Evaluating the Role of Expectations in Response to Caffeine Consumption: An RCT
13. juni 2017 opdateret af: David Allison, Phd, University of Alabama at Birmingham
Evaluating the Role of Expectations in Response to Caffeine Consumption: A Randomized Control Trial
The purpose of this project is to examine the effect of expectancy on mood and alertness after consumption of caffeine "treatment" or placebo "control" pill, given that participants know their probability for receiving the caffeine versus placebo pill.
Participants will be randomly assigned a probability (ranging from 0-100%) of receiving caffeine vs. placebo, and this probability will be revealed to them before consumption of the assigned pill and subsequent cognitive testing.
At the time of consumption, neither study staff administering the intervention nor participants will know for certain which pill is given to each participant.
Pill assignment will depend on pre-determined randomization probabilities, which will be provided and assigned by the study statistician.
By revealing participants' individual probability of receiving the caffeine pill, we will induce positive or negative expectancies regarding likelihood for receipt of the caffeine pill.
These experimental manipulations will: 1) estimate the effect of expectancy on cognitive and affective outcomes, and 2) allow for a more direct estimate of the effect of the caffeine pill under real-world conditions than would a conventional randomized trial.
Studieoversigt
Status
Afsluttet
Betingelser
Intervention / Behandling
Undersøgelsestype
Interventionel
Tilmelding (Faktiske)
205
Fase
- Ikke anvendelig
Deltagelseskriterier
Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.
Berettigelseskriterier
Aldre berettiget til at studere
18 år og ældre (Voksen, Ældre voksen)
Tager imod sunde frivillige
Ingen
Køn, der er berettiget til at studere
Alle
Beskrivelse
Inclusion Criteria:
- 18 years-old or older
- available to participate on the dates specified
- willing to take a caffeine or placebo pills at study session
- willingness to abstain from caffeine for 12 hours prior to study visit (8:30pm-8:30am)
- UAB employees or students with some college education (including current enrollment)
Exclusion Criteria:
- self-reported use of ADHD medication
- self-reported use of anxiety medication
- self-reported use of sleep medication
- self-reported use of nicotine products
- self-reported lactose intolerance
- self-reported uncorrected vision
- self-reported pregnancy or trying to become pregnant
Studieplan
Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.
Hvordan er undersøgelsen tilrettelagt?
Design detaljer
- Primært formål: Andet
- Tildeling: Randomiseret
- Interventionel model: Parallel tildeling
- Maskning: Dobbelt
Våben og indgreb
Deltagergruppe / Arm |
Intervention / Behandling |
|---|---|
|
Eksperimentel: Caffeine
One-time treatment with 200mg caffeine pill
|
200mg delivered as pill; one-time dose
|
|
Placebo komparator: Placebo
One-time treatment with lactose-based placebo pill
|
Lactose-based pill; one-time dose
|
Hvad måler undersøgelsen?
Primære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
|---|---|---|
|
Mood State Score on POMS-2 Test
Tidsramme: 30 minutes post pill consumption
|
Profile of Mood States (POMS-2)- "Volunteers rated a series of 65 mood-related adjectives with regard to how they were feeling "right now" on a scale of 0 (not at all) to 4 (extremely).
The adjectives factor into six mood sub-scales: Tension-Anxiety; Depression-Dejection; Anger-Hostility; Vigor-Activity; Fatigue-Inertia; Confusion-Bewilderment and a Total Mood Disturbance score which aggregates the six sub-scales into a single variable."
- from our publication.
The minimum and maximum possible raw scores were: 0 and 40 for Tension-Anxiety, 0 and 52 for Depression-Dejection, 0 and 44 for Anger-Hostility, 0 and 36 for Vigor-Aactivity, 0 and 24 for Fatigue-Inertia, 0 and 40 for Confusion-Bewilderment, -36 and 200 for Total Mood Disturbance, and 0 and 24 for Friendliness.
For Friendliness and Vigor-Activity, the more positively a person feels, the higher the score.
For all other sub-scales and Total Mood Disturbance, the more negatively a person feels, the higher the score.
|
30 minutes post pill consumption
|
|
Vigilance Score on Computer-based Test Using Random, Visual Stimulus: Proportion Correct (Out of 60)
Tidsramme: 45 to 105 minutes post pill consumption
|
Scanning Visual Vigilance Test.
