scholarly journals Binding language: Structuring sentences through precisely timed oscillatory mechanisms

2017 ◽  
Author(s):  
Katrien Segaert ◽  
Ali Mazaheri ◽  
Peter Hagoort
Keyword(s):  
Target Word ◽  
Cognitive Processes ◽  
Alpha Power ◽  
Frequency Bands ◽  
Beta Power ◽  
Neural Processes ◽  
Data Driven Approach ◽  
Oscillatory Mechanisms ◽  
Beta Frequency ◽  
Syntactic Binding

AbstractSyntactic binding refers to combining words into larger structures. Using EEG, we investigated the neural processes involved in syntactic binding. Participants were auditorily presented two-word sentences (i.e. a pronoun and pseudoverb such as ‘she dotches’, for which syntactic binding can take place) and wordlists (i.e. two pseudoverbs such as ‘pob dotches’, for which no binding can occur). Comparing these two conditions, we targeted syntactic binding while minimizing contributions of semantic binding and of other cognitive processes such as working memory. We found a converging pattern of results using two distinct analysis approaches: one approach using frequency bands as defined in previous literature, and one data-driven approach in which we looked at the entire range of frequencies between 3-30 Hz without the constraints of pre-defined frequency bands. In the syntactic binding (relative to the wordlist) condition, a power increase was observed in the alpha and beta frequency range shortly preceding the presentation of the target word that requires binding, which was maximal over frontal-central electrodes. Our interpretation is that these signatures reflect that language comprehenders expect the need for binding to occur. Following the presentation of the target word in a syntactic binding context (relative to the wordlist condition), an increase in alpha power maximal over a left lateralized cluster of frontal-temporal electrodes was observed. We suggest that this alpha increase relates to syntactic binding taking place. Taken together, our findings suggest that increases in alpha and beta power are reflections of distinct the neural processes underlying syntactic binding.

scholarly journals Modulation in Alpha Band Activity Reflects Syntax Composition: An MEG Study of Minimal Syntactic Binding

2021 ◽  
Author(s):  
Sophie M Hardy ◽  
Ole Jensen ◽  
Linda Wheeldon ◽  
Ali Mazaheri ◽  
Katrien Segaert
Keyword(s):  
Target Word ◽  
Sentence Comprehension ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Inferior Temporal Cortex ◽  
Alpha Power ◽  
Sentence Structure ◽  
Alpha Band ◽  
Syntactic Binding

Successful sentence comprehension requires the binding, or composition, of multiple words into larger structures to establish meaning. Using magnetoencephalography (MEG), we investigated the neural mechanisms involved in binding of language at the level of syntax, in a task in which contributions from semantics were minimized. Participants were auditorily presented with minimal sentences that required binding (pronoun and pseudo-verb with the corresponding morphological inflection; "she grushes") and wordlists that did not require binding (two pseudo-verbs; "cugged grushes"). Relative to the no binding wordlist condition, we found that syntactic binding in a minimal sentence structure was associated with a modulation in alpha band (8-12 Hz) activity in left-lateralized brain regions. First, in the sentence condition, we observed a significantly smaller increase in alpha power around the presentation of the target word ("grushes") that required binding (-0.05s to 0.1s), which we suggest reflects an expectation of binding to occur. Second, following the presentation of the target word (around 0.15s to 0.25s), during syntactic binding we observed significantly decreased alpha phase-locking between the left inferior frontal gyrus and the left middle/inferior temporal cortex. We suggest that this results from alpha-driven cortical disinhibition serving to increase information transfer between these two brain regions and strengthen the syntax composition neural network. Together, our findings highlight that successful syntax composition is underscored by the rapid spatial-temporal activation and coordination of language-relevant brain regions, and that alpha band oscillations are critically important in controlling the allocation and transfer of the brain's resources during syntax composition.

scholarly journals Quantitative Eeg as a Biomarker in Mild Cognitive Impairment With Lewy Bodies

