SSI



Spatial Sound
Institute


Hearing and Body
Scientific Research/Article.


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1
Title

Selective processing of auditory evoked responses with iterative-randomized stimulation and averaging: A strategy for evaluating the time-invariant assumption


2
Author(s)

Joaquin T. Valderrama, Angel de la Torre, Carlos Medina, Jose C. Segura, A. Roger D. Thornton
4
Key Words

#Randomizedstimulationandaveraging #RSA # Jitter Deconvolution Evoked #potentials #Timeinvariant #ABR # MLR #SOA
5
Year

2016
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Abstract

The recording of auditory evoked potentials (AEPs) at fast rates allows the study of neural adaptation, improves accuracy in estimating hearing threshold and may help diagnosing certain pathologies. Stimulation sequences used to record AEPs at fast rates require to be designed with a certain jitter, i.e., not periodical. Some authors believe that stimuli from wide-jittered sequences may evoke auditory re- sponses of different morphology, and therefore, the time-invariant assumption would not be accom- plished. This paper describes a methodology that can be used to analyze the time-invariant assumption in jittered stimulation sequences. The proposed method [Split-IRSA] is based on an extended version of the iterative randomized stimulation and averaging (IRSA) technique, including selective processing of sweeps according to a predefined criterion. The fundamentals, the mathematical basis and relevant implementation guidelines of this technique are presented in this paper. The results of this study show that Split-IRSA presents an adequate performance and that both fast and slow mechanisms of adaptation influence the evoked-response morphology, thus both mechanisms should be considered when time- invariance is assumed. The significance of these findings is discussed

1
Title

Neurons in primary auditory cortex represent sound source location in a cue-invariant manner   


2
Author(s)

Katherine C. Wood, Stephen M. Town, Jennifer K. Bizley.
4
Key Words

#Auditorycortex #auditorycorticalneurons #localizations #binaural #soundsourcelocation #spatialtuning
5
Year

2019
6
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3
Abstract

Auditory cortex is required for sound localisation, but how neural firing in auditory cortex underlies our perception of sound sources in space remains unclear. Specifically, whether neurons in auditory cortex represent spatial cues or an integrated representation of auditory space across cues is not known. Here, we measured the spatial receptive fields of neurons in primary auditory cortex (A1) while ferrets performed a relative localisation task. Manipulating the availability of binaural and spectral localisation cues had little impact on ferrets’ performance, or on neural spatial tuning. A subpopulation of neurons encoded spatial position consistently across localisation cue type. Furthermore, neural firing pattern decoders outperformed two-channel model decoders using population activity. Together, these observations suggest that A1 encodes the location of sound sources, as opposed to spatial cue values.


1
Title

Study of Objective Evaluation of Effect of Psychological Relaxation Using Classic Music


2
Author(s)

Toshihide Harada, Fumiko Ishizaki, Shoji Ito, Satomi Aoi, Marina Miyaguchi, Hiromi Ikeda, Yumiko Nitta, Mikako Mibu, Tadayuki Iida, Chiho Chikamura, Noriko Tamura, Kohsaku Nitta
4
Key Words

#classicmusic #musictherapy #psychologicalrelaxation #vesselwidthandvenousoxygenationindexofperipheralvein #spectralanalysisofheartratevariability
5
Year

2017
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3
Abstract

Objective: Some of classic musics make both relaxation and adequate stress. In brain cortex some classic musics make fruit- ful concentration and attention.
Design: A clinical study.Materials and methods: The subjects were healthy young 1 man and 19 women. We did them Tomita’s stress questionnaire. They enjoyed classic music CD with headphone. Accelerated plethysmography (APG) was performed using a pulsimeter with the sensor positioned on the tip of the ventral side of the index finger. Peripheral venous circulation was monitored with venous oxygenation index (VOI) and width of peripheral vein.Results: Tomita's stress questionnaire scores were significantly correlated with low frequency (LF) component powers (maxi- mum entropy method (MEM) and fast fourier transform (FFT)). LF and LF/HF decreased after enjoying classic music. VOI was significantly positive correlated with LF/HF before enjoying classic music.Conclusions: These results suggest that APG, VOI and width of peripheral vein is useful for objective evaluation of psycho- logical stress and relaxation.

1
Title

Sound and trance in a ritualistic setting visualised with EEG Brainmapping


2
Author(s)

Jצrg Fachner, Sabine Rittner
4
Key Words

#trance #EEG #brainmapping #sound #monochord #ritualbodypostures #pre/postdesign #ergotropic #trophotropic #alteredstatesofconsciousness #setting #grouptherapy.
5
Year

2009
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3
Abstract

In this article we analyse the results of two receptive trance-inducing methods (Body Monochord; Goodman Ritual Body Postures with fast rattling) that were compared between amplitude/significance mapping and rest. 28 EEG traces of two subjects (male/female) were obtained with a mobile brain imager during a group therapy ritual. Emphasis was put on an authentical group setting. Both trance inductions caused an increase of Beta-II waves, the posture an additional Delta wave increase. While monochord playing induced frontal desynchronisation with increase of Beta-II waves in the male subject, the female EEG showed a synchronisation with changes (p<0.001) in visual and somato-sensoric regions. Her Alpha changes might indicate change of processing to a trophotropic trance state. Both showed increase of Beta-II waves indicating ergotropic trance. During rattling both subjects exhibited frontal-central increases of Delta waves. While female subject exhibited more pre-/frontal increases, male subject exhibited more parietal-occipital increases. Changes (p<0.001) on Beta ranges, spectral edge frequencies and Delta wave increases mark this state. Guttmann (1990) observed high and low frequency increases in the DC-EEG and called it “paradoxical arousal”. Our results might support his observation.
1
Title

Repeated Stimulus Exposure Alters the Way Sound Is Encoded in the Human Brain



2
Author(s)

Kelly L. Tremblay, Kayo Inoue,
Katrina McClannahan, Bernhard Ross.
4
Key Words

#Auditory #communicationdisorders #auditorylearning #brainactivity #auditorytraining
5
Year

2010
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Abstract

Auditory training programs are being developed to remediate various types of communication disorders. Biological changes have been shown to coincide with improved perception following auditory training so there is interest in determining if these changes represent biologic markers of auditory learning. Here we examine the role of stimulus exposure and listening tasks, in the absence of training, on the modulation of evoked brain activity. Twenty adults were divided into two groups and exposed to two similar sounding speech syllables during four electrophysiological recording sessions (24 hours, one week, and up to one year later). In between each session, members of one group were asked to identify each stimulus. Both groups showed enhanced neural activity from session-to-session, in the same P2 latency range previously identified as being responsive to auditory training. The enhancement effect was most pronounced over temporal-occipital scalp regions and largest for the group who participated in the identification task. The effects were rapid and long-lasting with enhanced synchronous activity persisting months after the last auditory experience. Physiological changes did not coincide with perceptual changes so results are interpreted to mean stimulus exposure, with and without being paired with an identification task, alters the way sound is processed in the brain. The cumulative effect likely involves auditory memory; however, in the absence of training, the observed physiological changes are insufficient to result in changes in learned behavior.