Age effects shrink when motor learning is predominantly supported by nondeclarative, automatic memory processes: Evidence from golf putting

Abstract

Can motor learning be equivalent in younger and older adults? To address this question, 48 younger (M = 23.5 years) and 48 older (M = 65.0 years) participants learned to perform a golf-putting task in two different motor learning situations: one that resulted in infrequent errors or one that resulted in frequent errors. The results demonstrated that infrequent-error learning predominantly relied on nondeclarative, automatic memory processes whereas frequent-error learning predominantly relied on declarative, effortful memory processes: After learning, infrequent-error learners verbalized fewer strategies than frequent-error learners; at transfer, a concurrent, attention-demanding secondary task (tone counting) left motor performance of infrequent-error learners unaffected but impaired that of frequent-error learners. The results showed age-equivalent motor performance in infrequent-error learning but age deficits in frequent-error learning. Motor performance of frequent-error learners required more attention with age, as evidenced by an age deficit on the attention-demanding secondary task. The disappearance of age effects when nondeclarative, automatic memory processes predominated suggests that these processes are preserved with age and are available even early in motor learning.

Keywords:

• Cognitive ageing
• Motor learning
• Frequency of errors
• Memory
• Attention

Acknowledgments

Jon Maxwell passed away on Sunday 25th January 2009. We were privileged to have the opportunity to work with Jonny Max. This research was supported by a doctoral fellowship from the Ministère de l'Enseignement Supérieur et de la Recherche to Guillaume Chauvel. Sven Joubert is supported by a Chercheur Boursier award from the Fonds de la Recherché en Santé du Québec (FRSQ). Rich S. W. Masters is supported by the Research Grants Council of the Hong Kong Special Administrative region (HKU 748709H). We thank Eric Ruthruff for his commentary and invaluable insights on an earlier draft of the manuscript.

Notes

¹ Relative to Maxwell et al. (2001), the present tone-counting task was more difficult in terms of perceptual discrimination (a single tone embedded in a stream of single tones and pairs of tones, instead of a high-pitched tone embedded in a stream of high-pitched and low-pitched tones) and of presentation rate (1.2 s per stream instead of 1.5 s). The rationale for using a more difficult tone-counting task was to preclude participants from directing attentional resources toward motor execution between two successive tones—in other words, to reduce the likelihood of task-switching strategies in the transfer test.

² These findings cannot be accounted for by age differences in the duration necessary to perform a block of putts, as revealed by an ANOVA carried out with age group, type of transfer group, and type of learning as between-subjects variables and block as a within-subjects variable. First, the mean time necessary to perform a block of putts was equivalent between younger adults (M = 4 min 47 s) and older adults (M = 4 min 46 s), F(1, 88) < 1 (η² _p = .001). Second, there was a main effect of type of learning with the duration being shorter for infrequent-error learners (M = 4 min) than for frequent-error learners (M = 5 min 33 s), F(1, 88) = 82.48, p < .001 (η² _p = .484). Third, the type of learning effect combined additively with age group, F(1, 88) = 1.33, p = .253 (η² _p = .015). For purposes of information, the duration necessary to perform a block of putts steadily increased as the distance from the hole increased, more so for infrequent-error learners (M = 3 min 18 s at the distance of 25 cm to M = 4 min 27 s at the distance of 100 cm) than for frequent-error learners (M = 5 min 23 s at the distance of 150 cm to M = 6 min 16 s at the distance of 225 cm for frequent-error learners), as evidenced by a significant interaction between block and type of learning, F(3, 264) = 68.79, p < .001 (η² _p = .439).

³ One may contend that motor execution of the golf-putting task was slowed by the tone-counting task for frequent-error learners, more so with age. As a consequence, the time to complete the transfer block may have been greater for older than younger adults. This hypothetical disadvantage for older adults (i.e., higher number of tones to count) may explain the observed age difference on the tone-counting task. To address this speculation, a factorial ANOVA of the time taken to complete the transfer block was carried out with age group, type of learning, and type of transfer group as between-subjects variables. Time to complete the transfer block was actually faster when the tone-counting task was simultaneously performed (4.0 min for the experimental transfer group vs. 4.8 min for the control transfer group), F(1, 88) = 9.11, p < .01 (η² _p = .094). The main effect of type of transfer group did not interact with either age group, F(1, 88) < 1 (η² _p = .003), or type of learning, F(1, 88) < 1 (η² _p = .005), no other effect being significant. Therefore, the age difference on the percentage correct on the cognitive task in frequent-error learners cannot be due to an age difference in the amount of time necessary to complete the transfer block, but rather probably reflects an age deficit in the ability to carry out the motor and the cognitive tasks simultaneously.