What happens in the first 200 ms of word reading : ERP studies on visual word recognition with top-down and bottom-up approaches /

In this thesis, three main questions were addressed using event-related potentials (ERPs): (1) the timing of lexical semantic access, (2) the influence of "top-down" processes on visual word processing, and (3) the influence of "bottom-up" factors on visual word processing. The timing of lexical semantic access was investigated in two studies using different designs. In Study 1,14 participants completed two tasks: a standard lexical decision (LD) task which required a word/nonword decision to each target stimulus, and a semantically primed version (LS) of it using the same category of words (e.g., animal) within each block following which participants made a category judgment. In Study 2, another 12 participants performed a standard semantic priming task, where target stimulus words (e.g., nurse) could be either semantically related or unrelated to their primes (e.g., doctor, tree) but the order of presentation was randomized. We found evidence in both ERP studies that lexical semantic access might occur early within the first 200 ms (at about 170 ms for Study 1 and at about 160 ms for Study 2). Our results were consistent with more recent ERP and eye-tracking studies and are in contrast with the traditional research focus on the N400 component. "Top-down" processes, such as a person's expectation and strategic decisions, were possible in Study 1 because of the blocked design, but they were not for Study 2 with a randomized design. Comparing results from two studies, we found that visual word processing could be affected by a person's expectation and the effect occurred early at a sensory/perceptual stage: a semantic task effect in the PI component at about 100 ms in the ERP was found in Study 1 , but not in Study 2. Furthermore, we found that such "top-down" influence on visual word processing might be mediated through separate mechanisms depending on whether the stimulus was a word or a nonword. "Bottom-up" factors involve inherent characteristics of particular words, such as bigram frequency (the total frequency of two-letter combinations of a word), word frequency (the frequency of the written form of a word), and neighborhood density (the number of words that can be generated by changing one letter of an original word or nonword). A bigram frequency effect was found when comparing the results from Studies 1 and 2, but it was examined more closely in Study 3. Fourteen participants performed a similar standard lexical decision task but the words and nonwords were selected systematically to provide a greater range in the aforementioned factors. As a result, a total of 18 word conditions were created with 18 nonword conditions matched on neighborhood density and neighborhood frequency. Using multiple regression analyses, we foimd that the PI amplitude was significantly related to bigram frequency for both words and nonwords, consistent with results from Studies 1 and 2. In addition, word frequency and neighborhood frequency were also able to influence the PI amplitude separately for words and for nonwords and there appeared to be a spatial dissociation between the two effects: for words, the word frequency effect in PI was found at the left electrode site; for nonwords, the neighborhood frequency effect in PI was fovind at the right elecfrode site. The implications of otir findings are discussed.

Reflections upon the late correspondence between Mr. Secretary Smith, and Francis James Jackson, esq., Minister Plenipotentiary of His Britannic Majesty /

Originally published in the Federal Republican of Baltimore.

David William Smith House correspondence, 1798 [transcription]

The correspondence from D.W. [David William] Smith to President Peter Russell regarding Smith’s desire to sell a certain piece of property in Newark (now Niagara-on-the-Lake, Ont.) to be used as a location for a common grammar school. The notice gives a description of the building situated on the property as being adaptable for the use of a school. The Board of Survey convened in December 1798 to examine Smith’s property and gave an appropriate valuation of the properties and buildings Smith was offering for sale. Smith was the deputy surveyor general of lands for Upper Canada.

John Smith, M.P fonds, 1930, 1949-1950, 1954, 1957-1962, n.d.

John Smith (1894-1977), son of Daniel Smith and Annie Douglas was a native of Scotland, immigrating to Canada in 1913. He first worked as a coach builder, then as a carpenter, finally developing his own contracting business. During WWI he served overseas with the 10th Battery, RCA as a sergeant. In 1924 Smith married Jean Wood, and together they had a daughter Irene (Hugh Langley). Smith first entered politics in 1940 serving as an alderman for the next 11 years. In 1954 he was elected mayor of the city of St. Catharines, and was twice returned to office by acclamation, serving until 1957 when he successfully ran as the Progressive Conservative candidate representing Lincoln County in the federal election. He won the election by a 10 000 vote majority. He served his constituents in Ottawa until he was defeated in the 1962 election. After leaving politics Mr. Smith was active in his community. He spearheaded the establishment of the St. Catharines Museum, and then was appointed its first director in 1966, serving in that capacity until 1972. He was an active member of the board of governors of the St. Catharines General Hospital and a life member and former president of the Lincoln County Humane Society. In 1971 he was voted Citizen of the Year for the city of St. Catharines. John Smith died on February 8, 1977 and was buried at Victoria Lawn Cemetery. Source: The St. Catharines Standard, February 9, 1977, page 1

