Marco Roccato

Ritratto di Marco Roccato

Neuroscience, Technology and Society, XXXVII series
Gianluca Campana

Project description
The arising of visual experience can be self-generated rather than dependent on externally-sourced sensory stimulation. Offline perception has been proposed as an overarching category grouping internally-sourced perceptual phenomena such as mental imagery and hallucinations, as these present similarities that are likely to be underlied by shared neural bases. However, offline perception and online (i.e. stimulus-driven) perception also have a commonality of features that is likely accounted for by the activation of brain areas which enable both endogenous and exogenous visual experiences. There is evidence that the overlap between visual imagery and visual perception is not limited to anatomical substrates, but extends to functional processes. For instance, top-down processes are known to intervene in both imagery and perception, pointing to shared mechanisms in externally and internally generated conscious visual experience. Questions such as how the visual system is able to simulate sensory content in order to make predictions, and how it discriminates between imagined and perceived objects, remain nonetheless open to investigation. My project's aim is to study some of the factors that foster visual illusions and experimentally induced low-level hallucinations in the normal population, through the use of psychophysical methods, electroencephalography, non-invasive brain stimulation, self-report instruments, and web-based applications designed for online research.