Table 1.

Correlations of individual activity measures with their principal components

Activity measure	Principal component
	1	2	3	4	5	6
Ambulatory distance, novel open field	.86
Ambulatory distance, familiar open field	.80
Rearing frequency, familiar open field	.77
Rearing frequency, novel open field	.76
Velocity, light/dark	−.54
Voluntary time spent in light, light/dark		.91
Ambulatory distance, light/dark		.85
Latency to exit dark, light/dark		−.85
Rearing frequency, light/dark		.76
Rearing duration, novel open field			.87
Rearing duration, familiar open field			.81
Rearing duration, dark			.78
Rearing duration, light/dark			.56
Velocity, dark				−.84
Ambulatory distance, dark				.67
Rearing frequency, dark				.52
Velocity, novel open field					.92
Velocity, familiar open field						.93

Correlations with absolute value <.50 are omitted from table