scholarly journals Theta/delta coupling across cortical laminae contributes to semantic cognition

2019 ◽  
Vol 121 (4) ◽  
pp. 1150-1161 ◽  
Author(s):  
Natalie E. Adams ◽  
Catarina Teige ◽  
Giovanna Mollo ◽  
Theodoros Karapanagiotidis ◽  
Piers L. Cornelissen ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Rhythmic Activity ◽  
Brain Regions ◽  
Decision Task ◽  
Distributed Network ◽  
Spatially Distributed ◽  
Semantic Decision ◽  
Semantic Decision Task ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

Rhythmic activity in populations of neurons is associated with cognitive and motor function. Our understanding of the neuronal mechanisms underlying these core brain functions has benefitted from demonstrations of cellular, synaptic, and network phenomena, leading to the generation of discrete rhythms at the local network level. However, discrete frequencies of rhythmic activity rarely occur alone. Despite this, little is known about why multiple rhythms are generated together or what mechanisms underlie their interaction to promote brain function. One overarching theory is that different temporal scales of rhythmic activity correspond to communication between brain regions separated by different spatial scales. To test this, we quantified the cross-frequency interactions between two dominant rhythms—theta and delta activity—manifested during magnetoencephalography recordings of subjects performing a word-pair semantic decision task. Semantic processing has been suggested to involve the formation of functional links between anatomically disparate neuronal populations over a range of spatial scales, and a distributed network was manifest in the profile of theta-delta coupling seen. Furthermore, differences in the pattern of theta-delta coupling significantly correlated with semantic outcome. Using an established experimental model of concurrent delta and theta rhythms in neocortex, we show that these outcome-dependent dynamics could be reproduced in a manner determined by the strength of cholinergic neuromodulation. Theta-delta coupling correlated with discrete neuronal activity motifs segregated by the cortical layer, neuronal intrinsic properties, and long-range axonal targets. Thus, the model suggested that local, interlaminar neocortical theta-delta coupling may serve to coordinate both cortico-cortical and cortico-subcortical computations during distributed network activity. NEW & NOTEWORTHY Here, we show, for the first time, that a network of spatially distributed brain regions can be revealed by cross-frequency coupling between delta and theta frequencies in subjects using magnetoencephalography recording during a semantic decision task. A biological model of this cross-frequency coupling suggested an interlaminar, cell-specific division of labor within the neocortex may serve to route the flow of cortico-cortical and cortico-subcortical information to promote such spatially distributed, functional networks.

The role of phonology in visual word recognition

2009 ◽  
Vol 11 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Martina Penke ◽  
Kathrin Schrader
Keyword(s):  
Word Recognition ◽  
Visual Word Recognition ◽  
Age Groups ◽  
Reading Proficiency ◽  
Visual Word ◽  
Decision Task ◽  
Semantic Field ◽  
Semantic Decision ◽  
Semantic Decision Task ◽  
The Given

The goal of this paper is to investigate the role phonology plays for visual word recognition and the change this role undergoes in the course of reading acquisition by providing data on German readers at different stages of reading proficiency. Erroneous responses in a semantic decision task, which employs words that are either homophonous or graphemically similar to a word of a previously introduced semantic field, were compared at different stages of reading development (i.e. in second- and fourth-grade school children and adults). In all age groups, subjects committed significantly more errors with homophones than with words graphemically similar to a word related to the given semantic field. The results show that phonological recoding plays an important role for visual word recognition not only with beginners but also in skilled readers and, hence, corroborate phonological models of reading.

The Relationship of BOLD and Flow Sensitive fMRI Across Sensory and Association Cortices During a Semantic Decision Task

NeuroImage ◽  
1998 ◽  
Vol 7 (4) ◽  
pp. S264
Author(s):  
J.M. Goodman ◽  
A.D. Wagner ◽  
K. Kwong ◽  
R.M. Weisskoff ◽  
B.R. Rosen
Keyword(s):  
Decision Task ◽  
Semantic Decision ◽  
Semantic Decision Task ◽  
Relationship Of ◽  
The Relationship

scholarly journals Faulty Suppression of Irrelevant Material in Patients with Thought Disorder Linked to Attenuated Frontotemporal Activation

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
S. M. Arcuri ◽  
M. R. Broome ◽  
V. Giampietro ◽  
E. Amaro ◽  
T. T. J. Kircher ◽  
...  
Keyword(s):  
Language Processing ◽  
Semantic Processing ◽  
Event Related Potential ◽  
Thought Disorder ◽  
Decision Task ◽  
Formal Thought Disorder ◽  
Specific Effects ◽  
Semantic Decision ◽  
Semantic Decision Task ◽  
Schizophrenic Patients

