A influência do consumo moderado de bebida alcóolica na codificação da memória motora sob diferentes tipos de aprendizagem motora

Abstract

Introduction: Motor learning involves relatively permanent changes in motor behavior resulting from practice and experience. Moderate alcohol intake prior to practice tends to impair explicit processes of encoding and conscious retention due to reduced efficiency of working memory and information processing, whereas already automatized skills or the implicit learning of movement patterns may remain more preserved or even demonstrate stability as a result of reduced interference from deliberate control. However, it remains unclear how motor memory encoding processes that occur after practice are affected by alcohol. Objective: To investigate the influence of moderate alcohol consumption on motor memory encoding in explicit and implicit motor learning. Methods: Sixty neurologically healthy men aged between 18 and 40 years participated in a single experiment in which the Serial Reaction Time Task (SRTT) was performed. Participants were allocated into four groups with twenty individuals each: IMP-ALC (implicit practice + alcohol), in which participants consumed an alcoholic beverage and, after 30 minutes, practiced the task without declarative knowledge; IMP-PLA (implicit practice + placebo), in which participants consumed an alcohol-flavored soft drink and, after 30 minutes, practiced the task without declarative knowledge; EXP-ALC (explicit practice + alcohol), in which participants consumed an alcoholic beverage and, after 30 minutes, practiced the task with declarative knowledge; and EXP-PLA (explicit practice + placebo), in which participants consumed an alcohol-flavored soft drink and, after 30 minutes, performed the task with declarative knowledge. Practice of the SRTT occurred on a single day for all groups and consisted of seven blocks (five blocks with repeated stimuli and two blocks with random stimuli). Alcohol consumption corresponded to a dose of 0.4 g/kg of absolute alcohol, divided into two drinks mixed with orange soda; in the placebo condition, alcohol was sprayed onto the soft drink. The dependent variable was the change score, calculated by subtracting response times between repeated and random blocks at the beginning of practice (B1 – B2), at the end of practice (B6 – B7), and during the retention test (fixed RT – random RT). Declarative knowledge was assessed by the number of participants who identified and/or recognized the repeated sequence. Results: Both groups showed performance improvement during practice, with shorter response times for repeated sequences compared to random sequences, and no significant differences were observed between the groups. Conclusion: Moderate alcohol consumption does not impair the encoding and consolidation mechanisms involved in implicit and explicit motor learning when alcohol intake occurs prior to task practice.