Method and system for testing cognition by processing the reaction of a subject to stimuli

A method for processing the responses of a human or animal subject to sensory stimuli, the method comprising:

• a step of emitting the stimuli toward a subject, the step of emitting the stimuli including subjecting the subject to instructions for responding to the stimuli, of increasing or decreasing complexity according to at least three difficulty levels,
• a step of measuring a response time of the subject to the stimuli, comprising:
• a step for measuring a reaction time to simple stimuli corresponding to a first difficulty level,
• a step for measuring a reaction time to stimuli linked to a choice on a categorization corresponding to a second difficulty level, in response to an instruction previously taught to the subject,
• a step for measuring a reaction time linked to a third difficulty level comprising a task in which the subject must carry out two simultaneous categorizations on the same stimulus,
• a processing step for processing the response times thus measured,
• wherein the processing step comprises:
• a step for generating normalized response times, by subtraction of the response time to simple stimuli from the response time to stimuli linked to a choice and to stimuli linked to two simultaneous categorizations, and
• a step for analyzing the normalized response times according to two independent factors (S, Δ), which are representative, respectively, (i) of average executive reaction times and (ii) of the reaction of the subject to the difficulty of the stimuli,
• wherein the set of emitted stimuli is intended for distinguishing at least two choices, each choice referring to two categories, which are mutually exclusive,
• wherein the processing of the reaction times corresponding to the first, second and third difficulty levels comprises:
• identifying errors caused by incorrect choices and/or early reactions and/or by no choice being made,
• identifying errors caused by incorrect choices and/or early reactions and/or by reactions that are too slow,
• access to the processing time of the difficulty associated with the categorization instructions of the subject, having removed, for each one, their simple reaction time corresponding to the visual detection and to the motive response, so as to deliver average executive reaction times,
• mapping of the measurement results corresponding to the subject, on a plurality of axes comprising a first axis(S), which represents average executive reaction times, and a second axis (A), which represents the reaction of the subject to the difficulty of the stimuli, and
• placing the performance times of tasks of different difficulty levels into a same scale, in order to be able to compare them.