Motor learning in children: feedback effects on skill acquisition

Physical Therapy, June, 2008 by Katherine J. Sullivan, Shailesh S. Kantak, Patricia A. Burtner

On a daily basis, children engage in motor activity that leads to the progressive development of motor skills. Some of this activity leads to skill in functional tasks such as running, jumping, kicking, and throwing. Other motor activity leads to the acquisition of fine motor skills that involve eye-hand coordination, such as playing a video game or using a computer. Despite the extensive literature on the effects of feedback during motor task practice on motor skill acquisition and learning in adults, 1-7 there is a paucity of literature in the area of motor learning in children.

Adults who practice motor skills in reduced feedback conditions perform with greater accuracy and consistency in a delayed retention test compared with those who practice with feedback provided during every practice trial. (1,3-6) Reduced feedback practice conditions are hypothesized to increase information-processing demands during practice that are advantageous to the relatively permanent effects associated with motor learning observed in a delayed retention test. (8-10) In contrast, frequent feedback may guide the learner to a correct response during practice and interfere with the problem-solving processes associated with more effortful practice. (8,9)

Cognitive effort during practice, while advantageous for some people, may exceed the optimal capability for other individuals, especially those with reduced or impaired information-processing abilities. Guadagnoli and Lee (11) have proposed the Challenge Point Framework, which suggests that motor learning depends on the level of challenge emerging from an interaction of the information-processing capability of the learner, task demands, and practice condition. This framework serves as a model to predict the interaction that may occur when the challenge posed by a practice condition exceeds the information-processing capability of the learner.

According to this framework, challenge is required to engage the cognitive processes associated with motor learning. There is a point of optimal challenge that yields maximum practice benefits when optimal cognitive effort is invoked. A level of challenge below or above this optimal challenge point may attenuate learning. That is, conditions that demand too much cognitive effort may interfere with learning effects. (11)

It is well established that children have different information-processing capabilities compared with adults. (12,13) Children have differences in cognitive processes such as selective attention (14) and speed of information processing (15,16) that increase with age. In addition, children use different strategies to process information compared with adults in tasks that require visuo-spatial working memory, (17,18) object recognition memory, (19) verbal learning, (20) copying spatial patterns, (21) or higher-level attention focusing. (22,23) These differences in cognitive ability may contribute to motor learning differences between children and adults, (12) bringing into question the generalizability of motor learning principles derived primarily from young adults to children. Specifically, it is unknown whether reduced frequency of feedback during practice benefits motor learning in children in a manner that is similar to or different from that of adults.

The present study was designed to investigate the effect of different frequencies of feedback during practice on acquisition and retention of a fast, discrete motor skill in children compared with young adults. Based on the Challenge Point Framework, (11) we hypothesized that children who practiced in a reduced feedback frequency condition would not realize the same motor learning benefits compared with young adults. Our long-term goal is to understand the effects of feedback schedules on motor learning in children in order to provide additional insights regarding optimizing feedback delivery during skill acquisition in children with and without neurological impairments.

Method

Participants

Twenty young adults (12 male, 8 female; mean age = 25.6 years, SD = 2.5, range = 22-30) and 20 children who were healthy and developing typically (12 male, 8 female; mean age = 10.7 years, SD = 2.0, range = 8-14) voluntarily participated in the study. All participants were recruited from the greater Los Angeles area. Prior to participating in the experiment, informed consent was provided by the adult participants, and parental consent and child assent were obtained for the children who participated. Inclusion criteria were young adults aged 21 to 35 years and children aged 8 to 14 years who were developing typically and performing at grade level in school. Exclusion criteria were any orthopedic or neurological problems that would interfere with the ability to perform a coordinated arm movement. All participants used their dominant arm to practice the movement task. All participants were evaluated for visual perception and gross motor dexterity.

Instrumentation and Task

The motor task was to learn a discrete, coordinated arm movement using a lightweight lever. This lever was affixed to a frictionless vertical axle such that the lever movement was restricted to the horizontal plane above the surface of a table. The handle at the end of the lever was adjusted to accommodate the participant's forearm. A linear potentiometer attached to the base of the vertical axle recorded lever-position information. Signals from the potentiometer were converted to digital signals by an A/D board of a computer and sampled at 1,000 Hz to provide feedback on the computer monitor. The template software program (Allen Weekly, 2004) was used for manipulation of the movement trajectory and the interval duration and for data storage for off-line analysis of each trial.