scholarly journals Elicitation of the Acoustic Change Complex to Long-Duration Speech Stimuli in Four-Month-Old Infants

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ke Heng Chen ◽  
Susan A. Small
Keyword(s):  
Auditory Evoked Potential ◽  
English Learning ◽  
Discrimination Ability ◽  
Speech Stimuli ◽  
Young Infants ◽  
Long Duration ◽  
Cortical Responses ◽  
Acoustic Change Complex ◽  
Speech Token ◽  
The Brain

The acoustic change complex (ACC) is an auditory-evoked potential elicited to changes within an ongoing stimulus that indicates discrimination at the level of the auditory cortex. Only a few studies to date have attempted to record ACCs in young infants. The purpose of the present study was to investigate the elicitation of ACCs to long-duration speech stimuli in English-learning 4-month-old infants. ACCs were elicited to consonant contrasts made up of two concatenated speech tokens. The stimuli included native dental-dental /dada/ and dental-labial /daba/ contrasts and a nonnative Hindi dental-retroflex /daDa/ contrast. Each consonant-vowel speech token was 410 ms in duration. Slow cortical responses were recorded to the onset of the stimulus and to the acoustic change from /da/ to either /ba/ or /Da/ within the stimulus with significantly prolonged latencies compared with adults. ACCs were reliably elicited for all stimulus conditions with more robust morphology compared with our previous findings using stimuli that were shorter in duration. The P1 amplitudes elicited to the acoustic change in /daba/ and /daDa/ were significantly larger compared to /dada/ supporting that the brain discriminated between the speech tokens. These findings provide further evidence for the use of ACCs as an index of discrimination ability.

Relation Between Level of Prefrontal Activity and Subject's Performance

1999 ◽  
Vol 13 (2) ◽  
pp. 117-125 ◽  
Author(s):  
Laurence Casini ◽  
Françoise Macar ◽  
Marie-Hélène Giard
Keyword(s):  
Brain Activity ◽  
Sensory Information ◽  
Practice Phase ◽  
Trained Subjects ◽  
Anagram Task ◽  
Economic Information ◽  
Long Duration ◽  
Level Of Activity ◽  
The Brain ◽  
Processing Mechanism

Abstract The experiment reported here was aimed at determining whether the level of brain activity can be related to performance in trained subjects. Two tasks were compared: a temporal and a linguistic task. An array of four letters appeared on a screen. In the temporal task, subjects had to decide whether the letters remained on the screen for a short or a long duration as learned in a practice phase. In the linguistic task, they had to determine whether the four letters could form a word or not (anagram task). These tasks allowed us to compare the level of brain activity obtained in correct and incorrect responses. The current density measures recorded over prefrontal areas showed a relationship between the performance and the level of activity in the temporal task only. The level of activity obtained with correct responses was lower than that obtained with incorrect responses. This suggests that a good temporal performance could be the result of an efficacious, but economic, information-processing mechanism in the brain. In addition, the absence of this relation in the anagram task results in the question of whether this relation is specific to the processing of sensory information only.

Informational Masking Effects of Speech Versus Nonspeech Noise on Cortical Auditory Evoked Potentials

2021 ◽  
Vol 64 (10) ◽  
pp. 4014-4029
Author(s):  
Kathy R. Vander Werff ◽  
Christopher E. Niemczak ◽  
Kenneth Morse
Keyword(s):  
Auditory Processing ◽  
Auditory Evoked Potentials ◽  
Spectral Characteristics ◽  
Auditory Evoked Potential ◽  
Informational Masking ◽  
Neural Encoding ◽  
Speech Stimuli ◽  
Typical Morphology ◽  
Cortical Auditory Evoked Potentials ◽  
Speech Information

