scholarly journals Visual category representations in the infant brain

2021 ◽  
Author(s):  
Siying Xie ◽  
Stefanie Hoehl ◽  
Merle Moeskops ◽  
Ezgi Kayhan ◽  
Christian Kliesch ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Developmental Trajectory ◽  
Cognitive Capacity ◽  
Visual Features ◽  
Neural Oscillations ◽  
High Complexity ◽  
Theta Band ◽  
Beta Band ◽  
Key Characteristics ◽  
Infant Brain

Visual categorization is a human core cognitive capacity that depends on the development of visual category representations in the infant brain. The nature of infant visual category representations and their relationship to the corresponding adult form however remain unknown. Our results clarify the nature of visual category representations in 6- to 8-month-old infants and their developmental trajectory towards adult maturity in the key characteristics temporal dynamics, representational format, and spectral properties. Temporal dynamics change from slowly emerging, developing representations in infants to quickly emerging, complex representations in adults. Despite those differences infants and adults already partly share visual category representations. The format of infants' representations are visual features of low to intermediate complexity, whereas adults' representations also encoded high complexity features. Theta band neural oscillations form the basis of visual category representations in infants, and these representations are shifted to the alpha/beta band in adults.

scholarly journals Neural oscillations reflect meaning identification for novel words in context

2021 ◽  
pp. 1-40
Author(s):  
Jacob Pohaku Momsen ◽  
Alyson D. Abel
Keyword(s):  
Language Processing ◽  
Memory Retrieval ◽  
Contextual Information ◽  
Neural Oscillations ◽  
The Novel ◽  
Theta Band ◽  
Beta Band ◽  
New Words ◽  
Meaning Representation ◽  
Novel Words

Abstract During language processing, people make rapid use of contextual information to promote comprehension of upcoming words. When new words are learned implicitly, information contained in the surrounding context can provide constraints on their possible meaning. In the current study, EEG was recorded as participants listened to a series of three sentences, each containing an identical target pseudoword, with the aim of using contextual information in the surrounding language to identify a meaning representation for the novel word. In half of trials, sentences were semantically coherent so that participants could develop a single representation for the novel word that fit all contexts. Other trials contained unrelated sentence contexts so that meaning associations were not possible. We observed greater theta band enhancement over the left-hemisphere across central and posterior electrodes in response to pseudowords processed across semantically related compared to unrelated contexts. Additionally, relative alpha and beta band suppression was increased prior to pseudoword onset in trials where contextual information more readily promoted pseudoword-meaning associations. Under the hypothesis that theta enhancement indexes processing demands during lexical access, the current study provides evidence for selective online memory retrieval to novel words learned implicitly in a spoken context.

scholarly journals Dissociable oscillatory networks support gain and loss processing in human orbitofrontal cortex

2021 ◽  
Author(s):  
Ignacio Saez ◽  
Jack Lin ◽  
Edward Chang ◽  
Josef Parvizi ◽  
Robert T. Knight ◽  
...  
Keyword(s):  
Neural Activity ◽  
Orbitofrontal Cortex ◽  
Low Frequency ◽  
Brain Regions ◽  
Reward Processing ◽  
Neural Oscillations ◽  
Beta Band ◽  
Neuronal Ensembles ◽  
Gain And Loss

AbstractHuman neuroimaging and animal studies have linked neural activity in orbitofrontal cortex (OFC) to valuation of positive and negative outcomes. Additional evidence shows that neural oscillations, representing the coordinated activity of neuronal ensembles, support information processing in both animal and human prefrontal regions. However, the role of OFC neural oscillations in reward-processing in humans remains unknown, partly due to the difficulty of recording oscillatory neural activity from deep brain regions. Here, we examined the role of OFC neural oscillations (<30Hz) in reward processing by combining intracranial OFC recordings with a gambling task in which patients made economic decisions under uncertainty. Our results show that power in different oscillatory bands are associated with distinct components of reward evaluation. Specifically, we observed a double dissociation, with a selective theta band oscillation increase in response to monetary gains and a beta band increase in response to losses. These effects were interleaved across OFC in overlapping networks and were accompanied by increases in oscillatory coherence between OFC electrode sites in theta and beta band during gain and loss processing, respectively. These results provide evidence that gain and loss processing in human OFC are supported by distinct low-frequency oscillations in networks, and provide evidence that participating neuronal ensembles are organized functionally through oscillatory coherence, rather than local anatomical segregation.

