Table 2.

Zero-Order Correlations between the Communication and Symbolic Behavior Scales and Physiological Activity

	Play Phase RSA	Play Phase Heart Period	RSA Suppression	Physiological Arousal	Sustained Attention Duration	Sustained Attention Deceleration
Communication and Symbolic Behavior Scales – Caregiver Questionnaire
Social Composite	0.37	0.02	−0.52*	−0.03	0.26	0.37
Emotion and Eye Gaze	0.38	0.26	−0.50*	−0.20	0.02	0.29
Communication	0.45*	0.05	−0.65**	0.02	0.11	0.45*
Gestures	−0.05	−0.08	−0.12	−0.08	0.23	−0.04
Speech Composite	0.07	−0.13	−0.06	−.004	0.15	0.06
Sounds	−0.12	−0.16	0.18	0.03	0.04	−0.17
Words	0.19	0.06	−0.30	−0.14	0.17	0.25
Symbolic Composite	0.17	0.28	−0.19	.002	0.35	0.30
Understanding	0.20	0.40	−0.22	0.01	0.31	0.27
Object Use	0.02	−0.15	−0.07	0.08	0.53*	0.27
Total	0.37	0.08	−0.43*	−0.15	0.31	0.50*

Note:

^*p≤.05,

^**p≤.01