The Averaged Evoked Response to Auditory Stimulation

1966 ◽  
Vol 9 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Lloyd L. Price ◽  
Benjamin Rosenblüt ◽  
Robert Goldstein ◽  
David C. Shepherd
Keyword(s):  
Contralateral Side ◽  
Auditory Stimulation ◽  
Normal Hearing ◽  
Evoked Response ◽  
Auditory Stimuli ◽  
Frequency Of Occurrence ◽  
Ipsilateral Side ◽  
The Subject ◽  
Positive Peak ◽  
Older Subjects

Evoked responses of 160 normal-hearing subjects to auditory stimuli (clicks) were recorded, and data related to the latency, amplitude, and frequency of occurrence of various late components were studied. Negative peaks (vertex referred to earlobe) at 85 and 260 msec and a positive peak at 160 msec occurred often enough and with sufficient amplitude to be useful as indicators of response to auditory stimulation. Frequency of occurrence and latency did not appear related to the race, sex, or age of the subject nor to the side of the head from which the recording was taken. The amplitudes are related to these variables. White subjects gave larger responses than colored subjects, females gave larger responses than males, younger and older subjects gave larger responses than those in between, and the responses from the contralateral side of the head (re stimulated ear) tended to be larger than those from the ipsilateral side. Thresholds for the evoked response to clicks are very near voluntary thresholds for the same stimuli in normal-hearing young adults.

Early Components of Averaged Evoked Responses to Rapidly Repeated Auditory Stimuli

1967 ◽  
Vol 10 (4) ◽  
pp. 697-705 ◽  
Author(s):  
Robert Goldstein ◽  
Leslie B. Rodman
Keyword(s):  
Response Pattern ◽  
Normal Hearing ◽  
Auditory Stimuli ◽  
Evoked Responses ◽  
Negative Peak ◽  
Positive Peak ◽  
The Right ◽  
Two Peaks

Averaged evoked responses to clicks were elicited from 20 normal-hearing subjects between the ages of 16 and 41. Two thousand clicks were presented to the right ear at the rate of 10 per sec at 60, 30, 10, 5, 0, −5, and −10 dB SL. Sensation levels were varied randomly. In each series two control conditions without stimulation were randomly interspersed. Electroencephalic potentials were recorded from an electrode on the vertex of the skull referred to the left earlobe. The response pattern was relatively consistent with a vertex-negative peak (N a ) at about 20–24 msec, and a vertex-positive peak (P a ) at about 31–35 msec. Another vertex-negative peak (N b ) at about 46–50 msec was seen less frequently. Criteria for response were established on the basis of the occurrence of N a and P a within prescribed latencies as well as the interval between the two peaks of about 12–13 msec. The number of identifiable responses diminished with diminishing sensation levels but responses were observed in about one-half of the subjects as low as −5 dB SL.

Habituation and Dishabituation of the Averaged Auditory Evoked Response

1970 ◽  
Vol 13 (2) ◽  
pp. 387-394 ◽  
Author(s):  
Bruce A. Weber
Keyword(s):  
Young Adults ◽  
Stimulus Duration ◽  
Simple Form ◽  
Stimulus Frequency ◽  
Auditory Stimulation ◽  
Normal Hearing ◽  
Evoked Response ◽  
Auditory Evoked Response ◽  
Normal Adults

Two experiments investigated amplitude reduction in the averaged evoked response (AER) resulting from repeated auditory stimulation. The first experiment examined the effects of stimulus duration on the rate of AER habituation. Three groups of 10 normal-hearing young adults received 16 series of 1000-Hz tone bursts with durations of 50 msec, 500 msec, and 950 msec. A comparison of AER habituation rates revealed that longer stimulus durations resulted in faster rates of habituation. The second experiment was designed to determine if the AER demonstrated dishabituation (recovery of a habituated response when a parameter of the habituating stimulus is changed). Ten additional normal adults received series of 1000-Hz tone bursts. When the stimulus frequency was changed from 1000 Hz to 500 Hz, all subjects meeting the habituation criterion demonstrated recovery of the AER. The results of the two experiments are compatible with an interpretation of AER habituation as a simple form of learning.

