Exploring the nature of the P300 in normal hearing adults in response to filtered words

Sammanfattning: The present study explored the nature of the auditory P300 in response to filtered words in ten normal hearing adults. P300 waveforms were elicited by a classic oddball paradigm, and recorded using a net of 128 electrodes (HydroCel Geodesic Sensor Net 128 1.0.). P300 waveforms from central, parietal, temporal right and temporal left regions were selected for data collection. P300 latencies and amplitudes for the largest deflection distinguishing responses to filtered from unfiltered words between 248 and 652 ms post stimuli were collected from each electrode in each region and these values were averaged obtain electrode group values. All filtered versions of the word successfully elicited P300 waveforms at all four recording locations in the form of large, vertex-positive deflections, which differed significantly (p<0.05) compared to the electrophysiological responses to the unfiltered stimulus. However, among the responses to the different filtered versions of the stimulus the overall tendency was that statistical differences could not be seen, neither in terms of amplitudes or latencies. The lack of substantial change in the P300 waveforms elicited by the different filtered versions of the stimulus word suggests the use of the P300 as a measure of filtered word performance is limited to the detection of a filtered version of a word and not the degree