scholarly journals Beta-band desynchronization reflects uncertainty in effector selection during motor planning

2021 ◽  
Author(s):  
Milou J.L. van Helvert ◽  
Leonie Oostwoud Wijdenes ◽  
Linda Geerligs ◽  
W. Pieter Medendorp
Keyword(s):  
Time Window ◽  
Brain Activity ◽  
Motor Planning ◽  
Reaction Times ◽  
Motor Preparation ◽  
Motion Artifact ◽  
Theta Band ◽  
Beta Band ◽  
Target Uncertainty ◽  
Band Power

AbstractWhile beta-band activity during motor planning is known to be modulated by uncertainty about where to act, less is known about its modulations to uncertainty about how to act. To investigate this issue, we recorded oscillatory brain activity with EEG while human participants (n = 17) performed a hand choice reaching task. The reaching hand was either predetermined or of participants’ choice, and the target was close to one of the two hands or at about equal distance from both. To measure neural activity in a motion-artifact-free time window, the location of the upcoming target was cued 1000-1500 ms before the presentation of the target, whereby the cue was valid in 50% of trials. As evidence for motor planning during the cueing phase, behavioral observations showed that the cue affected later hand choice. Furthermore, reaction times were longer in the choice than in the predetermined trials, supporting the notion of a competitive process for hand selection. Modulations of beta-band power over central cortical regions, but not alpha-band or theta-band power, were in line with these observations. During the cueing period, reaches in predetermined trials were preceded by larger decreases in beta-band power than reaches in choice trials. Cue direction did not affect reaction times or beta-band power, which may be due to the cue being invalid in 50% of trials, retaining effector uncertainty during motor planning. Our findings suggest that effector uncertainty, similar to target uncertainty, selectively modulates beta-band power during motor planning.New & NoteworthyWhile reach-related beta-band power in central cortical areas is known to modulate with the number of potential targets, here we show, using a cueing paradigm, that the power in this frequency band, but not in the alpha or theta-band, is also modulated by the uncertainty of which hand to use. This finding supports the notion that multiple possible effector-specific actions can be specified in parallel up to the level of motor preparation.

scholarly journals Temporal Dysbiosis of Infant Nasal Microbiota Relative to Respiratory Syncytial Virus Infection

2020 ◽  
Author(s):  
Alex Grier ◽  
Ann L Gill ◽  
Haeja A Kessler ◽  
Anthony Corbett ◽  
Sanjukta Bandyopadhyay ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Respiratory Disease ◽  
Disease Severity ◽  
Temporal Dynamics ◽  
Disease Risk ◽  
Developmental Trajectory ◽  
Microbiota Composition ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Nasal Microbiota

Abstract Rationale Respiratory Syncytial Virus (RSV) is a leading cause of infant respiratory disease. Infant airway microbiota has been associated with respiratory disease risk and severity. The extent to which interactions between RSV and microbiota occur in the airway, and their impact on respiratory disease susceptibility and severity, are unknown. Objectives Characterize temporal associations between microbiota and RSV infection before, during, and after infants’ first respiratory illness. Methods 16S rRNA microbiota profiling of two infant cohorts in the first year of life: 1) a cross-sectional cohort of 89 RSV infected infants sampled during illness and 102 matched healthy controls, and 2) a matched longitudinal cohort of 12 infants who developed RSV infection and 12 who did not, sampled before, during, and after infection. Results We identified 12 taxa significantly associated with RSV infection. All 12 taxa were differentially abundant during infection, with 8 associated with disease severity. Nasal microbiota composition was more discriminative of healthy vs. infected than of disease severity. Conclusions Our findings elucidate the chronology of nasal microbiota dysbiosis and suggest an altered developmental trajectory associated with RSV infection. Microbial temporal dynamics reveal indicators of disease risk, correlates of illness and severity, and impact of RSV infection on microbiota composition.

