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 ◽  
...  

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.

2001 ◽  
Vol 44 (4) ◽  
pp. 814-825 ◽  
Author(s):  
Christine Weber-Fox

The role of neurolinguistic factors in stuttering was investigated by determining whether individuals who stutter display atypical neural functions for language processing, even with no speech production demands. Event-related brain potentials (ERPs) were obtained while 9 individuals who stutter (IWS) and 9 normally fluent speakers (NS) read sentences silently. The ERPs were elicited by: (a) closed-class words that provide structural or grammatical information, (b) open-class words that convey referential meaning, and (c) semantic anomalies (violations in semantic expectation). In standardized tests, adult IWS displayed similar grammatical and lexical abilities in both comprehension and production tasks compared to their matched, normally fluent peers. Yet the ERPs elicited in IWS for linguistic processing tasks revealed differences in functional brain organization. The ERPs elicited in IWS were characterized by reduced negative amplitudes for closed-class words (N280), open-class words (N350), and semantic anomalies (N400) in a temporal window of approximately 200–450 ms after word onsets. The overall pattern of results indicates that alterations in processing for IWS are related to neural functions that are common to word classes and perhaps involve shared, underlying processes for lexical access.


2019 ◽  
Author(s):  
Umesh Vivekananda ◽  
Daniel Bush ◽  
James A Bisby ◽  
Sallie Baxendale ◽  
Roman Rodionov ◽  
...  

AbstractHippocampal theta oscillations have been implicated in spatial memory function in both rodents and humans. What is less clear is how hippocampal theta interacts with higher frequency oscillations during spatial memory function, and how this relates to subsequent behaviour. Here we asked ten human epilepsy patients undergoing intracranial EEG recording to perform a desk-top virtual reality spatial memory task, and found that increased theta power in two discrete bands (‘low’ 2-5Hz and ‘high’ 6-9Hz) during cued retrieval was associated with improved task performance. Similarly, increased coupling between ‘low’ theta phase and gamma amplitude during the same period was associated with improved task performance. These results support a role of theta oscillations and theta-gamma phase-amplitude coupling in human spatial memory function.


2020 ◽  
Author(s):  
Megha Ghosh ◽  
Benjamin E. Shanahan ◽  
Sharon C. Furtak ◽  
George A. Mashour ◽  
Rebecca D. Burwell ◽  
...  

ABSTRACTHippocampal theta oscillations have a temporally asymmetric waveform shape, but it is not known if this theta asymmetry extends to all other cortical regions involved in spatial navigation and memory. Here, using both established and improved cycle-by-cycle analysis methods, we show that theta waveforms in the postrhinal cortex are also temporally asymmetric. On average, the falling phase of postrhinal theta cycles lasts longer than the subsequent rising phase. There are, however, rapid changes in both the instantaneous amplitude and instantaneous temporal asymmetry of postrhinal theta cycles. These rapid changes in amplitude and asymmetry are very poorly correlated, indicative of a mechanistic disconnect between these theta cycle features. We show that the instantaneous amplitude and asymmetry of postrhinal theta cycles differentially encode running speed. Although theta amplitude continues to increase at the fastest running speeds, temporal asymmetry of the theta waveform shape plateaus after medium speeds. Our results suggest that the amplitude and waveform shape of individual postrhinal theta cycles may be governed by partially independent mechanisms and emphasize the importance of employing a single cycle approach to understanding the genesis and behavioral correlates of cortical theta rhythms.


Author(s):  
Mattson Ogg ◽  
L. Robert Slevc

Music and language are uniquely human forms of communication. What neural structures facilitate these abilities? This chapter conducts a review of music and language processing that follows these acoustic signals as they ascend the auditory pathway from the brainstem to auditory cortex and on to more specialized cortical regions. Acoustic, neural, and cognitive mechanisms are identified where processing demands from both domains might overlap, with an eye to examples of experience-dependent cortical plasticity, which are taken as strong evidence for common neural substrates. Following an introduction describing how understanding musical processing informs linguistic or auditory processing more generally, findings regarding the major components (and parallels) of music and language research are reviewed: pitch perception, syntax and harmonic structural processing, semantics, timbre and speaker identification, attending in auditory scenes, and rhythm. Overall, the strongest evidence that currently exists for neural overlap (and cross-domain, experience-dependent plasticity) is in the brainstem, followed by auditory cortex, with evidence and the potential for overlap becoming less apparent as the mechanisms involved in music and speech perception become more specialized and distinct at higher levels of processing.


Probus ◽  
2020 ◽  
Vol 32 (1) ◽  
pp. 93-127
Author(s):  
Bradley Hoot ◽  
Tania Leal

AbstractLinguists have keenly studied the realization of focus – the part of the sentence introducing new information – because it involves the interaction of different linguistic modules. Syntacticians have argued that Spanish uses word order for information-structural purposes, marking focused constituents via rightmost movement. However, recent studies have challenged this claim. To contribute sentence-processing evidence, we conducted a self-paced reading task and a judgment task with Mexican and Catalonian Spanish speakers. We found that movement to final position can signal focus in Spanish, in contrast to the aforementioned work. We contextualize our results within the literature, identifying three basic facts that theories of Spanish focus and theories of language processing should explain, and advance a fourth: that mismatches in information-structural expectations can induce processing delays. Finally, we propose that some differences in the existing experimental results may stem from methodological differences.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andrew J. Kesner ◽  
Rick Shin ◽  
Coleman B. Calva ◽  
Reuben F. Don ◽  
Sue Junn ◽  
...  

AbstractThe supramammillary region (SuM) is a posterior hypothalamic structure, known to regulate hippocampal theta oscillations and arousal. However, recent studies reported that the stimulation of SuM neurons with neuroactive chemicals, including substances of abuse, is reinforcing. We conducted experiments to elucidate how SuM neurons mediate such effects. Using optogenetics, we found that the excitation of SuM glutamatergic (GLU) neurons was reinforcing in mice; this effect was relayed by their projections to septal GLU neurons. SuM neurons were active during exploration and approach behavior and diminished activity during sucrose consumption. Consistently, inhibition of SuM neurons disrupted approach responses, but not sucrose consumption. Such functions are similar to those of mesolimbic dopamine neurons. Indeed, the stimulation of SuM-to-septum GLU neurons and septum-to-ventral tegmental area (VTA) GLU neurons activated mesolimbic dopamine neurons. We propose that the supramammillo-septo-VTA pathway regulates arousal that reinforces and energizes behavioral interaction with the environment.


2014 ◽  
Vol 19 (1) ◽  
pp. 1-18 ◽  
Author(s):  
EDITH KAAN ◽  
JOSEPH KIRKHAM ◽  
FRANK WIJNEN

According to recent views of L2-sentence processing, L2-speakers do not predict upcoming information to the same extent as do native speakers. To investigate L2-speakers’ predictive use and integration of syntactic information across clauses, we recorded event-related potentials (ERPs) from advanced L2-learners and native speakers while they read sentences in which the syntactic context did or did not allow noun-ellipsis (Lau, E., Stroud, C., Plesch, S., & Phillips, C. (2006). The role of structural prediction in rapid syntactic analysis. Brain and Language, 98, 74–88.) Both native and L2-speakers were sensitive to the context when integrating words after the potential ellipsis-site. However, native, but not L2-speakers, anticipated the ellipsis, as suggested by an ERP difference between elliptical and non-elliptical contexts preceding the potential ellipsis-site. In addition, L2-learners displayed a late frontal negativity for ungrammaticalities, suggesting differences in repair strategies or resources compared with native speakers.


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