TitleAttentional Fluctuations Across Frequency and Amplitude: a Dual-Task Study
Publication TypeConference Paper
Year of Publication2006
AuthorsLoui, P, Wessel, D
Conference NameCognitive Neuroscience Society (Poster Presentaton)
Conference LocationSan Francisco, California

How is attention distributed between different dimensions of sound? Prior studies have shown that temporal cues can heighten attention to frequency whereas dual tasking can disrupt attention to amplitude, but these effects have not been shown to transfer to other auditory dimensions. In this study we investigate relative attentional processing to frequency and amplitude, two dimensions of auditory processing, as a function of time. Series of seven pure tones of the same pitch were presented over background noise. In each trial, one of the seven tones was slightly mistuned, and another of the tones was time-locked to a short increase in the background noise level. The participants task was either to identify the mistuned tone (frequency-only condition), to identify the tone that co-occurred with the background noise increase (amplitude-only condition), or to identify both tones simultaneously (dual-task condition). Results show significantly lower accuracy in the dual-task condition compared to the frequency-only and amplitude-only conditions, suggesting sharing of neural resources across dimensions of frequency and amplitude. In addition, accuracy in the frequency-only condition improved significantly over the course of the seven notes within the trial, suggesting a heightening of attention to frequency over short time courses. This temporal effect was not observed in dual-task or amplitude-only conditions, suggesting that the temporal dependence of frequency discrimination requires attention and does not transfer to the amplitude dimension. In conclusion, results support a sharing of endogenous attentional resources, but a dimension-specific neural coupling of time and frequency.