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Cited by 190Coffee research and impactsNeural dynamics and brain functionAttention Deficit Hyperactivity Disorder

Caffeine effects on resting-state arousal

Barry, Robert J., Rushby, Jacqueline A., Wallace, Mark J., Clarke, Adam R., Johnstone, Stuart J., Zlojutro, Ilinka·2005·Clinical Neurophysiology
DOI 10.1016/j.clinph.2005.08.008
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Abstract

Objective This study examined the use of caffeine to manipulate arousal level without the confounds associated with task-related activation. From previous work in our laboratory, an increase in skin conductance level (SCL) and EEG alpha frequency, together with a global decrease in alpha power, were used as markers of arousal increase, and we sought to identify these effects with caffeine ingestion.Methods We examined the effect of a single oral dose of caffeine (250 mg) in a randomised double-blind placebo-controlled repeated-measures cross-over study. Eighteen healthy university students (mean age 21 years; 13/18 females) participated in two sessions 1 week apart. EEG and autonomic data (SCL, heart rate, systolic and diastolic blood pressure, and respiration rate) from a 2 min eyes-closed epoch, commencing approximately 30 min after ingestion of caffeine or placebo, were examined.Results Caffeine was associated with increased SCL, a global reduction in EEG power in the alpha band, and a global increase in alpha frequency. There were no cardiovascular effects.Conclusions The positive results are consistent with recent electrodermal and EEG studies of arousal and suggest that caffeine may be utilised as a task-free means of manipulating arousal in future investigations. Further work is necessary to clarify the absence of cardiovascular effects, and to integrate those data with emerging conceptualisations of arousal and activation.Significance The present data support the use of caffeine as a simple tool to explore the role of arousal in both normal and atypical functioning, and this may be useful in determining the validity and importance of supposed hyper- or hypo-arousal in such syndromes as attention-deficit/hyperactivity disorder (AD/HD).

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  • Barry et al. (2005, 2007, 2008) found that increased alpha power was associated with reduced SCL during eyes-closed resting-state, while switching to eyes-open caused an increase in SCL and a decrease in alpha power.

    “Barry et al. (2005Barry et al. ( , 2007Barry et al. ( , 2008) ) investigated the relationships between EEG spectral power and SCL during resting-state and found that increased alpha power was associated with reduced SCL during eyes-closed resting-state, while switching to eyes-open caused an increase in SCL and a decrease in alpha power.”

    From Is autonomic nervous system function atypical in Attention Deficit Hyperactivity Disorder (ADHD)? A systematic review of the evidence (2020) · cites this paper as Barry et al. (2005

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Authors
Barry, R. J., Rushby, J. A., Wallace, M. J., Clarke, A. R., Johnstone, S. J., & Zlojutro, I.
Affiliations
University of Wollongong (AU)
Corresponding author
Barry, Robert J.
ORCID
Venue
Clinical Neurophysiology
Publisher
Elsevier BV
Published
2005-11
Volume
116
Issue
11
Pages
2693-2700
ISSN
1388-2457 (ISSN-L)
DOI
10.1016/j.clinph.2005.08.008
OpenAlex
W1989695510
Cited by
190
References
55
Citations by year
2026: 9 · 2025: 9 · 2024: 15 · 2023: 12 · 2022: 17 · 2021: 12 · 2020: 7 · 2019: 11 · 2018: 6 · 2017: 7 · 2016: 6 · 2015: 6 · 2014: 5 · 2013: 8 · 2012: 8
FWCI
4.25
Type
journal article
Language
en
Open access
closed
Licence
Locations
  • Clinical Neurophysiology (publishedVersion)
  • PubMed (publishedVersion)
  • Research Online (University of Wollongong) (submittedVersion)
Topics
  • Health Sciences › Medicine › Pharmacology › Coffee research and impacts
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Neural dynamics and brain function
  • Health Sciences › Medicine › Psychiatry and Mental health › Attention Deficit Hyperactivity Disorder
Keywords
caffeine, arousal, skin conductance level, EEG alpha power, alpha frequency, autonomic arousal, cardiovascular effects, attention deficit hyperactivity disorder, hyperarousal, hypoarousal
MeSH terms
Adult, Alpha Rhythm, Central Nervous System Stimulants, Arousal, Caffeine, Double-Blind Method, Electroencephalography, Female, Galvanic Skin Response, Humans, Male, Rest, Cross-Over Studies

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