Learning conflicting information in the motor system: from anterograde interference to facilitation

ALBERT SCOTT; REZA SHADMEHR; CAFFARO PEDRO; JORGE VILLALTA; JACOBACCI FLORENCIA; VALERIA DELLA MAGGIORE

Ciudad Autónoma de Buenos Aires

Congreso; 2nd Congress of the Federation of Latin-American and Caribbean Societies for Neuroscience (FALAN); 2016

FALAN y Sociedad Argentina de Investigación en Neurociencias (SAN)

Anterograde interference takes place when 2 similar tasks are learned in close proximity. A significant body of evidence implies that in the motor system anterograde effects may be very strong, lasting from days to weeks. This has been specifically suggested for force-field and visuomotor adaptation (Miall,2004; Caithness,2004).Here, we decided to characterize the time course of anterograde effects by varying the time interval elapsed between adaptation to opposite visuomotor perturbations.Participants were divided into 6 groups that adapted to a counterclockwise rotation(A) followed by a clockwise rotation(B) after a variable interval of 1´, 15´, 1h, 3h, 5.5h and 24h. We assessed the level of anterograde effect of A on B based on how the rate of learning of B was affected by having learned A. We found that the rate of learning of B was only slower than A when subjects learned the task 1min apart. No differences were found for the remaining time intervals except in the 24h group in which the rate of learning of A was slower than B. Thus, 2 opposite anterograde effects could arise depending on the interval between tasks: interference occurred when the tasks were 1min apart and facilitation arose when the tasks were separated by 24h. Which feature of learning B was affected? Was the capacity to retain information or the ability to learn from the error of one movement to the other? This matter was adressed by applying a mathematical model in the study presented by Jacobacci F.