Jeffrey Schaeffer, PH.D.
Director, Neuropsychological Laboratory

6317 Wilshire Boulevard
Suite 606
Los Angeles, California 90048
(213) 275-9553



Referral Source:
Date of Evaluation:
Date of Report:
Carl Olsen (Brother Carl)
Jeffrey Schaeffer, Ph.D.
April 26, 1980
January 2, 1981


As per your recent request, I have now completed a re-analysis of data obtained during my evaluation of you earlier this year.  The following is my report of findings.

PERTINENT HISTORICAL INFORMATION:  Mr. Olsen (Brother Carl) earlier this year requested a comprehensive neuropsychological evaluation of himself to determine his current level of cognitive/intellectual functioning.  Mr. Olsen believes that, despite his very heavy and long-term use of ganja (canabis), his mental functioning has not been impaired in any way whatsoever.  Further, it is Mr. Olsen's belief that ganja (canabis) has improved his mental functioning.  Mr. Olsen is a member of the ETHIOPIAN COPTIC ZION CHURCH, and resides at 43 Star Island Drive, Miami, Florida (the location of the CHURCH).  A comprehensive test-sequence that is a routine set of measures used in many different settings for the purpose of detailing cognitive/intellectual functioning with reference to functioning of the brain was administered to Mr. Olsen.

The following test-sequence was administered to Mr. Olsen in order to characterize his current cognitive/intellectual functioning.

    Wechsler Adult Intelligence Scale (prorated)
    Benton Visual Retention Test
    Symbol-Digit Modalities Test
    Rey Auditory-Verbal Learning Test
    Hooper Visual Organization Test
    Raven's Colored Matrices Test
    Trailmaking Test (Form A & B)
    Initial Interview & Mental Status Examination

RESULTS:     (Performance By Function)

Language Related Areas of functioning
    Expressive language:
    Receptive Language:
    Numerical Calculation:
    Language Abstraction:
Non-language Related Areas of Functioning
    Non-Verbal Analagous Reasoning:

    Remote Events:
    Recent Events:
    Immediate Auditory:
    Immediate Visual:

Complex Multi-Modal Learning

Level of Intellectual Functioning:
    Verbal I.Q. (prorated):
    Performance I.Q. (prorated):
    Full Scale I.Q. (prorated):
Very Superior

DISCUSSION:  The results of this study do not indicate that cerebral/cognitive dysfunction contributes to Mr. Olsen's present status.  There was absolutely nothing in either the brief mental status examination or psychometric evaluation that could suggest dysfunction of the central nervous system, despite the well-documented (presence of cannabinoid metabolites in urine sample) presence of cannabinoids in Mr. Olsen's body, as well as the history of very heavy long-term use of ganja (cannabis).

Language related areas of functioning were found to be intact for an individual of this age and level of education.  There was absolutely nothing to suggest disruption or damage to language areas of functioning of the brain.  No evidence of an aphasic disorder was noted.  Mr. Olsen had no difficulty finding the correct words to express his thoughts, and to organized his thinking in a very clear, concise, and appropriate manner.  Further, he was able to understand that which was spoken to him without difficulty. Simple numerical calculations were completed rapidly and correctly without the aid of pencil and paper.   There were absolutely no calculation errors present in this man's performance.   Further, language abstraction ability (use of complex language concepts for problem-solving) was found to be entirely without impairment.

Non-Language related areas of functioning were found to be intact for an individual-of this age and level of education.  There was absolutely nothing to suggest difficulty with sensory intake and cognitive integration, particularly with regard to visual functioning.  Non-language mediated problem solving ability (problem solving with non-language, color-pattern media) was also found to be entirely without deficit.  The performances on these particular tasks were found to be virtually flawless, and certainly reflect the extremely high level of mental functioning that is present for Mr. Olsen.  There was absolutely nothing present in any of the performances on this test sequence that could suggest impairment of cognitive/intellectual functioning, and further, absolutely nothing to suggest damage to the central nervous system.

Four areas of memory functioning were assessed on the basis of this study.  Memory for both remote events (monhs and years) as well as for recent events (weeks, days, and hours) were found to be entirely without deficit.  He was able to recall all events in his past upon questioning without difficulty.  Further, two areas of memory function were assessed via the standardized psychometric instruments.  Both immediate auditory memory (serial wordlist learning) and immediate visual memory (memory for abstract designs presented on cards, 10-second presentation time) were found to be entirely unimpaired, based on the extensive norms and standards for these particular instruments.  Thus, there is absolutely no evidence to suggest difficulty with any area of memory function (even with measurable amounts of cannabinoid metabolites in Mr. Olsen's urine sample).

Tasks of complex multi-modal learning with numbers and symbols (number/symbol substitution tasks) were performed at a very superior level.  These tasks often considered as a rough index of "new learning ability: rely upon immediate visual memory, hand-eye coordination, reading-writing ability, and attention-concentration.  There was absolutely nothing to suggest impairment in any of these areas.  Thus, the ability to adapt successfully to a changing environment with varying demand characteristics has not been impaired, and continues to remain at the very superior level.

SUMMARY:  Mr. Carl Olsen is a 28-year-old, Caucasian, male.  He is a member of the ETHIOPIAN COPTIC ZION CHURCH and resides at 43 Star Island Drive, Miami, Florida.  This neuropsychological evaluation was undertaken at the request of Mr. Olsen in an effort to characterize current mental functioning in light of very heavy and prolonged use of ganja (cannabis).  A urine sample taken at the time of this evaluation confirmed the presence of cannabinoid metabolites in Mr. Olsen's body.  The results of this study did not suggest that cerebral/cognitive dysfunction was present in any way whatsoever.  According to the well-recognized Wechsler criteria, Mr. Olsen is functioning at the very superior level of intellectual ability.  There was no evidence to suggest impairment of mental functioning characteristic of damage or dysfunction of the central nervous system.   Further, there was nothing found that could suggest that Mr. Olsen was in error if he believes that his mental abilities have actually improved as a result of heavy and long-term use of ganja (canabis).

Thank you for permitting me the opportunity to complete this neuropsychological evaluation.


Cognitive and Long-Term Use of Ganja (Cannabis) - Science, July 24, 1981