Can we consciously influence our perception of the external world?
Alex Billig, Matt Davis, & Bob Carlyon, from the MRC Cognition and Brain Sciences Unit (MRC CBU), addressed this question in a recently published article in the Journal of Neuroscience. They did this by using sound sequences that can be heard either as coming from a single source or as two distinct auditory streams. Listen to examples here.
Listeners reported spontaneous changes in their perception between these two interpretations while neural activity was recorded to identify signatures of such integration and segregation. They also indicated that they could, to some extent, choose between these alternatives.
This claim was supported by corresponding changes in responses in auditory cortex as measured with magnetoencephalography. By linking neural and behavioural correlates of perception, the authors demonstrate that the number of objects that we perceive can depend not only on the physical attributes of our environment, but also on how we intend to experience it.
The full article can be read here: Journal of Neuroscience: Neural decoding of bistable sounds reveals an effect of intention on perceptual organisation.