Author(s): TAUBERT, M., MATKE, M., LEHMANN, N., ZIEGLER, G., PRABHU, N., Institution: UNIVERSITÄT MAGDEBURG, Country: GERMANY, Abstract-ID: 1144

INTRODUCTION:
Tailored intervention programs consider individual characteristics and abilities of athletes or patients. Yet, we know little about how person-specific predispositions (e.g., phenotype) interact with task demands during skill practice. The supply-demand mismatch model (Lövden et al., 2010) predicts that optimal task demands (not too easy nor too difficult) expand current brain and behavioral capacities if exceeding intrinsic anatomical constraints (“supply”). While a moderate task difficulty during practice may enhance learning in old age, it is currently unclear how task demands interact with individual brain anatomy to modulate learning. Stabilometer balance learning (a seesaw-like platform) depends, in part, on genotype (Grossman, 1980) and is associated with individual differences in premotor cortical folding in young adults (Taubert et al., 2024). Cortical folding largely develops in utero and remain relatively stable throughout life (Storsve et al., 2014). Here we tested the effects of two different task demands (moderate vs. low) during practice and determined cortical folding patterns from brain MRI scans. We hypothesized that (1) both moderate vs. low task demands and higher premotor folding positively influence learning, moreover, (2) moderate task demands increase effects of cortical folding on learning (due to inherent performance limitations under high loads).
METHODS:
61 healthy participants (mean age= 67.6 years, 36 females) were randomized into moderate or low task demand groups (manipulated through balance board mechanics) receiving five consecutive weeks of stabilometer practice. Both groups received three testing sessions (pre, inter, post), five practice sessions, and a baseline MRI session. The balance task was performed on a movable platform with a maximum deviation of ±26° (Lafayette Instrument). “Time in balance” was used to calculate improvements in performance after three (pre to inter) and five (pre to post) weeks of practice. Moderation analyses considered cortical folding in left premotor cortex as predictor (Taubert et al., 2024), group assignment (moderate vs. low task demands) as moderator whereas performance improvements after three (“early”) or five (“late”) weeks of training as dependent variables.
RESULTS:
Results revealed a significant direct effect of higher cortical folding on performance improvements during late (t=2.86, p=0.006) but not early (t=1.12, p=0.24) practice. Moderate compared to low task demands significantly enhanced improvements during both early (t=2.29, p=0.025) and late (t=3.04, p=0.004) learning. Finally, task demands moderated (interaction effect) the impact of cortical folding on early (t=2.03, p=0.047, rmoderate=.32, rlow=-.21) but not late performance improvements (t=1.585, p=0.119, rmoderate=.42, rlow=.12).
CONCLUSION:
Our findings extend the supply-demand mismatch model (Lövden et al., 2010) and show that, under sufficiently high task demands, neuroanatomical predispositions constrain performance improvements.