Top-down controlled and bottom-up triggered orienting of auditory attention to pitch activate overlapping brain networks.

A number of previous studies have suggested segregated networks of brain areas for top-down controlled and bottom-up triggered orienting of visual attention. However, the corresponding networks involved in auditory attention remain less studied. Our participants attended selectively to a tone stream with either a lower pitch or higher pitch in order to respond to infrequent changes in duration of attended tones.

Task-dependent activations of human auditory cortex during spatial discrimination and spatial memory tasks.

In the present study, we applied high-resolution functional magnetic resonance imaging (fMRI) of the human auditory cortex (AC) and adjacent areas to compare activations during spatial discrimination and spatial n-back memory tasks that were varied parametrically in difficulty. We found that activations in the anterior superior temporal gyrus (STG) were stronger during spatial discrimination than during spatial memory, while spatial memory was associated with stronger activations in the inferior parietal lobule (IPL). We also found that wide AC areas were strongly deactivated during the spatial memory tasks.

Effects of significance of auditory location changes on event related brain potentials and pitch discrimination performance.

We examined effects of significance of task irrelevant changes in the location of tones on the mismatch negativity (MMN) and P3a event related brain potentials. The participants were to discriminate between two frequency modulated tones differing from each other in the direction of frequency glide. Each tone was delivered through one of five loudspeakers in front of the participant.

Task-dependent activations of human auditory cortex during pitch discrimination and pitch memory tasks.

The functional organization of auditory cortex (AC) is still poorly understood. Previous studies suggest segregation of auditory processing streams for spatial and nonspatial information located in the posterior and anterior AC, respectively (Rauschecker and Tian, 2000; Arnott et al., 2004; Lomber and Malhotra, 2008).

Brain networks of bottom-up triggered and top-down controlled shifting of auditory attention.

During functional magnetic resonance imaging (fMRI), our participants selectively attended to tone streams at the left or right, and occasionally shifted their attention from one stream to another as guided by a centrally presented visual cue. Duration changes in the to-be-attended stream served as targets. Loudness deviating tones (LDTs) occurred infrequently in both streams to catch attention in a bottom-up manner, as indicated by their effects on reaction times to targets.

Auditory selective attention modulates activation of human inferior colliculus.

Selective auditory attention powerfully modulates neural activity in the human auditory cortex (AC). In contrast, the role of attention in subcortical auditory processing is not well established. Here, we used functional MRI (fMRI) to examine activation of the human inferior colliculus (IC) during strictly controlled auditory attention tasks.