scholarly journals Reduced Visual Magnocellular Event-Related Potentials in Developmental Dyslexia

2021 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
John Stein
Keyword(s):  
Steady State ◽  
Developmental Dyslexia ◽  
Reading Ability ◽  
Event Related Potentials ◽  
Black And White ◽  
Reverse Pattern ◽  
Related Potentials ◽  
The Right ◽  
Visual Hemifields ◽  
Electroencephalogram Eeg

(1) Background—the magnocellular hypothesis proposes that impaired development of the visual timing systems in the brain that are mediated by magnocellular (M-) neurons is a major cause of dyslexia. Their function can now be assessed quite easily by analysing averaged visually evoked event-related potentials (VERPs) in the electroencephalogram (EEG). Such analysis might provide a useful, objective biomarker for diagnosing developmental dyslexia. (2) Methods—in adult dyslexics and normally reading controls, we recorded steady state VERPs, and their frequency content was computed using the fast Fourier transform. The visual stimulus was a black and white checker board whose checks reversed contrast every 100 ms. M- cells respond to this stimulus mainly at 10 Hz, whereas parvocells (P-) do so at 5 Hz. Left and right visual hemifields were stimulated separately in some subjects to see if there were latency differences between the M- inputs to the right vs. left hemispheres, and these were compared with the subjects’ handedness. (3) Results—Controls demonstrated a larger 10 Hz than 5 Hz fundamental peak in the spectra, whereas the dyslexics showed the reverse pattern. The ratio of subjects’ 10/5 Hz amplitudes predicted their reading ability. The latency of the 10 Hz peak was shorter during left than during right hemifield stimulation, and shorter in controls than in dyslexics. The latter correlated weakly with their handedness. (4) Conclusion—Steady state visual ERPs may conveniently be used to identify developmental dyslexia. However, due to the limited numbers of subjects in each sub-study, these results need confirmation.

Electrophysiology in developmental populations: Key methods and findings

2020 ◽  
Author(s):  
Ryan Barry-Anwar ◽  
Tracy Riggins ◽  
Lisa S. Scott
Keyword(s):  
Steady State ◽  
Evoked Potentials ◽  
Human Development ◽  
Visual Evoked Potentials ◽  
Event Related Potentials ◽  
Eeg Signal ◽  
Electrophysiological Studies ◽  
Related Potentials ◽  
Electroencephalogram Eeg ◽  
Electrophysiological Methods

This chapter aims to provide a methodological and empirical overview of electrophysiological techniques used to study human development including: 1) electroencephalogram (EEG), 2) event-related potentials (ERPs), and 3) steady-state visual evoked potentials (ssVEPs). This overview is written to encourage the use of multiple techniques in electrophysiological studies of development. The chapter begins with an introduction to electrophysiological methods and the underlying neural events that give rise to the EEG signal. Second, each technique is described and important electrophysiological empirical contributions to our understanding of development from infancy through childhood and into adolescence are highlighted. Third, considerations and recommendations for the collection, processing, analysis, and publication of developmental electrophysiological data are discussed. Finally, the chapter ends with a look at the future of electrophysiology for the study of development.

Asymmetry in Event-Related Potentials to Simulated Auditory Motion in Children, Young Adults, and Seniors

2002 ◽  
Vol 13 (01) ◽  
pp. 001-013 ◽  
Author(s):  
James Jerger ◽  
Rebecca Estes
Keyword(s):  
Young Adults ◽  
Right Hemisphere ◽  
Apparent Movement ◽  
Event Related Potentials ◽  
Auditory Evoked Responses ◽  
Age Related ◽  
Related Potentials ◽  
Velocity Information ◽  
The Right ◽  
Age Range

We studied auditory evoked responses to the apparent movement of a burst of noise in the horizontal plane. Event-related potentials (ERPs) were measured in three groups of participants: children in the age range from 9 to 12 years, young adults in the age range from 18 to 34 years, and seniors in the age range from 65 to 80 years. The topographic distribution of grand-averaged ERP activity was substantially greater over the right hemisphere in children and seniors but slightly greater over the left hemisphere in young adults. This finding may be related to age-related differences in the extent to which judgments of sound movement are based on displacement versus velocity information.

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.

