The P300 event-related potential (ERP) in response to minimal changes in duration and intensity

The primary purposes of this study were to determine if the auditory P300 could be evoked with just perceptible changes in intensity and duration, and to evaluate response growth. Behavioral measures of intensity and duration difference limen were taken from ten healthy, female participants with normal auditory function. These data were compiled, and increments based on the mean just noticeable difference data were utilized in an oddball paradigm to evoke the P300 response. A P300 response was evoked to a just perceptible difference in intensity. A larger duration contrast than the average just noticeable difference was required to evoke a P300 response. Response patterns emerged that suggested earlier response latencies and larger response amplitudes to increasing contrasts, but statistical testing failed to yield significant differences between adjacent contrasts.;A secondary purpose of this study was to evaluate test-retest reliability of the auditory P300 response in a single testing session, to an easily perceptible contrast in intensity and duration. The largest intensity and duration contrasts were presented twice during a single testing session. No statistically significant differences were observed in P300 latency or area under the P300 curve for either intensity or duration contrasts. A significant difference in response amplitude was observed to a large duration contrast. Although this difference in amplitude was observed, it was concluded that the P300 response is generally replicable within a single testing session to easily perceptible contrasts. Future research should include both increment and decrement changes to standard/target contrasts, as well as larger sample sizes.