Autonomic and Electrophysiological Correlates of Cognitive Control in Aging

This thesis tested a model of neurovisceral integration (Thayer & Lane, 2001) wherein parasympathetic autonomic regulation is considered to play a central role in cognitive control. We asked whether respiratory sinus arrhythmia (RSA), a parasympathetic index, and cardiac workload (rate pressure product, RPP) would influence cognition and whether this would change with age. Cognitive control was measured behaviourally and electrophysiologically through the error-related negativity (ERN) and error positivity (Pe). The ERN and Pe are thought to be generated by the anterior cingulate cortex (ACC), a region involved in regulating cognitive and autonomic control and susceptible to age-related change. In Study 1, older and younger adults completed a working memory Go/NoGo task. Although RSA did not relate to performance, higher pre-task RPP was associated with poorer NoGo performance among older adults. Relations between ERN/Pe and accuracy were indirect and more evident in younger adults. Thus, Study 1 supported the link between cognition and autonomic activity, specifically, cardiac workload in older adults. In Study 2, we included younger adults and manipulated a Stroop task to clarify conditions under which associations between RSA and performance will likely emerge. We varied task parameters to allow for proactive versus reactive strategies, and motivation was increased via financial incentive. Pre-task RSA predicted accuracy when response contingencies required maintenance of a specific item in memory. Thus, RSA was most relevant when performance required proactive control, a metabolically costly strategy that would presumably be more reliant on autonomic flexibility. In Study 3, we included older adults and examined RSA and proactive control in an additive factors framework. We maintained the incentive and measured fitness. Higher pre-task RSA among older adults was associated with greater accuracy when proactive control was needed most. Conversely, performance of young women was consistently associated with fitness. Relations between ERN/Pe and accuracy were modest; however, isolating ACC activity via independent component analysis allowed for more associations with accuracy to emerge in younger adults. Thus, performance in both groups appeared to be differentially dependent on RSA and ACC activation. Altogether, these data are consistent with a neurovisceral integration model in the context of cognitive control.

Port Dalhousie and the Thorold Railway pay roll for the months of June, July, August and September, 1854

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of June, July, August and September, 1854.

Port Dalhousie and the Thorold Railway pay roll the months of April and May, 1854, signed by S.D. Woodruff, May 31, 1854

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of April and May, 1854, signed by S.D. Woodruff, May 31, 1854.

Port Dalhousie and the Thorold Railway pay roll for the months of June, July, August and September, 1854, signed by S.D. Woodruff, Sept. 30, 1854

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of June, July, August and September, 1854, signed by S.D. Woodruff, Sept. 30, 1854.

Port Dalhousie and the Thorold Railway pay roll for the months of October, November and December, 1854

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of October, November and December, 1854.

Port Dalhousie and the Thorold Railway pay roll for the months of October, November and December, 1854, signed by S.D. Woodruff, Jan. 8, 1855

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of October, November and December, 1854, signed by S.D. Woodruff, Jan. 8, 1855.

Port Dalhousie and the Thorold Railway pay roll for the months of January and February, 1855

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of January and February, 1855.

Port Dalhousie and the Thorold Railway pay roll for the months of October, January, February and March, 1855, signed by S.D. Woodruff, Mar. 22, 1855

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of October, January, February and March, 1855, signed by S.D. Woodruff, Mar. 22, 1855.

Port Dalhousie and the Thorold Railway pay roll for the months of April and May, 1855, signed by S.D. Woodruff, June 13, 1855

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of April and May, 1855, signed by S.D. Woodruff, June 13, 1855.

Port Dalhousie and the Thorold Railway pay roll for the months of June, July and August, 1855, signed by S.D. Woodruff. There is an envelope included with this document, Aug. 21, 1855

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of June, July and August, 1855, signed by S.D. Woodruff. There is an envelope included with this document, Aug. 21, 1855.

Port Dalhousie and the Thorold Railway pay roll for the months of March, April and May, 1856

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of March, April and May, 1856.

Port Dalhousie and the Thorold Railway pay roll for the months of March, April and May, 1856, signed by S.D. Woodruff, June 3, 1856

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of March, April and May, 1856, signed by S.D. Woodruff, June 3, 1856.

Port Dalhousie and the Thorold Railway pay roll for the months of June, July and August, 1856, signed by S.D. Woodruff, Sept. 2, 1856

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of June, July and August, 1856, signed by S.D. Woodruff, Sept. 2, 1856.