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CogScreen CogScreen is a product of CogScreen, LLC. in Saint Petersburg, Florida.

Overview

CogScreen-Aeromedical Edition (CogScreen-AE) is a computer administered and scored cognitive-screening instrument designed to rapidly assess deficits or changes in attention, immediate- and short-term memory, visual-perceptual functions, sequencing functions, logical problem solving, calculations skills, reaction time, simultaneous information processing abilities, and executive functions.

CogScreen-AE was initially designed to meet the Federal Aviation Administration's (FAA) need for an instrument that could detect subtle changes in cognitive functioning. CogScreen-AE meets the FAA's requirement for a sensitive and specific neurocognitive test battery for use in the medical recertification evaluation of pilots with known or suspected neurological and/or psychiatric conditions. CogScreen-AE is not a test of aviation knowledge or flying skill, but rather a measure of the underlying perceptual, cognitive, and information processing abilities associated with flying.

Subtests

CogScreen-AE is comprised of 11 subtests:

Backward digit span (BDS)

Recall of a sequence of visually presented digits in reverse order.

Math

Math word problems with multiple-choice answer format.

Visual Sequence Comparison (VSC)

Comparison of two simultaneously presented series of letters and numbers.

Symbol Digit Coding (SDC)

Substitution of digits for symbols using a key, followed by immediate and delayed recall of symbol digit pairs.

Matching to Sample (MTS)

Immediate recognition for a checkerboard pattern.

Manikan (MAN)

mental rotation task requiring respondent to identify the hand in which a rotated human figure is holding a flag.

Divided Attention (DAT)

task employs a visual monitoring task, which is presented alone and in combination with the Visual Sequence Comparison Task.

Auditory Sequence Comparison (ASC)

Comparison of two series of tone patterns.

Pathfinder (PF)

Visual sequencing and scanning task that requires respondents to sequence numbers, letters, and an alternating set of numbers and letters.

Shifting Attention (SAT)

Rule-acquisition and rule-application test requiring mental flexibility and conceptual reasoning.

Dual Task (DTT)

Consists of two tasks, each of which is performed alone and then together as a simultaneous test. One task is a visual-motor tracking test. The second task is a continuous memory task involving serial digit recall.

Historical Background

CogScreen-AE represents the culmination of an 8-year international effort aimed at developing a sensitive and specific instrument for the detection of cognitive changes resulting from mild brain dysfunction. In 1987, the FAA issued a Request for Proposals from investigators to evaluate existing cognitive testing approaches with respect to their ability to detect mild degrees of brain dysfunction and the extent to which such measures were related to actual risks of aviation safety. Based on the results of initial studies, the FAA sought proposals for developing an automated of computerized instrument that would meet the needs for neuropsychological screening in medical certification.

Phase A

The first phase (Phase A) of the resulting three-phase research and development project included an extensive review of the literature on cognitive testing that surveyed mental status examinations, neuropsychologcial screening tests, neuropsychological test batteries, and computer-based performance assessment batteries (Kay & Horst, 1988). upon completion of the literature review , an empirical study was conducted, comparing performance of aviators and mildly brain-impaired patients on formal mental status tests, conventional neuropsychological measures, and computerized performance tests of aviation related abilities (Kay & Horst, 1988; 1989). The literature review was used to select neuropsychological tests with known sensitive and specificity to brain dysfunction and performance tests with known validity for predictions of aviation -related performance. The primary mental status test used in the study, as specified by the FAA, was the Mini-Mental State Examination (Folstein, Folstein, & McHugh, 1975). The battery of tests was administered to 60 pilots (equal numbers of Class I, II, and III medical certificates) between the ages of 20 and 72. Sixty age- and education-matched patients with mild brain dysfunction secondary, to head trauma, brain tumor, epilepsy, multiple sclerosis, dementia, alcoholism, and central nervous system infection were also tested.

Patients with brain dysfunction could not be discriminated from pilots by performance on the Mini-Mental State Examination. In contrast, one of the computerized subtests from the Naval Medical Research Institute Performance Assessment Battery (Matching-to-Sample; Thomas & Shrot, 1988) revealed significant group differences. Overall the computerized performance measures demonstrated excellent sensitivity to mild brain dysfunction. In addition, a number of these measure also had acceptable levels of specificity. The main conclusion drawn from this exploratory study was related cognitive abilities were at least as sensitive as conventional neuropsychological instruments in detecting the presence of mild brain dysfunction (Horst & Kay, 1988).

Phase B

Recognizing the advantages of computer-based test administration, the FAA awarded Phase B contracts for the development of a full computerized, 30 minute, cognitive-screening examination.

Validation of the Phase B version of the CogScreen battery was conducted with 40 pilots with valid medical certificates, approximately balanced across four age groups and medical certification status (Class I-III), 40 age- and IQ-matched nonpilot normals, and 40 age- and IQ-matched patients with mild brain dysfunction secondary to head injury, tumor, stroke, substance abuse, and mild dementia. Other than havuing a valid meidcal certificate, there was no independent verification of the health status of the aviators. Respondents were administered a partial Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981), the Paced Auditory Serial Addition Test (PASAT; Gronwall, 1977), the Trail Making Test (TMT; Reitan & Wolfson, 1985), the Symbol Digit Modalities Test (SDMT; Smith, 1973), and the 11 subtests of CogScreen. The conventional neuropsychological tests ere selected for inclusion in the study based on their reported ability to detect brain dysfunction (Kay & Horst, 1989).