Welland Canal Survey of Lands Smith Shotwell, 1834

Survey map and description of Smith Shotwell's land created by The Welland Canal Company. Included is a written description of the land along with a drawing of the land. Noteable features include; the Welland River, road. The deed for the land is dated October 14, 1834. The land totals 10 acres, 3 roads and 10 perches. Surveyor notes are seen in pencil on the map.

Reflections upon the late correspondence between Mr. Secretary Smith, and Francis James Jackson, esq., Minister Plenipotentiary of His Britannic Majesty

Originally published in the Federal Republican of Baltimore. Printed by Benjamin Edes

John Adams Smith letter, Jan. 14, 1813

Transcript: New York Jan. 14. 1813. My dear uncle, I had nearly concluded to have made my [jaunt?] earlier than I had mentioned in my last letter to you, for Swartout had intended to have written by me to Father & yourself; having [Louisa?] concluded not so soon to depart he sends me his letters which I forward in mail, I shall hope to have letters from home soon, it is a great pleasure to hear from any of you. I said last week in Hollands letter mentioning [bladeworth?] account, I have explained to him. It is a mistake about me agreeing to pay Mr. [Dening?] [their?] account. Caroline mentions to me your jaunt to [Sophia?], but I regret our friend there should be unpleasantly situated. I have not yet seen Col. Willett but will see him as mentioned. I have neglected to go there for some time which has been remiss in me. We have nothing new I believe unless it be that Armstrong & Jones of Philadelphia have been nominated as Secretarys of War & the Navy & [cer?] this in all probability may be appointed. There may be room for speculation, but perhaps it is not probable that Canada will be ceded to American Valor in the year 1813. There is a Bill before congress by which it may be made penal to enter on board American vessels, either British subjects or naturalized Americans, which it is presoomed by many will [spon?] the accommodation of Peace – may be yes may be no – the proof of the pudding is in the eating of it. I imagine pacification is not so near at hand although it is much to be desired. Whatever might be for the honor & prosperity of the Country I would strenuously advocate, aloof from partial & party considerations. We have not a word as yet what the Council at Albany may be thinking of as yet. I suppose these things will come in time, perhaps untimely to many. I desire for the present not to be found among the untimely. I am your sincerely, with love to all. John Adams Smith

Photograph - Helen Stanley Smith, age 9

A photograph of Helen Stanley Smith at age 9 (1913). There are two other poses of Helen in the same photography session available in the collection.

Communion Certificate - Helen Stanley Smith, 1919

A communion certificate for Helen Stanley Smith dated 31 January, 1919. The certificate is signed by George H. Smith D.D. (minister).

Photograph - Colin Campbell and Helen Stanley Smith with Judge Campbell, 1910.

A photograph of Colin Campbell and Helen Stanley Smith sitting in a horse buggy in front of the Campbell home. Judge Campbell is saddled on a horse behind the buggy. There are two other unidentified females sitting on the porch of the Campbell home on Church Street.

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.

Map of part of the “Smith & Kerby” tract in the City of Brantford, County of Brant, Ontario, no date.

An abstract map of a part of the “Smith & Kerby tract” lying within the City of Brantford, County of Brant, Ontario. There is no date on the map. The map shows parts from McMurray’s Survey, Mrs. G.S. Wilkes Survey, and the Howell Survey.

Probate of Last Will and Testament - William Smith

Probate of Last Will and Testament of William Smith of the township of Lincoln. Mr. Smith was a farmer. His goods and chattels are left to his children and grandchildren. The document was registered May 9, 1865 - instrument no. 15383 and the original date of the document is January 20, 1856.

Indenture - Land sold by Hart Smith of Lincoln County to James Fields of Newark in Oxford County

Indenture regarding land sold by Hart Smith of Lincoln County to James Fields of Newark in Oxford County, First Concession, Lot no. 3. October 11, 1797.