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The Effect of Tablet Size on Cognitive Performance Caffeine

Phase 4
Completed
Conditions
Placebo Effect
Interventions
Other: Placebo - small sucrose pill
Other: Placebo - large sucrose pill
Registration Number
NCT03694886
Lead Sponsor
University of Colorado, Denver
Brief Summary

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.

Detailed Description

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
120
Inclusion Criteria
  • Fluent in written and spoken English
  • Ability to see color
  • No uncontrolled high blood pressure
  • No allergies to caffeine or sucrose
  • No history of heart disease
  • No untreated anxiety or depression
  • Non-pregnant
  • No caffeine consumed the day of participation
Exclusion Criteria
  • Not fluent in written and/or spoken English
  • Uncontrolled high blood pressure
  • Color-blindness
  • Allergies to caffeine and/or sucrose
  • History of heart disease
  • Untreated anxiety or depression
  • Pregnant
  • Consumed caffeine on the day of participation

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Caffeine with small sucrose pillCaffeine Anhydrous with small sucrose pillParticipants will be given one dose of 90 milligrams caffeine anhydrous dissolved in 8 ounces of water and a 1 mm sucrose pill to consume in 10 minutes. After 30 minutes post-administration, the cognitive tests will be administered.
Caffeine with large sucrose pillCaffeine Anhydrous with large sucrose pillParticipants will be given one dose of 90 milligrams caffeine anhydrous dissolved in 8 ounces of water and a 5 mm sucrose pill to consume in 10 minutes. After 30 minutes post-administration, the cognitive tests will be administered.
No caffeine with small sucrose pillPlacebo - small sucrose pillParticipants will be given 8 ounces of water and a 1 mm sucrose pill to consume in 10 minutes. After 30 minutes post-administration, the cognitive tests will be administered.
No caffeine with large sucrose pillPlacebo - large sucrose pillParticipants will be given 8 ounces of water and a 1 mm sucrose pill to consume in 10 minutes. After 30 minutes post-administration, the cognitive tests will be administered.
Primary Outcome Measures
NameTimeMethod
Trail Making task AWithin 90 minutes of receiving informed consent. Actual task time: approximately 2 minutes

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.

Stroop Color testWithin 90 minutes of receiving informed consent. Actual task time: approximately 1.5 minutes

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.

Stroop Word testWithin 90 minutes of receiving informed consent. Actual task time: approximately 1.5 minutes

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.

Secondary Outcome Measures
NameTimeMethod
Rey Auditory Verbal Learning testWithin 90 minutes of receiving informed consent. Actual task time: approximately 40 minutes

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.

Trail Making task BWithin 90 minutes of receiving informed consent. Actual task time: approximately 3 minutes

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.

Stroop Color-and-Word testWithin 90 minutes of receiving informed consent. Actual task time: approximately 2 minutes

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.

Trial Locations

Locations (1)

University of Colorado Denver

🇺🇸

Denver, Colorado, United States

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