2020 ◽  
Author(s):  
Julia Schumacher ◽  
John-Paul Taylor ◽  
Calum A. Hamilton ◽  
Michael Firbank ◽  
Ruth A. Cromarty ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Lewy Bodies ◽  
Quantitative Eeg ◽  
Dominant Frequency ◽  
Alpha Power ◽  
Healthy Controls ◽  
Operating Characteristics ◽  
Frequency Bands ◽  
Beta Power

Abstract Objectives:To investigate using quantitative EEG (1) differencesbetween patients with mild cognitive impairment with Lewy bodies (MCI-LB) and MCI with Alzheimer’s disease (MCI-AD) and (2) its utilityas a potential biomarker for early differential diagnosis.Methods:We analyzed eyes-closed, resting state, high-density EEG data from highly phenotyped participants (39 MCI-LB, 36 MCI-AD, and 31 healthy controls). EEG measures included spectral power in different frequency bands (delta, theta, pre-alpha, alpha, and beta), theta/alpha ratio, dominant frequency, and dominant frequency variability.Receiver operating characteristics (ROC) analyses were performed to assess diagnostic accuracy.Results:There was a shift in power from beta and alpha frequency bands towards slower frequencies in the pre-alpha and theta range in MCI-LB compared to healthy controls. Additionally, dominant frequency was slower in MCI-LB compared to controls. We found significantly increased pre-alpha power, decreased beta power, and slower dominant frequency in MCI-LB compared to MCI-AD. EEG abnormalities were more apparent in MCI-LB cases with more diagnostic features.There were no significant differences between MCI-AD and controls. In the ROC analysis, beta power and dominant frequency showed the highest area under the curve values of 0.71 and 0.70, respectively. While specificity was high for some measures (up to 0.97 for alpha power and 0.94 for theta/alpha ratio), sensitivity was generally much lower. Conclusions:Early EEG slowing is a specific feature of MCI-LB compared to MCI-AD.However, there is overlap between the two MCI groups which makes it difficult to distinguish between them based on EEG alone.

scholarly journals Relating neural oscillations to laminar fMRI connectivity

2020 ◽  
Author(s):  
René Scheeringa ◽  
Mathilde Bonnefond ◽  
Tim van Mourik ◽  
Ole Jensen ◽  
David G. Norris ◽  
...  
Keyword(s):  
Brain Regions ◽  
Superficial Layer ◽  
Gamma Band ◽  
Alpha Power ◽  
Beta Band ◽  
Beta Power ◽  
Neural Processes ◽  
Complex Picture ◽  
Deep Layers ◽  
Strong Relation

AbstractLaminar fMRI can non-invasively study brain activation and potentially connectivity at the laminar level in humans. In a previous simultaneous laminar fMRI/EEG experiment, we observed that attention effects in alpha, beta and gamma band EEG power relate to attention effects in fMRI activation in V1/V2/V3 at distinct cortical depths: alpha and gamma band EEG attention effects related to fMRI effects in superficial layers, whereas beta attention effects related to deep layers. Here we reanalyzed these data to investigate how EEG-attention effects relate to changes in connectivity between regions. We computed the fMRI-based attention effect on laminar connectivity between regions within a hemisphere and connectivity between layers within brain regions. We observed that the beta band strongly relates to laminar specific changes in connectivity. Our results indicate that the attention-related decrease in beta power relates to an increase in deep-to-deep layer connectivity between regions and deep/middle to superficial layer connectivity within brain regions. The attention related alpha power increase predominantly relates to increases in connectivity between deep and superficial layers within brain regions. We observed no strong relation between laminar connectivity and gamma band oscillations. These results indicate that especially beta band oscillations, and to a lesser extent alpha band oscillations relate to laminar specific changes in connectivity as measured by laminar fMRI. Together, the effects for the alpha and beta bands suggest a complex picture of possibly co-occurring neural processes that can differentially affect laminar connectivity.

