Health Experiment -- Measuring Reaction

Health Experiment -- Measuring Reaction Times Reaction time is defined as the time interval in between the perception of an external stimulus and the response of the individual perceiving that external stimulus (Gerrig & Zimbardo, 2009). It is a measurement that is often considered useful in connection with evaluating relative ability to perform well in certain occupations and it is an essential component of athleticism in many respects.

Reaction time is also an important factor in driving abilities and the extent to which it declines as a function of chronological age is one factor in considering the appropriateness of driving beyond a certain age and level of cognitive decline in the elderly (Gerrig & Zimbardo, 2009). This experiment is designed to illustrate the difference between the relative reaction times of different test subjects. It is also designed to illustrate the difference between reaction times associated with sequences of multiple random-interval external stimuli and sequences of multiple regular-interval external stimuli.

Specifically, there are three experimental hypotheses: (1) Reaction times will be shorter in the second trial in each sequence set; (2) Reaction times will be shorter in connection with sequences of multiple regular-interval external stimuli than in connection with sequences of multiple random-interval external stimuli; and (3) to the extent that reaction time improves in subsequent trials, performance will improve more as between the first and second sets of fixed-interval trials than as between random-interval trials.

The setup of the experiment will be a test of one subject at a time utilizing a piece of equipment that records the time interval in between an external stimulus triggered by the experimenter and the voluntary response reaction of the test subject. Two sets of trials will be conducted using random-interval sequences followed by two sets of identical trials substituting regular-interval sequences. The trial results will then be compared.

Materials and Methods The materials used for this experiment will be a PC computer, an iWorx system consisting of an IWX/214 data acquisition unit, USB cable, IWX/214 power supply, and an EM-100 Event marker. The method used will be as follows: The test subject will be positioned in front of a computer monitor and keyboard and instructed to respond by pressing the Enter key as quickly as possible after perceiving a visual event on the screen.

The visual event will be triggered by the experimenter positioned out of the sight of the test subject. In the first series of trials, the experimenter will provide stimulus events at random intervals; in the second series of trials, experimenter will provide stimulus events at random intervals. The results will be analyzed and compared with reference to the two hypotheses. Experimental Results The results of the experiment were statistically significant with respect to all three experimental hypotheses and all three experimental hypotheses were confirmed.

Specifically, (1) reaction times were shorter in the second sequence of each sequence set, averaging a .040/second difference as between the first and second random sequences and averaging .080/sec difference as between the first and second fixed-interval sequences; (2) reaction times were shorter in connection with regular or fixed-interval sequences than in connection with random-interval sequences by an average of .064 as between the first random sequences and the first fixed-interval sequences, and by an average of 0.80 as between the second random sequence and the second fixed-interval sequences; and (3) the differential increased by an average time of .024 as between the first trials and the second trials of random/fixed-sequence measurements.

Discussion All three of the initial experimental hypotheses were confirmed. In 6 out of 10 test subjects, average reaction time was faster in connection with fixed-interval stimuli than in connection with random-interval stimuli. In 7 out of 10 subjects, reaction time decreased as between the first and second set of random-interval sequences. In 8 out of 10 subjects, reaction time decreased as between the first and second set of both the fixed-interval sequences and as between the first and second set of fixed-interval sequences.

Further, the subjects whose relative differences in reaction time were greatest were those who improved as between successive trials.