Frontal Brain Activity during Episodic and Semantic Retrieval: Insights from Event-Related Potentials

1999 ◽  
Vol 11 (6) ◽  
pp. 598-609 ◽  
Author(s):  
Charan Ranganath ◽  
Ken A. Paller
Keyword(s):  
Prefrontal Cortex ◽  
Memory Retrieval ◽  
Brain Activity ◽  
Novelty Detection ◽  
Event Related Potentials ◽  
Episodic Retrieval ◽  
Semantic Retrieval ◽  
Retrieval Task ◽  
Related Potentials ◽  
The Right

Previous neuropsychological and neuroimaging results have implicated the prefrontal cortex in memory retrieval, although its precise role is unclear. In the present study, we examined patterns of brain electrical activity during retrieval of episodic and semantic memories. In the episodic retrieval task, participants retrieved autobiographical memories in response to event cues. In the semantic retrieval task, participants generated exemplars in response to category cues. Novel sounds presented intermittently during memory retrieval elicited a series of brain potentials including one identifiable as the P3a potential. Based on prior research linking P3a with novelty detection and with the frontal lobes, we predicted that P3a would be reduced to the extent that novelty detection and memory retrieval interfere with each other. Results during episodic and semantic retrieval tasks were compared to results during a task in which subjects attended to the auditory stimuli. P3a amplitudes were reduced during episodic retrieval, particularly at right lateral frontal scalp locations. A similar but less lateralized pattern of frontal P3a reduction was observed during semantic retrieval. These findings support the notion that the right prefrontal cortex is engaged in the service of memory retrieval, particularly for episodic memories.

scholarly journals Auditory attention alterations in migraine: a behavioral and MEG/EEG study

2019 ◽  
Author(s):  
Rémy Masson ◽  
Yohana Lévêque ◽  
Geneviève Demarquay ◽  
Hesham ElShafei ◽  
Lesly Fornoni ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Orienting Response ◽  
List Type ◽  
Top Down ◽  
Attention Task ◽  
Bottom Up ◽  
Attentional Processes ◽  
Related Potentials ◽  
The Right ◽  
Task Irrelevant

AbstractObjectivesTo evaluate alterations of top-down and/or bottom-up attention in migraine and their cortical underpinnings.Methods19 migraineurs between attacks and 19 matched control participants performed a task evaluating jointly top-down and bottom-up attention, using visually-cued target sounds and unexpected task-irrelevant distracting sounds. Behavioral responses and MEG/EEG were recorded. Event-related potentials and fields (ERPs/ERFs) were processed and source reconstruction was applied to ERFs.ResultsAt the behavioral level, neither top-down nor bottom-up attentional processes appeared to be altered in migraine. However, migraineurs presented heightened evoked responses following distracting sounds (orienting component of the N1 and Re-Orienting Negativity, RON) and following target sounds (orienting component of the N1), concomitant to an increased recruitment of the right temporo-parietal junction. They also displayed an increased effect of the cue informational value on target processing resulting in the elicitation of a negative difference (Nd).ConclusionsMigraineurs appear to display increased bottom-up orienting response to all incoming sounds, and an enhanced recruitment of top-down attention.SignificanceThe interictal state in migraine is characterized by an exacerbation of the orienting response to attended and unattended sounds. These attentional alterations might participate to the peculiar vulnerability of the migraine brain to all incoming stimuli.HighlightsMigraineurs performed as well as healthy participants in an attention task.However, EEG markers of both bottom-up and top-down attention are increased.Migraine is also associated with a facilitated recruitment of the right temporo-parietal junction.

The dysfunction of affective picture processing in pituitary patients: an ERPs study

2020 ◽  
Author(s):  
Chenglong Cao ◽  
Jian Song ◽  
Binbin Liu ◽  
Jianren Yue ◽  
Yuzhao Lu ◽  
...  
Keyword(s):  
Pituitary Adenoma ◽  
Patient Group ◽  
Electric Potential ◽  
Emotional Processing ◽  
Right Hemisphere ◽  
Event Related Potentials ◽  
Emotional Stimuli ◽  
Affective Stimuli ◽  
Related Potentials ◽  
The Right