scholarly journals Quantitative EEG as a biomarker in mild cognitive impairment with Lewy bodies

2020 ◽  
Author(s):  
Julia Schumacher ◽  
John-Paul Taylor ◽  
Calum A. Hamilton ◽  
Michael Firbank ◽  
Ruth A. Cromarty ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Lewy Bodies ◽  
Quantitative Eeg ◽  
Dominant Frequency ◽  
Alpha Power ◽  
Healthy Controls ◽  
Operating Characteristics ◽  
Frequency Bands ◽  
Beta Power

Abstract Objectives: To investigate using quantitative EEG (1) differences between patients with mild cognitive impairment with Lewy bodies (MCI-LB) and MCI with Alzheimer’s disease (MCI-AD) and (2) its utility as a potential biomarker for early differential diagnosis. Methods: We analyzed eyes-closed, resting state, high-density EEG data from highly phenotyped participants (39 MCI-LB, 36 MCI-AD, and 31 healthy controls). EEG measures included spectral power in different frequency bands (delta, theta, pre-alpha, alpha, and beta), theta/alpha ratio, dominant frequency, and dominant frequency variability. Receiver operating characteristics (ROC) analyses were performed to assess diagnostic accuracy. Results: There was a shift in power from beta and alpha frequency bands towards slower frequencies in the pre-alpha and theta range in MCI-LB compared to healthy controls. Additionally, dominant frequency was slower in MCI-LB compared to controls. We found significantly increased pre-alpha power, decreased beta power, and slower dominant frequency in MCI-LB compared to MCI-AD. EEG abnormalities were more apparent in MCI-LB cases with more diagnostic features. There were no significant differences between MCI-AD and controls. In the ROC analysis to distinguish MCI-LB from MCI-AD, beta power and dominant frequency showed the highest area under the curve values of 0.71 and 0.70, respectively. While specificity was high for some measures (up to 0.97 for alpha power and 0.94 for theta/alpha ratio), sensitivity was generally much lower. Conclusions: Early EEG slowing is a specific feature of MCI-LB compared to MCI-AD. However, there is overlap between the two MCI groups which makes it difficult to distinguish between them based on EEG alone.

scholarly journals Linking the Rapid Cascade of Visuo-Attentional Processes to Successful Memory Encoding

2020 ◽  
Author(s):  
B R Geib ◽  
R Cabeza ◽  
M G Woldorff
Keyword(s):  
Visual Processing ◽  
Memory Retrieval ◽  
Current Knowledge ◽  
High Temporal Resolution ◽  
Alpha Power ◽  
Attentional Orienting ◽  
Memory Encoding ◽  
Attentional Processes ◽  
Neural Processes ◽  
Dm Effect

Abstract While it is broadly accepted that attention modulates memory, the contribution of specific rapid attentional processes to successful encoding is largely unknown. To investigate this issue, we leveraged the high temporal resolution of electroencephalographic recordings to directly link a cascade of visuo-attentional neural processes to successful encoding: namely (1) the N2pc (peaking ~200 ms), which reflects stimulus-specific attentional orienting and allocation, (2) the sustained posterior-contralateral negativity (post-N2pc), which has been associated with sustained visual processing, (3) the contralateral reduction in oscillatory alpha power (contralateral reduction in alpha > 200 ms), which has also been independently related to attentionally sustained visual processing. Each of these visuo-attentional processes was robustly predictive of successful encoding, and, moreover, each enhanced memory independently of the classic, longer-latency, conceptually related, difference-due-to memory (Dm) effect. Early latency midfrontal theta power also promoted successful encoding, with at least part of this influence being mediated by the later latency Dm effect. These findings markedly expand current knowledge by helping to elucidate the intimate relationship between attentional modulations of perceptual processing and effective encoding for later memory retrieval.

