�Believing is Seeing�: Brunner and Postman�s Experiment
I perceive you are puzzled and in doubt. You wish to raise an objection. You were taught and you believe that seeing is believing. What is all this nonsense that it should be the other way around. You have come to understand that metaphorically speaking the eye is a camera that passively collects light and brings it in to record photographs of what is actual out there. There is no alteration of the sense data going on. What I am proposing is that in actuality the reverse of that simple phrase is true. It is more like believing is seeing. What I am proposing is that the eye is a camera which filters out most of the electromagnetic spectrum to only record visible light, and that significantly the camera is controlled by a photographer who chooses consciously or unconsciously what to photograph, and lastly and most significantly of all, that upon the lens of the camera is a filter inherited by the photographer and which the photographer has spent her whole life adjusting its qualities and hence its effects.
A recounting of Brunner and Postman�s experiment will illustrate how this can be so. Thomas Kuhn, in his seminal book: The Structure of Scientific Revolutions, refers to this experiment as one �that deserves to be far better known outside the trade�[3].
The results of the experiment conducted by Jerome S. Bruner and Leo Postman of Harvard University was published in The Journal of Personality in 1949 [4] . The experiment was conducted with twenty-eight student volunteers from Harvard and Radcliff. These student volunteers were shown a series of five different playing cards projected by a tachistoscope, which is a device that can expose to the eye an image for a set time measurable in milliseconds. The exposure times used in the experiment started with 10 ms., then progressed as follows: 30 ms., 50 ms., 70 ms., 100 ms., 150 ms., 200 ms., 250 ms., 300 ms., 400 ms., 450 ms., 500 ms., 600 ms., 700 ms., 800 ms., 900 ms., and finally 1000 ms. Each card was presented successively until correct recognition occurred, three times each at the varying exposure times. If at 1000 milliseconds recognition did not occur, the next card was presented. Correct recognition was two successive responses by the students of the identity of the card�s actual color and shape. The arrangement of five cards out of a total collection of ten, was randomized into a series of fourteen possible patterns. The ten total playing cards used in this experiment were the following. One group was: the 5 of hearts, the ace of hearts, the 5 of spades, and the 7 of spades. Added to these cards were cards that had been altered by painting over the actual color with poster paint to make the black symbols appear red and the red symbols appear black. These altered cards were: a black 3 of hearts, a black 4 of hearts, a red 2 of spades, a red 6 of spades, a black ace of diamonds, and a red 6 of clubs. The students were asked to report everything they saw or thought they saw.
Now it had been demonstrated in other experiments using a tachistoscope that though we may claim that we can not tell what it was that flash before our eyes in so brief a moment in time, we actually will accurately report what that object was when we are told to �guess�. Our conscious mind requires a certain exposure time and duration to comfortably feel that accurate seeing has occurred. It has been demonstrated that when we guess because we don�t feel we have seen correctly, in actuality our guess is accurate. Thus demonstrating that our unconscious mental processes have indeed recorded the sensory impressions and recognized them, therefore enabling the conscious mind to say the guess.
Now, if seeing were truly believing then the students would have been able to correctly identify all the cards. Having been shown the card they should have been able to describe what they saw. They would have �guessed� each card at each of the time exposures. But this is not what occurred. The students were able to �guess�/ recognize and describe only the normal cards. They had difficulties with the altered cards. �The reader will note that even at the longest exposure used, 1000 ms., only 89.7 per cent of the incongruous cards had been correctly recognized, while 100 per cent of the normal cards had been recognized by 350 milliseconds.�[5] While the experimental results recorded that correct guessing for normal cards did occur with some students as low as 10 and 30 milliseconds, correct guessing for the altered cards occurred for some students at 100 or 150 milliseconds, which is at least a fourfold increase in the time needed to recognize correctly the alteration done to the cards.
What was reported by the student subject was the fact that they consciously denied what their physiology, the eye and the visual system, and hence their sub-conscious was actually accurately presenting to them. They were unconsciously choosing to guess wrongly by denying the thought that was trying to become conscious when confronted by an anomalous card. They denied what it was they were seeing on the basis of a prior belief. They expected to see something: red diamonds, red hearts, black spades and black clubs, and so confronted with something that contradicted those expectations: black diamonds, black hearts, red spades or red clubs, they denied the contradictory reality.
