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Wenjung Wang

Publications and source records attributed to Wenjung Wang.

2 recordsLinked to original sources

The development of the length of the temporal window of integration for rapidly presented auditory information as indexed by MMN.

OBJECTIVE: The length of the temporal window integrating successive auditory stimuli into unitary percepts has been estimated to be less than 200 ms in adults. The aim of the study was to investigate the development of the integrating window in children to determine whether it is similar to young adults. METHODS: A modified auditory oddball paradigm was presented at a rapid (150-400 ms) onset-to-onset pace during recording of electroencephalogram in two groups of children (aged 5-8 and 9-11 years) and one group of adults. Latencies and amplitudes of the P1, N1, and the mismatch negativity (MMN) components of event-related brain potentials (ERPs) were measured. RESULTS: The length of the temporal window of integration (TWI) was shorter in adults (<200 ms) than older children (<300 ms in 9-11-year-olds) and younger children (<350 ms in the 5-8-year-olds). In addition, age-related changes were found in the latency and amplitude of the ERP components. CONCLUSIONS: The results demonstrate a general maturational development of the auditory evoked potentials and also a specific maturational process for temporal encoding of information in auditory cortex. SIGNIFICANCE: Rapid stimulus presentation rates can be successfully used in school-aged children to study neural mechanisms of auditory processes.

Acoustic Stimulation↗

MMN and attention: competition for deviance detection.

We addressed the question of whether the mismatch negativity (MMN) event-related potential reflects an attention-independent process. Previous studies have shown that the MMN response to intensity deviation was significantly reduced or even abolished when attention was highly focused on a concurrent sound channel, whereas no conclusive evidence of attentional sensitivity has been obtained for frequency deviation. We tested a new hypothesis suggesting that competition between detection of identical deviations in attended and unattended channels and the biasing of this competition induced by the subject's task account for the observed MMN effects. In a fast-paced dichotic paradigm, we set up competition for frequency MMN and removed it for intensity MMN. We found that frequency MMN was now abolished in the unattended channel, whereas the amplitude of the intensity MMN was unaffected. These results support the competition hypothesis and suggest that selective attention in and of itself does not affect the MMN. Top-down processes can determine what information reaches the deviance-detection process when changes in multiple channels vie for the same MMN resource and one of the competing changes is relevant for the subject's task.

Acoustic Stimulation↗