Saliency-based Rhythmic Coordination of Perceptual Predictions

2020 ◽  
Vol 32 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Qiaoli Huang ◽  
Huan Luo
Keyword(s):  
Temporal Dynamics ◽  
Theta Band ◽  
Behavioral Profile ◽  
Fine Grained ◽  
Attentional Process ◽  
Behavioral Measurement ◽  
Processing Resources ◽  
Rhythmic Coordination ◽  
The Brain ◽  
Different Levels

Objects, shown explicitly or held in mind internally, compete for limited processing resources. Recent studies have demonstrated that attention samples locations and objects rhythmically. Interestingly, periodic sampling not only operates over objects in the same scene but also occurs for multiple perceptual predictions that are held in attention for incoming inputs. However, how the brain coordinates perceptual predictions that are endowed with different levels of bottom–up saliency information remains unclear. To address the issue, we used a fine-grained behavioral measurement to investigate the temporal dynamics of processing of high- and low-salient visual stimuli, which have equal possibility to occur within experimental blocks. We demonstrate that perceptual predictions associated with different levels of saliency are organized via a theta-band rhythmic course and are optimally processed in different phases within each theta-band cycle. Meanwhile, when the high- and low-salient stimuli are presented in separate blocks and thus not competing with each other, the periodic behavioral profile is no longer present. In summary, our findings suggest that attention samples and coordinates multiple perceptual predictions through a theta-band rhythm according to their relative saliency. Our results, in combination with previous studies, advocate the rhythmic nature of attentional process.

Merging visual features and temporal dynamics in sequential recommendation

2019 ◽  
Vol 362 ◽  
pp. 11-18 ◽  
Author(s):  
Cairong Yan ◽  
Qinglong Zhang
Keyword(s):  
Temporal Dynamics ◽  
Visual Features

scholarly journals Event-related and oscillatory signatures of response inhibition: A magnetoencephalography study with subclinical high and low impulsivity adults

2021 ◽  
Author(s):  
Ainara Jauregi ◽  
Hongfang Wang ◽  
Stefanie Hassel ◽  
Klaus Kessler
Keyword(s):  
Response Inhibition ◽  
Temporal Dynamics ◽  
Error Rates ◽  
Stop Signal ◽  
Self Report ◽  
Stop Signal Task ◽  
Alpha Power ◽  
Theta Band ◽  
Band Power ◽  
Theta Band Power

Inhibition, the ability to withhold a response or to stop an initiated response, is a necessary cognitive function that can be vulnerable to an impairment. High levels of impulsivity have been shown to impact response inhibition and/or cognitive task performance. The present study investigated the spectral and spatio-temporal dynamics of response inhibition, during a combined go/no-go/stop-signal task, using magnetoencephalography (MEG) in a healthy undergraduate student population. Participants were divided by their level of impulsivity, as assessed by self-report measures, to explore potential differences between high (n=17) and low (n=17) impulsivity groups. Results showed that individuals scoring high on impulsivity failed significantly more NOGO and STOP trials than those scoring low, but no significant differences were found between stop-signal reaction times. During NOGO and STOP conditions, high impulsivity individuals showed significantly smaller M1 components in posterior regions, which could suggest an attentional processing deficit. During NOGO trials, the M2 component was found to be reduced in individuals scoring high, possibly reflecting less pre-motor inhibition efficiency, whereas in STOP trials, the network involved in the stopping process was engaged later in high impulsivity individuals. The high impulsivity group also engaged frontal networks more during the STOP-M3 component only, possibly as a late compensatory process. The lack of response time differences on STOP trials could indicate that compensation was effective to some degree (at the expense of higher error rates). Decreased frontal delta and theta band power was observed in high impulsivity individuals, suggesting a possible deficit in frontal pathways involved in motor suppression, however, unexpectedly, increased delta and theta band power in central and posterior sensors was also observed, which could be indicative of an increased effort to compensate for frontal deficits. Individuals scoring highly also showed decreased alpha power in frontal sensors, suggesting decreased inhibitory processing, along with reduced alpha suppression in posterior regions, reflecting reduced cue processing. These results provide evidence for how personality traits, such as impulsivity, relate to differences in the neural correlates of response inhibition.

