Table I.

Descriptive statistics of head motion (in units of pixels, each pixel has dimensions of 4 × 4 × 5 mm)

Tasks	Age group	Sex	N	Mean	STD
Prosody processing	Younger	Girl	52	0.496	0.343
		Boy	52	0.590	0.613
		Total	104	0.543	0.497
	Middle	Girl	60	0.353	0.246
		Boy	79	0.384	0.312
		Total	139	0.370	0.285
	Older	Girl	43	0.274	0.178
		Boy	37	0.371	0.219
		Total	80	0.319	0.202
	Total	Girl	155	0.379	0.281
		Boy	168	0.445	0.424
		Total	323	0.413	0.364
Story processing	Younger	Girl	52	0.390	0.259
		Boy	52	0.813	1.076
		Total	104	0.602	0.807
	Middle	Girl	60	0.341	0.274
		Boy	79	0.396	0.277
		Total	139	0.372	0.276
	Older	Girl	43	0.236	0.204
		Boy	37	0.354	0.262
		Total	80	0.290	0.239
	Total	Girl	155	0.328	0.257
		Boy	168	0.516	0.667
		Total	323	0.426	0.520
Word‐picture matching	Younger	Girl	52	0.330	0.187
		Boy	52	0.325	0.205
		Total	104	0.328	0.195
	Middle	Girl	60	0.308	0.197
		Boy	79	0.323	0.200
		Total	139	0.317	0.198
	Older	Girl	43	0.264	0.402
		Boy	37	0.251	0.123
		Total	80	0.258	0.304
	Total	Girl	155	0.303	0.267
		Boy	168	0.308	0.189
		Total	323	0.306	0.229
Verb generation	Younger	Girl	52	0.604	0.926
		Boy	52	0.413	0.202
		Total	104	0.509	0.673
	Middle	Girl	60	0.310	0.147
		Boy	79	0.451	0.550
		Total	139	0.390	0.430
	Older	Girl	43	0.226	0.155
		Boy	37	0.365	0.358
		Total	80	0.290	0.276
	Total	Girl	155	0.385	0.569
		Boy	168	0.420	0.427
		Total	323	0.403	0.500