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

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Benjamin James Griffiths ◽  
Stephen D Mayhew ◽  
Karen J Mullinger ◽  
João Jorge ◽  
Ian Charest ◽  
...  
Keyword(s):  
Information Processing ◽  
Visual Memory ◽  
Cognitive Task ◽  
Memory Task ◽  
Significant Negative Correlation ◽  
Neuronal Firing ◽  
Specific Information ◽  
Beta Power ◽  
Alpha Beta ◽  
Task Irrelevant

Massed 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, such synchronisation can contribute to alpha/beta (8–30 Hz) oscillations. Reducing the amplitude of these oscillations, therefore, may enhance information processing. 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 post-stimulus alpha/beta power decreased, stimulus-specific information increased. Critically, we found this effect in three unique tasks: visual perception, auditory perception, and visual memory retrieval, indicating that this phenomenon transcends both stimulus modality and cognitive task. 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 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 The Athlete’s Brain: Cross-Sectional Evidence for Neural Efficiency during Cycling Exercise

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Sebastian Ludyga ◽  
Thomas Gronwald ◽  
Kuno Hottenrott
Keyword(s):  
Maximal Oxygen Consumption ◽  
Cortical Function ◽  
Cross Sectional ◽  
Eyes Closed ◽  
Exercise Condition ◽  
Beta Power ◽  
Neural Efficiency ◽  
Alpha Beta ◽  
The Individual ◽  
Task Irrelevant

The “neural efficiency” hypothesis suggests that experts are characterized by a more efficient cortical function in cognitive tests. Although this hypothesis has been extended to a variety of movement-related tasks within the last years, it is unclear whether or not neural efficiency is present in cyclists performing endurance exercise. Therefore, this study examined brain cortical activity at rest and during exercise between cyclists of higher (HIGH;n=14; 55.6 ± 2.8 mL/min/kg) and lower (LOW;n=15; 46.4 ± 4.1 mL/min/kg) maximal oxygen consumption (VO2MAX). Male and female participants performed a graded exercise test with spirometry to assessVO2MAX. After 3 to 5 days, EEG was recorded at rest with eyes closed and during cycling at the individual anaerobic threshold over a 30 min period. Possible differences in alpha/beta ratio as well as alpha and beta power were investigated at frontal, central, and parietal sites. The statistical analysis revealed significant differences between groups (F=12.04;p=0.002), as the alpha/beta ratio was increased in HIGH compared to LOW in both the resting state (p≤0.018) and the exercise condition (p≤0.025). The present results indicate enhanced neural efficiency in subjects with highVO2MAX, possibly due to the inhibition of task-irrelevant cognitive processes.

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

2019 ◽  
Author(s):  
Benjamin James Griffiths ◽  
Stephen D Mayhew ◽  
Karen J Mullinger ◽  
João Jorge ◽  
Ian Charest ◽  
...  
Keyword(s):  
Author Response ◽  
Specific Information ◽  
Beta Power ◽  
Alpha Beta

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 Associative Memory Storage and Retrieval: Involvement of Theta Oscillations in Hippocampal Information Processing

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Federico Stella ◽  
Alessandro Treves
Keyword(s):  
Information Processing ◽  
Associative Memory ◽  
Memory Retrieval ◽  
Critical Role ◽  
Neuronal Firing ◽  
Memory Storage ◽  
Theta Oscillations ◽  
Hippocampal Region ◽  
Storage And Retrieval ◽  
Current Flows

Theta oscillations are thought to play a critical role in neuronal information processing, especially in the hippocampal region, where their presence is particularly salient. A detailed description of theta dynamics in this region has revealed not only a consortium of layer-specific theta dipoles, but also within-layer differences in the expression of theta. This complex and articulated arrangement of current flows is reflected in the way neuronal firing is modulated in time. Several models have proposed that these different theta modulators flexibly coordinate hippocampal regions, to support associative memory formation and retrieval. Here, we summarily review different approaches related to this issue and we describe a mechanism, based on experimental and simulation results, for memory retrieval in CA3 involving theta modulation.

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):  
Specific Information ◽  
Beta Power ◽  
Alpha Beta

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 Shaping information processing: the role of oscillatory dynamics in a working-memory task

2021 ◽  
Author(s):  
Hesham A. ElShafei ◽  
Ying Joey Zhou ◽  
Saskia Haegens
Keyword(s):  
Information Processing ◽  
Information Flow ◽  
Alpha Power ◽  
Match To Sample ◽  
Beta Power ◽  
Phase Alignment ◽  
Alpha Beta ◽  
Comprehensive Framework ◽  
High Beta

AbstractNeural oscillations are thought to reflect low-level operations that can be employed for higher-level cognitive functions. Here, we investigated the role of brain rhythms in the 1–30 Hz range by recording MEG in participants performing a visual delayed match-to-sample paradigm in which orientation or spatial frequency of sample and probe gratings had to be matched. A cue occurring before or after sample presentation indicated the to-be-matched feature. We demonstrate that alpha/beta power decrease tracks the presentation of the informative cue and indexes faster responses. Moreover, these faster responses coincided with an augmented phase alignment of slow oscillations, as well as phase-amplitude coupling between slow and fast oscillations. Importantly, stimulus decodability was boosted by both low alpha power and high beta power. In summary, we provide support for a comprehensive framework in which different rhythms play specific roles: slow rhythms control input sampling, while alpha (and beta) gates the information flow, beta recruits task-relevant circuits, and the timing of faster oscillations is controlled by slower ones.Highlights- We test a comprehensive framework of rhythms as building blocks for information processing- Participants performed a visual delayed match-to-sample task with pre- & retro-cues- Phase alignment of slow rhythms, governing input sampling, indexes faster responses- Alpha/beta power, gating information flow, boost behavior & track informative cues- Low alpha (gating) & high beta (circuit-setup) power boost signal information content

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