A developmental study of the influence of task characteristics on motor overflow.
Motor overflow refers to involuntary movement or muscle activity that may coincide with voluntary movement. This study examined factors influencing motor overflow in 17 children (8-11 years), and 17 adults (18-35 years). Participants performed a finger pressing task by exerting either 33% or 66% of their maximal force output using their dominant or non-dominant hand. Attention was manipulated by tactile stimulation to one or both hands. Overflow relative to the target force was greater in children compared to adults, and at the lower target force for both groups, but was not influenced by attentional stimulation. Childhood overflow was greater when the left-hand performed the task. Although an immature motor system may underlie an inability to suppress involuntary movement, childhood overflow may provide motor stabilization.
Addamo
Patricia K
PK
Experimental Neuropsychology Research Unit, School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton, Vic. 3800, Australia. patricia.dredge@med.monash.edu.au
Farrow
Maree
M
Hoy
Kate E
KE
Bradshaw
John L
JL
Georgiou-Karistianis
Nellie
N
D000293:Adolescent; D000328:Adult; D000375:Aging; D000704:Analysis of Variance; D002648:Child; D006225:Hand / Q000502:physiology*; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D009119:Muscle Contraction; D010812:Physical Stimulation; D011312:Pressure; D055815:Young Adult