1. THE EFFECTS OF CAFFEINE, SUGAR AND ASPARTAME ON SIMPLE REACTION TIME
Samantha Gerold Antonio Salluzzi  Usha Sankar Ph. D.
BISC 3242 Human Physiology
FCRH
Discussion
Predicted Results
Hypotheses
Reactions times will decrease with the consumption of caffeine,
sugar, a mixture of both, and caffeine with aspartame-based
sweetener, but reactions times will not show significant increases
when a person ingests aspartame-based sweetener without caffeine.
Table 1: Reaction Times before & After Substance Consumption
From the data collected, we expect that there would be a notable
improvement in the reaction time of the subjects that consumed caffeine,
sugar, or a combination of both. Within these groups, we should see that
caffeine consumption would decrease reaction times at a higher percent
than sugar and that a combination of both would improve reaction times
at an even higher percentage than sugar or caffeine alone. In regards to
aspartame and reaction times, we should see that aspartame does not
cause any significant change in a person’s reaction times. To clarify,
drinking water with aspartame or coffee sweetened with aspartame
would have similar reaction time measurements as that of drinking plain
water or coffee, respectively. This should be consistent amongst a large
number of subjects in each of their respective groups.”
There may be some limitations in our experiment. Most of the
limitations came in the form of substance specifics. One limitation could be
due to the coffee. While the brand, type, and amount of coffee consumed by
the three subjects are congruent, we were unsure as to whether or not the
caffeine content was exactly at one-hundred (100) milligrams (mg) in each
cup; this assumption comes from data from previous studies used as
reference. Another limitation to note is also the amounts of aspartame per
teaspoons. Most artificial sweeteners also come with other saccharides, such
as maltodextrin and dextrose, thus not making the aspartame addition to the
coffee and water pure. This also puts into question whether or not thirty-four
(34) grams (g) of sugar is equivalent to the same amount of aspartame or if
there is a certain ratio that needs to be upheld in order to get certain results.
References
Introduction
There has been a variety of studies regarding reaction time
influenced by caffeine as well as increased blood glucose levels.
Reaction time is simply the interval of time between a stimulation and a
response. Based on previous studies it is known that caffeine enhances
simple reaction time (Duvnjak-Zaknich, et. al. 2011). It does this by
blocking adenosine, which causes sleepiness, from binding to receptors
in the brain thus creating a sense of wakefulness and alertness. NASA
also conducted a study which demonstrated that elevated blood glucose
levels increased reaction time and overall cognitive function and that low
blood glucose levels decreased simple reaction time and cognitive
function. Low plasma glucose levels lead to symptoms of central
nervous dysfunction (Feldman 2007).
There are very few studies regarding the effects of artificial
sweeteners on reaction time. This study will compare the effectiveness
of caffeine, sugar and aspartame on simple reaction time on five
subjects, with the addition of one control of water ingested. Each subject
was given an individual substance or combination an hour previous to
taking the test. Simple reaction times of each subject were used to
determine which individual substance or combination yielded the most
significant increase in simple reaction time.
Methods
The effect of reaction time will be tested using various substances which
include:
•Control: subject drinks 12 oz. of water
•Ingestion of an 8 fluid oz. caffeinated drink with no sugar
•Ingestion of a sugar sweetened drink – 12 oz. water containing 34g (or 8
teaspoons) of sugar
• Ingestion of an 8 oz. caffeinated drink with 34g of sugar added
• Ingestion of an artificially-sweetened drink – 12 oz. water containing
34g (or 8 teaspoons) of aspertane
•Ingestion of an 8 oz. caffeinated drink with 34g of artificial sweetener
Procedure:
• Each groups initial reaction time will be recorded before any
substances are consumed.
•The aforementioned substances which included caffeine, sugar,
aspertane and various combinations of the three will then be ingested
•Each subject will wait 60 minutes before performing the test for simple
reaction time, to give each substance adequate time to be absorbed into
that persons bloodstream. (Duvnjak-Zaknich et. al. and Souissi et. al.
2011)
•After the 60 minute wait, the subject will perform the test for a total of
three times, with a 5 minute distracted break between each test
•6 groups will be test, each group containing 5 subjects
•In order to gain an average for reaction time, the test will be taken by
each subject three times.
•In order to control for the subjects acclimation to the test, a five minute
period between each test will be taken - during that break, the subject will
performe alternate, distracting activities which include reading and using
their cellphone
Figure 1: Simple Reaction Times Before and After Ingestion
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Before Consumption
(s)
After Consumption (s) Percent Change (%)
Group 1 0.2912 0.2873 1.00
Group 2 0.2996 0.2807 6.31
Group 3 0.2817 0.2636 6.43
Group 4 0.2640 0.2508 5.00
Group 5 0.3678 0.3423 6.93
Group 6 0.2982 0.2862 4.02