Electrophysiology of Oculomotor Delayed Response Tasks: A Model for the Maturation of Visual-Spatial Working Memory Networks

In the literature, persistent neural activity over frontal and parietal areas during the delay period of oculomotor delayed response (ODR) tasks has been interpreted as an active representation of task relevant information and response preparation. Following a recent ERP study (Tekok-Kilic, Tays, & Tkach, 2011 ) that reported task related slow wave differences over frontal and parietal sites during the delay periods of three ODR tasks, the present investigation explored developmental differences in young adults and adolescents during the same ODR tasks using 128-channel dense electrode array methodology and source localization. This exploratory study showed that neural functioning underlying visual-spatial WM differed between age groups in the Match condition. More specifically, this difference is localized anteriorly during the late delay period. Given the protracted maturation of the frontal lobes, the observed variation at the frontal site may indicate that adolescents and young adults may recruit frontal-parietal resources differently.

Erie & Niagara Railway Collection, 1864-1884

William Alexander Thomson (1816-1878) was a promoter and developer of railway systems in western Ontario. He incorporated the Fort Erie Railroad Company in 1857, purchased the Erie and Ontario Railroad in 1863, and incorporated the Erie and Niagara Extension Railway Company in 1868 (later renamed the Canada Southern Railway). Thomson was also elected to the House of Commons for Welland in 1872, and re-elected in 1874. He was known for his support of public management of the currency and is seen as a pioneer advocate of government monetary policy. He was also an advocate of radical agrarian economic doctrine, believing that Canadian laws favoured mercantile interests over those of the producers of goods, and that this hindered national development.

Age-Related Changes in Visual Spatial Working Memory Cognits: Frontal-Parietal EEG Coherence During Delay

This study explored changes in scalp electrophysiology across two Working Memory (WM) tasks and two age groups. Continuous electroencephalography (EEG) was recorded from 18 healthy adults (18-34 years) and 12 healthy adolescents (14-17) during the performance of two Oculomotor Delayed Response (ODR) WM tasks; (i.e. eye movements were the metric of motor response). Delay-period, EEG data in the alpha frequency was sampled from anterior and parietal scalp sites to achieve a general measure of frontal and parietal activity, respectively. Frontal-parietal, alpha coherence was calculated for each participant for each ODR-WM task. Coherence significantly decreased in adults moving across the two ODR tasks, whereas, coherence significantly increased in adolescents moving across the two ODR tasks. The effects of task in the adolescent and adult groups were large and medium, respectively. Within the limits of this study, the results provide empirical support that WM development during adolescence include complex, qualitative, change.

The role of retinoic acid in long-term memory formation and synaptic plasticity in the mollusc Lymnaea stagnalis

The active metabolite of vitamin A, retinoic acid (RA), is involved in memory formation and hippocampal plasticity in vertebrates. A similar role for retinoid signaling in learning and memory formation has not previously been examined in an invertebrate species. However, the conservation of retinoid signaling between vertebrates and invertebrates is supported by the presence of retinoid signaling machinery in invertebrates. For example, in the mollusc Lymnaea stagnalis the metabolic enzymes and retinoid receptors have been cloned from the CNS. In this study I demonstrated that impairing retinoid signaling in Lymnaea by either inhibiting RALDH activity or using retinoid receptor antagonists, prevented the formation of long-term memory (LTM). However, learning and intermediate-term memory were not affected. An additional finding was that exposure to constant darkness (due to the light-sensitive nature of RA) itself enhanced memory formation. This memory-promoting effect of darkness was sufficient to overcome the inhibitory effects of RALDH inhibition, but not that of a retinoid receptor antagonist, suggesting that environmental light conditions may influence retinoid signaling. Since RA also influences synaptic plasticity underlying hippocampal-dependent memory formation, I also examined whether RA would act in a trophic manner to influence synapse formation and/or synaptic transmission between invertebrate neurons. However, I found no evidence to support an effect of RA on post-tetanic potentiation of a chemical synapse. Retinoic acid did, however, reduce transmission at electrical synapses in a cell-specific manner. Overall, these studies provide the first evidence for a role of RA in the formation of implicit long-term memories in an invertebrate species and suggest that the role of retinoid signaling in memory formation has an ancient origin.

Photograph - Baie Comeau, welding railway line

A photograph of men working to weld the railway line at Baie Comeau. The caption reads, "Welding railway line as rails joined immediately behind the temporary staff house".

Photograph - Baie Comeau, Last Railway Spike

A photograph of the "last spike in the Baie Comeau railway. Photo shows, left to right; A.I.Cunningham, managing engineer of the Ontario Paper Company driving the spike: V.G. Younghusband, vice president of the Foundation Company of Canada; R.W. Shaver, construction manager for the paper company; K.W. Bash, general superintendent, Foundation Company; and His Lordship the Bishop of Quebec.

Photograph - Baie Comeau, Railway line

A photograph with the caption "Railway line, on trestle, immediately behind millsite".

