Hold tests are
neuropsychological test
Neuropsychological tests are specifically designed tasks that are used to measure a psychological function known to be linked to a particular brain structure or pathway. Tests are used for research into brain function and in a clinical setting f ...
s which measure abilities which are thought to be largely resistant to
cognitive
Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...
decline following
neurological damage
Nerve injury is an injury to nervous tissue. There is no single classification system that can describe all the many variations of nerve injuries. In 1941, Seddon introduced a classification of nerve injuries based on three main types of nerve ...
. As a result, these tests are widely used for estimating
premorbid intelligence in conditions such as
dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
,
traumatic brain injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic b ...
, and
stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
.
Usage
In
neuropsychological assessment
Neuropsychological assessment was traditionally carried out to assess the extent of impairment to a particular skill and to attempt to determine the area of the brain which may have been damaged following brain injury or neurological illness. Wit ...
it is important to be able to accurately estimate
premorbid intelligence. Accurate estimation allows the quantification of the impacts of neurological damage or decline, when compared to tests of current intelligence. The magnitude of decline is important for prognosis, rehabilitation planning and financial compensation.
Hold tests used
Hold tests typically measure
crystallised intelligence, that is stored knowledge and skills, such as vocabulary and pronunciation.
Of course, hold tests of abilities directly affected by neurological damage are likely to underestimate intelligence. For example, using reading tests in patients with
aphasia
Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in th ...
. Examples of hold tests used:
*
National Adult Reading Test
The National Adult Reading Test (NART) is a widely accepted and commonly used method in clinical settings for estimating premorbid intelligence levels of English-speaking patients with dementia in neuropsychological research and practice. Such te ...
(NART)
*North American Adult Reading Test (NAART)
*Picture Completion subtest of
Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale (WAIS) is an IQ test designed to measure intelligence and cognitive ability in adults and older adolescents. The original WAIS (Form I) was published in February 1955 by David Wechsler, as a revision of the ...
*Similarities subtest of
Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale (WAIS) is an IQ test designed to measure intelligence and cognitive ability in adults and older adolescents. The original WAIS (Form I) was published in February 1955 by David Wechsler, as a revision of the ...
*
Wechsler Test of Adult Reading (WTAR)
*
Wide Range Achievement Test The Wide Range Achievement Test, currently in its fifth edition (WRAT5), is an achievement test which measures an individual's ability to read words, comprehend sentences, spell, and compute solutions to math problems.Wilkinson, G. S., & Robertson ...
(WRAT)
Alternate methods
The use of hold tests is only one of a few possible methods of quantification of premorbid function. In practice a
neuropsychologist
Neuropsychology is a branch of psychology concerned with how a person's cognition and behavior are related to the brain and the rest of the nervous system. Professionals in this branch of psychology often focus on how injuries or illnesses of t ...
may use a combination of methods to yield the most accurate estimate of premorbid intelligence.
Some of the other methods used are:
*Previous testing: While this method can be highly accurate and useful, it is rare that such information is available and even rarer still that any information beyond basic IQ testing was obtained. In the majority of cases this information is not available and other methods of estimation are required.
*Historical method: This involves a clinical interview and review of records to make a subjective estimation of premorbid Intelligence.
An advantage of this method is that a clinical interview and review of records are an essential part of assessment and thus can be assessed from information that is obtained in the normal course of assessment.
*Statistical estimation: Involves the incorporation of demographic information, such as age, race education and occupational attainment into a
regression equation
In statistical modeling, regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one o ...
that yields a probable intelligence complete with standard error of the estimate. One advantage of this method is the avoidance of the use current performance levels.
*Best estimate: This method determined from test scores, other observations and historical data what is the best performance of an individual. Once the highest level of functioning has been identified this is the standard against which all other performance is measured. In general a single high score should not be relied upon, unless supported from other observations. In most cases the best performance estimate will be based on a cluster of highest scores and a single. For example, a doctor who performs in tests at an average level but who has displayed superior function in prior education and occupational performance is obviously underperforming upon potential in test and past education and occupation would represent the best estimate. The advantage of the best estimate method is that a broad range of abilities are taken into account and neuropsychologists are not bound to any single battery of tests.
A review examined whether hold tests, best estimate or regression equation methods were most accurate in predicting overall IQ (full scale IQ) as determined by
Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale (WAIS) is an IQ test designed to measure intelligence and cognitive ability in adults and older adolescents. The original WAIS (Form I) was published in February 1955 by David Wechsler, as a revision of the ...
(WAIS-R) in a non-neurologically impaired population. It was found that different methods were more accurate depending on the IQ level of participants e.g. WRAT-3 (hold test) was most accurate for those of below average intelligence, NAART (hold test) was most accurate for those of average intelligence and the best estimate method was most accurate for above average intelligence. This provides support for the idea that no single method is superior in all cases and a combination of approaches is most appropriate in
clinical practice
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practice ...
.
References
{{Neuropsychology tests
Neuropsychological tests
Cognitive tests