Objective: To study early cognitive processes and hemispheric differences in the primary auditory cortex during selective attention.
Methods: We measured auditory evoked magnetic fields (AEFs) to 400 and 4000 Hz tone pips that were randomly presented at the right or left ear. Subjects paid attention to target stimuli during pitch (high or low) or laterality (left or right) discrimination tasks. In the control session, 400 or 4000 Hz tone alone was presented at the left or right ear. We calculated the location and strength of N100m dipole for 400 and 4000 Hz tones, based on the AEFs obtained from the hemisphere contralateral to the stimulated ear.
Results: N100m amplitude increased in both hemispheres in pitch or laterality discriminating conditions. N100m latency also shortened during selective attention. The N100m dipole distance between 400 and 4000 Hz tones was enlarged, especially in the right auditory cortex during pitch discrimination task, but was unchanged during the laterality discrimination task.
Conclusions: We conclude that these dynamic changes in the N100m dipole reflect short-term plastic changes in the primary auditory cortex, supporting early selection models.
Significance: This work is the first to disclose short-term plastic changes during pitch discrimination in the human auditory cortex based on the analysis of magnetoencephalography.
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http://dx.doi.org/10.1016/j.clinph.2004.02.011 | DOI Listing |
Background And Hypothesis: We have reported previously a reduction in superior temporal gyrus (STG) activation and in auditory verbal hallucinations (AHs) after real-time fMRI neurofeedback (NFB) in schizophrenia patients with AHs.
Study Design: With this randomized, participant-blinded, sham-controlled trial, we expanded our previous results. Specifically, we examined neurofeedback effects from the STG, an area associated with auditory hallucinations.
Imaging Neurosci (Camb)
April 2024
Department of Electrical Engineering, Columbia University, New York, NY, United States.
Listeners with hearing loss have trouble following a conversation in multitalker environments. While modern hearing aids can generally amplify speech, these devices are unable to tune into a target speaker without first knowing to which speaker a user aims to attend. Brain-controlled hearing aids have been proposed using auditory attention decoding (AAD) methods, but current methods use the same model to compare the speech stimulus and neural response, regardless of the dynamic overlap between talkers which is known to influence neural encoding.
View Article and Find Full Text PDFCereb Cortex
January 2025
Optical Imaging and Brain Sciences Medical Discovery Team, Department of Neuroscience, University of Minnesota, 2021 6th St. SE, Minneapolis, MN 55455, United States.
Processing sensory information, generating perceptions, and shaping behavior engages neural networks in brain areas with highly varied representations, ranging from unimodal sensory cortices to higher-order association areas. In early development, these areas share a common distributed and modular functional organization, but it is not known whether this undergoes a common developmental trajectory, or whether such organization persists only in some brain areas. Here, we examine the development of network organization across diverse cortical regions in ferrets using in vivo wide field calcium imaging of spontaneous activity.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
February 2025
Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
Background: Recent disease-modifying treatments for Alzheimer's disease show promise to slow cognitive decline, but show no efficacy towards reducing symptoms already manifested.
Objectives: To investigate the efficacy of a novel noninvasive brain stimulation technique in modulating cognitive functioning in Alzheimer's dementia (AD).
Design: Pilot, randomized, double-blind, parallel, sham-controlled study SETTING: Clinical research site at UT Southwestern Medical Center PARTICIPANTS: Twenty-five participants with clinical diagnoses of AD were enrolled from cognition specialty clinics.
Prog Neurobiol
January 2025
Department of Biomedicine, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland. Electronic address:
The brain faces the challenging task of preserving a consistent portrayal of the external world in the face of disruptive sensory inputs. What alterations occur in sensory representation amidst noise, and how does brain activity adapt to it? Although it has previously been shown that background white noise (WN) decreases responses to salient sounds, a mechanistic understanding of the brain processes responsible for such changes is lacking. We investigated the effect of background WN on neuronal spiking activity, membrane potential, and network oscillations in the mouse central auditory system.
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