Purpose Background noise has been categorized as energetic masking due to spectrotemporal overlap of the target and masker on the auditory periphery or informational masking due to cognitive-level interference from relevant content such as speech. The effects of masking on cortical and sensory auditory processing can be objectively studied with the cortical auditory evoked potential (CAEP). However, whether effects on neural response morphology are due to energetic spectrotemporal differences or informational content is not fully understood. The current multi-experiment series was designed to assess the effects of speech versus nonspeech maskers on the neural encoding of speech information in the central auditory system, specifically in terms of the effects of speech babble noise maskers varying by talker number. Method CAEPs were recorded from normal-hearing young adults in response to speech syllables in the presence of energetic maskers (white or speech-shaped noise) and varying amounts of informational maskers (speech babble maskers). The primary manipulation of informational masking was the number of talkers in speech babble, and results on CAEPs were compared to those of nonspeech maskers with different temporal and spectral characteristics. Results Even when nonspeech noise maskers were spectrally shaped and temporally modulated to speech babble maskers, notable changes in the typical morphology of the CAEP in response to speech stimuli were identified in the presence of primarily energetic maskers and speech babble maskers with varying numbers of talkers. Conclusions While differences in CAEP outcomes did not reach significance by number of talkers, neural components were significantly affected by speech babble maskers compared to nonspeech maskers. These results suggest an informational masking influence on neural encoding of speech information at the sensory cortical level of auditory processing, even without active participation on the part of the listener.

Context-Dependent Modulation of Early Visual Cortical Responses to Numerical and Nonnumerical Magnitudes

2021 ◽  
pp. 1-12
Author(s):  
Joonkoo Park ◽  
Sonia Godbole ◽  
Marty G. Woldorff ◽  
Elizabeth M. Brannon
Keyword(s):  
Visual Processing ◽  
Context Dependency ◽  
Numerical Magnitude ◽  
Continuous Variables ◽  
Processing Stream ◽  
Cortical Responses ◽  
Early Visual Cortex ◽  
Context Dependent ◽  
Visual Cortical ◽  
The Brain

Abstract Whether and how the brain encodes discrete numerical magnitude differently from continuous nonnumerical magnitude is hotly debated. In a previous set of studies, we orthogonally varied numerical (numerosity) and nonnumerical (size and spacing) dimensions of dot arrays and demonstrated a strong modulation of early visual evoked potentials (VEPs) by numerosity and not by nonnumerical dimensions. Although very little is known about the brain's response to systematic changes in continuous dimensions of a dot array, some authors intuit that the visual processing stream must be more sensitive to continuous magnitude information than to numerosity. To address this possibility, we measured VEPs of participants viewing dot arrays that changed exclusively in one nonnumerical magnitude dimension at a time (size or spacing) while holding numerosity constant and compared this to a condition where numerosity was changed while holding size and spacing constant. We found reliable but small neural sensitivity to exclusive changes in size and spacing; however, changing numerosity elicited a much more robust modulation of the VEPs. Together with previous work, these findings suggest that sensitivity to magnitude dimensions in early visual cortex is context dependent: The brain is moderately sensitive to changes in size and spacing when numerosity is held constant, but sensitivity to these continuous variables diminishes to a negligible level when numerosity is allowed to vary at the same time. Neurophysiological explanations for the encoding and context dependency of numerical and nonnumerical magnitudes are proposed within the framework of neuronal normalization.

scholarly journals Development of Auditory Evoked Responses in Normally Developing Preschool Children and Children with Autism Spectrum Disorder

2017 ◽  
Vol 39 (5) ◽  
pp. 430-441 ◽  
Author(s):  
Julia M. Stephen ◽  
Dina E. Hill ◽  
Amanda Peters ◽  
Lucinda Flynn ◽  
Tongsheng Zhang ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Tone Burst ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Auditory Evoked Potential ◽  
Spectrum Disorder ◽  
Evoked Responses ◽  
Auditory Evoked Responses ◽  
Cortical Responses ◽  
The Mean