Abstract Background: Cognitive impairments have been reported in patients with pituitary adenoma; however, there is a lack of knowledge of investigating the emotional stimuli processing in pituitary patients. Thus, we aimed to investigate whether there is emotional processing dysfunction in pituitary patients by recording and analyzing the late positive potential (LPP) elicited by affective stimuli.Methods: Evaluation of emotional stimuli processing by LPP Event related potentials (ERPs) was carried out through central- parietal electrode sites (C3, Cz, C4, P3, Pz, P4) on the head of the patients and healthy controls (HCs).Results: In the negative stimuli, the amplitude of LPP was 2.435 ± 0.419μV for HCs and 0.656 ± 0.427μV for patient group respectively ( p = 0.005). In the positive stimuli, the elicited electric potential 1.450 ± 0.316μV for HCs and 0.495 ± 0.322μV for patient group respectively ( p = 0.040). Moreover, the most obvious difference of LPP amplitude between the two groups existed in the right parietal region. On the right hemisphere (at the P4 site), the elicited electric potential was 1.993 ± 0.299μV for HCs and 0.269 ± 0.305μV for patient group respectively( p = 0.001).Conclusion: There are functional dysfunction of emotional stimuli processing in pituitary adenoma patients. Our research provides the electrophysiological evidence for the presence of cognitive dysfunction which need to be intervened in the pituitary adenoma patients.

scholarly journals High-density EEG of auditory steady-state responses during stimulation of basal forebrain parvalbumin neurons

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Eunjin Hwang ◽  
Hio-Been Han ◽  
Jung Young Kim ◽  
Jee Hyun Choi
Keyword(s):  
Steady State ◽  
Basal Forebrain ◽  
Event Related Potentials ◽  
High Density ◽  
Time Stamps ◽  
Related Potentials ◽  
Steady State Responses ◽  
Auditory Steady State Responses ◽  
State Responses ◽  
Stimulation Of

Abstract We present high-density EEG datasets of auditory steady-state responses (ASSRs) recorded from the cortex of freely moving mice with or without optogenetic stimulation of basal forebrain parvalbumin (BF-PV) neurons, known as a subcortical hub circuit for the global workspace. The dataset of ASSRs without BF-PV stimulation (dataset 1) contains raw 36-channel EEG epochs of ASSRs elicited by 10, 20, 30, 40, and 50 Hz click trains and time stamps of stimulations. The dataset of ASSRs with BF-PV stimulation (dataset 2) contains raw 36-channel EEG epochs of 40-Hz ASSRs during BF-PV stimulation with latencies of 0, 6.25, 12.5, and 18.75 ms and time stamps of stimulations. We provide the datasets and step-by-step tutorial analysis scripts written in Python, allowing for descriptions of the event-related potentials, spectrograms, and the topography of power. We complement this experimental dataset with simulation results using a time-dependent perturbation on coupled oscillators. This publicly available dataset will be beneficial to the experimental and computational neuroscientists.

scholarly journals Event-Related Potential Evidence of Enhanced Visual Processing in Auditory-Associated Cortex in Adults with Hearing Loss

2020 ◽  
Vol 25 (5) ◽  
pp. 237-248
Author(s):  
Maojin Liang ◽  
Jiahao Liu ◽  
Yuexin Cai ◽  
Fei Zhao ◽  
Suijun Chen ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Visual Processing ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Occipital Area ◽  
Mapping Analysis ◽  
Related Potentials ◽  
The Difference ◽  
The Right ◽  
Frontotemporal Area

Objective: The present study investigated the characteristics of visual processing in the auditory-associated cortex in adults with hearing loss using event-related potentials. Methods: Ten subjects with bilateral postlingual hearing loss were recruited. Ten age- and sex-matched normal-hearing subjects were included as controls. Visual (“sound” and “non-sound” photos)-evoked potentials were performed. The P170 response in the occipital area as well as N1 and N2 responses in FC3 and FC4 were analyzed. Results: Adults with hearing loss had higher P170 amplitudes, significantly higher N2 amplitudes, and shorter N2 latency in response to “sound” and “non-sound” photo stimuli at both FC3 and FC4, with the exception of the N2 amplitude which responded to “sound” photo stimuli at FC3. Further topographic mapping analysis revealed that patients had a large difference in response to “sound” and “non-sound” photos in the right frontotemporal area, starting from approximately 200 to 400 ms. Localization of source showed the difference to be located in the middle frontal gyrus region (BA10) at around 266 ms. Conclusions: The significantly stronger responses to visual stimuli indicate enhanced visual processing in the auditory-associated cortex in adults with hearing loss, which may be attributed to cortical visual reorganization involving the right frontotemporal cortex.

Sign in / Sign up

Export Citation Format

Share Document