How sensory stimuli become perceived is one of the greatest mysteries in neuroscience. At its most fundamental level is the question of why is it that some stimuli are perceived at all, enabling the subject to report on their presence, while other stimuli remain subliminal.
To uncover the neural correlates of stimulus perception, experimenters commonly use tasks in which subjects are repeatedly presented with a weak stimulus and instructed to report, via movement, if they perceived the stimulus. The difference in neural activity between reported stimulus (hit) and unreported stimulus (miss) trials is then seen as potentially perception-related.
However, recent studies found that activity related to the report spreads throughout the brain, calling into question to what extent such tasks conflate perception-related activity with report-related activity.
The goal of this research is to develop new behavioral paradigms that isolate perception-related activity and combine these paradigms with neural recording and manipulation approaches to uncover the mechanism by which stimuli become perceived by the brain.
In particular, recently made extensive use of widefield calcium imaging, wherein activity is optically recorded from the entire cortex of a behaving mouse.