The cortical responses to auditory stimuli undergo rapid and dramatic changes during the first 3 years of life in normally developing (ND) children, with decreases in latency and changes in amplitude in the primary peaks. However, most previous studies have focused on children >3 years of age. The analysis of data from the early stages of development is challenging because the temporal pattern of the evoked responses changes with age (e.g., additional peaks emerge with increasing age) and peak latency decreases with age. This study used the topography of the auditory evoked magnetic field (AEF) to identify the auditory components in ND children between 6 and 68 months (n = 48). The latencies of the peaks in the AEF produced by a tone burst (ISI 2 ± 0.2 s) during sleep decreased with age, consistent with previous reports in awake children. The peak latencies of the AEFs in ND children and children with autism spectrum disorder (ASD) were compared. Previous studies indicate that the latencies of the initial components of the auditory evoked potential (AEP) and the AEF are delayed in children with ASD when compared to age-matched ND children >4 years of age. We speculated whether the AEF latencies decrease with age in children diagnosed with ASD as in ND children, but with uniformly longer latencies before the age of about 4 years. Contrary to this hypothesis, the peak latencies did not decrease with age in the ASD group (24-62 months, n = 16) during sleep (unlike in the age-matched controls), although the mean latencies were longer in the ASD group as in previous studies. These results are consistent with previous studies indicating delays in auditory latencies, and they indicate a different maturational pattern in ASD children and ND children. Longitudinal studies are needed to confirm whether the AEF latencies diverge with age, starting at around 3 years, in these 2 groups of children.

What Is Electroconvulsive Therapy?

2010 ◽  
Author(s):  
Max Fink MD
Keyword(s):  
Emotional Disorders ◽  
Electroconvulsive Therapy ◽  
The Elderly ◽  
The Body ◽  
Electroconvulsive Treatment ◽  
Single Episode ◽  
Psychotropic Medicines ◽  
Long Duration ◽  
Motor Activities ◽  
The Brain

Electroconvulsive therapy (ECT) is an effective medical treatment for severe and persistent psychiatric disorders. It relieves de pressed mood and thoughts of suicide, as well as mania, acute psychosis, delirium, and stupor. It is usually applied when medications have given limited relief or their side effects are intolerable. Electroconvulsive therapy is similar to a surgical treatment. It requires the specialized skills of a psychiatrist, an anesthesiologist, and nurses. The patient receives a short-acting anesthetic. While the patient is asleep, the physician, following a prescribed procedure, induces an epileptic seizure in the brain. By making sure that the patient’s lungs are filled with oxygen, the physician precludes the gasping and difficult breathing that accompany a spontaneous epileptic fit. By relaxing the patient’s muscles with chemicals and by inserting a mouth guard (not unlike those used in sports), the physician prevents the tongue biting, fractures, and injuries that occasionally occur in epilepsy. The patient is asleep, and so experiences neither the painful effects of the stimulus nor the discomforts of the seizure. The physiological functions of the body, such as breathing, heart rate, blood pressure, blood oxygen concentration, and degree of motor relaxation, are monitored, and anything out of the ordinary is immediately treated. Electroconvulsive therapy relieves symptoms more quickly than do psychotropic drugs. A common course of ECT consists of two or three treatments a week for two to seven weeks. To sustain the recovery, weekly or biweekly continuation treatments, either ECT or medications, are often administered for four to six months. If the illness recurs, ECT is prescribed for longer periods. The duration and course of ECT are similar to those of the psychotropic medicines frequently used for the same conditions. Electroconvulsive therapy has been used safely to treat emotional disorders in patients of all ages, from children to the elderly, in people with debilitating physical illnesses, and in pregnant women. Emotional disorders may be of short or long duration; they may be manifest as a single episode or as a recurring event. Electroconvulsive treatment is an option when the emotional disorder is acute in onset; when changes in mood, thought, and motor activities are pronounced; when the cause is believed to be biochemical or physiological; when the condition is so severe that it interferes with the patient’s daily life; or when other treatments have failed.

scholarly journals Acoustic Change Complex (ACC) using Speech and Non-Speech Stimuli in Normal Hearing Children

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
W A Elkholy ◽  
D M Hassan ◽  
N A Shafik ◽  
Y E K Eltoukhy
Keyword(s):  
Auditory Evoked Potentials ◽  
Temporal Frequency ◽  
Normal Hearing ◽  
Auditory Discrimination ◽  
Auditory Evoked Potential ◽  
Frequency Change ◽  
Spectral Change ◽  
Speech Stimuli ◽  
Significant Difference ◽  
Hearing Children

