TY - JOUR PY - 1940// TI - The time of administration and some effects of 2 grs. of alkaloid caffeine JO - Journal of experimental psychology A1 - Barmack, Joseph Ephraim SP - 690 EP - 698 VL - 27 IS - 6 N2 - Subjects added pairs of numbers for eight 15-min. periods, after which they filled out a rating sheet with 4 nine-point scales of bored-interested, peppy-fatigued, sleepy-wide-awake, and attentive-inattentive. This was done under the following conditions: (1) control, (2) 2 grs. of alkaloid caffeine one hour before adding, (3) 2 grs. 2 hours before adding, and (4) 2 grs. 3 hours before adding. The following results were obtained: (1) 2 grs. administered one hour before adding allayed: (a) loss in rate of adding, (b) development of unfavorable reports on all subjective rating scales. (2) Caffeine given 2 or 3 hours before adding had a similar, though lesser effect. (3) The effect of caffeine on the initial rate of addition, or on initial subjective reports, was negligible, regardless of time of administration. In a second experiment to determine whether caffeine is actually without initial effect subjects added for one 15 minutes period only and filled out rating scales under 3 conditions: (1) control, (2) 2 grs. of caffeine 2 hours before adding, and (3) 2 grs. 3 hours before adding. Under these conditions: (1) caffeine had no effect on rate of addition; (2) caffeine affected subjective reports in the favorable direction, particularly those given immediately after adding. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

LA - SN - 0022-1015 UR - http://dx.doi.org/10.1037/h0056657 ID - ref1 ER -