scholarly journals Enhancing oscillations in intracranial electrophysiological recordings with data-driven spatial filters

2021 ◽  
Vol 17 (8) ◽  
pp. e1009298
Author(s):  
Natalie Schaworonkow ◽  
Bradley Voytek
Keyword(s):  
Temporal Dynamics ◽  
Noise Removal ◽  
Data Driven ◽  
Neural Oscillations ◽  
Fast Method ◽  
Multiple Use ◽  
Spatial Filters ◽  
Spatial Spread ◽  
Electrophysiological Recordings ◽  
Improve Measurement

In invasive electrophysiological recordings, a variety of neural oscillations can be detected across the cortex, with overlap in space and time. This overlap complicates measurement of neural oscillations using standard referencing schemes, like common average or bipolar referencing. Here, we illustrate the effects of spatial mixing on measuring neural oscillations in invasive electrophysiological recordings and demonstrate the benefits of using data-driven referencing schemes in order to improve measurement of neural oscillations. We discuss referencing as the application of a spatial filter. Spatio-spectral decomposition is used to estimate data-driven spatial filters, a computationally fast method which specifically enhances signal-to-noise ratio for oscillations in a frequency band of interest. We show that application of these data-driven spatial filters has benefits for data exploration, investigation of temporal dynamics and assessment of peak frequencies of neural oscillations. We demonstrate multiple use cases, exploring between-participant variability in presence of oscillations, spatial spread and waveform shape of different rhythms as well as narrowband noise removal with the aid of spatial filters. We find high between-participant variability in the presence of neural oscillations, a large variation in spatial spread of individual rhythms and many non-sinusoidal rhythms across the cortex. Improved measurement of cortical rhythms will yield better conditions for establishing links between cortical activity and behavior, as well as bridging scales between the invasive intracranial measurements and noninvasive macroscale scalp measurements.

scholarly journals Neural encoding of reliability and validity of directional information during the preparation of targeted movements

2020 ◽  
Author(s):  
Charidimos Tzagarakis ◽  
Sarah West ◽  
Giuseppe Pellizzer
Keyword(s):  
Reaction Time ◽  
Visual Information ◽  
Motor Response ◽  
Reliability And Validity ◽  
Motor Preparation ◽  
Theta Band ◽  
Beta Band ◽  
Motor Processes ◽  
Band Power ◽  
The Brain

AbstractVisual information about an upcoming target can be used to prepare an appropriate motor response and reduce its reaction time. However, when the anticipation is incorrect and the planned response must be changed, the reaction time is lengthened. Here, we investigated the brain mechanisms associated with the reliability and validity of visual information used for motor preparation. We recorded brain activity using magnetoencephalography (MEG) during a delayed reaching task in which a visual cue provided valid information about the location of the upcoming target with 50, 75 or 100% reliability. We found that reaction time increased as cue reliability decreased and that trials with invalid cues had longer reaction times than trials with valid cues. MEG channel analysis showed that beta-band power from left mid-anterior channels correlated with the reliability of the cue after cue onset but before target onset. This effect was source localized over a large motor-related cortical and subcortical network. In addition, during invalid-cue trials there was a phasic increase of theta-band power following target onset from left posterior channels, localized to the left occipito-parietal cortex. Furthermore, the theta-beta cross-frequency coupling between left mid-occipital and motor cortex also transiently increased before responses to invalid-cue trials. In conclusion, beta-band power in motor-related areas reflected the reliability of visual information used during motor preparation, whereas phasic theta-band activity signaled whether the target was at the expected location or not. These results elucidate mechanisms of interaction between attentional and motor processes.Significance StatementWe used magnetoencephalography to investigate how the brain mechanisms preparing a motor response take into account the reliability of information about the upcoming location of a target to reach, and how these mechanisms adjust when that information turns out to be incorrect. We found that during the response preparation, the power of motor-related beta-band oscillations changed with the reliability of the visual information. In addition, we found that after the onset of the target the power of the left occipito-parietal theta-band signaled whether the prior information was correct or not. The pattern of activity of the beta-band and theta-band explain the pattern of latency of responses in the task, and demonstrate how attentional and motor processes interact.

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