Canadian Niagara Power Glass Slide - Sketch Showing Proposed Masonry Lining Near Portal of Tunnel

Drawing by consulting engineer dated October 19, 1901. Scale is noted as 1/4 inch = 1 foot.

Top-down and Bottom-up influences on ACC activation: Evaluation of a proposed model of the feedback-related negativity

The Feedback-Related Negativity (FRN) is thought to reflect the dopaminergic prediction error signal from the subcortical areas to the ACC (i.e., a bottom-up signal). Two studies were conducted in order to test a new model of FRN generation, which includes direct modulating influences of medial PFC (i.e., top-down signals) on the ACC at the time of the FRN. Study 1 examined the effects of one’s sense of control (top-down) and of informative cues (bottom-up) on the FRN measures. In Study 2, sense of control and instruction-based (top-down) and probability-based expectations (bottom-up) were manipulated to test the proposed model. The results suggest that any influences of medial PFC on the activity of the ACC that occur in the context of incentive tasks are not direct. The FRN was shown to be sensitive to salient stimulus characteristics. The results of this dissertation partially support the reinforcement learning theory, in that the FRN is a marker for prediction error signal from subcortical areas. However, the pattern of results outlined here suggests that prediction errors are based on salient stimulus characteristics and are not reward specific. A second goal of this dissertation was to examine whether ACC activity, measured through the FRN, is altered in individuals at-risk for problem-gambling behaviour (PG). Individuals in this group were more sensitive to the valence of the outcome in a gambling task compared to not at-risk individuals, suggesting that gambling contexts increase the sensitivity of the reward system to valence of the outcome in individuals at risk for PG. Furthermore, at-risk participants showed an increased sensitivity to reward characteristics and a decreased response to loss outcomes. This contrasts with those not at risk whose FRNs were sensitive to losses. As the results did not replicate previous research showing attenuated FRNs in pathological gamblers, it is likely that the size and time of the FRN does not change gradually with increasing risk of maladaptive behaviour. Instead, changes in ACC activity reflected by the FRN in general can be observed only after behaviour becomes clinically maladaptive or through comparison between different types of gain/loss outcomes.

Unsigned letter to Charles Stuart, clerk of the municipality of the township of Thorold regarding the proposed line of macadamized road from Hurst’s Bridge to Port Robinson

Unsigned letter to Charles Stuart, clerk of the municipality of the township of Thorold regarding the proposed line of macadamized road from Hurst’s Bridge to Port Robinson (1 ¼ pages, handwritten), May 9, 1855.

Notes on the proposed roadway

Notes on the proposed roadway (1 page, handwritten), n.d.

Plan of levels of marsh land on the line of the proposed ditch from Lyons Creek Culvert on the Welland Canal to lot no. 32 in the 2nd concession of Wainfleet

Plan of levels of marsh land on the line of the proposed ditch from Lyons Creek Culvert on the Welland Canal to lot no. 32 in the 2nd concession of Wainfleet (1 page, hand drawn), n.d.

Blueprint of proposed lily pond at DeVeaux Hall drawn by T. Wiley

Blueprint of proposed lily pond at DeVeaux Hall drawn by T. Wiley, Apr. 1916.

Map of the proposed canal through the district of Niagara and Gore to form a junction of Lake Erie and Ontario by the Grand River

Map, 55 cm. x 75 cm. (printed, coloured and mounted on a board). The map is of the proposed canal through the district of Niagara and Gore to form a junction of Lake Erie and Ontario by the Grand River compiled from the actual survey by order of the commissioners of internal navigation by James G. Chewett. James G. Chewett was Assistant Draftsman under the direction of Thomas Ridout, Surveyor General of the Province, n.d.