Table 2.

Description of behaviors scored

Category	Behavior	Description
Approach	Move forward	Shifts body forward, closer to stimulus
	Touch	Handles Plexiglas box with hand or foot
	Take/eat reward	Picks up or mouths the food reward
Defense	Freezing	Motionless for ≥3 s
	Startle	Jerks suddenly
	Eye/head aversion	Avoids eye contact or turns head away for ≥3 s
	Piloerection	Hair stands on end
	Move away/withdrawal	Retreats to back of the cage, away from stimulus, standing with a tense posture

Definitions for each behavior scored within approach and defense behavior categories.