Finger-to-Nose Testing Explained

When you are stopped for driving under the influence, an officer may have you perform one or more field sobriety tests. The purpose of these tests is to determine whether you are under the influence of drugs or alcohol. The National Highway Traffic Safety Administration (NHTSA) has approved and standardized three field sobriety tests for use during DUI investigations:

  • HGN (horizontal gaze nystagmus) test
  • Walk and turn test
  • One-leg stand test

Many police officers use the “finger-to-nose” test during DUI investigations. However, this test is an unofficial field sobriety test that the NHTSA does not approve. As such, several issues can arise when a police officer uses the finger-to-nose test as part of a DUI investigation. 

What is the Finger-to-Nose Test?

A police officer instructs you to close your eyes and slightly tilt your head backward. Then, with your index finger, you touch the tip of your nose. The police officer has you repeat the process three times with each hand. Before each attempt, the police officer informs you which hand to use to touch the tip of your nose.

During the finger-to-nose test, a police officer observes you for signs of impairment. Specifically, the officer observes:

  • Your ability to follow instructions during the test
  • The direction and amount your body sways during the test
  • Whether you have body, leg, or eyelid tremors
  • Your depth perception and muscle tone
  • Unusual sounds or statements you make during the test
  • Whether you can touch your nose with your index finger or other parts of your face

Because the finger-to-nose test is not a standardized field sobriety test, police officers are not required to use specific procedures to instruct the person how to perform the test. Likewise, officers are not required to perform the test under specific conditions.

Therefore, the test can produce wildly inaccurate results because of a police officer’s subjective view of the suspect’s performance. A DUI defense lawyer may attack the validity and results of the finger-to-nose test on many points.

Field Sobriety Tests Used During a DUI Investigation

The three NHTSA standardized three field sobriety tests used during DUI investigations. Several scientific studies validate the correlation between performance during these tests and DUI impairment through statistical means. 

Police officers must follow strict and specific procedures for administering standardized field sobriety tests. Failing to follow the requirements for testing could make the results subject to challenge in court.

Even though the NHTSA only has three standardized DUI field sobriety tests, police officers often use several non-standard field sobriety tests during a DUI investigation. In addition to the finger-to-nose test, a police officer may use  the following tests to judge your impairment level during a DUI investigation:

Hand Pat Test

You extend your hand out in front of your palm up and then place your other hand on top of that hand palm down, as if you are about to start clapping. Then, counting “one, two, one, two, etc.,” you pat your hands together. Your bottom hand remains stationary. 

However, you turn the top hand from palm down to palm up between each movement. The result is that you “pat” your bottom hand with your top hand palm down on the “one” counts and palm up on the “two” counts.

Romberg Balance Test

During this test, you stand with your feet together and your head slightly tilted backward. Then, with your eyes closed, you must estimate when 30 seconds have passed. At that time, you tilt your head forward, open your eyes, and say stop.

Finger Count Test

The police officer instructs you to put one hand in front of you with your palm facing upward. You then touch your thumb to the tip of each finger, beginning with your index finger and ending with your little finger. As you touch each finger, you count from one to four. Then, the process is reversed and performed three times. 

As with standardized field sobriety tests, police officers observe your ability to follow instructions, coordination, balance, body tremors, and comments made during these non-standardized field sobriety tests. The purpose is to determine if you are impaired by alcohol or drugs.

However, the results of these non-standardized field sobriety tests are also highly subjective. The same problems exist with these tests as with the finger-to-nose test.

Using the Finger-to-Nose Test to Examine the Cerebellum and Measure Ataxia

The instructions provided for the finger-to-nose test are designed to help measure ataxia. Ataxia is the lack of muscle control or coordination of voluntary movements. It may be caused by alcohol use. 

The finger-to-nose test is supposed to detect a lack of voluntary coordination of voluntary muscle movements. A lack of coordination could indicate problems with the cerebellum, which could indicate intoxication. 

Because the finger-to-nose test is not a standardized test, the instructions police officers give to suspects can vary. However, general instructions include:

  • Stand with your feet together and your arms down at your side
  • Make a fist with each hand, keeping the index finger extended and turn your hand so your palm faces upward
  • Tilt your head back slightly
  • Close your eyes (closing your eyes before tilting your head back could impair normal equilibrium)
  • Extend your right (or left) arm straight out in front of your body and then touch your index finger to your nose before returning your arm back down to your side

As you perform the test, the police officer watches for “clues” or indicators of neurological dysfunctions that suggest you may have been driving under the influence of drugs or alcohol. 

Specific “clues” the police officer notes include:

  • Your inability to follow instructions, such as keeping your feet apart or extending the incorrect finger when making a fist.
  • Being unable to stand still. You sway from side to side or back to front, so the police officer finds that your inability to maintain balance is a sign of impairment. 
  • You exhibit the “shakes” because you involuntarily tremble when performing the test. Your muscle tone may appear more rigid or limp than is expected for a sober person.
  • You utter unusual sounds or make statements that the officer believes indicate you are intoxicated, such as signing while performing the test or repeatedly stating you have to “pee.”
  • You take too much time or you try too fast to touch your finger to your nose. Either action could indicate a problem with depth perceptions. 
  • The officer notes whether you use the correct sequence for touching your nose that the officer gave you.

As stated above, the results of the finger-to-nose test are subjective. For example, an officer might believe that asking to use the bathroom is an unusual statement, while another officer might assume that you just need to urinate. Likewise, belching could be interpreted as being intoxicated, but it could result from having just eaten a large meal.

Therefore, the reliability of the finger-to-nose test can be questionable.

Challenging the Results of the Finger-to-Nose Test 

Because the NHTSA has not approved the finger-to-nose test, police officers do not have a specific list of criteria to use when determining if a person “fails” the test. Furthermore, the procedure for administering the test can vary significantly from one jurisdiction to another and even more from one officer to another. Therefore, the validity of the test and the accuracy of the results are subject to scrutiny.

Additionally, there are numerous reasons why a person could fail the finger-to-nose test that have nothing to do with intoxication. Conditions or circumstances that could impact the results of the finger-to-nose test include, but are not limited to:

  • Ataxia caused by medications instead of being caused by alcohol intoxication. Certain medications may cause a lack of coordination of muscle movements, such as anti-seizure medications and medications for depression.
  • Brain damage and neurological defects could negatively impact the function of the cerebellum, which may impact coordination. 
  • Mental disabilities may prevent a person from understanding the instructions given by police officers when performing the finger-to-nose test.
  • Roadside conditions could impact the results of the test. For example, load noises from traffic, flashing lists, and other distractions could be the cause of the “clues” of intoxication the officer notes instead of alcohol use.
  • Incorrect sequences of instructions could impair the person’s equilibrium. Therefore, if a police officer tells the person to close their eyes and then tilt their head back, the test results could be invalid.

Without standardization, the results of a finger-to-nose test at a DUI stop can be inaccurate. Furthermore, without standard instructions to guide officers in judging the “clues” they observe during the test, it is impossible to know whether a police officer judged the person’s responses too harshly.

A DUI defense attorney can argue that the inherent defects in the finger-to-nose test make the results inconclusive, especially if there is no other evidence that the driver was intoxicated. 

Talk with a DUI defense lawyer if your DUI arrest was based partially on a finger-to-nose test. You may have a strong defense that could result in a dismissal of charges.

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