An Adaptive and Learning System for Feedback-Controlled Evoked Response Studies

1981 ◽  
Vol 20 (03) ◽  
pp. 169-173
Author(s):  
J. Wagner ◽  
G. Pfurtscheixer
Keyword(s):  
Brain Activity ◽  
Evoked Response ◽  
Learning System ◽  
Time Interval ◽  
Electrical Brain Activity ◽  
Long Time ◽  
The Subject ◽  
Eeg Power ◽  
Stimulation System ◽  
Background Eeg

The shape, latency and amplitude of changes in electrical brain activity related to a stimulus (Evoked Potential) depend both on the stimulus parameters and on the background EEG at the time of stimulation. An adaptive, learnable stimulation system is introduced, whereby the subject is stimulated (e.g. with light), whenever the EEG power is subthreshold and minimal. Additionally, the system is conceived in such a way that a certain number of stimuli could be given within a particular time interval. Related to this time criterion, the threshold specific for each subject is calculated at the beginning of the experiment (preprocessing) and adapted to the EEG power during the processing mode because of long-time fluctuations and trends in the EEG. The process of adaptation is directed by a table which contains the necessary correction numbers for the threshold. Experiences of the stimulation system are reflected in an automatic correction of this table. Because the corrected and improved table is stored after each experiment and is used as the starting table for the next experiment, the system >learns<. The system introduced here can be used both for evoked response studies and for alpha-feedback experiments.

Auditory Evoked Responses in Normal Hearing Adults and Children Before and During Sedation

1969 ◽  
Vol 12 (2) ◽  
pp. 394-401 ◽  
Author(s):  
Paul Skinner ◽  
Frank Antinoro
Keyword(s):  
Preschool Children ◽  
Evoked Potential ◽  
Normal Hearing ◽  
Auditory Stimuli ◽  
Evoked Responses ◽  
Auditory Evoked Responses ◽  
Adults And Children ◽  
Awake Condition ◽  
Wave Complex ◽  
Prominent Peak

Averaged evoked responses (AER) to auditory stimuli presented to young children and adults were compared between awake and induced sleep conditions. Eight adults and twenty preschool children with normal hearing were tested before and during sedation at two suprathreshold levels with tone pips centered at 510, 1020, and 2040 Hz. Responses obtained during sedation assumed a distinctly different wave complex than those obtained under the awake condition. The P2 peak that is most prominent in the AERs obtained from awake subjects was diminished considerably under sedation and P3 became the prominent peak. Moreover, the P3 peaks in the AERs obtained under sedation were of considerably greater amplitude than the P2 peaks obtained in the awake condition. In all cases where responses were obtained from awake subjects, greater amplitude responses were obtained during sedation. The use of sedation with the preschool children proved to be most important in obtaining more detectable responses and permitting evoked potential audiometry with otherwise unmanageable children.

Abstract 182: Thermal Imaging as a Diagnostic Biomarker in Acute Ischemic Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Linda F Aulmann ◽  
Kira Busch ◽  
Andrea Zegelin ◽  
Thomas Eckey ◽  
Alexander Neumann ◽  
...  
Keyword(s):  
Thermal Imaging ◽  
Arterial Occlusion ◽  
Current Method ◽  
Contralateral Side ◽  
Temperature Pattern ◽  
Ipsilateral Side ◽  
Anterior Circulation ◽  
Vessel Occlusion ◽  
Clear Trend ◽  
Infrared Thermal Imaging

Purpose: With highly portable mobile infrared cameras thermal imaging during acute stroke triage has become possible. The purpose of this pilot study was to evaluate the pattern of superficial facial skin temperature in patients with acute proximal arterial occlusion of the anterior circulation compared to non-ischemic controls. We hypothesize, that temperature dysregulation in stroke with associated thermal pattern may be used to predict presence of proximal vessel occlusion. Methods: In 46 patients suffering from acute occlusion in the anterior circulation (ICA: 17, M1-MCA: 13, M2-MCA: 16) infrared thermal imaging of the face was performed before endovascular treatment. Asymmetric temperature patterns were evaluated visually. Quantitative temperature values were obtained from regions of interest (ROIs) placed symmetrically on the left and right half of on the facial thermal image. Presence and side of vessel occlusion was correlated with temperature measurements. Results: Regional facial asymmetric temperature was readily visible at 0.5°C. Temperature differences ranged from 0.5 to 1.5° C in stroke patients, and <0.5°C in controls. In 16 of 17 patients with ICA occlusion, facial asymmetric temperature was detected (in 13 lower temperatures on ipsilateral side, in 3 on the contralateral side). In 11 of 13 patients with M1-MCA occlusion, facial asymmetric temperature was detected (in 8 lower temperatures on the contralateral side, 3 on the ipsilateral side). In 15 of 16 patients with an occlusion of M2-segment, asymmetric temperature pattern was apparent, however no clear trend with regard. In 16 of 20 controls, no asymmetric temperature pattern >0.5°C was observed. Conclusion: Thermal imaging could serve as a fast point-of-care test to detect asymmetrical pattern in facial temperature as a predictor of proximal vessel occlusion in stroke. However, the current method is prone to imaging artifacts and reliability of detected asymmetry is moderate.

