In the 1940s and 1950s, there was an ongoing controversy in psychology as to whether the interpretation of individual tests should be quantitative or qualitative. Quantitative methods were entirely scientific and psychometric in that the interpretation was derived from a numerical cutting point on a scale that had been statistically validated. For instance, the quantitative methods used a numerical cutting point to distinguish brain damaged from normal subjects. The validity of the cutting points were derived by statistically comparing brain damaged subjects to normal subjects using a particular test.
In contrast, the interpretation of a test could be derived from qualitative clinical judgment utilizing clinical intuition. Initially, most of the tests used by clinical psychologists, such as the Bender Gestalt and the Goldstein and Scheerer tests (1941), were qualitative. The qualitative approach used with this method was summarized by Goldstein and Scheerer (1941) as follows:
The usual scoring method based on a scale of difficulty which has been standardized on a statistical basis offers no adequate instrument for determining the nature or degree of impairment in a patient. Unless one takes into account the entire procedure, the specific reasons for the difficulty the patient encounters, one cannot simply read off from a score which task represents a greater difficulty and which a lesser. Any statistical evaluation has to be based upon a qualitative analysis of test results; qualitative has to precede statistical analysis (p. 19).
At that time, in the 1940s and 1950s, such qualitative testing usually provided the accepted interpretation method of individual tests in neuropsychology. However, by the end of the 1960s, the quantitative approach had been largely accepted by American psychologists as the APA Standards of 1974 state: It is intended that these standards apply to any assessment procedure, assessment device, or assessment aid; that is, to any systematic basis for making inferences about characteristics of people.
However, the concept of using a group of tests as the psychological assessment instrument was scarcely considered in psychology or neuropsychology (Lezak, Howieson, & Loring, 2004; Russell, 2012). A major contribution of Reitan to neuropsychological assessment was the utilization of an entire battery of tests as the instrument for assessment. While other psychologists had emphasized the need for a battery of tests, it was Reitan who made the use of a battery necessary for a valid neuropsychological assessment. By the 1960s, the field of neuropsychology had advanced to where reliable evaluations required the utilization of a full battery of tests (Lezak, Howieson, & Loring, 2004). However, the method of analysis that was applied to the whole battery was still largely qualitative, and consequently, the method was almost identical to that which Goldstein and Scheerer had advocated for single tests in 1941. With the exception of Reitan and his advocates, this qualitative method of analysis was and is generally accepted by the entire field of neuropsychology.
Reitan introduced into neuropsychological assessment the quantitative approach to a battery of tests in 1955. His assessment method utilized the same battery of tests for all neuropsychological examinations (Reitan & Wolfson, 1993). This repetition is necessary to transform a procedure from an intuitive qualitative approach into a quantitative scientific approach. A major characteristic of an individual test is that the items in the test are not changed from one administration to another. This fixity is a necessary characteristic of a psychometric procedure, that is, a scientific procedure (Russell, 2012). Reitan applied this concept of invariance to the battery as well as to individual tests.
An accomplished description of his method is provided in a book whose material was based on Reitan's general method (Russell, 2012). Reitan's method was a research method that was also utilized in assessment. He described this research as a “great experiment.”). The primary condition of his method was that the same battery of tests was utilized in every examination given by a neuropsychologist (Reitan & Wolfson, 1993). Reitan interpreted the test battery results, in a blind analysis, without knowing any conditions of the patients other than their age and gender.
This research enabled him to perceive and demonstrate various types of brain-related behaviors, particularly those related to pathological conditions, that were evident in test battery patterns. This recognition of patterns would have been impossible to accomplish if the battery of tests was changed with each administration.
Reitan's research approach provided major contributions to clinical neuropsychology that included: (i) The utilization of a group of tests to derive a conclusion concerning the condition of an individual's brain; (ii) the utilization of the same battery for each examination so that the results were repeatable (This provided the scientific reliability for neuropsychological interpretations.); (iii) the demonstration that the two sides of the brain had different functions, which could be determined by the comparison of tests in a battery; (iv) the demonstration that damage to various areas of the brain could also be assessed by comparison of tests in a battery; (v) the demonstration that many major diagnostic differences in types of brain damage could be determined by test comparisons; (vi) the demonstration that the level of brain functioning could be determined through the comparison of tests in a battery; (vii) the demonstration by means of his Neuropsychological Deficit Scale that neuropsychological patterns can be placed into a computerized format that can be validated (Reitan & Wolfson, 1993). Thus, Reitan introduced many advances in neuropsychology by transforming the intuitive discipline into a science.
