Benjamin J. Griffiths ◽  
Stephen D. Mayhew ◽  
Karen J. Mullinger ◽  
João Jorge ◽  
Ian Charest ◽  
...  
Keyword(s):  
Information Processing ◽  
Memory Retrieval ◽  
Negative Relationship ◽  
Memory Task ◽  
Significant Negative Correlation ◽  
Neuronal Firing ◽  
Specific Information ◽  
Beta Power ◽  
Alpha Beta ◽  
Task Irrelevant

AbstractMassed synchronised neuronal firing is detrimental to information processing. When networks of task-irrelevant neurons fire in unison, they mask the signal generated by task-critical neurons. On a macroscopic level, mass synchronisation of these neurons can contribute to the ubiquitous alpha/beta (8-30Hz) oscillations. Reductions in the amplitude of these oscillations, therefore, may reflect a boost in the processing of high-fidelity information within the cortex. Here, we test this hypothesis. Twenty-one participants completed an associative memory task while undergoing simultaneous EEG-fMRI recordings. Using representational similarity analysis, we quantified the amount of stimulus-specific information represented within the BOLD signal on every trial. When correlating this metric with concurrently-recorded alpha/beta power, we found a significant negative correlation which indicated that as alpha/beta power decreased, our metric of stimulus-specific information increased. This effect generalised across cognitive tasks, as the negative relationship could be observed during visual perception and episodic memory retrieval. Further analysis revealed that this effect could be better explained by alpha/beta power decreases providing favourable conditions for information processing, rather than directly representing stimulus-specific information. Together, these results indicate that alpha/beta power decreases parametrically track the fidelity of both externally-presented and internally-generated stimulus-specific information represented within the cortex.

scholarly journals Oscillatory dynamics underlying noun and verb production in highly proficient bilinguals

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuang Geng ◽  
Nicola Molinaro ◽  
Polina Timofeeva ◽  
Ileana Quiñones ◽  
Manuel Carreiras ◽  
...  
Keyword(s):  
Time Window ◽  
Premotor Cortex ◽  
Naming Task ◽  
Neural Representation ◽  
Middle Temporal Gyrus ◽  
Oscillatory Dynamics ◽  
Beta Power ◽  
Essential Components ◽  
Visual Cortices ◽  
Alpha Beta

AbstractWords representing objects (nouns) and words representing actions (verbs) are essential components of speech across languages. While there is evidence regarding the organizational principles governing neural representation of nouns and verbs in monolingual speakers, little is known about how this knowledge is represented in the bilingual brain. To address this gap, we recorded neuromagnetic signals while highly proficient Spanish–Basque bilinguals performed a picture-naming task and tracked the brain oscillatory dynamics underlying this process. We found theta (4–8 Hz) power increases and alpha–beta (8–25 Hz) power decreases irrespectively of the category and language at use in a time window classically associated to the controlled retrieval of lexico-semantic information. When comparing nouns and verbs within each language, we found theta power increases for verbs as compared to nouns in bilateral visual cortices and cognitive control areas including the left SMA and right middle temporal gyrus. In addition, stronger alpha–beta power decreases were observed for nouns as compared to verbs in visual cortices and semantic-related regions such as the left anterior temporal lobe and right premotor cortex. No differences were observed between categories across languages. Overall, our results suggest that noun and verb processing recruit partially different networks during speech production but that these category-based representations are similarly processed in the bilingual brain.

scholarly journals Disentangling the roles of neocortical alpha/beta and hippocampal theta/gamma oscillations in human episodic memory formation

2020 ◽  
Author(s):  
Benjamin J. Griffiths ◽  
María Carmen Martín-Buro ◽  
Bernhard P. Staresina ◽  
Simon Hanslmayr
Keyword(s):  
Episodic Memory ◽  
Memory Performance ◽  
Empirical Support ◽  
Memory Formation ◽  
Information Representation ◽  
Gamma Phase ◽  
Beta Power ◽  
Alpha Beta ◽  
Phase Amplitude ◽  
Hippocampal Theta

AbstractEpisodic memory formation relies on at least two distinct capabilities: 1) our ability to process a vast amount of sensory information, and 2) our ability to bind these sensory representations together to form a coherent memory. The first process is thought to rely on a reduction in neocortical alpha/beta power, while the second is thought to be supported by hippocampal theta-gamma phase-amplitude coupling. However, most studies investigating human episodic memory use paradigms where the two cognitive capabilities overlap. As such, empirical support for the distinction of the two associated neural phenomena is lacking. Here, we addressed this by asking seventeen human participants (11 female, 6 male) to complete a sequence-learning paradigm that temporally separated information representation from mnemonic binding, while MEG recordings were acquired. We found that a decrease in neocortical alpha/beta power during the perception of the sequence correlated with enhanced memory performance. Similar power decreases during mnemonic binding, however, had no bearing on memory formation. In contrast, an increase in hippocampal theta/gamma phase-amplitude coupling during mnemonic binding correlated with enhanced memory performance, but similar coupling during sequence perception bared no relation to later memory performance. These results demonstrate that alpha/beta power decreases and hippocampal theta/gamma phase-amplitude coupling represent two temporally dissociable processes in episodic memory, with the former relating to information representation while the latter relates to mnemonic binding.

scholarly journals Action Observation and Execution Differentially Modulate Basal Ganglia-Cortical Activity in Humans

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Mahsa Malekmohammadi ◽  
Kathryn Cross ◽  
Jeongwoo Choi ◽  
Nader Pouratian
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Sensorimotor Cortex ◽  
Spectral Power ◽  
Action Observation ◽  
Neural Representation ◽  
Movement Execution ◽  
Action Execution ◽  
Gamma Power ◽  
Alpha Beta

