How does the time of day affect HGN test results?

The impact of the time of day on HGN test results is significant because impairment levels and eye behavior can indeed vary due to factors such as fatigue and natural body rhythms. Research indicates that human performance, including motor skills and cognitive functions, can be influenced by the body's circadian rhythms.

During different times of the day, individuals may experience varying levels of alertness and attentiveness. For instance, fatigue commonly accumulates throughout the day and can affect coordination and judgment, potentially mimicking or amplifying the symptoms associated with impairment. Similarly, certain individuals may feel more alert and capable in the morning compared to later in the evening or night when they might be more fatigued.

Recognizing this variability is crucial for officers conducting HGN tests, as it can influence both the officer's observations and the individual's performance on the test. Understanding these physiological factors helps ensure that the results of the HGN test are interpreted in the context of how time of day may be impacting the individual's state at the moment of the test.