Perception and Attention Functions: Alertness - WAFA - 1 Year License

Test Overview

On account of their theory-led construction basis the tests of the WAF battery can be used for the differentiated assessment of almost all the sub-functions of attention which are currently regarded as relevant.

Main Areas of Application

• Neuropsychology
• Clinical psychology
• Health psychology
• Sport psychology
• Aviation psychology
• Performance and aptitude assessment
• Educational psychology
• Pharmacology

Theoretical Background

Modern views of the dimensionality of attention can be summarised by the model proposed by van Zomeren and Brouwer (1994). According to this model the central factors include the distinguishing of intensity and selectivity aspects of attention; these need to be differentiated into their more specific components. The intensity aspect of attention is made up of alertness and vigilance components which are basal processes of short-term and of longer-term attention activation or of the sustaining of this activation. With regard to the selectivity aspect of attention processes the model distinguishes between focused or selective attention and divided attention.

The spatial direction of attention is an additional, independent dimension that the above model does not at present take into account (Posner et al., 1978, 1984) but which is included in more recent taxonomies (Sturm 2005).  Both Posner and Raichle (1994) and Fernandez-Duque and Posner (2001) distinguish three types of attention networks:

• Orienting (corresponds to the network of spatial direction of attention),
• Vigilance (corresponds to the intensity dimension) and
• Executive Attention (corresponds to the selectivity dimension).

Administration

The WAF test battery consists of 6 tests that can be administered independently of each other or, as a test battery, in any desired combination: For each of the WAF tests different test forms are available, enabling dimensions of attention to be assessed under different presentation modalities. Thus the WAF tests systematically include sub-tests for visual, auditory and cross-modal presentation. In some subtests of the WAF test battery automated and controlled aspects of attention are measured separately; the stimuli either become more prominent because the intensity level is increased (popping out), or they become less prominent because their intensity is decreased and cognitively controlled top down processes are then required. Both attention processes are relevant in everyday life; both can interact and both can be selectively impaired, for example as a result of brain damage, since they are based on different cerebral networks (Corbetta & Schulman, 2002).

The WAFA involves the measurement of reaction time in response to simple visual or auditory stimulus material. The stimulus is presented either with or without a warning signal in the same stimulus modality or the contrasting one (intrinsic vs. phasic alertness). A special norming process enables fatigue or stress parameters to be measured.

Subtests

Intrinsic (visual), phasic (unimodal visual), phasic (cross-modal visual / auditory), intrinsic (auditory), phasic (unimodal auditory), and phasic (cross-modal auditory / visual)

Scoring

In all WAF tests the reaction times and the various error types are scored. For most variables a norm comparison (percentile ranks and T scores) is also carried out.

Reliability

Very good reliabilities – particularly in view of the short testing time – are obtained for the main variables of the WAF tests. WAFA: depending on subtest between a=0.93 and a=0.98.

Validity

A study of the tests' construct validity involving a sample of n=256 subjects provided empirical evidence of the theoretical model on which the WAF test battery is based and was able to distinguish it from other models.

Norms

For all WAF tests norms representative of the general population are available; the norms relate to 295 individuals in the age range 16 - 77. The norms are available both for the sample as a whole and also separated according to educational level. In addition all WAF tests provide raw scores adjusted for age effects for the main variables. Work on enlarging the norm sample is currently in progress.

Testing Time

The time required to complete the individual WAF tests is relatively short. It is therefore possible to create batteries of tests for complex assessment purposes without requiring too much of the respondent in terms of time or motivational commitment. It is usually not necessary to administer each test in all stimulus modalities. The tests to be administered must be decided by the user, taking into account any information about a patient's difficulties or disabilities that has already been gathered. The test results can only be interpreted without qualification if the respondent / patient meets the sensory and motor requirements for satisfactory completion of the test. WAFA: approx. 5 mins. for each subtest.

VTS System Overview

The Schuhfried VTS enables computer-assisted application of a large number of highly diverse psycho-diagnostic tests and measuring procedures. In developing the system much emphasis was placed on transparent structure and largely uniform design. It is therefore simple to operate and easy to understand and does not require any special computer skills.

The VTS basic module is required for administration of any of the available tests.

The Schuhfried VTS supports the administration of both single tests and test batteries. Many of the single tests are available in different test versions. These test versions may differ, for example, in terms of test duration or difficulty or may be parallel forms. They are characterized by different parameters reflecting specific test requirements. They have been designed for administration to a specific population (e.g. psychiatric patients, children, etc.) or for special measuring purposes (e.g. repeated measurements). Test batteries are compiled from the available single tests and test versions.