scholarly journals Attention for Speaking: Prestimulus Motor-cortical Alpha Power Predicts Picture Naming Latencies

2020 ◽  
Vol 32 (5) ◽  
pp. 747-761
Author(s):  
Suzanne R. Jongman ◽  
Ardi Roelofs ◽  
Ashley G. Lewis
Keyword(s):  
Language Production ◽  
Alpha Power ◽  
Attentional State ◽  
Inhibitory Function ◽  
Manual Responses ◽  
Picture Presentation ◽  
Single Speaker ◽  
Motor Cortical ◽  
Cortical Regions ◽  
Naming Latencies

There is a range of variability in the speed with which a single speaker will produce the same word from one instance to another. Individual differences studies have shown that the speed of production and the ability to maintain attention are related. This study investigated whether fluctuations in production latencies can be explained by spontaneous fluctuations in speakers' attention just prior to initiating speech planning. A relationship between individuals' incidental attentional state and response performance is well attested in visual perception, with lower prestimulus alpha power associated with faster manual responses. Alpha is thought to have an inhibitory function: Low alpha power suggests less inhibition of a specific brain region, whereas high alpha power suggests more inhibition. Does the same relationship hold for cognitively demanding tasks such as word production? In this study, participants named pictures while EEG was recorded, with alpha power taken to index an individual's momentary attentional state. Participants' level of alpha power just prior to picture presentation and just prior to speech onset predicted subsequent naming latencies. Specifically, higher alpha power in the motor system resulted in faster speech initiation. Our results suggest that one index of a lapse of attention during speaking is reduced inhibition of motor-cortical regions: Decreased motor-cortical alpha power indicates reduced inhibition of this area while early stages of production planning unfold, which leads to increased interference from motor-cortical signals and longer naming latencies. This study shows that the language production system is not impermeable to the influence of attention.

scholarly journals Alpha Oscillations Prior to Encoding Preferentially Modulate Memory Consolidation during Wake Relative to Sleep

2017 ◽  
Author(s):  
Zachariah R. Cross ◽  
Amanda Santamaria ◽  
Andrew W. Corcoran ◽  
Phillip M. Alday ◽  
Scott Coussens ◽  
...  
Keyword(s):  
Memory Consolidation ◽  
Memory Performance ◽  
Oscillatory Activity ◽  
Alpha Power ◽  
Attentional State ◽  
Linear Mixed Effects ◽  
Cortical Regions ◽  
Individual Alpha Frequency ◽  
The Impact ◽  
Flow Of Information

ABSTRACTSleep promotes memory consolidation through unique neuromodulatory activity. However, little is known about the impact of attention during pre-sleep memory encoding on later memory performance. The current study aimed to address the question of whether attentional state prior to encoding, as indexed by alpha oscillatory activity, modulates the consolidation of images across periods of sleep and wake. 22 participants aged 18 – 41 years (mean age = 27.3) viewed 120 emotionally valenced images (positive, negative, neutral) before a 2hr afternoon sleep opportunity and an equivalent period of wake. Following the sleep and wake conditions, participants were required to distinguish between 120 previously seen (target) images and 120 new (distractor) images. Relative alpha power – adjusted according to participants’ individual alpha frequency – was computed to index attentional state prior to the learning phase. Generalised linear mixed-effects modelling revealed memory performance was modulated by attention, such that greater pre-encoding alpha power preferentially promoted memory consolidation during wake compared to sleep. There was no difference in memory performance between positive, negative and neutral stimuli. Modulations in alpha oscillatory activity may help to coordinate the flow of information between task-relevant cortical regions and a thalamo-cortical loop that preferentially subserves the formation of memory during times of wake relative to sleep.

Spatiotemporal Oscillatory Patterns During Working Memory Maintenance in Mild Cognitive Impairment and Subjective Cognitive Decline

2019 ◽  
Vol 30 (01) ◽  
pp. 1950019
Author(s):  
N. Serrano ◽  
D. López-Sanz ◽  
R. Bruña ◽  
P. Garcés ◽  
I. C. Rodríguez-Rojo ◽  
...  
Keyword(s):  
Working Memory ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Subjective Cognitive Decline ◽  
Alpha Power ◽  
Time Frequency ◽  
Neuronal Processes ◽  
Cortical Regions ◽  
Local Synchronization

