Temporal resolution properties of human auditory cortex: reflections in the neuromagnetic auditory evoked M100 component
| Autor: | Nicole M. Gage, Timothy P.L. Roberts, Gregory Hickok |
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| Rok vydání: | 2005 |
| Předmět: |
Adult
Male medicine.medical_specialty Time Factors Sensory system Stimulus (physiology) Audiology Auditory cortex medicine Reaction Time Auditory system Humans Molecular Biology Auditory Cortex Brain Mapping medicine.diagnostic_test General Neuroscience Magnetoencephalography Middle Aged medicine.anatomical_structure Amplitude Acoustic Stimulation Temporal resolution Auditory Perception Evoked Potentials Auditory Female Neurology (clinical) Psychology Temporal acuity Developmental Biology |
| Zdroj: | Brain research. 1069(1) |
| ISSN: | 0006-8993 |
| Popis: | Previous work has provided evidence for a brief, finite (∼35 ms) temporal window of integration (TWI) in M100 formation, during which stimulus attributes are accumulated in processes leading to the M100 peak. Here, we investigate resolution within the TWI by recording responses to tones containing silent gaps (0–20 ms). Gaps were inserted in 1 kHz tones in 2 conditions: +10 ms post-onset (10 ms masker) wherein the masker and gap of longest duration (20 ms) were contained within the initial 35 ms of the stimulus and +40 ms (40 ms masker) wherein all gaps were inserted +40 ms post-onset. Tones were presented binaurally and responses sampled from both hemispheres in 12 adults using a twin 37-channel biomagnetometer (MAGNES-II™, BTi, San Diego, CA). Results —10 ms masker: M100 latency was prolonged and amplitude decreased as a function of gap duration, even with the shortest duration (2 ms) gap, indicating that integrative processes underlying M100 formation are sensitive to fine-grained discontinuities within a brief, finite TWI. Results —40 ms masker: M100 latency and amplitude were unaffected by gaps inserted at +40 ms, providing further evidence for an M100 TWI of Conclusion : within a brief integrative window in M100 formation, population-level responses are sensitive to discontinuities in sounds on a scale corresponding to psychophysical detection thresholds and minimum detectable gap thresholds in single unit recordings. Cumulatively, results provide evidence that M100 resolution for brief fluctuations in sounds reflects temporal acuity properties that are both intrinsic to the auditory system and critical to the accurate perception of speech. |
| Databáze: | OpenAIRE |
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