Evaluating the Role of Expectations in Response to Caffeine Consumption: An RCT
13 de junio de 2017 actualizado por: 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.
Descripción general del estudio
Estado
Terminado
Condiciones
Intervención / Tratamiento
Tipo de estudio
Intervencionista
Inscripción (Actual)
205
Fase
- No aplica
Criterios de participación
Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.
Criterio de elegibilidad
Edades elegibles para estudiar
18 años y mayores (Adulto, Adulto Mayor)
Acepta Voluntarios Saludables
No
Géneros elegibles para el estudio
Todos
Descripción
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
Plan de estudios
Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.
¿Cómo está diseñado el estudio?
Detalles de diseño
- Propósito principal: Otro
- Asignación: Aleatorizado
- Modelo Intervencionista: Asignación paralela
- Enmascaramiento: Doble
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
|---|---|
|
Experimental: Caffeine
One-time treatment with 200mg caffeine pill
|
200mg delivered as pill; one-time dose
|
|
Comparador de placebos: Placebo
One-time treatment with lactose-based placebo pill
|
Lactose-based pill; one-time dose
|
¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
|---|---|---|
|
Mood State Score on POMS-2 Test
Periodo de tiempo: 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)
Periodo de tiempo: 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
Periodo de tiempo: 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
Periodo de tiempo: 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
|
Colaboradores e Investigadores
Aquí es donde encontrará personas y organizaciones involucradas en este estudio.
Patrocinador
Investigadores
- Investigador principal: David B Allison, PhD, University of Alabama at Birmingham
Publicaciones y enlaces útiles
La persona responsable de ingresar información sobre el estudio proporciona voluntariamente estas publicaciones. Estos pueden ser sobre cualquier cosa relacionada con el estudio.
Fechas de registro del estudio
Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.
Fechas importantes del estudio
Inicio del estudio
1 de junio de 2015
Finalización primaria (Actual)
1 de octubre de 2015
Finalización del estudio (Actual)
1 de octubre de 2015
Fechas de registro del estudio
Enviado por primera vez
1 de junio de 2015
Primero enviado que cumplió con los criterios de control de calidad
2 de junio de 2015
Publicado por primera vez (Estimar)
3 de junio de 2015
Actualizaciones de registros de estudio
Última actualización publicada (Actual)
12 de julio de 2017
Última actualización enviada que cumplió con los criterios de control de calidad
13 de junio de 2017
Última verificación
1 de junio de 2017
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
- Efectos fisiológicos de las drogas
- Agentes neurotransmisores
- Mecanismos moleculares de acción farmacológica
- Inhibidores de enzimas
- Antagonistas purinérgicos
- Agentes Purinérgicos
- Inhibidores de la fosfodiesterasa
- Antagonistas del receptor P1 purinérgico
- Estimulantes del Sistema Nervioso Central
- Cafeína
Otros números de identificación del estudio
- F150410009
Plan de datos de participantes individuales (IPD)
¿Planea compartir datos de participantes individuales (IPD)?
Sí
Descripción del plan IPD
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.
Información sobre medicamentos y dispositivos, documentos del estudio
Estudia un producto de dispositivo regulado por la FDA de EE. UU.
No
producto fabricado y exportado desde los EE. UU.
No
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