Abstract Background Cortical auditory evoked potentials (CAEPs) are brain responses evoked by sound and are processed in or near the auditory cortex. ACC is a cortical auditory evoked potential (P1-N1-P2) elicited by a change within an ongoing sound stimulus. Objective To reach the best stimuli that can elicit ACC and act as an objective tool for assessment of cortical auditory discrimination in normal hearing children. Patients and Methods The present study was originally designed to standardize ACC evoked response in 41 children aged from 2 to 10 years. The mean age in our study group was 6.2 years with no significant difference between males and females. Stimuli used in this study were specifically designed to be used by AEP equipment that is capable of uploading short duration stimuli (500 msec.), thus can be used in a regular AEP lab. ACC was elicited by three groups of stimuli. Gap-in-tones stimuli represent temporal change (6, 10, 30 and 50 msec. gap introduced to 1000 Hz tone separately), frequency pairs stimuli represent frequency change (2%, 4%, 10% and 25% change from base freq. 1000 Hz) and vowel pairs stimuli represent spectral change (/i-u/, /u-i/, /i-a/. /a-i/, /u-a/, /a-u/). ACC response parameters were compared when using the different stimuli as regards percent detectability, morphology, latency and amplitude. Results Gap-in-tones at 6 msec. and 4% frequency change could elicit ACC response in 100% of subjects. For spectral change, /u-i/ was the highest in eliciting ACC (78%) followed by /i-u/ (68.2%) then /a-i/ (58.5%). ACC had the same morphology of the onset response in the majority of subjects, with longer latency and smaller amplitude. ACC amplitude is a better indicator of cortical discrimination compared to latency because it is consistently affected by magnitude of change. Conclusion ACC is a good electrophysiological tool for cortical auditory discrimination for temporal, frequency and spectral change.

Transient and sustained processing of musical consonance in auditory cortex and the effect of musicality

2020 ◽  
Vol 123 (4) ◽  
pp. 1320-1331 ◽  
Author(s):  
Martin Andermann ◽  
Roy D. Patterson ◽  
André Rupp
Keyword(s):  
Auditory Cortex ◽  
Physiological Activity ◽  
Stimulus Onset ◽  
Auditory Evoked Potential ◽  
Source Analysis ◽  
Source Modeling ◽  
Sustained Activity ◽  
Long Duration ◽  
Musical Sounds ◽  
N1 Wave

In recent years, electroencephalography and magnetoencephalography (MEG) have both been used to investigate the response in human auditory cortex to musical sounds that are perceived as consonant or dissonant. These studies have typically focused on the transient components of the physiological activity at sound onset, specifically, the N1 wave of the auditory evoked potential and the auditory evoked field, respectively. Unfortunately, the morphology of the N1 wave is confounded by the prominent neural response to energy onset at stimulus onset. It is also the case that the perception of pitch is not limited to sound onset; the perception lasts as long as the note producing it. This suggests that consonance studies should also consider the sustained activity that appears after the transient components die away. The current MEG study shows how energy-balanced sounds can focus the response waves on the consonance-dissonance distinction rather than energy changes and how source modeling techniques can be used to measure the sustained field associated with extended consonant and dissonant sounds. The study shows that musical dyads evoke distinct transient and sustained neuromagnetic responses in auditory cortex. The form of the response depends on both whether the dyads are consonant or dissonant and whether the listeners are musical or nonmusical. The results also show that auditory cortex requires more time for the early transient processing of dissonant dyads than it does for consonant dyads and that the continuous representation of temporal regularity in auditory cortex might be modulated by processes beyond auditory cortex. NEW & NOTEWORTHY We report a magnetoencephalography (MEG) study on transient and sustained cortical consonance processing. Stimuli were long-duration, energy-balanced, musical dyads that were either consonant or dissonant. Spatiotemporal source analysis revealed specific transient and sustained neuromagnetic activity in response to the dyads; in particular, the morphology of the responses was shaped by the dyad’s consonance and the listener’s musicality. Our results also suggest that the sustained representation of stimulus regularity might be modulated by processes beyond auditory cortex.

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