Reitan's Scientific Procedures
Reitan utilized two general types of procedures in his interpretations. These were the use of validated indexes, and clinical judgment using the whole battery. The Indexes included the Halstead Impairment Index (HII) (Halstead, 1947; Reitan, 1955; Reitan & Wolfson, 1993; Russell, 2012) and the Neuropsychological Deficit Scale (NDS) (Reitan & Wolfson, 1993).
The Halstead Impairment Index
There were many studies that demonstrated the validity of the HII (Russell, 2012). Except for the NDS, this index has remained the major index of brain damage from 1955 to the present. A number of other indexes were created, some of which were validated (Russell, 2012). However, probably due to the rejection by neuropsychology of psychometric procedures applied to batteries, these indexes have not been extensively utilized or developed. Most neuropsychologists today would rather utilize their own battery and base their clinical judgment on their unvalidated battery. This is unfortunate, since only a validated index can provide a dependable or forensically reliable determination of the existence of brain damage (Russell, 2012; Russell, Russell, & Hill, 2005).
The Neuropsychological Deficit Scale
Reitan also created one of the alternate indexes, the NDS (Reitan & Wolfson, 1993). While the validation research for the NDS was less extensive than that devoted to the HII, this existing research found the NDS to be the most accurate indicator of brain damage that has been utilized in neuropsychology (Russell, 2012).
Reitan's Clinical Judgment
Reitan's other general method, that of clinical judgment, was applied to various forms of brain functioning. While many illustrations of this use of clinical judgment are provided in the Halstead Reitan Neuropsychological Test Battery manual (Reitan & Wolfson, 1993), there has been only one psychometric study of clinical judgment applied to a whole battery, and that was Reitan's (1964) study. It found that Reitan's clinical judgment to be valid (Russell, 2012) for several dimensions of brain damage. Reitan's judgment was 93% correct when only the difference between right and left hemisphere lateralized lesions were considered. His accuracy for lateralization when the diffuse category was considered was 88.4%. His accuracy for anterior vs. posterior lesions and for diagnoses was less than the lateralization accuracy, but all differences were significant (Reitan, 1964). No other studies of clinical judgment as extensive as this have been reported in the literature to the present.
The Accuracy of Clinical Judgment
In neuropsychology, research is almost always psychometric and therefore scientific. Either a scale or a cutting point, both of which are quantitative, are determined in the validation process. When individual tests are utilized in psychometric assessment, validation is required in order for the test to be reliable as a clinical or forensic instrument (AERA, APA, & NCME, 2005).
The problem with clinical judgment is that it is not demonstrably reliable when derived from a variable battery of tests. Many clinicians are highly skilled in utilizing clinical judgment for variable groups of tests. However, this reliability cannot be verified since their clinical judgment in any specific case has not been validated utilizing psychometric methods. Reitan's work demonstrated that the validation of clinical judgment for any specific battery used in an assessment has four requirements: (i) the judgment for the particular battery used in an assessment must be demonstrated to be psychometrically reliable. (ii) The use of clinical judgment with a particular battery must be demonstrated to be valid by statistical validation studies. (iii) This validated battery must be used as the basis for judgment in a specific case as in a forensic opinion. (iv) The neuropsychologist who utilizes his/her judgment must have been trained in the use of the battery that was validated.
The consequence of these requirements is that only Reitan's general method of clinical judgment has been demonstrated to be psychometrically dependable or forensically reliable when applied to individual cases clinically or in court. Thus, clinical judgment for the validation of a flexible battery in general is difficult, and it is almost impossible when the flexible battery is used for a specific case as occurs in forensic cases (Russell, 2012; Russell, Russell, & Hill, 2005).
