Effects of Isometric Hand-Grip Muscle Contraction on Young Adults' Free Recall and Recognition Memory.
OBJECTIVE
The purpose of this study was to determine if physical arousal produced by isometric hand-dynamometer contraction performed during word-list learning affects young adults' free recall or recognition memory.


METHODS
Twenty-four young adults (12 female; Mage= 22 years) were presented with 4 20-item word lists. Moderate arousal was induced in 12 adults by an initial 30-s maximal hand-dynamometer squeeze with force productions of 50% maximum; low arousal was induced in 12 adults by an initial 1-s maximal dynamometer squeeze with force production of 10% maximum during learning. Memory performances following dual-task conditions experienced during the encoding, consolidation, and recall phases of learning were compared to a single-task control condition during which words were learned in the absence of isometric exercise.


RESULTS
Planned contrasts revealed that arousal coinciding with word encoding led to significantly poorer immediate recall, F(1, 23) = 10.13, p < .05, [Formula: see text] = .31, delayed free recall, F(1, 23) = 15.81, p < .05, [Formula: see text] = .41, and recognition memory, F(1, 23) = 6.07, p < .05, [Formula: see text] = .21, compared with when there was no arousal. Neither arousal condition facilitated participants' memory performance.


CONCLUSIONS
The reduction in long-term memory performance specific to the encoding phase of learning is explained in terms of the dual-task attentional demands placed on participants.
a University of Georgia.
Phillip D
PD
Tomporowski
a University of Georgia.
Chelesa
C
Albrecht
a University of Georgia.
Daniel M
DM
Pendleton
D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology; D011939:Mental Recall / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D055815:Young Adult
Arousal; dual task; explicit memory; memory consolidation