IVA-2 – Evaluate Visual and Auditory Attention
The Integrated Visual and Auditory (I.V.A.) continuous performance test (CPT) is a screening tool used in conjunction with other diagnostic procedures (parent and teacher behaviour rating scales, QEEG, T.O.V.A.) to assist in the screening of individuals with Attention Deficit Hyperactivity Disorder (ADHD). Developed by John Sandford (psychologist) and Anne Turner (physician). It was designed to discriminate ADHD populations from individuals with Conduct Disorder and without behaviour problems and is based on the research of Chee (1989) and Connors (1994).
FEATURES OF THE I.V.A.
Administration of the test is automated to standardise the presentation of auditory and visual stimuli. The computer "speaks" all test instructions in order to minimise test variability.
The I.V.A. is a 13 minute computerised test which combines two types of CPTs for both visual and auditory modalities. By combining impulsivity and inattention in a counter-balanced design and presenting each in the auditory and visual mode, the I.V.A. incorporates four CTPs into one.
The test task is very simple and requires the person to click the mouse only when he hears or sees the target (in this case the number "1") and not to click when he sees or hears the non-target (foil) item (in this case the number "2").
The test contains two conditions in two modalities for a total of 200 trials.
ANALYSIS OF RESULTS
The scores are divided into four primary diagnostic scale: Response Control, Attention, Attribute and Validity.
1. Full Scale Response Control Quotient based on separate Auditory and Visual Response Control
Quotient scores. The Response Control Quotient score are derived from visual and auditory
Prudence, Consistency and Stamina scales. A. Prudence: is a measure of impulsivity and response inhibition as evidenced by three different
types of errors of commission (impulsivity, propensity and mode shift) B. Consistency : measures the general reliability and variability of the response times and is used to
measure the ability to stay on task C. Stamina : compares the mean reaction times of correct responses during the first 200 trials to the
last 200 trials. This score is used to identify problems related to sustaining attention and effort
over time. . 2. Full Scale Attention Quotient is derived from separate Auditory and Visual Attention Quotients.The
Attention Quotient scores are based on equal measures of visual and auditory Vigilance, Focus and
Speed A. Vigilance : is a measure of inattention as evidenced by two types of different errors of omission
(inattention ie failure to respond to a target when a response set of inhibition has been
established and propensity i.e. non-response to a target immediately after a foil has been
presented.) B. Focus : reflects the total variability of mental processing speed for all correct responses C. Speed : reflects the average reaction time for all correct responses throughout the test and helps
identify attention problems related to slow discriminatory mental processing. The Fine Motor Regulation scale provides additional information by recording off-task behaviours
with the mouse, including multiple clicking, spontaneous clicks during instruction periods,
anticipatory clicks and holding the mouse button down. In behavioural terms, the Fine Motor
Regulation scale quantifies fidgetiness and restlessness associated with small motor
3. The Attribute scores provide information regarding the individual’s learning style: A. Balance : indicates whether the individual processes information more quickly visually or aurally,
or is equally quick in both modalities B. Readiness : indicates whether the individual processes information more quickly when the
demand is quicker or when it is slower. This scale also provides a subtle measure of inattention
when the test taker just "can’t keep up" with the demand.
4. There are three Validity scales used to evaluate whether a test taker’s responses can be interpreted in
a meaningful way: A. Comprehension : identifies random responding which would lead to faulty interpretation of other
I.V.A. scale scores. Research has shown this to be the single most sensitive sub-scale in
discriminating ADHD B. Persistence : is a measure of motivation when the individual is asked to do "one more thing". It
can also reflect mental or motor fatigue C. The Sensory / Motor : scales are used to rule out neurological, psychological or learning
problems as evidenced by slow simple reaction time.
VALIDITY AND RELIABILITY
Validity research using the IVA CPT with children ages 7 to 12 had a sensitivity of 92% in identifying individuals diagnosed by a clinician as having ADHD. The IVA CPT also correctly identified the 90% of non-ADHD children (i.e., false positives = 10%). Another validity study for a typical mixed age clinical population (ages 6 to 55) found that as part of a clinician’s comprehensive psychological evaluation, the combination of the ADHD rating scale data with the IVA CPT matched the clinical diagnosis 90% of the time. In addition, this study did not misclassify 89% of individuals who did not have ADHD (i.e., 11% false positives).