Visualisation of different harmonisations varying in mode, consonance & dissonance

2021 ◽  
Author(s):  
Konstantinos Giannos ◽  
George Athanasopoulos ◽  
Emilios Cambouropoulos
Keyword(s):  
Past Research ◽  
Auditory Stimuli ◽  
Modal Interaction ◽  
Variable Roughness ◽  
The Subject ◽  
Highly Correlated ◽  
Listening Task ◽  
The Relationship ◽  
Tonal Stimuli ◽  
Musical Elements

Visual associations with auditory stimuli have been the subject of numerous studies. Colour, shape, size, and several other parameters have been linked to musical elements like timbre and pitch. In this paper we aim to examine the relationship between harmonisations with varying degrees of dissonance and visual roughness. Based on past research in which high sensory dissonance was associated with angular shapes, we argued that non-tonal and highly dissonant harmonisations will be associated with angular and rough images, while more consonant stimuli will be associated with images of low visual roughness. A fixed melody was harmonised in 7 different styles, including highly tonal, non-tonal, and random variations. Through a listening task, musically trained participants rated the stimuli in terms of enjoyment, familiarity, and matched them to images of variable roughness. The overall consonance of the stimuli was calculated using two distinct models (Wang et al., 2013; Harrison &amp; Pearce, 2020) and a variant of the aggregate dyadic consonance index (Huron, 1994). Our results demonstrate that dissonance, as calculated by all models, was highly correlated with visual roughness, and enjoyment and familiarity followed expected patterns compared to tonal and non-tonal stimuli. In addition to sensory dissonance, however, it appears that other factors, such as the typicality of chord progressions and the sense of tonality may also influence this cross-modal interaction.

Stability of the Early Components of the Averaged Electroencephalic Response

1969 ◽  
Vol 12 (2) ◽  
pp. 351-361 ◽  
Author(s):  
Maurice I. Mendel ◽  
Robert Goldstein
Keyword(s):  
Response Pattern ◽  
Normal Hearing ◽  
Peak Latency ◽  
Term Stability ◽  
Response Index ◽  
Long Term Stability ◽  
Negative Peak ◽  
The Subject ◽  
The Right

The early components of the averaged electroencephalic response (AER) were examined at three-hour intervals in eight normal hearing adults over a single, sleepless 24-hour span. During each of the eight sessions, three series of clicks at 50 dB SL were presented to the right ear of the subject as he sat reading. 1024 clicks at the rate of 9.6/sec were used in obtaining each averaged response. Electroencephalic activity was recorded from an electrode on the vertex referred to the left earlobe. The response pattern was very stable, characterized by a polyphasic configuration with mean peak latencies of (P o ) 13.3 msec, (N a ) 22.0 msec, (P a ) 32.3 msec, and (N b ) 45.1 msec. An earlier negative peak (N o ) with a mean peak latency of 8.3 msec occurred in many of the responses. At the conclusion of the 24-hour span, three of the subjects were tested with the same stimuli during various stages of sleep. The early components of the AER remained consistent even during sleep. Threshold searches were successfully carried out on two of the sleeping subjects. The long-term stability of the early components of the AER in the awake and sleep states makes them practical as a response index for electroencephalic audiometry. Their characteristics are more compatible with a neurogenic than with a myogenic theory of their origin.

scholarly journals Regional resting state perfusion variability and delayed cerebrovascular uniform reactivity in subjects with chronic carotid artery stenosis

2018 ◽  
Vol 65 (1) ◽  
pp. 151-162
Author(s):  
Arkadiusz Szarmach ◽  
Mariusz Kaszubowski ◽  
Agnieszka Sabisz ◽  
Andrzej F Frydrychowski ◽  
Grzegorz Halena ◽  
...  
Keyword(s):  
White Matter ◽  
Carotid Artery ◽  
Temporal Lobe ◽  
Resting State ◽  
Carotid Artery Stenosis ◽  
Parietal Lobe ◽  
Contralateral Side ◽  
Artery Stenosis ◽  
Ipsilateral Side ◽  
Acetazolamide Challenge

