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101.
A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented
as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly
and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor,
but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference
engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by
the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition,
the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance
for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the
regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made
for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences
in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older
adults as well as from studies of depressed and age-matched control groups. 相似文献
102.
The safety and efficacy of medications for preventive treatment of migraine is the subject of current concern and investigation in health care. Two single-center, double-blind, placebo-controlled studies were conducted to evaluate the efficacy and safety of topiramate for migraine prophylaxis. Seventy patients with a diagnosis of migraine were randomly assigned to topiramate-treated and placebo groups. The studies consisted of a 4-week baseline phase, a 6-8 week titration, and 8-12 weeks of maintenance. Topiramate was titrated from an initial dose of 25 mg/day to a target dose of 100 mg BID. The primary efficacy measure, the mean 28-day migraine frequency, was lower in topiramate-treated patients than in the placebo group (3.2 versus 3.8, P=.001). Similarly, topiramate treatment resulted in a significantly greater mean reduction in migraine frequency than did placebo (1.55 versus 0.47, P=.001) and a significantly higher responder rate (35.3% versus 8.3%, P=.008). Paresthesia was the most common side effect reported with topiramate treatment. Other topiramate-associated adverse events included altered taste, memory impairment, diarrhea, and appetite suppression/weight loss. The rates of discontinuation were similar for the topiramate group (n=10) and the placebo group (n=8). These results suggest that topiramate is effective and well tolerated in the preventive treatment of migraine headaches. 相似文献
103.
Christopher?A.?KurbyEmail author Katja?Wiemer-Hastings Nagasai?Ganduri Joseph?P.?Magliano Keith?K.?Millis Danielle?S.?McNamara 《Behavior research methods》2003,35(2):244-250
The effectiveness of a domain-specific latent semantic analysis (LSA) in assessing reading strategies was examined. Students were given self-explanation reading training (SERT) and asked to think aloud after each sentence in a science text. Novice and expert human raters and two LSA spaces (general reading, science) rated the similarity of each think-aloud protocol to benchmarks representing three different reading strategies (minimal, local, and global). The science LSA space correlated highly with human judgments, and more highly than did the general reading space. Also, cosines from the science LSA spaces can distinguish between different levels of semantic similarity, but may have trouble in distinguishing local processing protocols. Thus, a domain-specific LSA space is advantageous regardless of the size of the space. The results are discussedin the context of applying the science LSA to a computer-based version of SERT that gives online feedback based on LSA cosines. 相似文献
104.
Authors tested the validity of the Peabody Picture Vocabulary Test-Third Edition (PPVT-III) as a screening measure for intelligence and achievement. The PPVT-III and Kaufman Assessment Battery for Children (KABC) were administered to 416 African American children of low socioeconomic status in a counterbalanced design. Results indicated that the PPVT-III correlated .58 with the KABC Mental Processing Composite (MPC) score; however, participants scored significantly lower (M = 8.3 points) on the PPVT-III than on the MPC. Although receiver operating characteristic (ROC) analyses supported the use of the PPVT-III as a valid intellectual and achievement screener, the selection of a single cutoff score for the PPVT-III was problematic. The purpose of the screening program should guide selection of a cutoff score for the PPVT-III. 相似文献
105.
The use of diagrams in analogical problem solving 总被引:2,自引:0,他引:2
In four experiments, we examined the impact of perceptual properties on the effectiveness of diagrams in analogical problem solving, using variants of convergence diagrams as source analogues for the radiation problem. Static diagrams representing the initial problematic state (one large line directed at a target) and the final state for a convergence solution (multiple converging lines) were not accessed spontaneously but were often used successfully once a hint to consider the diagram had been provided. The inaccessibility of static diagrams was not alleviated by adding additional diagrams to represent intermediate states (Experiment 1), but spontaneous access was improved by augmenting static diagrams with a verbal statement of the convergence principle (Experiment 3). Spontaneous retrieval and noticing were increased markedly by animating displays representing converging forces and thereby encouraging encoding of the lines as indicating motion toward a target (Experiments 3 and 4). However, neither static nor animated diagrams were effective when the arrows were reversed to imply divergence rather than convergence (Experiment 2). The results indicate that when animation encourages the interpretation of a diagram as a helpful source analogue, it can greatly enhance analogical transfer. 相似文献
106.
Global context effects on processing lexically ambiguous words: Evidence from eye fixations 总被引:2,自引:0,他引:2
Readers' eye movements were monitored as they read biased ambiguous target words in the context of a short paragraph. Two aspects of context were manipulated. The global context was presented in the topic sentence of the paragraph and instantiated either the dominant or the subordinate meaning of biased ambiguous target words (those with highly dominant meanings). Local contextual information either preceded or followed the target word and was always consistent with the subordinate interpretation. Consistent with prior research, we obtained a subordinate bias effect wherein readers looked longer at the ambiguous words than control words when the preceding context instantiated the subordinate meaning. More importantly, the magnitude of the subordinate bias effect was the same when global context alone, local context alone, or local and global context combined were consistent with the subordinate meaning of the ambiguous word. The results of this study indicate that global contextual information (1) has an immediate impact on lexical ambiguity resolution when no local disambiguating information is available, (2) has no additional effect when it is consistent with local information, but (3) does have a slightly delayed effect when inconsistent with local information. 相似文献
107.
108.
Oudejans RR Michaels CF Bakker FC Davids K 《Journal of experimental psychology. Human perception and performance》1999,25(2):531-542
To catch a lofted ball, a catcher must pick up information that guides locomotion to where the ball will land. The acceleration of tangent of the elevation angle of the ball (AT) has received empirical support as a possible source of this information. Little, however, has been said about how the information is detected. Do catchers fixate on a stationary point, or do they track the ball with their gaze? Experiment 1 revealed that catchers use eye and head movements to track the ball. This means that if AT is picked up retinally, it must be done by means of background motion. Alternatively, AT could be picked up by extraretinal mechanisms, such as the vestibular and proprioceptive systems. In Experiment 2, catchers reliably ran to intercept luminous fly balls in the dark, that is, in absence of a visual background, under both binocular and monocular viewing conditions. This indicates that the optical information is not detected by a retinal mechanism alone. 相似文献
109.
Thiede KW 《Psychonomic bulletin & review》1999,6(4):662-667
Theory suggests that accuracy of metacognitive monitoring and self-regulation of study will affect test performance, but there is little empirical evidence linking these variables. I examined the relation among these variables in a multitrial learning task. Regression analyses showed that monitoring accuracy and self-regulation were reliably related to test performance--greater monitoring accuracy and more effective self-regulation were associated with greater test performance. These analyses were contrasted with analyses typically conducted in previous research, to show the importance of using a multitrial learning task and of attending to the theoretically based causal relation among variables when evaluating how monitoring accuracy and self-regulation are related to test performance. The results of this investigation may help to explain why previous research has failed to link these variables. 相似文献
110.
In their reply to Binder and Rayner (1998), Kellas and Vu (1999) raised questions about the criteria we used to exclude items from the Kellas, Martin, Yehling, Herman, and Vu (1995) stimulus set. In this reply, we further document these criteria and also address the issue of local versus published norms. We continue to believe that the stimulus set used by Kellas et al. (1995) was problematic. We also address the issue of strength of context, a concept used in earlier research that dealt with the subordinate bias effect. We argue that the contexts used by Kellas et al. (1995) were no stronger than the contexts previously used that established this effect. Therefore, we continue to think that our finding that context does not eliminate the subordinate bias effect is valid. 相似文献