Effects of Practice upon the Metabolic Cost of Mental Work

Modification of the galvanic reflex by daily repetition of a stimulus.

“…This finding K^s considerable resemblance to that reported by Rounds, Shubert, and Poffenberger, (22) working with metabolism during mental work. They found the metabolic change at successive sittings remained practically constant.…”

Adaptation in energy mobilization: changes in general level of palmar skin conductance.

“…Becker and Olsen (4), measuring the effect of practice upon the metabolic 'cost' of learning nonsense syllables, have reported that practice increases the number of lists learned in a given time and reduces the cost per unit of time. Rounds, Schubert and Poffenberger (29), measuring the metabolic change during mental work, found that it remained practically constant at successive sittings, but, since the number of problems solved increased, there was a considerable decrease in the expenditure of energy per problem. On the other hand, Davis (12, p. 522), measuring skin resistance during work on problems in addition, reported "no discernible decrease in the resistance change accompanying mental work when the performance is repeated."…”

Blocking in mental fatigue and anoxemia compared.

“…On the other hand, there is the evidence from studies of respiratory calorimetry of the body as a whole, and from chemical analysis of the blood and urine, during and after mental work. Recent studies report increases in metabolic rate all the way from zero up to 28 percent and more, above the resting rate (9). A good review of this literature is contained in the report of Benedict and Benedict (1).…”