The aim of this study was to assess regional perfusion at baseline and regional cerebrovascular resistance (CVR) to delayed acetazolamide challenge in subjects with chronic carotid artery stenosis.Sixteen patients (ten males) aged 70.94±7.71 with carotid artery stenosis ≥90% on the ipsilateral side and ≤50% on the contralateral side were enrolled into the study. In all patients, two computed tomography perfusion examinations were carried out; the first was performed before acetazolamide administration and the second 60 minutes after injection.The differences between mean values were examined by paired two-sample t-test and alternative nonparametric Wilcoxon’s test. Normality assumption was examined using W Shapiro-Wilk test.The lowest resting-state cerebral blood flow (CBF) was observed in white matter (ipsilateral side: 18.4±6.2; contralateral side: 19.3±6.6) and brainstem (ipsilateral side: 27.8±8.5;  contralateral side: 29.1±10.8). Grey matter (cerebral cortex) resting state CBF was below the normal value for subjects of this age: frontal lobe – ipsilateral side: 30.4±7.0, contralateral side: 33.7±7.1; parietal lobe – ipsilateral side: 36.4±11.3, contralateral side: 42.7±9.9; temporal lobe – ipsilateral side: 32.5±8.6, contralateral side: 39.4±10.8; occipital lobe – ipsilateral side: 24.0±6.0, contralateral side: 26.4±6.6). The highest resting state CBF was observed in the insula (ipsilateral side: 49.2±17.4; contralateral side: 55.3±18.4). A relatively high resting state CBF was also recorded in the thalamus (ipsilateral side: 39.7±16.9; contralateral side: 41.7±14.1) and cerebellum (ipsilateral side: 41.4±12.2; contralateral side: 38.1±11.3). The highest CVR was observed in temporal lobe cortex (ipsilateral side: +27.1%; contralateral side: +26.1%) and cerebellum (ipsilateral side: +27.0%; contralateral side: +34.6%). The lowest CVR was recorded in brain stem (ipsilateral side: +20.2%; contralateral side: +22.2%) and white matter (ipsilateral side: +18.1%; contralateral side: +18.3%). All CBF values were provided in milliliters of blood per minute per 100 g of brain tissue [ml/100g/min]. Resting state circulation in subjects with carotid artery stenosis is low in all analysed structures with the exception of insula and cerebellum. Acetazolamide challenge yields relatively uniform response in both hemispheres in the investigated population.Grey matter is more reactive to acetazolamide challenge than white matter or brainstem.

scholarly journals EVALUATION OF THE CORRELATION BETWEEN FACIAL MUSCLE AND BRAIN ACTIVITIES IN AUDITORY STIMULATION

Fractals ◽  
2021 ◽  
Vol 29 (01) ◽  
pp. 2150100
Author(s):  
MIRRA SOUNDIRARAJAN ◽  
MARTIN AUGUSTYNEK ◽  
ONDREJ KREJCAR ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Human Body ◽  
Strong Correlation ◽  
Rock Music ◽  
Sample Entropy ◽  
Auditory Stimulation ◽  
Auditory Stimuli ◽  
Facial Muscle ◽  
Eeg Signals ◽  
Facial Muscles ◽  
The Brain

Evaluation of the correlation of the activities of various organs is an important area of research in physiology. In this paper, we evaluated the correlation among the brain and facial muscles’ reactions to various auditory stimuli. We played three different music (relaxing, pop, and rock music) to 13 subjects and accordingly analyzed the changes in complexities of EEG and EMG signals by calculating their fractal exponent and sample entropy. Based on the results, EEG and EMG signals experienced more significant changes by presenting relaxing, pop, and rock music, respectively. A strong correlation was observed among the alterations of the complexities of EMG and EEG signals, which indicates the coupling of the activities of facial muscles and brain. This method could be further applied to investigate the coupling of the activities of the brain and other organs of the human body.

The Physiology of a Lepidopteran Muscle Receptor

1966 ◽  
Vol 45 (2) ◽  
pp. 229-249
Author(s):  
R. DE G. WEEVERS
Keyword(s):  
Negative Feedback ◽  
Sense Organ ◽  
Great Majority ◽  
Motor Units ◽  
Contralateral Side ◽  
Ipsilateral Side ◽  
Major Function ◽  
Muscle Receptor ◽  
Spatial Facilitation ◽  
Adjacent Segments

1. When a single MRO of a caterpillar is stretched at least 32 motor units show clear reflex changes in activity. 2. The great majority of muscles are excited and the latency of the reflex differs only slightly from one muscle to another. The response has both tonic and phasic components which reflect more or less faithfully the magnitudes of the same components in the sensory discharge. 3. Muscles are affected on the contralateral side of the stimulated segment and on the ipsilateral side of adjacent segments. The reflex fields of neighbouring receptors therefore overlap; spatial facilitation produces a disproportionate increase in the overall response when two receptors are stimulated simultaneously. 4. The reflex pathway for muscles innervated by nerve 2 is shown to involve synaptic connexions in the ganglion of the segment anterior to the stimulated receptor and responding muscles. 5. The muscles most strongly excited are those which lie functionally in parallel with a stretched sense organ. It is concluded that a major function of the caterpillar MRO is to mediate a negative feedback reflex tending to stabilize bodily position independent of load.

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