Researchers wanted to assess the effect of low alcohol consumption on
reation time in seniors. Their belief was that even low levels of
alcohol consumption can impair the ability to walk, thereby increasing
the likelihood of falling. They identified 13 healthy seniors who were
not heavy consumers of alcohol. The experiment took place in late
afternoon. Each subject was instructed to have a light lunch (such as a
sandwich) and not drink any caffeinated drinks in the 4 hours prior to
arriving at the lab. The seniors were asked to walk on a treadmill on
which an obstable would appear randomly. The reaction time was measured
by determining the time it took the senior to life his or her foot upon
the appearance of the obstacle. First, each senior walked the treadmill
by consuming a drink consisting water mixed with orange juice with the
scent and taste of vodka. The senior was then sked to walk on the
treadmill. The senior was then asked to drink two additional drinks (40%
vodka mixed with orange juice). The goal was to have the senior reach a
blood alcohol concentration of around 0.05%. The senior then walked on
the treadmill again. The average response time increased by 19
milliseconds after the alcohol treatment. The researchers concluded that
response times are significantly delayed even for low levels of alcohol
- What type of experimental design is this?
- What is the response variable in this experiment? Is it quantitative or qualitative?
- What is the treatment?
- What factors were controlled and set at a fixed level in this experiment?
- Can you think of any factors thatmay affect reaction to alcohol that were not controlled?
- Why do you think researchers
used a drink that had the scent and taste of vodka to serve as the
treatment for a baseline measure?
Source: Judith Hegeman et al. "Even Low Alcohol Concentrations Affect Obstacle Avoidance Reactions in Healthly Senior Individuals," BMS Research Notes 3:243, 2010.