Working memory (WM) is a crucial cognitive process and its disruption is among the earliest symptoms of Alzheimer’s disease. While alterations of the neuronal processes underlying WM have been evidenced in mild cognitive impairment (MCI), scarce literature is available in subjective cognitive decline (SCD). We used magnetoencephalography during a WM task performed by MCI [Formula: see text], SCD [Formula: see text] and healthy elders [Formula: see text] to examine group differences during the maintenance period (0–4000[Formula: see text]ms). Data were analyzed using time–frequency analysis and significant oscillatory differences were localized at the source level. Our results indicated significant differences between groups, mainly during the early maintenance (250–1250[Formula: see text]ms) in the theta, alpha and beta bands and in the late maintenance (2750–3750[Formula: see text]ms) in the theta band. MCI showed lower local synchronization in fronto-temporal cortical regions in the early theta–alpha window relative to controls [Formula: see text] and SCD [Formula: see text], and in the late theta window relative to controls [Formula: see text] and SCD [Formula: see text]. Early theta–alpha power was significantly correlated with memory scores [Formula: see text] and late theta power was correlated with task performance [Formula: see text] and functional activity scores [Formula: see text]. In the early beta window, MCI showed reduced power in temporo-posterior regions relative to controls [Formula: see text] and SCD [Formula: see text]. Our results may suggest that these alterations would reflect that memory-related networks are damaged.

scholarly journals Synchronized presentation of a language task to the electrical stimulation of cortical regions during speech mapping in an awake surgery

2018 ◽  
Vol 4 (1) ◽  
pp. 547-550
Author(s):  
Laura Hansmeyer ◽  
Thilo B. Krueger
Keyword(s):  
Electrical Stimulation ◽  
Image Display ◽  
Awake Surgery ◽  
Line Drawings ◽  
Cortical Areas ◽  
Trigger Signal ◽  
Speech Mapping ◽  
Picture Presentation ◽  
Cortical Regions ◽  
Stimulation Of

AbstractIntraoperative speech mapping is performed to preserve language function during tumour resections that involve eloquent cortical areas. For this technique the synchronization of the picture presentation to the patient with the electrical stimulation of the cortex is of major importance. During the operative routine images are manually presented by a psychologist or neurologist to the patient and have to be coordinated with the neurosurgeon stimulating the cortex by a neurostimulator, operated by an engineer. To increase the efficiency of this procedure and to minimize the time needed to localize functional cortical areas, images should appear automatically with electrical stimulation. To achieve this synchronization, the potential combination of an existing neurostimulator with commercially available software for image display was studied. A trigger signal was created to induce the presentation of a series of line drawings showing different objects. The software to control the neurostimulator and the software for image displaying were installed on two different computers. A cable was developed to transfer the trigger signal from the neurostimulator to the computer used for picture presentation. It was shown that it is possible to induce the image display via the neurostimulator using square-wave pulses of 5 V and a width of 10 ms. Thus, we present a system that enables the automated picture presentation synchronized to the electrical stimulation of cortical regions.

scholarly journals Direct brain recordings reveal hippocampal rhythm underpinnings of language processing

2016 ◽  
Vol 113 (40) ◽  
pp. 11366-11371 ◽  
Author(s):  
Vitória Piai ◽  
Kristopher L. Anderson ◽  
Jack J. Lin ◽  
Callum Dewar ◽  
Josef Parvizi ◽  
...  
Keyword(s):  
Language Processing ◽  
Sentence Processing ◽  
Memory Function ◽  
Semantic Knowledge ◽  
Theta Oscillations ◽  
Linguistic Processing ◽  
Picture Presentation ◽  
Cortical Regions ◽  
Hippocampal Theta ◽  
Hippocampal Complex

Language is classically thought to be supported by perisylvian cortical regions. Here we provide intracranial evidence linking the hippocampal complex to linguistic processing. We used direct recordings from the hippocampal structures to investigate whether theta oscillations, pivotal in memory function, track the amount of contextual linguistic information provided in sentences. Twelve participants heard sentences that were either constrained (“She locked the door with the”) or unconstrained (“She walked in here with the”) before presentation of the final word (“key”), shown as a picture that participants had to name. Hippocampal theta power increased for constrained relative to unconstrained contexts during sentence processing, preceding picture presentation. Our study implicates hippocampal theta oscillations in a language task using natural language associations that do not require memorization. These findings reveal that the hippocampal complex contributes to language in an active fashion, relating incoming words to stored semantic knowledge, a necessary process in the generation of sentence meaning.

Working Memory Processes Are Mediated by Local and Long-range Synchronization of Alpha Oscillations

2013 ◽  
Vol 25 (8) ◽  
pp. 1343-1357 ◽  
Author(s):  
Maite Crespo-Garcia ◽  
Diego Pinal ◽  
Jose L. Cantero ◽  
Fernando Díaz ◽  
Montserrat Zurrón ◽  
...  
Keyword(s):  
Working Memory ◽  
Long Range ◽  
Alpha Phase ◽  
Alpha Power ◽  
Phase Synchrony ◽  
Top Down ◽  
Alpha Oscillations ◽  
Memory Processes ◽  
Time Frequency ◽  
Cortical Regions

