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Predicting perceptual decisions using spectro-spatio-temporal EEG features
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Multi-stable perception: a continuous decision–making process
A visual multi-stable stimulus is a temporally stationary, but ambiguous stimulus, i.e., a stimulus that allows for dif-
ferent, mutually exclusive interpretations when visioned. When a subject is presented with a such stimulus, his or
her perception is spontaneously alternating over time between the different interpretations[Hupé and Rubin, 2003].
This perceptive multi-stability has been characterised in literature, mainly using descriptive statistics such as mean
residence time in a given interpretation, or the probability of changing from one defined percept to another defined
percept[Leopold and Logothetis, 1999, Parisot, 2020].
In our study, we investigate whether the underlying cognitive—but unconscious—decision process that makes
the subject change interpretation at some given time can be observed using electrophysiological and behavioural
measurements. Thereto, we are collecting electro-encephalographic (EEG), gaze, and behavioural measures in a
controlled experiment design (2x2 factorial design: ambiguous/non-ambiguous stimulus ; perceptual report by key-
press/no report). The stimulus that is used is composed of a moving plaid, superposed with a random dot kine-
matogram. Whereas the former is completely ambiguous, the latter allows to help enforce a given interpretation, as
such controlling what is perceived in half of the experimental trials. The collected data allows to have a proxy for the
perceptual decision (through a key-press; half of the trials) and comes accompanied by a continuous recording of eye
movements and positioning on the screen (gaze) as well as a cognitive window on the cerebral functioning (EEG).
The goal is to come up with a temporally predictive model of evidence accumulation resulting in perceptual decision making.