This study examined the neural basis of auditory selective attention using functional magnetic resonance imaging. The main hypothesis stated that attending to a particular sound frequency would significantly enhance the neural response within those tonotopic regions of the auditory cortex sensitive to that frequency. To test this prediction, low- and high-frequency sound sequences were interleaved to produce two concurrent auditory streams. Six normally hearing participants either performed a task which required them to attend to one or the other stream or listened passively to the sounds while functional images were acquired using a high-resolution (1.5 mm × 1.5 mm × 2.5 mm) sequence. Two statistical comparisons identified the attention-specific and general effects of enhancement. The first controlled for task-related processes, while the second did not. Results demonstrated frequency-specific, attention-specific enhancement in the response to the attended frequency, but no response suppression for the unattended frequency. Instead, a general effect of suppression was found in several posterior sites, possibly related to resting-state processes. Furthermore, there was widespread general enhancement across auditory cortex when performing the task compared to passive listening. This enhancement did include frequency-sensitive regions, but was not restricted to them. In conclusion, our results show partial support for frequency-specific enhancement.
- Attentional modulation
- Frequency-dependent response region
- Task-related effects
ASJC Scopus subject areas
- Sensory Systems