This study aims to assess if tablet size, due to placebo effect, alters participants' performance on cognitive tests after consuming caffeine. Participants will be randomly assigned to one of four groups: 1) 90 mg caffeine with a 1 mm diameter sucrose pillule; 2) no caffeine with the small sucrose pillule; 3) 90 mg caffeine with a 5 mm sucrose pillule; 4) no caffeine with the large sucrose pillule.
Background: A capsule's physical design (e.g. shape, size, and color) affects individuals' perception of drug efficacy; that is, how well a drug is likely to work. The goal of this study is to assess the effects tablet size may have on participant's performance on cognitive testing since research has found differences between preparation methods. Method: 120 participants will be randomly assigned to one of four groups: 1) 90 mg caffeine with a 1 mm diameter sucrose pillule; 2) no caffeine with the small sucrose pillule; 3) 90 mg caffeine with a 5 mm sucrose pillule; 4) no caffeine with the large sucrose pillule. Participants will consume the designated placebo tablet with water (caffeinated or non-caffeinated); then, participants will provide weekly caffeine intake and complete the neutral portion of Velten's Mood Induction Procedure until 30 minutes have passed to allow for caffeine activation. Participants will complete the Stroop test, Trial Making Tests A and B, and the Rey Auditory Verbal Learning Test. Previous literature, as far as the author knows, relied on evaluating drug efficacy based on appearance alone. This study aims to assess if tablet size, due to placebo effect, alters participants' performance on cognitive tests after consuming caffeine.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
120
caffeine anhydrous that has been weighed out to 90 mg per dose presented with a 1 mm sucrose pillule
sucrose pillules of 5 mm diameter will be given to all participants in the large pill groups
caffeine anhydrous that has been weighed out to 90 mg per dose presented with a 5 mm sucrose pillule
University of Colorado Denver
Denver, Colorado, United States
Stroop Color test
Measures processing speed. 100-item, time-trial task where participants read the color of printed items on the task paper as quickly as possible for 45 seconds. Scores are measured in the number of correct responses within the allotted time.
Time frame: Within 90 minutes of receiving informed consent. Actual task time: approximately 1.5 minutes
Stroop Word test
Measures processing speed. 100-item, time-trial task where participants read color names printed on the task paper as quickly as possible for 45 seconds. Scores are measured in the number of correct responses within the allotted time.
Time frame: Within 90 minutes of receiving informed consent. Actual task time: approximately 1.5 minutes
Trail Making task A
Measures processing speed. 25 item, time-trial task where participants must connect numbers in order as quickly as possible. Scores are measured by the amount of time (in seconds) for participants to complete the task.
Time frame: Within 90 minutes of receiving informed consent. Actual task time: approximately 2 minutes
Stroop Color-and-Word test
Measures processing speed. 100-item, time-trial task where participants must read the color of the ink instead of color names printed on the task paper as quickly as possible for 45 seconds. Scores are measured in the number of correct responses within the allotted time.
Time frame: Within 90 minutes of receiving informed consent. Actual task time: approximately 2 minutes
Trail Making task B
Measures processing speed. 25 item, time-trial task where participants must connect numbers and letters in order (e.g. 1-A-2-B, etc.) as quickly as possible. Scores are measured by the amount of time (in seconds) for participants to complete the task.
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sucrose pillules of 1 mm diameter will be given to all participants in the small pill groups
Time frame: Within 90 minutes of receiving informed consent. Actual task time: approximately 3 minutes
Rey Auditory Verbal Learning test
Measures memory. 30-item, 2 section task where participants are read 15 words and asked to recall as many words as possible in the first section. A second set of 15 words is then introduced and participants recall those. The second section consists of revisiting the original set of words and recalling as many of those. Scores are measured by the total words remembered in section one, and another score for the total intrusions from the second list into the recall of section two.
Time frame: Within 90 minutes of receiving informed consent. Actual task time: approximately 40 minutes