T.O.V.A: An Accurate Assessment for Attention Deficit Disorders?

By Dr. David Velkoff

ADHD Diagnosis & Testing is a complicated process that depends on the comprehensive analysis of the patient’s own unique situation. Ideally, coming to a conclusion about the status of a patient’s ADHD should be based upon the examination of both hard data (i.e., quantitative EEG brain mapping, etc.) and a comprehensive evaluation of the patient’s history by a qualified healthcare provider, which includes a history of symptoms for at least six months that are inappropriate for one’s developmental level which impair social, academic, or occupational functioning. Diagnosing a patient in this manner creates an “overview” by which an assessment of the patient’s ability to focus and concentrate can be made, and it's the primary protocol utilized at the Drake Institute. 

For the last 4 decades, the Drake Institute has utilized non-drug, non-invasive treatment protocols to treat ADD, ADHD, and a variety of other disorders, including General Anxiety Disorder, Autism, Depression, PTSD, and more. For more information regarding the Drake Institute's treatment protocols, please contact us at 800-700-4233 or fill out our Free Consultation Form. 

However, there are other strategies for evaluating patients for ADHD, one of which being the T.O.V.A assessment. The T.O.V.A  test is a  Continuous Performance Test (CPT) that has been used by some healthcare providers to determine if an individual is suffering from ADHD.

The T.O.V.A assessment has been around for a number of years, and in some cases, T.O.V.A is still used as part of the ADHD diagnostic process. When used as part of a comprehensive evaluation, T.O.V.A can provide some additional information that could be useful; however, it’s important to note that T.O.V.A testing carries some important caveats with it and that these caveats should be examined thoroughly before any real conclusions can be made.  

When it comes to the T.O.V.A  test, the question that gets asked most frequently is, “Just how accurate is the T.O.V.A?” Indeed, viewing the results from a T.O.V.A assessment can leave untrained individuals misguided or jumping to inaccurate diagnoses. It seems unintuitive to most people that any sort of real diagnosis of ADHD can be made through the T.O.V.A due to the simplistic nature of both the assessment and the results. And it’s true: it is a simplistic test, but simplicity doesn’t necessarily indicate unreliability.

As such, this article will be discussing the T.O.V.A assessment in detail to determine where the assessment’s shortcomings are and if there are any tangible reasons to believe that the assessment is an adequate means of diagnosing ADHD. To understand the T.O.V.A assessment, we must first start with a bit of history.

What is T.O.V.A?

The Test of Variables of Attention, or T.O.V.A for short, is a neuropsychological assessment that was created in the 1960s by Dr. Lawrence Greenberg . It measures the individual’s ability to remain focused during a repetitive , boring task, and their ability to control their impulses during  a more stimulating task. From this assessment, a series of variables are measured and eventually analyzed to determine whether or not the person truly had problems with paying attention and controlling impulses.

The theory behind the assessment is essentially this: by measuring the patient’s response time and the consistency of the patient’s response time during a boring repetitive task, you can screen for ADHD.

Today, this is still the fundamental philosophy behind the T.O.V.A assessment, and with the advent of computer advances  and micro switches, the T.O.VA has evolved from a mechanical device to a fully-fledged computerized device that has been available to the public as a consumer product since the early 1990s.

The  T.O.V.A  assessment was used to measure responses to various medications in order to titrate medications  to improve the variables it was measuring. Nowadays, the T.O.V.A test for ADHD is widely recognized as only an incremental step in the process of determining whether or not a patient has ADHD, and in some cases, the T.O.V.A assessment has been removed from the diagnostic process altogether.

Why has this happened? Looking deeper into the details of the T.O.V.A assessment, we can see that the assessment does not collect an adequate amount of data by which a true diagnosis  can be made.  The company that markets it states that the T.O.V.A test cannot be used alone to make a diagnosis of ADHD.

T.O.V.A Testing

The modern T.O.V.A test is a computerized assessment that is offered in two formats, auditory and visual, and typically lasts for 21.6 minutes for children ages 6 years and older, and 10.8 minutes for children who are between the ages of 4 and 5.

T.O.V.A assessments are always divided into two parts: a “target infrequent” half and a “target frequent” half. During the visual “target infrequent” half, the test subject is exposed to a series of targets and non-targets represented by geometric stimuli at a target ratio of 1:3.5. This means, that for every 3.5 non-targets, a target will be shown in which the patient will need to respond to by activating a specially designed micro switch. Conversely, during the target frequent half, the target ratio is 3.5:1 so the test subject experiences the inverse: for every 3.5 targets shown, a non-target will be shown that the patient shouldn’t respond to.

The auditory T.O.V.A test works in much the same fashion, but instead of geometric  stimuli, the test subject is exposed to two separate tones that are determined to be the “target” and the “non-target.” During this auditory test, the test subject is given the micro switch and must press it whenever they hear the target tone (typically a “G” note) and not press the switch when the non-target tone is presented (typically a “C” note).

Reading through this, one might ask, “What does any of this have to do with ADHD?”

It’s a fair question to ask since it’s not entirely obvious as to how pushing a simple micro switch can determine with any amount of accuracy whether or not a patient might have ADHD. There simply has to be more to it, right?

