scholarly journals Mindfulness meditators show enhanced working memory performance concurrent with different brain region engagement patterns during recall

2019 ◽  
Author(s):  
NW Bailey ◽  
G Freedman ◽  
K Raj ◽  
KN Spierings ◽  
LR Piccoli ◽  
...  
Keyword(s):  
Working Memory ◽  
Neural Activity ◽  
Memory Performance ◽  
Event Related Potentials ◽  
Response Strength ◽  
Neural Response ◽  
Neural Activation ◽  
List Type ◽  
Alpha Oscillations ◽  
Related Potentials

AbstractMindfulness meditation has been shown to improve working memory (WM). However, the altered brain activity underpinning these improvements is underexplored. In non-meditating individuals, modulation of theta and alpha oscillations and 1/f aperiodic activity during WM has been found to be related to WM performance. Resting theta and alpha oscillations have been found to differ in meditators, but WM related oscillation changes and 1/f aperiodic activity have not yet been examined. Additionally, WM event-related-potentials (ERPs) are modulated by attention, which is also enhanced by meditation, so these neural measures are candidates for exploring neural activity underpinning WM improvement in meditators. We recorded EEG from 29 controls and 29 meditators during a modified Sternberg WM task and compared theta, alpha, and 1/f aperiodic activity during the WM delay, and ERPs time-locked to the WM probe. Meditators responded more accurately (p = 0.008, Cohen’s d = 0.688). Meditators also showed different ERP distributions with earlier left-temporal activation and more frontal distribution of activity (FDR-p = 0.0186, η2 = 0.0903), as well as a reduction in overall neural response strength (FDR-p = 0.0098, η2 = 0.1251). While a higher proportion of meditators showed theta oscillations during the WM delay, no other differences in theta, alpha or 1/f aperiodic activity were present. These results suggest that increased WM performance in meditators might not be the result of higher amplitudes of typical WM activity, but instead due to an alternative neural strategy during WM decision making, which may allow more accurate responses with less neural activation.Highlights-Long term mindfulness meditators showed improved working memory (WM) accuracy-This was concurrent with earlier left temporal activation following probe stimuli-As well as a more frontal distribution and reduced overall neural response strength-No oscillation differences were present in the working memory delay period-Improved WM from altered neural strategy rather than increased neural activity

EVOKED OSCILLATIONS AND EARLY COMPONENTS OF EVENT-RELATED POTENTIALS: AN ANALYSIS

2004 ◽  
Vol 14 (02) ◽  
pp. 705-718 ◽  
Author(s):  
WOLFGANG KLIMESCH ◽  
MANUEL SCHABUS ◽  
MICHAEL DOPPELMAYR ◽  
WALTER GRUBER ◽  
PAUL SAUSENG
Keyword(s):  
Working Memory ◽  
Large Scale ◽  
Event Related Potentials ◽  
Theoretical Framework ◽  
Network Systems ◽  
General Hypothesis ◽  
Alpha Oscillations ◽  
Related Potentials ◽  
Individual Alpha Frequency ◽  
Scale Integration

In the present work, we provide new arguments and data indicating that early ERP components are generated at least in part by evoked theta and alpha oscillations. We proceed from the general hypothesis, originally proposed by Erol Basar that ERP's are generated by a superposition of evoked oscillations with different frequencies. Based on findings about event-related desynchronization/synchronization (ERD/ERS), we analyze the following specific hypotheses. If evoked theta and alpha oscillations contribute to the generation of ERP components and if their functional role, type of reactivity and frequency specificity are similar to those of event-related oscillations (measured by ERD/ERS), we expect (i) to see the same functional relationship between frequency and cognitive processes, (ii) the same type of "reactivity" and a (iii) dependency of latency measures of evoked components on IAF. By reviewing respective data, we demonstrate that similar to research about event-related oscillations, evoked alpha reflects attention, whereas evoked theta reflects working memory processes. Furthermore, it was found that individual alpha frequency (IAF) has a significant influence on P1 latency in particular. For a better understanding of these findings, we outline a new theoretical framework. We assume that the P1–N1 complex is generated by an interplay between the synchronous activation of three neuronal network systems, a working memory, attentional, and semantic memory system, each operating with a different frequency, the first in the theta (about 6 Hz), the second in the lower alpha (about 8 Hz) and the third in the upper alpha (about 12 Hz) frequency range. The implications of this theoretical framework are discussed by reviewing research using phase sensitive measures to analyze "local" and "large scale" integration processes between different neural networks.

scholarly journals Working memory templates are maintained as feature-specific perceptual codes

2011 ◽  
Vol 106 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Kartik K. Sreenivasan ◽  
Deepak Sambhara ◽  
Amishi P. Jha
Keyword(s):  
Working Memory ◽  
Neural Activity ◽  
Event Related Potentials ◽  
Visual Similarity ◽  
Visual Features ◽  
Memory Representation ◽  
Neural Basis ◽  
Neural Populations ◽  
Related Potentials ◽  
Target Probe