"This test assesses vigilance, ability to sustain attention during long, boring, continuous tasks that generate minimal cognitive load (Fine et al, 1994; Lieberman et al, 1998; 2002).
The volunteer continuously scans a computer screen to detect an infrequent, difficult-to-detect stimulus that appears at random intervals and locations for 2 s.
On average, a stimulus was presented once per minute.
Upon detection of the stimulus, the volunteer pressed the space bar as rapidly as possible.
Whether a stimulus was detected and time required for detection was recorded.
Responses before or after stimulus occurrence were false alarms.
The test lasted 60 minutes."
- from our publication
|
45 to 105 minutes post pill consumption
|
|
Vigilance Score on Computer-based Test Using Random, Visual Stimulus: Number Correct, Number of False Alarm Hits
Tidsramme: 45 to 105 minutes post pill consumption
|
Scanning Visual Vigilance Test.
"This test assesses vigilance, ability to sustain attention during long, boring, continuous tasks that generate minimal cognitive load (Fine et al, 1994; Lieberman et al, 1998; 2002).
The volunteer continuously scans a computer screen to detect an infrequent, difficult-to-detect stimulus that appears at random intervals and locations for 2 s.
On average, a stimulus was presented once per minute.
Upon detection of the stimulus, the volunteer pressed the space bar as rapidly as possible.
Whether a stimulus was detected and time required for detection was recorded.
Responses before or after stimulus occurrence were false alarms.
The test lasted 60 minutes."
- from our publication
|
45 to 105 minutes post pill consumption
|
|
Vigilance Score on Computer-based Test Using Random, Visual Stimulus: Mean Time to a Correct Hit
Tidsramme: 45 to 105 minutes post pill consumption
|
Scanning Visual Vigilance Test.
"This test assesses vigilance, ability to sustain attention during long, boring, continuous tasks that generate minimal cognitive load (Fine et al, 1994; Lieberman et al, 1998; 2002).
The volunteer continuously scans a computer screen to detect an infrequent, difficult-to-detect stimulus that appears at random intervals and locations for 2 s.
On average, a stimulus was presented once per minute.
Upon detection of the stimulus, the volunteer pressed the space bar as rapidly as possible.
Whether a stimulus was detected and time required for detection was recorded.
Responses before or after stimulus occurrence were false alarms.
The test lasted 60 minutes."
- from our publication
|
45 to 105 minutes post pill consumption
|
Samarbejdspartnere og efterforskere
Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.
Efterforskere
- Ledende efterforsker: David B Allison, PhD, University of Alabama at Birmingham
Publikationer og nyttige links
Den person, der er ansvarlig for at indtaste oplysninger om undersøgelsen, leverer frivilligt disse publikationer. Disse kan handle om alt relateret til undersøgelsen.
Datoer for undersøgelser
Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.
Studer store datoer
Studiestart
1. juni 2015
Primær færdiggørelse (Faktiske)
1. oktober 2015
Studieafslutning (Faktiske)
1. oktober 2015
Datoer for studieregistrering
Først indsendt
1. juni 2015
Først indsendt, der opfyldte QC-kriterier
2. juni 2015
Først opslået (Skøn)
3. juni 2015
Opdateringer af undersøgelsesjournaler
Sidste opdatering sendt (Faktiske)
12. juli 2017
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
13. juni 2017
Sidst verificeret
1. juni 2017
Mere information
Begreber relateret til denne undersøgelse
Yderligere relevante MeSH-vilkår
Andre undersøgelses-id-numre
- F150410009
Plan for individuelle deltagerdata (IPD)
Planlægger du at dele individuelle deltagerdata (IPD)?
Ja
IPD-planbeskrivelse
Raw de-identified data will be posted as a replication data set on ICPSR after publication of results in a journal.
Data will be free to download and accessible to anyone with access to ICPSR replication data sets.
Lægemiddel- og udstyrsoplysninger, undersøgelsesdokumenter
Studerer et amerikansk FDA-reguleret enhedsprodukt
Ingen
produkt fremstillet i og eksporteret fra U.S.A.
Ingen
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