Abstract INTRODUCTION To understand an observed action, without overt execution, the observer is thought to run similar motor plans; indicating a strong coupling between the neural representation of action observation and execution. Imaging studies show activation of basal ganglia (BG) and motor cortex during movement yet comparative studies using direct and invasive human recordings are sparse. We aimed to characterize how movement execution and observation differentially modulate local and inter-regional activity across BG and sensorimotor cortex. METHODS We recorded LFP from globus palidus internus (GPi) and electrocorticography from ipsilateral sensorimotor cortex in 9 PD subjects during deep brain stimulation surgery. Subjects performed block design tasks alternating between 30 s of rest and performing or observing finger tapping with random order. We assessed changes in spectral power, along with pallidocortical coherence and cortical PAC. RESULTS We observed suppression of alpha-beta (9-25 Hz) power in contralateral GPi and sensorimotor cortex during both activities. This power suppression was significantly weaker in the motor cortex during the action observation compared to the execution (P = .02). However pallidal spectral changes in alpha-beta frequencies were not different across tasks (P = .3). Uniquely during the action execution, there was a significant increase in the gamma power (80-200 Hz) at the motor cortex (P < .05). In addition, Pallidocortical beta coherence, and motor cortical beta-gamma PAC were significantly suppressed during action execution (P < .05) and not the observation. CONCLUSION Our results support the functional dissociation within the BG-cortical network during action observation and execution. Although spectral power changes in a-ß in the BG are largely similar across tasks, suppression of BG-cortical functional connectivity is a feature of movement execution. In addition, increase in the cortical gamma power and beta-gamma phase amplitude decoupling only happen during the movement execution, in line with the theory that during movement execution the gamma signal is released from the constraint of beta.

scholarly journals Oscillatory activity in alpha/beta frequencies coordinates auditory and prefrontal cortices during extinction learning

2020 ◽  
Author(s):  
Howard J. Gritton ◽  
Jian C. Nocon ◽  
Nicholas M. James ◽  
Eric Lowet ◽  
Moona Abdulkerim ◽  
...  
Keyword(s):  
Cognitive Flexibility ◽  
Training Session ◽  
Field Potential ◽  
Learning Task ◽  
Oscillatory Activity ◽  
Strongly Correlated ◽  
Extinction Learning ◽  
Beta Power ◽  
Alpha Beta

AbstractCortical synchrony is theorized to contribute to communication between connected networks during executive functioning. To understand the functional role of neural synchrony in cognitive flexibility, we recorded from auditory cortex (AC) and medial prefrontal cortex (mPFC), while mice performed an auditory extinction learning task. We found that while animals gradually showed reduced responding to the unrewarded tone over hundreds of trials, the power of local field potential (LFP) oscillations (8-18 Hz, centered at alpha/beta frequencies) in AC and mPFC exhibited immediate and robust increases, prior to behavioral changes. The strength of LFP alpha/beta power in the mPFC, but not AC, was strongly correlated with the behavioral performance that mice would achieve later in the training session. Further, we found that coherence between AC and mPFC at 8-18Hz was selectively enhanced only after mice learned to suppress licking, and this LFP coherence increase coincided with a reduction in spiking rate for the unrewarded tone in AC. These results reveal that enhanced interactions between PFC and AC is an inherent property of auditory discrimination learning, and that coordinated alpha/beta oscillations contribute to cognitive flexibility.

scholarly journals Alpha/beta power compresses time in sub-second temporal judgments

2017 ◽  
Author(s):  
Tara van Viegen ◽  
Ian Charest ◽  
Ole Jensen ◽  
Ali Mazaheri
Keyword(s):  
Working Memory ◽  
Short Interval ◽  
Oscillatory Activity ◽  
Button Press ◽  
Beta Activity ◽  
List Type ◽  
Beta Power ◽  
Significant Difference ◽  
Alpha Beta ◽  
Temporal Judgments

ABSTRACTWhile the perception of time plays a crucial role in our day-to-day functioning, the underlying neural mechanism of time processing on short time scales (~1s) remains to be elucidated. Recently, the power of beta oscillations (~20 Hz) has been suggested to play an important role in temporal processing. However, the paradigms supporting this view have often had confounds of working memory, as well as motor preparation. In the current EEG study, we set out to investigate if power of oscillatory activity would be involved in time perception without an explicit working memory component or confound of a motor response. Participants indicated through a button press whether the time between a tone and a visual stimulus was 1 or 1.5s.Critically, we focused on the differences in oscillatory activity in the alpha (~10 Hz) and beta (~20 Hz) ranges preceding correct versus incorrect temporal judgments. Behaviourally, we found participants made more errors on the long (1.5s) than on the short (1s) interval. In addition, we found that participants were fastest to correctly respond to a long interval. The onset of the tone induced a suppression of alpha and beta activity over occipital and parietal electrodes. In the long estimation intervals, this suppression was greater for correct than incorrect estimations. Interestingly, alpha and beta suppression allowed us to predict whether participants would judge the long interval correctly. For the short interval trials we did not find a significant difference in alpha or beta band activity for the correct and incorrect judgments. Taken together, our behavioural and EEG results suggest a multifaceted role of alpha and beta activity in the temporal estimation of sub- and supra-second intervals, where power increases seem to lead to temporal compression. Higher alpha and beta power resulted in shorter temporal judgments for sub-second intervals.HighlightsTemporal judgments without motor confounds were studied with EEG.Alpha/beta activity differences for correct and incorrect temporal judgments.Sub-second intervals were judged as short when alpha/beta power was higher.

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