[Features of the conflict adaptation effect in mild cognitive decline.]

Conflict adaptation effect in interference control tasks (like Stroop task or flanker task) consists in better interference suppression in incongruent trials following an incongruent trial. In a flanker task is shown that in normal cognitive aging there is a null conflict adaptation effect and that in mild cognitive impairment there is a reversed (negative) conflict adaptation effect. Using the drift diffusion model of reaction time, it is shown that the change in conflict adaptation effect in mild cognitive impairment is associated with the absence of adaptive increase in processing speed in the presence of distractors. This can be interpreted as the rigidity of perceptual control mechanisms, which are responsible for strategic distribution of attention in older age and in pathological aging, in particular. The conclusion is drawn that reversed conflict adaptation effect may be an early marker of pathological cognitive aging.