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Effect of Caffeine on Event
Related Potentials
Procedure Development
Gabrielle Notorgiacomo
Biomedical Engineering
WISE Summer 2015
Electrical and Computer Engineering, University of Cincinnati
Mentor: Dr. Fred Beyette Jr.
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Background
• EEG- “An
electroencephalogram
(EEG) is a test that
detects electrical
activity in your brain
using small, flat metal
discs (electrodes)
attached to your
scalp.”
– Mayo Clinic
(Barad, 2007)
Background
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• What is an event related potential (ERP)?
Measured Voltage (µV) Measured Voltage (µV)
– Averaged waveform of response to stimulus or event
– Epoch – selected period of time to be analyzed
Luck, S. J. (2014). An introduction to the event-related potential technique. MIT press.
Common Stimulus
Rare Stimulus
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Background
• Peak latency – time between stimulus
presentation and ERP
– Shift can indicate change in mental state
Peak Latency Shift (ms)
Average Peak Latency Across Experimental States
(Kadambi, 2014)
60
50
40
30
20
10
0
-10
Sleep Dep.
Control State
-20
-30
Caffeine
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Purpose: Lab
• Worker Safety
– Portable electroencephalograph (EEG) device
• Firemen helmets for real-time fatigue detection
• Casualties due to stress, sleep deprivation, and
physical exertion
Causes of Firefighter Fatalities 2010
(Kadambi, 2014)
Individual Goal
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• Protocol development
– Caffeine research
– Protocol documentation (IRB)
– Testing schedule
Drink
Red Bull
Fluid oz
8.4
Sugar (g)
27
Caffeine (mg)
80
Supplements (*abridged)
Taurine, B-group vitamins
5 hr energy
1.93
not listed
200
B-group vitamins, taurine, etc
Monster
16
54
160
B-group vitamins, taurine,
panax ginseng, guarana, etc
Coke
12
39
34
phosphoric acid
Diet Coke
12
0
45
Aspartame, phosphoric acid,
citric acid, potassium benzoate
Starbucks
DoubleShot
Espresso
6.5
18
128
panax ginseng root extract,
inositol, sodium ascorbate ,
guarana, etc
Lipton Black
Tea
8
0
55
none
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Process
The Institutional
Review Board
(IRB)
Pending Approval
Protocol development
and in-house study within Dr.
Beyette’s lab
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Methods: Population
• ~30 UC undergraduate students 18 or older
– Preliminary study parameter
– Generally healthy, any gender
• Cannot be:
– A student of Dr. Beyette’s  vulnerable population
– Pregnant
– Diagnosed with: health conditions related to consumption of caffeine
or sugar, skin sensitivity to sodium chloride based conductive gels,
medical sleep disorder, or serious heart conditions
– A metallic cranial implant(s) patient
– Hearing impaired
– On sedative or psychotropic medications
– Known to have a neurological condition including history of
stroke, epilepsy, pseudoseizures, or severe traumatic brain
injury
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Methods: Development
• Determine testing period length
– Decided to simulate typical ERP
studies
• Research drinks’ caffeine contents
and other ingredients that may
interfere
– Decided that caffeine content was
most important factor; fluid ounces
and energy supplements also
investigated
– Starbucks Doubleshot Espresso
chosen (small volume, safe yet high
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• Day one:
Methods: Protocol
– Apply EEG cap
according to
standard 10-20
system
– Audio test for
baseline data
sample (control)
– Caffeinated drink
(independent
variable) and next
audio test
– Peak latency shift
(dependent variable)
10-20 system
for
electrodes
• Day two- verification
(Kadambi et al., 2013)
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Results- Data
Example:
Raw Data
Time (ms)
Time (ms)
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Discussion
• Possible sources of
error
– Motion artifacts:
blinking, fidgeting
– Individualized
reactions to caffeine:
can cause fidgeting
– Sleep irregularities
– Outside stimuli:
changes in light,
environmental
sounds
http://www.eplimited.com/artifact.htm
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Conclusions
• The data collected using this procedure
would be useable in an actual experiment.
• This procedure is an effective means
to later verify the preliminary study
statistically.
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Future Work
• IRB approval and
recruitment
• Perform experiment
• Combine with
previous results
• Design fatigue
detection
software
• Implement in
portable EEG
– Also needs testing
(Kadambi et al., 2013)
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Acknowledgements
• Protégé Program
• Dr. James Boerio – Program Director
• WISE Program
• Dr. Urmila Ghia - Program Director
• Dr. Fred Beyette Principal Investigator
• Joe Lovelace - Study
Coordinator
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WISE Influence
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Questions?
Thank you for your time and consideration!