Dr. Michael Hamilton, Psy.D.
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About the T.O.V.A.™


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 written interpretation and graphics.


1. Increases Diagnostic Accuracy

The T.O.V.A. promotes data based clinical decision making with its objective information about attention and impulsivity - information that clinicians do not obtain from behavior ratings and history Alone, the T.O.V.A. correctly identifies over 86% of ADHD cases and the “hit” rate improves with the addition of other clinical information. However, as is true with all tests, the T.O.V.A. does not make a diagnosis - only a clinician does.

2. Improves Response to Treatment

The T.O.V.A. accurately predicts the effectiveness of medication by comparing T.O.V.A. tests (with and without medication). By administering the T.O.V.A. on various doses one can titrate dose for best results. It titrates medication doses to obtain optimal clinical results and minimize sequellae without costly and long clinical trials. And it minimizes the need for treatment of overlying, prominent symptoms such as depression, anxiety, learning and conduct disorders that may “mask” ADHD.

3. Facilitates Case Management and Planning

The T.O.V.A. provides cost-effective monitoring of treatment over time with yearly retesting to insure continued optimal treatment results and to determine when treatment is no longer necessary. The School Intervention Report, which is easily edited, personalized and individualized, facilitates communications with the school, saving valuable professional time. And it is an asset when treating substance abuse, including nicotine dependence, recognizing that over 70% of chemical dependency treatment failures and many treatment resistant nicotine dependent cases have underlying, undiagnosed and untreated ADHD.

4. Promotes Cost Savings

The T.O.V.A. can be administered by easily trained assistants in the primary care physician’s office or in a clinic setting. Referrals to specialists such as neurologists, psychiatrists and psychologists can be more specific and cost effective. Successful treatment of ADHD reduces incidence of accidents and injuries. We now know that attentional problems can be treated with lower doses of medications rather than the higher doses needed to suppress behavioral problems. T.O.V.A. use significantly reduces the costs of medication that may be needed for many years. Teenagers, adults and older patients generally need much less (50%) rather than more medication. You can determine when trade name medications are necessary or generic medications are sufficient.

5. Increases Patient and Family Satisfaction

By providing objective, “state of the art” techniques that patients want and graphic presentations of results that are easily understood by patients and family, promoting understanding and compliance with treatment.

6. Provides Objective, Reliable Outcome Criteria

Traditional but questionably effective treatments, new, often more costly medications, and potential alternative therapies can be evaluated and compared to medication efficacy.

7. The Services of the T.O.V.A.® Research Foundation

Provides training for professionals and clinical staff with newsletters, clinical updates, medical guidelines, seminars and workshops (with CE credit) with comprehensive information that is available directly from the experts in ADHD Provides ongoing research and development such as development of a Home Intervention Report and an Adult Intervention Report which will provide adjunctive support for counseling. Encourages and supports over 300 research studies in attention disorders. In summary, ADHD is over diagnosed and over treated because many clinicians use outdated as well as unnecessary expensive procedures. The use of the T.O.V.A., that specifically measures the important attentional variables, is a cost-effective means of significantly improving diagnostic accuracy and treatment results while decreasing per case expenditures.

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