Subjects

150 freshman and sophomore students at Richard J. Daley College, Chicago, Illinois, were selected as subjects. From this randomly selected population, seventy-five students were randomly chosen for a control group, & seventy-five were randomly chosen for an experimental group.

Materials

One control super 8mm film with numbers from 30 to 50 in sequence with no variations. This as the stimulus for the control group of Students. One experimental super 8mm film with numbers from 30 to 50 in sequence with variations of interspersed subliminal stimuli.

A super 8mm film projector was used to project the individual time to the S group. India ink was used to produce the stimuli assumed to be associated with the subliminal perception, and a film editor was used to cut, splice and secure the subliminal stimuli in the experimental film.

Procedure

Registration cards were drawn at random from the college administration office files for 150 freshman and sophomore students. All of the randomly selected students were asked if they might volunteer for the study. Students were than randomly selected to be either in the control or experimental group of 75 Students each. Dates and times convenient to Students and researchers were set for the film presentation.

Both s groups viewed the film in a darkened auditorium. The control group saw the control film, which was an un-spliced version, showing the numbers from 30 to 50 in sequence. Each number was visible on the screen for a viewing time of 5 seconds

  • After viewing the film, the control Students were asked to randomly write down any number from 30-50, which they had just viewed.

The experimental S group saw the experimental film, which was the spliced version. The cutting and splicing were done in the film by the addition of only 1 frame of the number 39 placed before the first number 30, and then after numbers 35, 40, 45, and 50. 

Using this procedure the number 39 appeared in only 5 additional frames (.01 sec. ea.) in the film, in addition to its normal succession in the number group. The increased stimuli were made by scratching several frames of the film with a film editor and then writing the number 39 in India ink

  • After viewing the film, as before, the experimental Students were asked to randomly write down any number from 30-50, which they just viewed.

Neither the control nor the experimental group was given any information about the purpose of the study in order to reduce response bias. The means of presentation of the film to each group, and the information requesting the Students randomly write down a number were the same.

Results

Data were collected and compiled relative to the control or experimental S group. 

Figure 1 illustrates the actual numbers used in the control film and the total number of responses by the Students to each number. It might be noted that there were five chosen numbers receiving the more frequent responses. They were, respectively, 34(11), 32(7), 47(7), 44(5), and 49(5).

In Figure 2, the actual numbers used in the experimental film the total number of responses by the experimental Students, it can be seen that the most frequently selected S response was the number 39
It was written down by 42 of the 75 (56%) experimental respondents!
The next two more frequently selected numbers were 44(13) and 36(12).

Figure 3 was obtained by dividing the experimental by the control responses, multiplying by 100, in order to calculate the percentage deviation in number selection between the two S groups. The spliced number (39) was found to have the greatest percent increase in responses between the two groups, it increased 2050% between the control and experimental Students!

Conclusion and Discussion

Subliminal number stimuli did seem to effect verbal responses of the Students. When comparing the percentage deviation in the number selection between the two Student groups, it can be noted the 5 additional frames of the number 39 (the subliminal stimuli appearing .01 sec. for each presentation) did greatly influence the selection of this number by the experimental Students.

The subliminal perceptual process involved might be assumed due to the bio-physiological theoretical position regarding retinal summation of the subliminal and supraliminal stimuli. The subliminal stimulus (39) was not sufficiently strong enough to allow an electrical charge to cross the synapse between neurons; however, it did allow a chemical change allowing the next supraliminal stimulus (numbers 30, 36, 41, and 46, respectively) to cross the synapse. The retinal summation of the subliminal and supraliminal stimuli stored in the retina, mixed, and they both influenced the experimental Students performance.

With regard to the review of literature considering the psychoanalytic theoretical position, 
the findings suggest that as the experimental Students were consciously perceiving the projected supraliminal numbers, they were unconsciously perceiving the number 39 and both numbers were registered in different parts of the brain - the former in the conscious; the latter in the unconscious or subconscious. 

With reference to randomly writing down any number from 30-50, the subliminal number of 39, whether in the unconscious or subconscious did influence the performance of the Students selections.