Testing systems for human behavioural neurotoxicity research
| Battery | Benefits | Limitations |
|---|---|---|
| Neurobehavioral core test battery (NCTB) Category: consensus recommendation Developer: WHO designated committee8 Availability: responsibility of investigator Instructions, sources of the tests, and operational guide are available from author | Least expensive choice for testing a small group of participants or where equipment is more expensive than trainable labour (examiners). Has been a popular choice in developing countries9,17,46–48,w23 Validity: Based on independent studies by different investigators using NCTB-recommended tests, though not necessarily using the NCTB tests as a unit or battery3 Key references10,1746–53,w23, w49–69 | Not suitable for people with limited education Not a commercially available testing system. The digit symbol, digit span, pursuit aiming II (which is difficult to score reliably), profile of mood states (which uses dated emotional terms), and Benton tests must be purchased from four different sources. The Santa Ana must be manufactured |
| Adult environmental neurobehavioral test battery (AENTB) Category: consensus recommendation Developer: ATSDR; Atlanta, Georgia, USA29,54 Availability: responsibility of investigator | The AENTB includes more tests than the NCTB and thus assesses more nervous system functions Validity: based on independent studies by different investigators using AENTB recommended tests, though not necessarily using the AENTB tests as a unit or battery3 Key reference: user manual available from ATSDR54 | Not suitable for people with limited education Not a commercially available system, although it can be assembled from commercial sources54 Limited use, and there are no peer reviewed publications in exposed populations |
| Behavioral assessment and research system (BARS) Category: computer based testing system Developers: Kent Anger (author of this article), Diane Rohlman, Dan Storzbach, Oregon Health & Science University; Portland, Oregon, USA35,36,w41 Availability: Collaborate with developers; 9BUTTON can be purchased from developers | Large graphics, simple instructions integrated with the test during practice,36 and a 9BUTTON response unit (fig 2) that is a better alternative to a keyboard.35 BARS is thus a preferred choice for marginal populations such as those with limited education Available with English, Spanish, Portuguese, Korean, Ukranian, and Arabic instructions Validity: based on implementation of valid tests and discrimination of Parkinson patients from controls.w74 Sensitivity for cross sectional comparisons established by detecting effects of neurotoxic agents and differences in occupational populations Key references35,36,4546,w13, w22, w41, w42, w48, w70–77 | Available only for limited computer operating systems 9BUTTON is required, tying collaborators to developers |
| Neurobehavioral evaluation system 2 (NES2) Category: computer based testing system Developer: Richard Letz Emory University Atlanta, Georgia, USA6,14 Availability: purchase from developer | Has been used far more extensively than any other battery by professionals in this field (see “NES” above) Validity: based on implementation of valid tests and discrimination between neurological patients.26 Sensitivity for cross sectional comparisons established by detecting effects of neurotoxic agents A large database is available for comparison on three tests20 NES-C is a Chinese language adaptation of the NESw32 Key references16,14–28,55,w26–33, w51, w78–81 | Not suitable for people with limited education Small graphics and lengthy instructions that are complicated Requires specialised joystick The two button response unit may lack durability and long term reliability |
| Neurobehavioral evaluation system 3 (NES3) Category: computer based testing system Developer: Richard Letz Emory University; Atlanta, Georgia, USA23 Availability: collaborate with developer | Implements a wide range of neuropsychological tests to focus the battery on detection of clinical cases in addition to neurotoxicity Validity: based on NES2 for some tests and other validated neuropsychological tests, correlations between test performance and cases with solvent encephalopathy, and ability to detect cognitive impairment Key references23,26,56,57 | Tests have fixed parameters (e.g. type of stimulus, number of trials) that must be changed by the developer NES3 requires a stylus for response and so may not be suitable for some people with limited education (e.g. those who do not practise writing or holding stylus shaped instruments in their hand) |
| Swedish performance evaluation system (SPES) Category: computer based testing system Developers: Anders Iregren, Francesco Gamberale, Anders Kjellberg, National Institute of Occupational Health (NIOH), Solna, Sweden13 Availability: purchase from NIOH | Valuable option for Swedish speakers; instructions are also in English Validity: based on implementation of valid tests. Sensitivity for cross sectional comparisons established by detecting effects of neurotoxic agents Key references13,30,58–60,w82–86 | May not be suitable for people with limited education Requires specialised joystick |
| Performance and information processing systems test battery (PIPS) Category: computer based testing system Developer: Ann Williamson, University of New South Wales, Australia61 Availability: collaborate with developer | Theory based test selection to provide a categorisation of deficits based on that theory Validity: tests were selected to reflect nervous system functions based on information processing theory, so the PIPS must be judged on the basis of the viability of that theory Sensitive to effects of exposure to mercury and stress Key references61–64,w87–91 | Limited research with exposed populations |
| Automated cognitive test (ACT) Category: computer based testing system Developer: Brian Stollery, University of Bristol, Bristol, UK65 Availability: collaborate with developer | Provides a very broad range of cognitive tests Validity: based on established relationship between valid tests of nervous system function, and studies of lead and solvent exposed workersw92, w93 Key references65,w92, w93 | Very limited research with exposed populations |
| CATSYS Category: computer based testing system Developer: Danish Product Development, Snekkersten, Denmarkw94 Availability: purchase from Danish Product Development | Assesses motor function (e.g. tremor, tapping, reaction time) that involves some sensory function Validity: extensive data on 150 normal controls, with evidence of sensitivity to effects of mercuryw95 Key referencesw94, w95 | Assessment limited primarily to motor functions Very limited research with exposed populations |