Pilots and nonpilot normals performed significantly better than mildly brain-impaired patients on 38 of the 50 dependent measures derived from CogScreen. CogScreen was able to correctly classify 32 out of 40 patients with brain dysfunction and incorrectly classified only 3 pilots. By comparison, the conventional neuropsychological tests batter correctly classified only 20 of the 40 patients with brain dysfunction and incorrectly classified 2 pilots. Pilots outperformed nonpilot normals on many of the response time measures; however, these differences failed to reach statistical significance.

Construct validity was evaluated by comparing CogScreen performance with performance on analogous paper-and-pencil cognitive and neuropsychological tests. For example, the CogScreeen Symbol Digit Coding Accuracy Measure and the conventional SDMT correlated .80 (p<.001). Pathfinder Number Speed correlated .44 (p<.001) with part A of the TMT, and Pathfinder Combined Speed correlated .73 (p<.001) with Part B of the TMT (Horst & Kay, 1991).

Phase C

The findings from the Phase B project demonstrated CogScreen's capability to serve as a relatively inexpensive and efficient adjunct to traditional neuropsychological assessment in the evaluation and medical certification of airmen. The FAA subsequently selected CogScreen for further test development and for normative and validation testing. The FAA Technical Panel requested the addition of a test of concept formation and abstract reasoning and a test of divided attention employing a tracking and memory component. These new tests were designed and implemented in the Phase C version of CogScreen, thereafter known as CogScreen-AE. Subsequently, a laboratory was established at a major airline facility, and 402 commercial airline pilots completed the battery and were entered into the normative database. Laboratories were also established at three major airports. In addition to CogScreen-AE, all pilots were administered the WAIS-R and completed an extensive demographic and medical history questionnaire.

Approximatedly 200 if the pilots returned for 6-month and 12-month follow-up testing with CogScreen-AE. An additional 100 pilots, who were not tested at 6-months, returned for the 12-month follow-up testing session. Data were analyzed to determine the test-retest reliability of CogScreen-AE measures. Comparisons of CogScreen-AE performance with scores from the WAIS-R, the SDMT, and the TMT were used to determine the convergent validity of the test.

CogScreen-AE was administered to 61 pilots from a smaller U.S. air carrier and 120 pilots from a medium-sized U.S. air carrier. Data from the three carriers were compared and demonstrated more similarities than differences among airlines. These findings suggested that the CogScreen-AE performance of the respondents from the major carrier (n=403) was fairly representative of the larger population of U.S. commercial airline pilots. The FAA Technical Panel recommended combining the three data samples to form the CogScreen-AE U.S. aviator normative sample.

The Phase C project was later expanded to include administration of a modified Haltsted-Reitan test battery to 120 of the commercial pilot subjects sampled from all three airlines who completed the initial CogScreen-AE testing. These data were used in further construct validation studies of CogScreen-AE.

Clinical and Research Applications

CogScreen-AE has been used in a number of biomedical research applications. A version of CogScreen-AE was designed for studying the effects of antihypertensive drugs on the orthostatic reflex with and without hypoxia (Kay, Eberle, Kaufman, & Hordinsky, 1995). The FAA's Civil Aeromedical Institute has used CogScreen-AE to examine the effects of low-dose alcohol on cognitive performance and to evaluate the influence of age on cognition and pilot flight performance (DeLarocca & Schroeder, 1992). In the latter study, CogScreen-AE was found to be significantly correlated with flight performance skills in a 727 simulator.

Researchers have been utilizing CogScreen-AE subtests in a number of applications. Versions of the battery have been used in studies of sleep apnea (Kay et al., 1990), diabetes (Zawadzki, Tatman, Grimes, Sobel, & Kay, 1991), and in a study of Eosinophilia Myalgia Styndrome (Clauw, Morris, Starbuck, Epstein, & Kay, 1993). In addition, a keyboard version of the test has been used to track changes in cognitive functioning during balloon trial occlusion of the internal carotid artery (Spector, Kay, Geyer, Deveikas, & Sullivan, 1991). The test was recently selected for use in a study of the effects of HIV seropositivity on the cognitive functioning of military aviators (Mapou et. al 1995). Moore (1994) used CogScreen-AE in a longitudinal study of repatriated Vietnamese Prisoners of War at the 20-year follow-up session.

CogScreen-AE, along with a United States Air Force (USAF) Armstrong Laboratory-developed computerized version of the Multidimensional Aptitude Battery (MAB; Jackson, Barton, & Blokker, 1992), comprises the baselining portion of the USAF Neuropsychiatrally Enhanced Flight Screening (N-EFS) program (King & Flynn, in press). All USAF pilot candidates take CogScreen-AE before receiving any military flight training. Their performance is archived for comparison purposes in the event that any individual sustains a head injury of other neurological insult. Additionally, investigators seek consent for participation in a research study using CogScreen-AE, the MAB, the revised NEO Personality Inventory (NEO-PI-R, Costa & McCrae, 1992) and the Personality Characteristics Inventory (PCI; Chidester, Helmreich, Gregorich, & Geis, 1991) to determine whether this psychological testing battery could be useful in future pilot selection and cockpit assignment decisions (King & Flynn, in press).