Different cortical dynamics of alpha oscillations (8–13 Hz) have been associated with increased working memory load, which have been mostly interpreted as a neural correlate of functional inhibition. This study aims at determining whether different manifestations of load-dependent amplitude and phase dynamics in the alpha band can coexist over different cortical regions. To address this question, we increased information load by manipulating the number and spatial configuration of domino spots. Time–frequency analysis of EEG source activity revealed (i) load-independent increases of both alpha power and interregional alpha-phase synchrony within task-irrelevant, posterior cortical regions and (ii) load-dependent decreases of alpha power over areas of the left pFC and bilateral posterior parietal cortex (PPC) preceded in time by load-dependent decreases of alpha-phase synchrony between the left pFC and the left PPC. The former results support the role of alpha oscillations in inhibiting irrelevant sensorimotor processing, whereas the latter likely reflect release of parietal task-relevant areas from top–down inhibition with load increase. This interpretation found further support in a significant latency shift of 15 msec from pFC to the PPC. Together, these results suggest that amplitude and phase alpha dynamics in both local and long-range cortical networks reflect different neural mechanisms of top–down control that might be crucial in mediating the different working memory processes.

scholarly journals High-Density EEG in a Charles Bonnet Syndrome Patient during and without Visual Hallucinations: A Case-Report Study

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1991
Author(s):  
Andrea Piarulli ◽  
Jitka Annen ◽  
Ron Kupers ◽  
Steven Laureys ◽  
Charlotte Martial
Keyword(s):  
Case Report ◽  
Resting State ◽  
High Density ◽  
Alpha Power ◽  
Visual Hallucinations ◽  
Charles Bonnet Syndrome ◽  
Eeg Data ◽  
Signal Diversity ◽  
Signal Complexity ◽  
Cortical Regions

Charles Bonnet syndrome (CBS) is a rare clinical condition characterized by complex visual hallucinations in people with loss of vision. So far, the neurobiological mechanisms underlying the hallucinations remain elusive. This case-report study aims at investigating electrical activity changes in a CBS patient during visual hallucinations, as compared to a resting-state period (without hallucinations). Prior to the EEG, the patient underwent neuropsychological, ophthalmologic, and neurological examinations. Spectral and connectivity, graph analyses and signal diversity were applied to high-density EEG data. Visual hallucinations (as compared to resting-state) were characterized by a significant reduction of power in the frontal areas, paralleled by an increase in the midline posterior regions in delta and theta bands and by an increase of alpha power in the occipital and midline posterior regions. We next observed a reduction of theta connectivity in the frontal and right posterior areas, which at a network level was complemented by a disruption of small-worldness (lower local and global efficiency) and by an increase of network modularity. Finally, we found a higher signal complexity especially when considering the frontal areas in the alpha band. The emergence of hallucinations may stem from these changes in the visual cortex and in core cortical regions encompassing both the default mode and the fronto-parietal attentional networks.

scholarly journals Dynamic signatures of the Eureka effect: An EEG study

2021 ◽  
Author(s):  
Yiqing Lu ◽  
Wolf Singer
Keyword(s):  
Prior Knowledge ◽  
Creative Thinking ◽  
Right Hemisphere ◽  
Fractal Dimensionality ◽  
Neural Dynamics ◽  
Perceptual Task ◽  
Alpha Power ◽  
Beta Band ◽  
Manual Responses ◽  
The Right

AbstractThe Eureka effect refers to the common experience of suddenly solving a problem. Here we study this effect in a pattern recognition paradigm that requires the segmentation of complex scenes and recognition of objects on the basis of Gestalt rules and prior knowledge. In the experiments both sensory evidence and prior knowledge were manipulated in order to obtain trials that do or do not converge towards a perceptual solution. Subjects had to detect objects in blurred scenes and signal recognition with manual responses. Neural dynamics were analyzed with high-density Electroencephalography (EEG) recordings. The results show significant changes of neural dynamics with respect to spectral distribution, coherence, phase locking, and fractal dimensionality. The Eureka effect was associated with increased coherence of oscillations in the alpha and theta band over widely distributed regions of the cortical mantle predominantly in the right hemisphere. This increase in coherence was associated with a decrease of beta band activity over parietal and central regions, and with a decrease of alpha power over frontal and occipital areas. In addition, there was a lateralized reduction of fractal dimensionality for activity recorded from the right hemisphere. These results suggest that the transition towards the solution of a perceptual task is mainly associated with a change of network dynamics in the right hemisphere that is characterized by enhanced coherence and reduced complexity. We propose that the Eureka effect requires cooperation of cortical regions involved in working memory, creative thinking, and the control of attention.

scholarly journals Sustained Attention Ability Affects Simple Picture Naming

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Suzanne R. Jongman
Keyword(s):  
Sustained Attention ◽  
Picture Naming ◽  
Language Production ◽  
Event Rate ◽  
Naming Task ◽  
Attention Task ◽  
Event Rates ◽  
Speed Accuracy ◽  
Naming Latencies ◽  
Simple Picture

