. Author manuscript; available in PMC: 2011 Mar 8.

Published in final edited form as: Psychol Aging. 2010 Dec;25(4):949–962. doi: 10.1037/a0020000

Table 3. Age Group Differences on Baseline and Dual Task Measures of Tracking Performance, Fluency, Grammatical Complexity, and Linguistic Content.

	Young Adults						Older Adults

	Baseline		Dual Task Conditions				Baseline		Dual Task Conditions
	Baseline		Moderate		Demanding		Baseline		Moderate		Demanding

	Mean	SE	Mean	SE	Mean	SE	Mean	SE	Mean	SE	Mean	SE
Performance
Time On Task	79.39^a	0.04	68.10	1.12	25.78	1.08	78.76^a	1.02	70.69	0.49	24.33	0.72
Error	3.72^a	0.02	4.17	0.06	8.34	0.07	3.66^a	0.05	3.82	0.02	7.94	0.03
Fluency
Speech rate	121.39	2.77	100.28	2.39	68.70	2.20	97.48	2.97	84.26	2.91	60.93	2.30
% with Fillers	55.68	3.21	24.51	1.34	21.19	1.24	5.59^a	0.61	5.40^a	0.39	5.48^a	0.49
% Grammatical	51.70^a	0.01	43.35	0.01	39.43	0.01	49.77^a,b	0.01	45.75^b	0.01	39.58	0.01
Mean Length Utterance	10.83	0.15	9.26	0.13	7.14	0.16	9.04^a	0.25	9.03^a	0.27	7.67	0.25
Complexity
Developmental Level	3.91	0.07	3.25	0.09	1.45	0.10	3.50^a	0.10	3.29^a	0.10	1.33	0.10
Grammatical Index	4.05	0.06	2.86	0.03	2. 12	0.04	3.99^a	0.06	3.55^a	0.04	3.11	0.04
Content
Propositional Density	51.57^a	0.03	61.57	0.04	35.91	0.06	53.82^a,b	0.03	53.61^b	0.03	38.68	0.03
Coherence Index	5.25^a	0.11	4.92	0.14	2.29	0.16	3.59^a,b	0.14	3.51^b	0.16	1.37	0.13
Type Token Ratio	0.35^a	.01	.60	.01	.51	.07	.64 ^a,b	.01	.66 ^b	.01	.65^b	.01

NOTE: Within age group, entries sharing the same superscript do not differ at p < .05; between age groups, baselines sharing the same superscripts do not differ at p < .05.