. 2019 Mar 8;7:e6486. doi: 10.7717/peerj.6486

Table 2. Mean stimulus intensity ratings (SD) for the three phases.

	Baseline phase	Acquisition phase	Test phase
CS⁺/US_P		3.722 (1.862)	12.213 (1.562)
CS⁻/US_NP		−19.181 (2.859)	−13.528 (2.376)
CS⁺/US_PT			6.174 (5.109)
CS⁻/US_PT			3.596 (3.714)
CS⁺ only	−32.811 (3.150)		−24.821 (15.464)
CS⁻ only	−35.489 (2.822)		−27.222 (12.992)

Note:

CS, conditioned stimulus; US_P, painful unconditioned stimulus; US_NP, non-painful unconditioned stimulus; US_PT, at-threshold unconditioned stimulus.