Sustained attention has previously been shown as a requirement for language production. However, this is mostly evident for difficult conditions, such as a dual-task situation. The current study provides corroborating evidence that this relationship holds even for simple picture naming. Sustained attention ability, indexed both by participants’ reaction times and individuals’ hit rate (the proportion of correctly detected targets) on a digit discrimination task, correlated with picture naming latencies. Individuals with poor sustained attention were consistently slower and their RT distributions were more positively skewed when naming pictures compared to individuals with better sustained attention. Additionally, the need to sustain attention was manipulated by changing the speed of stimulus presentation. Research has suggested that fast event rates tax sustained attention resources to a larger degree than slow event rates. However, in this study the fast event rate did not result in increased difficulty, neither for the picture naming task nor for the sustained attention task. Instead, the results point to a speed-accuracy trade-off in the sustained attention task (lower accuracy but faster responses in the fast than in the slow event rate), and to a benefit for faster rates in the picture naming task (shorter naming latencies with no difference in accuracy). Performance on both tasks was largely comparable, supporting previous findings that sustained attention is called upon during language production.

scholarly journals Joint language production: an electrophysiological investigation of simulated lexical access on behalf of task partner

2020 ◽  
Author(s):  
Anna K. Kuhlen ◽  
Rasha Abdel Rahman
Keyword(s):  
Lexical Access ◽  
Joint Action ◽  
Picture Naming ◽  
Language Production ◽  
Naming Latency ◽  
Semantic Category ◽  
Electrophysiological Investigation ◽  
Semantic Interference ◽  
Naming Response ◽  
Naming Latencies

AbstractThis study investigates in a joint action setting a well-established effect in speech production, cumulative semantic interference, an increase in naming latencies when naming a series of semantically related pictures. In a joint action setting, two task partners take turns naming pictures. Previous work in this setting demonstrated that naming latencies increase not only with each semantically related picture speakers named themselves, but also with each picture named by the partner (Hoedemaker, Ernst, Meyer, & Belke, 2017; Kuhlen & Abdel Rahman, 2017). This suggests that speakers pursue lexical access on behalf of their partner. In two electrophysiological experiments (N=30 each) we investigated the neuro-cognitive signatures of such simulated lexical access. As expected, in both experiments speakers’ naming latency increased with successive naming instances within a given semantic category. Correspondingly, speakers’ EEG showed an increasing posterior positivity between 250-400ms, an ERP modulation typically associated with lexical access. However, unlike previous experiments, speakers were not influenced by their partner’s picture naming. Accordingly, we found no electrophysiological evidence of lexical access on behalf of the partner. We conclude that speakers do not always represent their partner’s naming response and discuss possible factors that may have limited the participants’ evaluation of the task as a joint action.

Reactivating the Dormant Motor Cortex After Spinal Cord Injury With EEG Neurofeedback: A Case Study With a Chronic, Complete C4 Patient

2018 ◽  
Vol 50 (2) ◽  
pp. 100-110 ◽  
Author(s):  
Eduardo López-Larraz ◽  
Carlos Escolano ◽  
Luis Montesano ◽  
Javier Minguez
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Cortex ◽  
Cortical Activation ◽  
Alpha Power ◽  
Mu Rhythm ◽  
Cord Injury ◽  
Eeg Neurofeedback ◽  
Motor Cortical ◽  
Eeg Alpha

Chronic spinal cord injury (SCI) patients present poor motor cortex activation during movement attempts. The reactivation of this brain region can be beneficial for them, for instance, allowing them to use brain-machine interfaces for motor rehabilitation or restoration. These brain-machine interfacess generally use electroencephalography (EEG) to measure the cortical activation during the attempts of movement, quantifying it as the event-related desynchronization (ERD) of the alpha/mu rhythm. Based on previous evidence showing that higher tonic EEG alpha power is associated with higher ERD, we hypothesized that artificially increasing the alpha power over the motor cortex of these patients could enhance their ERD (ie, motor cortical activation) during movement attempts. We used EEG neurofeedback (NF) to enhance the tonic EEG alpha power, providing real-time visual feedback of the alpha oscillations measured over the motor cortex. This approach was evaluated in a C4, ASIA A, SCI patient (9 months after the injury) who did not present ERD during the movement attempts of his paralyzed hands. The patient performed 4 NF sessions (in 4 consecutive days) and screenings of his EEG activity before and after each session. After the intervention, the patient presented a significant increase in the alpha power over the motor cortex, and a significant enhancement of the mu ERD in the contralateral motor cortex when he attempted to close the assessed right hand. As a proof of concept investigation, this article shows how a short NF intervention might be used to enhance the motor cortical activation in patients with chronic tetraplegia.

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