Formal thought disorder is a feature schizophrenia that manifests as disorganized, incoherent speech, and is associated with a poor clinical outcome. The neurocognitive basis of this symptom is unclear but it is thought to involve an impairment in semantic processing classically described as a loosening of meaningful associations. Using a paradigm derived from the n400 event-related, potential, we examined the extent to which regional activation during semantic processing is altered in schizophrenic patients with formal thought disorder. Ten healthy control and 18 schizophrenic participants (9 with and 9 without formal thought disorder) performed a semantic decision sentence task during an event-related functional magnetic resonance imaging experiment. We employed analysis of variance to estimate the main effects of semantic congruency and groups on activation and specific effects of formal thought disorder were addressed using post-hoc comparisons. We found that the frontotemporal network, normally engaged by a semantic decision task, was underactivated in schizophrenia, particularly in patients with FTD. This network is implicated in the inhibition of automatically primed stimuli and impairment of its function interferes with language processing and contributes to the production of incoherent speech.

scholarly journals Differential Contributions of Bilateral Ventral Anterior Temporal Lobe and Left Anterior Superior Temporal Gyrus to Semantic Processes

2011 ◽  
Vol 23 (10) ◽  
pp. 3121-3131 ◽  
Author(s):  
M. Visser ◽  
M. A. Lambon Ralph
Keyword(s):  
Semantic Processing ◽  
Superior Temporal Gyrus ◽  
Auditory Stimuli ◽  
Decision Task ◽  
Environmental Sound ◽  
Environmental Sounds ◽  
Semantic Decision ◽  
Semantic Decision Task ◽  
Left And Right ◽  
Semantic Processes

Studies of semantic dementia and repetitive TMS have suggested that the bilateral anterior temporal lobes (ATLs) underpin a modality-invariant representational hub within the semantic system. However, it is not clear whether all ATL subregions contribute in the same way. We utilized distortion-corrected fMRI to investigate the pattern of activation in the left and right ATL when participants performed a semantic decision task on auditory words, environmental sounds, or pictures. This showed that the ATL is not functionally homogeneous but is more graded. Both left and right ventral ATL (vATL) responded to all modalities in keeping with the notion that this region underpins multimodality semantic processing. In addition, there were graded differences across the hemispheres. Semantic processing of both picture and environmental sound stimuli was associated with equivalent bilateral vATL activation, whereas auditory words generated greater activation in left than right vATL. This graded specialization for auditory stimuli would appear to reflect the input from the left superior ATL, which responded solely to semantic decisions on the basis of spoken words and environmental sounds, suggesting that this region is specialized to auditory stimuli. A final noteworthy result was that these regions were activated for domain level decisions to singly presented stimuli, which appears to be incompatible with the hypotheses that the ATL is dedicated (a) to the representation of specific entities or (b) for combinatorial semantic processes.

scholarly journals Perspectives of Non-Gaussianity in Atmospheric Synoptic and Low-Frequency Variability

2015 ◽  
Vol 28 (13) ◽  
pp. 5091-5114 ◽  
Author(s):  
Philip Sura ◽  
Abdel Hannachi
Keyword(s):  
Spatial Scales ◽  
Low Frequency ◽  
Atmospheric Sciences ◽  
Low Frequency Variability ◽  
Weather And Climate ◽  
Exact Shape ◽  
Gaussian Statistics ◽  
Frequency Coupling ◽  
Non Gaussian ◽  
Cross Frequency Coupling

Abstract Understanding non-Gaussian statistics of atmospheric synoptic and low-frequency variability has important consequences in the atmospheric sciences, not least because weather and climate risk assessment depends on knowing and understanding the exact shape of the system’s probability density function. While there is no doubt that many atmospheric variables exhibit non-Gaussian statistics on many time (and spatial) scales, a full and complete understanding of this phenomenon remains a challenge. Various mechanisms behind the observed atmospheric non-Gaussian statistics have been proposed but remain, however, multifaceted and scattered in the literature: nonlinear dynamics, multiplicative noise, cross-frequency coupling, nonlinear boundary layer drag, and others. Given the importance of this subject for weather and climate research, and in an attempt to contribute to this topic, a thorough review and discussion of the different mechanisms that lead to non-Gaussian weather and climate variability are presented in this paper and an outlook is given.

scholarly journals Orthography and phonology in reading Japanese kanji words: Evidence from the semantic decision task with homophones

1998 ◽  
Vol 26 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Naoko Sakuma ◽  
Sumiko Sasanuma ◽  
Itaru F. Tatsumi ◽  
Shinobu Masaki
Keyword(s):  
Decision Task ◽  
Semantic Decision ◽  
Semantic Decision Task

scholarly journals Epileptogenic Zone Location of Temporal Lobe Epilepsy by Cross-Frequency Coupling Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaotong Liu ◽  
Fang Han ◽  
Rui Fu ◽  
Qingyun Wang ◽  
Guoming Luan
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Single Channel ◽  
Brain Networks ◽  
Brain Regions ◽  
Functional Network ◽  
Epileptogenic Zone ◽  
Coupling Analysis ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