Reitan and the Future of Neuropsychology
After I Had Been Studying Neuropsychology and Especially
Reitan's method for some time, I believed that, as in other scientific disciplines, one would see a gradual development of the method. Neuropsychology had developed rapidly under Reitan's influence. He had introduced the scientific method into assessment procedures using groups of tests. He had set the discipline on a scientific course which had long been apparent in the psychometrics applied to individual tests and in the development of intelligence tests. His use of an invariant or “fixed” battery, which provided the foundation for the development of a more scientific psychometric approach to the assessment of brain functions, should have been the beginning of such development. This should have enabled neuropsychologists to add to assessment the development that was standard for research practices in other fields. With this method, Reitan discovered a number of patterns that indicated various conditions, generally pathological, of the brain and of the cognitive functions of the brain. He continued throughout his career to investigate various brain functions.
Development of Assessment Stalled
However, the development of his general method as a standardized method has remained largely stalled. There were a number of problems in neuropsychology obstructing such a development of Reitan's work, both exterior and interior to that work. The exterior problems were largely due to critiques by those who did not accept Reitan's concept that a valid battery was based on repetition of the same battery in multiple assessments. Controversy is, of course, part of science. However, the critics have had very little in the way of offering alternatives or new developments to Reitan's or any other assessment methodology using a battery. In recent years, the brilliance of many neuropsychologists was often wasted on their critiques of Reitan's work, particularly his insistence on an invariant battery. Much of the energy that neuropsychology should have used in developing the methodology begun by Reitan, was dissipated in their critiques of his method. Particularly damaging was their insistence on criticizing the very method which would have enabled the basis for developing an assessment methodology. This was Reitan's use of the “fixed” battery. Fixity does not mean that new tests cannot be added or subtracted from a battery but they must have an identified and scientifically validated relationships with other tests in the battery.
When the critics did produce methodological changes, it was often directed toward substituting some alternative to the concept of repeating a battery of tests for all assessments. Thus, while Reitan began what should have been a new approach to the development of neuropsychological assessment, this controversy brought the development to a halt.
Some of this lack of development was due to Reitan's insistence that his battery of tests was complete in itself. Consequently, this insistence that his battery could not be changed prevented development. (In contrast, due to a lack of rigidity, we are seeing some development in the methodology of intelligence testing.)
However, it was not the particular tests in Reitan's battery, although many tests had many advantages, that was his major contribution but rather his approach to a methodology for studying brain functions that should have been continued. In one sense, those who criticized Reitan's approach to adopting new tests were correct. The Halstead–Reitan Battery had a number of flaws and the insistence on not changing the battery prevented Reitan from utilizing his brilliance to correct the flaws. For instance, his battery contained almost no good memory tests. (The TPT Memory test is the only good memory test in the battery. However, the TPT Memory test is excellent in unmasking malingering. Most malingerers believe that memory is the primary function that is impaired in brain damage and they do not recognize that the TPT Memory test is a memory test. The examiners in our laboratory are careful never to call the TPT Memory test a test of memory. Consequently, it is fairly common in forensic cases to see people who completely fail the Wechsler Memory Scale's to excel in the TPT Memory test. They also usually fail other tests of motivation).
The Progress of Neuropsychological Assessment
For a period of ∼25 years, Reitan's method was utilized by many neuropsychologists and was further developed by others. However, the majority of neuropsychologists have rejected the approach on the basis of a few flawed studies and the neglect of studies which supported Reitan's approach (Russell, 2012).
This negative appraisal of Reitan's method was done around 1980 and was widely publicized in a number of papers quoting the flawed research (Russell, 2012). However, since then, neuropsychology has retreated to the type of intuitive methodology that I was taught in the 1950s. Except in the area of computerized testing, almost no new developments in assessment methodology have occurred in the last 30 years. There are a few exceptions such as the work on malingering and on determining premorbid ability. Also some standardized batteries have been published such as the Neuropsychological Assessment Battery (Stern & White, 2001) and the Meyers Neuropsychological Battery (Meyers & Rohling, 2004). However, these appear to have been largely ignored.
There is one great advantage of science over any other methods for obtaining information and creating methodologies, and that is that, once developed or discovered, a scientifically determined idea or method may be rejected for a time, as has often happened. However, if valid, the idea or method will be rediscovered, and the founders will receive their deserved recognition. This is true of all scientifically valid concepts and methods. Consequently, I am quite confident that this will happen in regard to the general concepts and method that Reitan developed. His initiation of a general scientific method for using a neuropsychological battery in assessment will be recognized in the future.