Baker report, 1968 congressional hearings

The subject's retinal pathology is such that he could not have accurately perceived on direct gaze a greenish, luminous disc
in the sky. It may well be that the initial stimulus for his "vision" was a distant light which then was grossly distorted by
both his abnormal retina and his highly disturbed emotional state.
Creditability score 5%.
VI. Integration of Findings and Composite Assessment of Central Nervous System Functioning
A. Discussion and Creditability Score
Without the benefit of the results of this medical evaluation, one would probably be inclined to view Mr. McC. as a highly
creditable observer. In favor of such an impression are 1) his respectable bank position, 2) his general demeanor (which is
very appropriate and does not suggest attention-seeking or his actual psychiatric problems), 3) his claim to seeming good
health and 4) the nature and quality of his report of the "light" observed event to the police.
However, on evaluation it was discovered that he was an early alcoholic cirrhotic who was suffering from early occult
alcohol-tobacco amblyopia such that he could not have perceived the detailed colored nocturnal event he thought he had
seen.
What had actually occurred was the first major hallucinatory experience of his life. In a twilight state, his eye first
perceived some kind of stimulus from the night time sky which was then transformed into a rather magnificent symbolic
representation of his unconscious wishes and underlying character pathology. The episode occurred when it did because of
the subject's state of psychic decompensation. His resistance to a transient hallucinatory experience was lowered by 1) his
currently agitated depressed state 2) the adverse effects of toxins (from drugs and liver) on his central nervous system and
3) the visual distortions produced by his diseased eyes.
The entire clinical picture is best explained in terms of the subject's passive-oral-dependent character pathology which is
intimately related not only to his acute emotional state but is the underlying source of his physical problems (i.e., alcoholic
liver and retina, drug toxicity). This case is thus a good example of multifactorial influences on observer creditability
which, in this instance, can be integrated in terms of an underlying source.
Overall observer creditability score 5%.
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THE USE OF PROBABILITY SCORING FOR OBSERVATIONAL CREDITABILITY
In order to translate the results of an extensive, multidisciplinary medical evaluation into a handy estimate of observer
creditability, a percentage-evaluation scoring method has been devised. These "probability of creditability" scores are
mainly intended to serve the non-medical expert. They are numerical statements reflecting the level and quality of
observational ability and are based on all the obtained findings relative to central nervous system integrity.
The scores will be presented in conjunction with (not in place of) summaries of the results of each part of the medical
assessment (i.e., medical, neurological, neuro-ophthalmological, and psychiatric) of an individual observer. A composite
score will also be offered to suggest the overall level of observational creditability. This final score is based on careful
scrutiny, extrapolation, and interpretative integration of all the findings at hand, as they would be expected to influence (in
a highly multifactorial way) any reported observations. The nature and extent of an individual's abnormalities will thus be
reflected in his creditability score(s), a scale for which has been set up as follows:
Degree of Impairment Creditability Score
none 95%
mild 75%
moderate 50%
severe 25%
extreme 5%