scholarly journals Neurophysiological and behavioural effects of conventional and high definition tDCS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabio Masina ◽  
Giorgio Arcara ◽  
Eleonora Galletti ◽  
Isabella Cinque ◽  
Luciano Gamberini ◽  
...  
Keyword(s):  
Response Times ◽  
Power Reduction ◽  
Alpha Power ◽  
High Definition ◽  
Mixed Effect ◽  
State Dependency ◽  
Mixed Effect Models ◽  
Beta Power ◽  
Neurophysiological Data ◽  
Spectrum Density

AbstractHigh-definition transcranial direct current stimulation (HD-tDCS) seems to overcome a drawback of traditional bipolar tDCS: the wide-spread diffusion of the electric field. Nevertheless, most of the differences that characterise the two techniques are based on mathematical simulations and not on real, behavioural and neurophysiological, data. The study aims to compare a widespread tDCS montage (i.e., a Conventional bipolar montage with extracephalic return electrode) and HD-tDCS, investigating differences both at a behavioural level, in terms of dexterity performance, and a neurophysiological level, as modifications of alpha and beta power as measured with EEG. Thirty participants took part in three sessions, one for each montage: Conventional tDCS, HD-tDCS, and sham. In all the conditions, the anode was placed over C4, while the cathode/s placed according to the montage. At baseline, during, and after each stimulation condition, dexterity was assessed with a Finger Tapping Task. In addition, resting-state EEG was recorded at baseline and after the stimulation. Power spectrum density was calculated, selecting two frequency bands: alpha (8–12 Hz) and beta (18–22 Hz). Linear mixed effect models (LMMs) were used to analyse the modulation induced by tDCS. To evaluate differences among the montages and consider state-dependency phenomenon, the post-stimulation measurements were covariate-adjusted for baseline levels. We observed that HD-tDCS induced an alpha power reduction in participants with lower alpha at baseline. Conversely, Conventional tDCS induced a beta power reduction in participants with higher beta at baseline. Furthermore, data showed a trend towards a behavioural effect of HD-tDCS in participants with lower beta at baseline showing faster response times. Conventional and HD-tDCS distinctively modulated cortical activity. The study highlights the importance of considering state-dependency to determine the effects of tDCS on individuals.

Constructive realism: In defense of the objective reality of perspectives

Human Affairs ◽  
2013 ◽  
Vol 23 (4) ◽  
Author(s):  
Roman Madzia
Keyword(s):  
Cognitive Processes ◽  
John Dewey ◽  
William James ◽  
Cognitive Sciences ◽  
Objective Reality ◽  
Constructive Realism ◽  
Neural Processes ◽  
The World ◽  
Epistemological Position ◽  
Epistemological Realism

AbstractThe paper proposes an outline of a reconciliatory approach to the perennial controversy between epistemological realism and anti-realism (constructionism). My main conceptual source in explaining this view is the philosophy of pragmatism, more specifically, the epistemological theories of George H. Mead, John Dewey, and also William James’ radical empiricism. First, the paper analyzes the pragmatic treatment of the goal-directedness of action, especially with regard to Mead’s notion of attitudes, and relates it to certain contemporary epistemological theories provided by the cognitive sciences (Maturana, Rizzolatti, Clark). Against this background, the paper presents a philosophical as well as empirical justification of why we should interpret the environment and its objects in terms of possibilities for action. In Mead’s view, the objects and events of our world emerge within stable patterns of organism-environment interactions, which he called “perspectives”. According to pragmatism as well as the aforementioned cognitive scientists, perception and other cognitive processes include not only neural processes in our heads but also the world itself. Elaborating on Mead’s concept of perspectives, the paper argues in favor of the epistemological position called “constructive realism.”

scholarly journals Eye-Fixation-Related Potentials: Insight into Parafoveal Processing

2005 ◽  
Vol 19 (3) ◽  
pp. 204-215 ◽  
Author(s):  
Thierry Baccino ◽  
Yves Manunta
Keyword(s):  
Target Word ◽  
Cognitive Processes ◽  
Event Related Potentials ◽  
Semantic Relatedness ◽  
Word Type ◽  
Factors Affecting ◽  
Eye Fixation ◽  
Related Potentials ◽  
The Right ◽  
Nonword Processing

