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.

Marketing Brock University in the 1980's: assessing freshman student feedback in strategic planning approach

Universities have entered a period of rapid change and upheaval due to an external environment beyond their control which includes shifting demographic patterns, accelerating technology, funding shortages, and keener competition for students. Strategic planning, a comprehensive vision which challenges universities to take bold and creative measures to meet the threats and opportunities of the future, is an institutional imperative in the 1980's. This paper examines freshman student feedback in an effort to incorporate this important element into a strategic plan for Brock University, a small, predominantly liberal arts university in St. Catharines, Ontario. The study was designed to provide information on the characteristics of the 1985-86 pool of freshman registrants: their attitudes towards Brock's recruitment measures, their general university priorities, and their influences in regard to university selection (along with other demographical and attitudinal data). A survey involving fixed-alternative questions of a subjective and objective nature was administered in two large freshman classes at Brock in which a broad cross-section of academic programs was anticipated. Computer analysis of the data for the 357 respondents included total raw frequencies and rounded percentages, as well as subgroup cross-tabulation by geographic home area of respondent, academic major, and high school graduating average. The four directional hypotheses put forward were all substantiatied by the survey data, indicating that 1) the university's current recruitment program had been a positive influence during their university search 2) parents were the most influential group in the students' decisions related to university 3) respondents viewed institutional reputation as less of a priority than an enjoyable university lifestyle in a personal learning atmosphere 4) students had a decided preference for co-operative study and internship programs. Strategic planning recommendations included a reduction in the faculty/student ratio through faculty hirings to restore the close rapport between professors and students, increased recruitment presentations in Ontario high schools to enlarge the applicant pool, creation of an Office of Co-operative Study and Internship Programs, institutional emphasis on a "customer orientation", and an extension of research into student demographics and attitudinal data.

Drop-In Clinics for Environmental Studies Students

The delivery of library instruction to students in those areas of the sciences and the social sciences dealing with biology and the environment has a long history (Bowden & Di Benedetto 2001; Kutner 2000; Kutner & Danks 2007; Sapp 2006; Sinn 1998). Often these instruction sessions take the form of a one hour lecture or workshop at the start of a semester before the students have begun their projects or papers. This "one-shot" approach, though popular, has its limitations. It may not be offered at a time when the students will actually start making use of library resources, it may not be tied very specifically to a particular assignment, or it may be too general in nature to be of much use to students later on when they need to look at particular topics in much more depth than can be addressed in one such session. The following article describes another approach: the strategic use of drop-in clinics as a method of instruction in which the students themselves determine how the instruction proceeds.