Some providers  of the T.O.V.A assessment claim  that the TOVA test can determine whether or not the patient has ADHD by comparing the patient’s measured “variables” with the variables of individuals who have taken the assessment and do not have attention problems. The T.O.V.A test results are generated and presented in a series of infographics and numeric tables, and it’s up to the test administrator to make the final diagnosis of whether or not the patient has ADHD. The  ADHD diagnosis should not be based on TOVA results alone.

Variables Measured during the T.O.V.A

Below is a breakdown of the variables measured during the T.O.V.A assessment.

Response Time Variability

This is a measurement of how fast or how slow (measured in milliseconds) a patient is able to respond to the targets presented during the T.O.V.A assessment by pressing the button.  

d’ Signal Detection

This is a measurement of how quickly the patient’s performance worsens over the duration of the T.O.V.A assessment.

Commission Errors

When a patient presses the button while a non-target visual or auditory note is presented, an error of “commission” is recorded. This type of error is used to measure the “impulsivity” of the patient. The greater the number of commission errors reflects the degree of impulsivity in taking the test.

Omission Errors

When a patient fails to activate their micro switch while a target visual or auditory note is presented, an error of “omission” is recorded. This type of error measures inattention and the greater the number of omission errors reflects the degree of inattention during the test.

Post-Commission Response Time

After a person has committed a Commission Error, the Post-Commission Response Time is a measurement of how fast or slow the patient becomes in the following target and non-target presentations.

Multiple Response

The “Multiple Response” variable is a measurement of the number of times a person activates their micro switch more than once when a target is displayed. This variable may help identify whether or not the patient is experiencing symptoms of other neurological conditions not related to ADHD.

Anticipatory Responses

Anticipatory Responses are a measurement of how often the patient is pressing  the button so quickly (less than 150msec) that they may be guessing.  Excessive anticipatory responses  are a measure of test validity of the TOVA. It is important that the patient taking the T.O.V.A  only press their switch in response to a target and that they don’t try to artificially inflate their response times by guessing.

Where the T.O.V.A Falls Short

Although the patient’s T.O.V.A test scores, or “variables,” are compared to the variables of other individuals who are free of ADHD symptoms, the T.O.V.A assessment still fails to portray the entirety of the patient’s situation.

The T.O.V.A assessment, in itself, is essentially a computer game, and some individuals who have been diagnosed with ADHD can maintain adequate levels of attention while participating in activities like video games because it is experienced as  a “preferred ”, stimulating  task by their brain.  An ADHD individual  can be an experienced computer game player  and  could score “a false negative” on the T.O.V.A . This means that a person who has ADHD could pass the T.O.V.A  assessment if they experience the T.O.V.A test as stimulating as a “preferred” task, as opposed to a “non-preferred” task. This  “false negative test” would provide inaccurate information about  not having an attentional disorder  in an ADHD patient who  needs treatment for ADHD. Indeed, if the TOVA test is used as the sole criteria  to diagnose or rule out ADHD, it is quite possible that because of  “false negatives” from the T.O.V.A assessment, the patient’s  ADHD  may remain undiagnosed  without treatment.

The main issue with the T.O.V.A assessment is that  some clinicians  attempt  to simplify and condense the ADHD evaluation process into a single  exam (TOVA test) that yields a set of data that is too incomplete for a proper diagnosis. There are many factors to take into consideration when evaluating a patient for ADHD, and the variables measured in the T.O.V.A assessment are not sufficient to diagnose ADHD. In addition, if the patient truly has ADHD and the TOVA test is positive for an attentional problem, the TOVA test does not identify  which brain regions or networks are dysregulated  that are linked to the patient’s symptoms . This information is essential to optimize qEEG brain map guided neurofeedback treatment  for ADHD. No logical conclusions can be made about the presence of ADHD in a patient from the analysis of data that is solely derived from the T.O.V.A assessment. But again, the TOVA test may add some value to an ADHD assessment  as long as it is part of a comprehensive evaluation.

Beyond T.O.V.A: The Drake Institute’s Method for Evaluating ADHD

The Drake Institute’s ADD/ADHD evaluation is a 2.5-hour process that incorporates both an extensive diagnostic interview and state of the art brain mapping technologies—both of which being key to understanding the connection between behavioral symptoms  and brain wave activity.

Unlike the T.O.V.A assessment, the Drake Institute’s ADHD comprehensive evaluation process is specifically designed to provide our clinical professionals with an analysis  that can determine with a high rate of accuracy whether or not the patient’s issues are rooted in ADHD or some other type of disorder. In fact, approximately 70% of patients who are experiencing symptoms of ADD and ADHD have a co-existing learning disorder or language processing deficit, and our evaluation processes  can help identify these disorders as well.

During the diagnostic interview, we can learn a great deal about the patient’s  family dynamics, family history, struggles at work/school, how the patient’s difficulties impact on other family members as well as well as the patient’s  self esteem,  etc., and through the brain mapping process, we can see which networks  of the brain are being over/under activated or having dysregulated connectivity that are linked to the symptoms. By combining all of this information , our ADHD evaluation process allows us to create treatment plans that are specifically tailored to meet the comprehensive, individual needs of each patient. Additionally, by incorporating biofeedback and neurofeedback, we can help the patient “train” their brain to improve brain functioning that reduces or resolves symptoms.

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