Working memory (WM) representations serve as templates that guide behavior, but the neural basis of these templates remains elusive. We tested the hypothesis that WM templates are maintained by biasing activity in sensoriperceptual neurons that code for features of items being held in memory. Neural activity was recorded using event-related potentials (ERPs) as participants viewed a series of faces and responded when a face matched a target face held in WM. Our prediction was that if activity in neurons coding for the features of the target is preferentially weighted during maintenance of the target, then ERP activity evoked by a nontarget probe face should be commensurate with the visual similarity between target and probe. Visual similarity was operationalized as the degree of overlap in visual features between target and probe. A face-sensitive ERP response was modulated by target-probe similarity. Amplitude was largest for probes that were similar to the target, and decreased monotonically as a function of decreasing target-probe similarity. These results indicate that neural activity is weighted in favor of visual features that comprise an actively held memory representation. As such, our findings support the notion that WM templates rely on neural populations involved in forming percepts of memory items.

Human Event-Related Potentials to Higher-Order Acoustic Spatial Changes

2002 ◽  
Vol 16 (2) ◽  
pp. 114-118 ◽  
Author(s):  
Timo Ruusuvirta ◽  
Heikki Hämäläinen
Keyword(s):  
Working Memory ◽  
Mismatch Negativity ◽  
Spatial Information ◽  
Free Field ◽  
Event Related Potentials ◽  
Negative Polarity ◽  
Positive Polarity ◽  
Spatial Changes ◽  
Related Potentials ◽  
Human Event

Abstract Human event-related potentials (ERPs) to a tone continuously alternating between its two spatial loci of origin (middle-standards, left-standards), to repetitions of left-standards (oddball-deviants), and to the tones originally representing these repetitions presented alone (alone-deviants) were recorded in free-field conditions. During the recordings (Fz, Cz, Pz, M1, and M2 referenced to nose), the subjects watched a silent movie. Oddball-deviants elicited a spatially diffuse two-peaked deflection of positive polarity. It differed from a deflection elicited by left-standards and commenced earlier than a prominent deflection of negative polarity (N1) elicited by alone-deviants. The results are discussed in the context of the mismatch negativity (MMN) and previous findings of dissociation between spatial and non-spatial information in auditory working memory.

scholarly journals Temporal Dynamics of Attention during Encoding versus Maintenance of Working Memory: Complementary Views from Event-related Potentials and Alpha-band Oscillations

2015 ◽  
Vol 27 (3) ◽  
pp. 492-508 ◽  
Author(s):  
Nicholas E. Myers ◽  
Lena Walther ◽  
George Wallis ◽  
Mark G. Stokes ◽  
Anna C. Nobre
Keyword(s):  
Working Memory ◽  
Visual Information ◽  
Temporal Dynamics ◽  
Recall Performance ◽  
Event Related Potentials ◽  
Alpha Band ◽  
Related Potentials ◽  
Frontoparietal Control Network ◽  
Anticipatory Attention ◽  
Processing Differences

Working memory (WM) is strongly influenced by attention. In visual WM tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar frontoparietal control network, the two are likely to exhibit some processing differences, because precues invite anticipation of upcoming information whereas retrocues may guide prioritization, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual WM task designed to permit a direct comparison between cueing conditions. We found marked differences in ERP profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha-band (8–14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that, whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information.

Abnormal auditory N400 in a case of zolpidem dependence, during a working memory test

2006 ◽  
Vol 21 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Ioannis A. Liappas ◽  
Charalabos C. Papageorgiou ◽  
Andreas D. Rabavilas
Keyword(s):  
Working Memory ◽  
Spatial Working Memory ◽  
Event Related Potentials ◽  
Short Term ◽  
Context Processing ◽  
Gaba A ◽  
Related Potentials ◽  
N400 Component ◽  
Underlying Mechanisms ◽  
Term Management

AbstractZolpidem is a GABA (A) agonist, which is indicated for the short-term management of insomnia. Recent research provide evidence suggesting that zolpidem produces spatial working memory (WM) deficits and dependence; however, the underlying mechanisms of these effects are unknown. Since the auditory N400 component of event-related potentials (ERPS) is considered as an index of memory use of context processing, the present study focused on N400 waveform of ERPs elicited during a WM task in a case suffering from zolpidem dependence. The patterns of N400 waveform of this case were compared to the patterns obtained from healthy controls. This comparison revealed that zolpidem dependence is accompanied by reduced amplitudes located at posterior brain areas and diffuse prolongation of N400. These findings may indicate that zolpidem dependence manifests alterations with regard to the memory use of context processing, involving or affecting a wide-ranging network of the brain's structures.

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