[Distracter inhibition in mild cognitive impairment]. / Osobennosti podavleniya otvlekayushchikh stimulov pri myagkom kognitivnom snizhenii.

OBJECTIVE: To study the effectiveness of interfering visual stimuli inhibition using the flanker task in a group of healthy young and healthy old participants, and in a group of participants with mild cognitive impairment (MCI). MATERIAL AND METHODS: Reaction times and accuracy, as well as the diffusion model of reaction times with parameters reflecting perceptual and motor processes, stimulus processing speed, and conservativeness of response selection were analyzed. RESULTS: We found reduced speed and accuracy in older age, especially in MCI patients. The reduction was especially pronounced in patients with the incongruent distracters. For diffusion model parameters, perceptual and motor processes took longer with older age, reduced processing speed was found only in pathological aging, and specific effectiveness reduction for incongruent probes in patients was driven by increased conservativeness of responses. CONCLUSIONS: The results indicate the joint influence of normal and pathological aging processes on patients with MCI. The deceleration of the perceptual-motor components of the reaction time reflects the processes of normal cognitive aging, while the deceleration of the processing speed (in the presence of any distractors, including congruent ones) characterizes pathological cognitive aging. Differential diagnosis of normal and pathological cognitive changes is possible using data based on the analysis of reaction time components. It is important to take into account the conservativeness of responses as a factor slowing down the reaction time in pathological and normal cognitive aging.

[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.