Introducing the T.O.V.A.® (Test Of Variables of Attention)
The T.O.V.A. uses geometric stimuli (to minimize the effects of cultural differences and learning problems), and contains two test conditions: target infrequent and target frequent. In the first half of the test (the target infrequent half), the target:nontarget ratio is 1:3.5, i.e.: a target is presented (randomly) only once every 3.5 nontarget presentations. In this half which is similar to most of the other Continuous Performance Tests (CPTs), the task is boring and fatiguing, and the subject must pay close attention to respond to the infrequent target correctly. When a subject does not respond to the target, it is called an error of omission and is a measure of inattention. In the second half of the test (target frequent half), the target:nontarget ratio is 3.5:1, i.e: 3.5 targets are presented for every 1 nontarget. In this half of the test, the subject expects to respond most of the time but occasionally must inhibit the tendency to respond.
When a subject responds to the nontarget, it is called an error of commission and is a measure of impulsivity. Thus the ability to pay attention to a boring, repetitive task is best measured in the first half of the T.O.V.A. while the ability to inhibit oneself is best measured in the second half.
Like most CPTs, the T.O.V.A. uses a fixed, mid-range interstimulus interval (2secs) and visual stimuli. However, unlike most CPTs, the T.O.V.A. stimuli are nonsequential, simple geometric configurations and monochromatic. Since these features along with the use of a 2.5 minute practice, minimize practice effects, the T.O.V.A. can be used for serial measurements.
Mode of response is a particularly important variable that significantly affects test reliability. Unfortunately, since most CPTs use the keyboard to record responses, they have large inherent errors of measurement of time (up to +/-28 msec). However, the T.O.V.A. uses a specially designed microswitch with an insignificant error of measurement (+/- 1 msec) and which minimizes muscular fatigue.
Duration The duration of testing is a significant factor, since subjects who are older and more intelligent can compensate for mild or moderate attention problems for 5, 10, even 15 minutes. As a result, the T.O.V.A. is 21.8 minutes long for 6 year olds and older. An appropriately shorter version (10.9 minutes) is administered for 4-5 year olds.
Variables measured T.O.V.A. measures include variability of response time (consistency), response time, commission (impulsivity), errors of omission (inattention), post-commission response times, multiple and anticipatory responses, and an ADHD score, which is a comparison to an age/gender specific ADHD group.
The T.O.V.A. immediately analyzes the results quarter by quarter and provides an easy to understand graphical report.
More questions about the T.O.V.A.?
Check out our Frequently Asked Questions page.