Abstract

This paper is an examination of how an individual responds to ingesting marijuana; covering the effects of the drug on psychomotor coordination as well as its effects on short-term memory and the ability to concentrate on a task. The first section of the paper examines the expected psychomotor reaction of the subject in a set experiment and analyzes the possible range of effects ingesting marijuana has on the individual. The results of this experiment were somewhat mixed as compared to what was predicted in the introduction though the expected level of variation from the control was lower than anticipated. A final discussion examines to what extent marijuana ingestion can alter reactions and behavior as well as discussing possible ways of improving the experiment design.

Studying reactions to marijuana ingestion

This experiment was conducted to examine the effects of ingesting marijuana on an individual. Through this experiment, I am hoping to examine the different planes in which marijuana effects the body and the mind compared to ordinary functioning of the subject. I am focusing specifically on the ability to perform motor skills and the possible affect marijuana has on short-term memory and concentration. The experiment is designed with expectations of irregular psychomotor activity. My understanding of marijuana as a mild hallucinogen led me to expect slow reactions to motor ability and varying physiological and psychological changes which would negatively affect the subject’s ability to concentrate and use short-term memory.

Method

Participants

This experiment involves a single male subject from the College of Wooster. He is 21 years old and weighs in at 133 pounds. He is a regular smoker of marijuana and smokes an average of 1 gram (in the form of unprocessed weed) every two days.

Research Materials

The materials used in this experiment consist of a notebook for recording observations, a digital clock to measure amount of time passed, 0.5 grams of unprocessed weed (provided by the subject), brownie mix and a pack of playing cards to measure responses.

Procedure

This experiment took place in the subject’s dorm room over a two-day period. Two sets of brownies were baked at an off-campus location; one set made from the original brownie mix, acting as a control and a second set containing 0.5 grams of weed. This was a double blind experiment where an outside assistant marked either brownie set as, ‘A’ or ‘B’ (with brownie set A containing the marijuana). Both the subject and I were unaware of which set contained the marijuana. On the first day of the experiment, the subject ingested brownie set, ‘A’. After allowing for a twenty-minute period for digestion, the subject was tested using a pack of cards for various motor abilities. The subject was asked to construct a card house with a base of eight cards. The time taken over this exercise was recorded. The subject was then made to play a memory game where pairs of similar cards had to be matched from a half-set of the pack which was laid out in rows inverted infront of him. The object of the game was to find a matching pair and remove it from the rows until all the cards were gone. If a mistake was made, the subject would have to memorize the positions of the cards previously flipped over before inverting them again, and flipping two more cards. The number of mistakes made during the game were recorded. These sets of experiments were performed in exactly the same manner the following day with brownie set, ‘B’. Observations were recorded into a series of tables.

Results

The results from the experiment are presented in a series of tables below:

The data shows that there was a diminished motor ability and a slight gain of ability to concentrate/memorize as a result of ingestion of brownie set A which contained the 0.5 grams of weed. During construction of the card pyramid after ingesting brownie set A, the subject actually toppled over half the pyramid, which resulted in a marked difference in time. There was also noticeably greater agitation at making mistakes in the memory game during the control experiment.

Discussion

The results of drug ingestion on the body and mind proved to be somewhat mixed in responses to psychomotor activity and short-term memory skills. The marijuana ingestion led the subject to behave in a manner which was observably different to the control (brownie set B).

There was a surprising rise in concentration in the subject after ingestion of brownie set A. It was interesting to note that the subject performed slightly better at the memory game when in an altered state as compared to his results in the control where no drug was affecting his ability. This could be related to the fact that the marijuana allowed the subject to relax and approach the game in a calm manner as compared to his slight agitation at making mistakes when playing the game in a normal frame of mind.

The drug’s influence was easily visible in the test of motor skills where the subject performed quite poorly in his attempt to build the card pyramid. The marijuana slowed his reaction time and possibly impaired his judgement of depth, which resulted in a slip-up, which dropped the semi-constructed pyramid.

The experiment was valuable in examining basic changes in an individual as a result of drug ingestion but the experiment could have been improved in a number of ways. Firstly, the experiment involved a regular user of marijuana which resulted in the subject quickly recognizing the oncoming effects of the drug despite this being a double-blind experiment. Using a subject who has not used marijuana on a regular basis could remove this possible form of bias. Perhaps using a smaller quantity of the drug so minimal changes occurring in the subject would have helped in covering this discrepancy.