Abstract. This paper presents a new methodology for studying cognition, which combines eye movements (EM) and event-related potentials (ERP) to track the cognitive processes that occur during a single eye fixation. This technique, called eye-fixation-related potentials (EFRP), has the advantage of coupling accurate time measures from ERPs and the location of the eye on the stimulus, so it can be used to disentangle perceptual/attentional/cognitive factors affecting reading. We tested this new technique to describe the controversial parafoveal-on-foveal effects on reading, which concern the question of whether two consecutive words are processed in parallel or sequentially. The experiment directly addressed this question by looking at whether semantic relatedness on a target word in a reading-like situation might affect the processing of a prime word. Three pair-word conditions were tested: A semantically associated target word (horse-mare), a semantically nonassociated target word (horse-table) and a nonword (horse-twsui); EFRPs were compared for all conditions. The results revealed that early ERP components differentiated word and nonword processing within 119 ms postfixation (N1 component). Moreover, the amplitude of the right centrofrontal P140 varied as a function of word type, being larger in response to nonassociated words than to nonwords. This component might index a spatial attention shift to the target word and its visual categorization, being highly sensitive to orthographic regularity and “ill-formedness” of words. The P2 consecutive component (peaking at 215 ms) differentiated associated words and nonassociated words, which can account for the semantic parafoveal effect. The EFRP technique, therefore, appears to be fruitful for establishing a time-line of early cognitive processes during reading.

scholarly journals The Significance of Neural Inter-Frequency Correlations

2021 ◽  
Author(s):  
Oscar Wiljam Savolainen
Keyword(s):  
Multiple Testing ◽  
Statistical Significance ◽  
Significance Test ◽  
Stationary Time Series ◽  
Frequency Bands ◽  
Neural Recordings ◽  
Time Frequency ◽  
Common Information ◽  
Neural Processes ◽  
Long Term Trends

Abstract It is of great interest in neuroscience to determine what frequency bands in the brain contain common information. However, to date, a comprehensive statistical approach to this question has been lacking. As such, this work presents a novel statistical significance test for correlated power across frequency bands in non-stationary time series. The test accounts for biases that often go untreated in time-frequency analysis, i.e. intra-frequency autocorrelation, inter-frequency non-dyadicity, and multiple testing under dependency. It is used to test all of the inter-frequency correlations between 0.2 and 8500 Hz in continuous intracortical extracellular neural recordings, using a very large, publicly available dataset. The results show that neural processes have signatures across a very broad range of frequency bands. In particular, LFP frequency bands as low as 20 Hz were found to almost always be significantly correlated to kHz frequency ranges. This test also has applications in a broad range of fields, e.g. biological signal processing, economics, finance, climatology, etc. It is useful whenever one wants to robustly determine whether short-term components in a signal are robustly related to long-term trends, or what frequencies contain common information.

How Does the Waking and Sleeping Brain Produce Spontaneous Thought and Imagery, and Why?

2018 ◽  
Author(s):  
John S. Antrobus
Keyword(s):  
Cognitive Processes ◽  
Mind Wandering ◽  
Future Research ◽  
Neural Processes ◽  
Hard Evidence ◽  
Future Value ◽  
Spontaneous Imagery ◽  
Spontaneous Thought

Although mind-wandering and dreaming often appear as trivial or distracting cognitive processes, this chapter suggests that they may also contribute to the evaluation, sorting, and saving of representations of recent events of future value to an individual. But 50 years after spontaneous imagery—night dreaming—was first compared to concurrent cortical EEG, there is limited hard evidence on the neural processes that produce either visual dreaming imagery or the speech imagery of waking spontaneous thought. The authors propose here an outline of a neurocognitive model of such processes with suggestions for future research that may contribute to a better understanding of their utility.

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