Working Memory in the Junior/Intermediate Classroom

This research project explored the connection between working memory and children’s learning. The project created a resource titled Working Memory Strategies for the Junior/ Intermediate Educator: A Handbook based on a literature review, the deconstruction of theoretical and empirical studies, teacher resources, and findings from a needs assessment completed by teachers that together show there is insufficient support for teachers working with students who have deficits in working memory along with other common classroom learning disabilities. As learning disabilities become more common in the classroom that increasingly affect working memory in a majority of cases, teachers must be prepared not only to address specific symptoms of the conditions, but also to help students learn how to navigate and become aware of their working memory ability. The handbook thus was developed as a useful resource for teachers looking to expand their knowledge about how learning occurs. A needs assessment completed by junior and intermediate division teachers in Ontario helped determine what educators found most important for inclusion in the handbook, and the same teachers were offered the opportunity to review the completed handbook. Teacher participants provided constructive feedback and indicated that the handbook would be a valuable resource for them and their colleagues when working with students who have working memory issues. It was suggested that the handbook would be useful when creating students’ Individual Education Plans and that the assessment checklist included in the handbook would be an excellent resource for teachers collecting data regarding students’ working memory and ability to learn.

Indenture of Release to Woodstock and Lake Erie Railway from Executors of Samuel Zimmerman

Indenture of release regarding a loan of 12, 500 pounds which Samuel Zimmerman (deceased) is said to have lent and advanced to the Woodstock and Lake Erie Railway and Harbour Company. This is put forward by the executors who include: Joseph A. Woodruff, Richard Woodruff, John L. Ranney and Richard Miller. This document releases and exonerates the Railway Company from any debts to the executors. [The outside of the document says 1857, but the actual date is Feb. 10, 1858].

Indenture of Release of All Existing Contracts and Agreements with Woodstock and Lake Erie Railway Co.

Indenture of release stating that all existing contracts and agreements made by the Woodstock and Lake Erie Railway Co. are cancelled. This release was between the executors of Samuel Zimmerman's will and the Woodstock and Lake Erie Railway Co. February 10, 1858.

Indenture between The St. Catharines and Niagara Central Railway Company and Samuel DeVeaux Woodruff

Indenture of deed of land situate between The St. Catharines and Niagara Central Railway Company and Samuel DeVeaux Woodruff of St. Catharines regarding parts of Lots no. 12 and 13 30 in the 8th Concession of the Township of Grantham. This was registered at Merritton on Feb. 2, 1891 – instrument no. 1021, Aug. 16, 1890.

Presentation from the Office of Macdonald and Rykert regarding the Case of O'Connor vs. the Great Western Railway Co.

Presentation from the Office of Macdonald and Rykert regarding the Case of O’Connor vs. the Great Western Railway Co. This is a handwritten, 9 ½ page double sided document). Some of the witnesses for the plaintiff included: Robert Johnson, John Ryder, Edward Duffy, Gilbert Gregory, John Cutter, James Patterson, Samuel Rush and Francis Bigger, among others. They claimed that the Great Western Railway Co. was destroying their land. Jacob Dittrick claimed that the culverts were not large enough to carry off water. Mr. Jackson noticed injury to his flats. Wild grass was destroying the bottom grass, May 6, 1836.

Clippings - Road Allowances, Lock 2 Bridge, Toronto Railway Company, St. Davids' History

Clipping regarding the original road allowance which was part of Mr. Woodruff’s property, n.d. Clipping regarding the Lock 2 Bridge. This is a letter to the editor of the Journal from Calvin Phelps of Lockport, Nov. 13, 1889. Clipping entitled “Settled beyond a Dispute”: a letter to the Editor of the Star from J. G. Currie regarding the road allowance in the 5th Concession of Grantham, Nov. 16, 1889. Clipping entitled “That Old Road Allowance” which is a rebuttal to Mr. Currie’s letter, [1889] 2 newspaper clippings regarding: “Reg. vs. Toronto Railway Company”. These 2 articles are glued to a piece of paper. Beneath the newspaper articles is the name M. Chambers, Nov. 18, 1898. Notes regarding the clippings are enclosed with the articles. These notes and written on the back of “Pattison, Collier and Shaw Barristers, Solicitors, Etc.” stationary (notes are 2 pages, handwritten), Nov. 18, 1898. Clipping entitled “History on the Site: St. Davids’ Students Learn Lessons where Events Occurred” (2 copies), n.d.

Michigan Central Railway to S.D. Woodruff

Letter from the Michigan Central Railway to S.D. Woodruff regarding the construction of a fence, June 16, 1883.

Letter to George Rykert (president of the Port Dalhousie and Thorold Railway), engineer from William Danforth, civil engineer

Letter to George Rykert (president of the Port Dalhousie and Thorold Railway), engineer from William Danforth, civil engineer in which he states that the preliminary survey has been made between Port Dalhousie and Centreville at which point it may intersect with the Great Western Railway. The estimate is included (2 pages, handwritten), July 25, 1853.