�Our design was such that we might test the hypothesis that the more experience a subject had had in the past with incongruity, the less difficulty would he have in recognizing incongruity of a related nature. Indeed, this is tantamount to saying that when one has experienced an incongruity often enough it cease to violate expectancy and hence ceases to be incongruous.� [6]
�Generally speaking there appears to be four kinds of reaction to rapidly presented incongruities. The first of these, we have called the dominance reaction. It consists, essentially, of a �perceptual denial� of the incongruous elements in the stimulus patterns.� [7] �A first datum is that 27 out of our 28 subjects showed dominance responses to the trick cards in their records, some considerably more than others.�[8] �An incongruous stimulus was rendered congruent with expectancy by the operation of either form or color dominance.�[9] Meaning that a student upon seeing the trick card which was a four of black heart described the card by focusing either on the color, thus describing the card as a four of black spade, or by focusing on the form, thus describing the card as a four of heart in the normal red color. The student observer forced the incongruent card into a congruent pattern making the observation to conform either by color dominance as the key or by shape dominance as the key. �Once there had occurred in these cases a partial confirmation of the hypothesis that the card in the tachistoscope was a black club or black spade, it seemed that nothing could change the subject�s report. One subject gave 24 successive black color-dominant responses to the black three of hearts, another 44 of them (both calling it the three of spades). Another persisted for 16 trails in calling it a red three of hearts. There were six instances in which subjects persisted in a color or form dominance response for over 50 exposures up to 1000 milliseconds, finally failing to recognize the card correctly.�[10]
�A second technique of dealing with incongruous stimuli we have called compromise.� [11] This is when a reporting is made that blends elements of the conflicting information. The observations of the students reporting compromise effects occur in their describing the anomalous colored cards as being neither red nor black but some color which was a imagined blend somehow of the two.
�A third reaction may be called disruption. A subject fails to achieve a perceptual organization at the level of coherence normally attained by him at a given exposure level. ��I don�t know what the hell it is now, not even sure whether it�s a playing card,� said one frustrated subject after an exposure well above his normal threshold.�[12] After repeated exposures of the anomalous card the observer loses confidence in what he was seeing and becomes so frustrated that he is no longer sure in any way what he has just seen. �I can�t make the suit out, whatever it is. It didn�t even look like a card that time. I don�t know what color it is now or whether it�s a spade or heart. I�m not even sure what a spade looks like! My God!� [13], reported their most extremely disrupted observer at 300 ms in response to the confrontation of seeing a red spade.
For some but not all students: �Finally, there is recognition of incongruity.� [14] �Good Lord, what have I been saying? That�s a red six of spades.�[15] �The uncertainty that sometimes comes before, the �sense of wrongness�, the disruptions � all these point to the gradual weakening of previous hypotheses before �sudden reorganization� can occur�A subject viewing a red spade may start by reporting a red tint which gradually becomes redder on succeeding trials until he finally asserts that the card is a red spade.�[16]
�Our major conclusion is�perceptual organization is powerfully determined by expectations built upon past commerce with the environment. When such expectations are violated by the environment, the perceiver�s behavior can be described as resistance to the recognition of the unexpected or incongruous. �[17]
�When these responses fail and when correct recognition does not occur, what results may best be described as perceptual disruption. Correct recognition itself results when inappropriate expectancies are discarded after failure of confirmation.� [18]
This is what I meant when I boldly said that the conscious mind operates on the principle of believing is seeing. We see what we expected to see on the basis of our previously held ideas, values and beliefs. The brain process the information accurately up to a point, that point is when the incoming sense data begins the next stage which is interpreting the data, the process of putting into words what was previously seen. At this stage the observers expectations becomes important and it is possible that the expectations will over rule and distort the input of the senses. At this stage there can become the refusal to acknowledge the possibility that something completely new is being seen, something that contradicts the previous expectation. The more strongly held is the expectation based upon this prior belief, the powerful will be the resistance and denial of anything seen or heard that contradicts that prior belief.
Let me repeat this most important conclusion: beliefs have power, beliefs have the power to effect the mind�s ability to accurately interpret incoming sense data. The stronger the beliefs, the stronger the convictions, the more resistant those beliefs will be to being challenged by incoming sense data. Those strongly held beliefs will fight off any incoming sense data that appears to, and attempts to, contradict that belief. The more committed you are to a belief the more powerfully you will resist having that belief challenged by incoming sense data. You will ignore, discount and distort that incoming sense data. The ideas that you come to believe in shape you and the world you live in, the world you perceive. This experiment demonstrates the validity of my first principle of humanly constructed reality: People are shaped by ideas.
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[3 ] Kuhn, pg. 62.
[4] J. S. Bruner and L. Postman, On the Perception of Incongruity: A Paradigm, The Journal of Personality, vol. 18, 1949, pp. 206 � 223.
[5] Pg. 211 of Bruner and Postman.
[6] Pg. 211 of Bruner and Postman.
[7] Pg 213 of Bruner and Postman.
[8] Pg. 214 of Bruner and Postman.
[9] Pg. 215 of Bruner and Postman.
[10] Pg 221 of Bruner and Postman.
[11] Pg. 213 of Bruner and Postman
[12] Pg. 214 of Bruner and Postman
[13] pg. 218 of Bruner and Postman
[14] pg 214 of Bruner and Postman
[15] pg. 222 of Bruner and Postman
[16] pg. 222 of Brunner and Postman.
[17] pg. 222 of Bruner and Postman
[18] pp. 222-3 of Bruner and Postman