Epilepsy is a chronic brain disease with dysfunctional brain networks, and electroencephalography (EEG) is an important tool for epileptogenic zone (EZ) identification, with rich information about frequencies. Different frequency oscillations have different contributions to brain function, and cross-frequency coupling (CFC) has been found to exist within brain regions. Cross-channel and inter-channel analysis should be both focused because they help to analyze how epilepsy networks change and also localize the EZ. In this paper, we analyzed long-term stereo-electroencephalography (SEEG) data from 17 patients with temporal lobe epilepsy. Single-channel and cross-channel CFC features were combined to establish functional brain networks, and the network characteristics under different periods and the localization of EZ were analyzed. It was observed that theta–gamma phase amplitude coupling (PAC) within the electrodes in the seizure region increased during the ictal (p < 0.05). Theta–gamma and delta–gamma PAC of cross-channel were enhanced in the early and mid-late ictal, respectively. It was also found that there was a strong cross-frequency coupling state between channels of EZ in the functional network during the ictal, along with a more regular network than interictal. The accuracy rate of EZ localization was 82.4%. Overall, the combination of single-channel and multi-channel cross-band coupling analysis can help identify seizures and localize EZ for temporal lobe epilepsy. Rhythmic coupling reveals a relationship between the functional network and the seizure status of epilepsy.

scholarly journals Semantic priming study of Russian aspect and resultativity

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Olga Batiukova ◽  
Pier Marco Bertinetto ◽  
Alessandro Lenci ◽  
Alessandra Zarcone
Keyword(s):  
Semantic Priming ◽  
Decision Task ◽  
Morphological Complexity ◽  
Semantic Decision ◽  
Russian Aspect ◽  
Semantic Decision Task ◽  
Induction Experiment ◽  
Morphological Cues ◽  
The Impact

This paper reports four priming experiments, in which resultative, processual, and delimitative Russian verbs were tested. The experiments were based on the semantic decision task: the participants had to decide whether the target denoted an event / situation with a clear outcome. To assess the impact of morphological cues on the decision latencies, verbs of different morphological complexity (prefixed and unprefixed perfectives) were used. The results obtained suggest that the aspectual feature of resultativity is consistently exploited in semantic priming (processual targets were primed in two experiments), and that the morphological cues facilitate the identification of resultative targets (prefixed perfectives exhibited faster decision latencies than unprefixed perfectives). As far as the delimitative forms are concerned, a category-induction experiment was designed to investigate the subjects’ tendency to group them with resultatives or with processuals, since the delimitatives represent an in-between category. The proportion of yes/no answers confirmed that the speakers place the delimitatives between these two domains, but much closer to the processuals than to the resultatives. These findings support the distinction of boundedness vs. telicity from both the theoretical and the behavioural perspective. The fact that the resultative interpretation of the delimitatives was not ruled out completely for most verbs suggests that, when certain conditions are met (when no cognate resultative form is readily available and when the delimitative is frequent enough), the delimitative can be conceptualized as the perfective counterpart of the basic imperfective, thus taking on the prototypical perfective role (resultativity).

Noninvasive Language Mapping in Patients With Epilepsy or Brain Tumors

Neurosurgery ◽  
2012 ◽  
Vol 72 (4) ◽  
pp. 555-565 ◽  
Author(s):  
Melanie Genetti ◽  
Frederic Grouiller ◽  
Serge Vulliemoz ◽  
Laurent Spinelli ◽  
Margitta Seeck ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Focal Epilepsy ◽  
Decision Task ◽  
Language Mapping ◽  
Resective Surgery ◽  
Language Outcome ◽  
Semantic Decision ◽  
Semantic Decision Task ◽  
Language Areas ◽  
Patients With Epilepsy

Abstract BACKGROUND: Functional magnetic resonance imaging (fMRI) has become part of routine brain mapping in patients with epilepsy or tumor undergoing resective surgery. However, robust localization of crucial functional areas is required. OBJECTIVE: To establish a simple, short fMRI task that reliably localizes crucial language areas in individual patients who undergo respective surgery. METHODS: fMRI was measured during an 8-minute auditory semantic decision task in 28 healthy controls and 35 consecutive patients who had focal epilepsy or a brain tumor. Nineteen underwent resective surgery. Group and individual analyses were performed. Results in patients were compared with postsurgical language outcome and electrocortical stimulation when available. RESULTS: fMRI activations concordant with the anterior and posterior language areas were found in 96% and 89% of the controls, respectively. The anterior and posterior language areas were both activated in 93% of the patients. These results were concordant with electrocortical stimulation results in 5 patients. Transient postsurgical language deficits were found in 2 patients in whom surgery was performed in the vicinity of the fMRI activations or who had postsurgical complications implicating areas of fMRI activations. CONCLUSION: The proposed fast fMRI language protocol reliably localized the most relevant language areas in individual subjects. It appears to be a valuable complementary tool for surgical planning of epileptogenic foci and of brain tumors.

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