Which categories of drugs do not present HGN/VGN?

The correct answer identifies that Cannabis, Stimulants, Hallucinogens, and Narcotics do not typically produce Horizontal Gaze Nystagmus (HGN) and Vertical Gaze Nystagmus (VGN). HGN is an involuntary jerking of the eyes that occurs as a person gazes to the side, and it can be used as an indicator of impairment by certain classes of substances, particularly alcohol.

Cannabis is known to affect the central nervous system but does not usually induce the eye signs associated with HGN. Stimulants can increase alertness and energy levels, while Hallucinogens can alter perception, but neither is commonly associated with HGN or VGN. Narcotics, on the other hand, tend to depress the nervous system, but again, do not typically result in these eye movement indicators.

Each category mentioned typically impacts motor control and perception differently than substances that do present HGN, such as alcohol. In understanding how these categories influence physical responses, it's crucial to recognize that the physiological effects on eye movement differ from the impairments caused by substances that do exhibit HGN and VGN.

Thus, the inclusion of all these substance categories as not producing HGN/VGN aligns with the established