The Cognitive Demands of Gait Retraining in Runners: An EEG Study

Abstract

High impact forces during running have been associated with tibial stress injuries. Previous research has demonstrated increasing step rate will decrease impact forces during running. However, no research has determined the cognitive demand of gait retraining. The primary purpose was to determine the cognitive demand and effectiveness of field-based gait retraining. We hypothesized that in-field gait retraining would alter running mechanics without increasing cognitive workload as measured by EEG following learning. Runners with a history of tibial injury completed a gait retraining protocol which included a baseline run, retraining phase, practice phase, and re-assessment following retraining protocol. Results demonstrated an increase in the theta, beta, and gamma power within prefrontal cortex during new learning and corresponding return to baseline following skill acquisition and changes across alpha, beta, gamma, mu, and theta in the motor cortex (p < .05). In the midline superior parietal cortex, spectral power was greater for theta activity during new learning with a corresponding alpha suppression. Overall, the results demonstrated the use of EEG as an effective tool to measure cognitive demand for implicit motor learning and the effectiveness of in-field gait retraining.     

In support of selective rehearsal: Double-item presentation in item-method directed forgetting

Psychonomic Bulletin & Review - Despite the substantial evidence highlighting the role of selective rehearsal in item-method directed forgetting, recent work has suggested that forgetting may...     

Logistic growth curve analysis in associative learning data

We propose an alternative statistical method, logistic growth curve analysis, for the analysis of associative learning data with two or more comparison groups. Logistic growth curve analysis is more sensitive and easier to interpret than previously published methods such as χ² or ANOVA, which require the data to be collapsed into individual total scores or proportion of responses over time. Additionally, this type of analysis better fits the typical graphical representation of associative learning data. An analysis is presented where associative learning data from honeybees are analyzed using the three techniques, and the accessibility and power of the logistic growth curve analysis is highlighted. Accepted after revision: 14 November 2000 Electronic Publication     

Conceptual structure and the structure of concepts: a distributed account of category-specific deficits

We present a new account of the fine-grained structure of semantic categories derived from neuropsychological, behavioral, and developmental data. The account places theoretical emphasis on the functions of the referents of concepts. We claim (i) that the distinctiveness of functional features correlated with perceptual features varies across semantic domains; and (ii) that category structure emerges from the complex interaction of these variables. The representational assumptions that follow from these claims make strong predictions about what types of semantic information are preserved in patients showing category-specific deficits following brain damage. These claims are illustrated with a connectionist simulation which, when damaged, shows patterns of preservation of distinctive and shared functional and perceptual information which varies across semantic domains. The data model both dissociations between knowledge for artifacts and for living things and recent neuropsychological evidence concerning the robustness of functional information in the representation of concepts.     

Replication of the factor structure of the Wechsler Adult Intelligence Scale--Third Edition with a Canadian sample

Exploratory and confirmatory factor analyses of the subtests of the Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997b) were conducted on a stratified sample of Canadian adults (n = 718). As was previously demonstrated for the children's version of this scale, the factor model of the American standardization sample was replicated across this Canadian national sample. Results of the factor analyses confirmed the presence of the 4 WAIS-III factors: Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed.     

Real-time comprehension processes in agrammatism: A case study

The ability of an agrammatic patient to construct structural syntactic and interpretative representations on-line was tested in two experiments. The first focused on global representations spanning an entire utterance, while the second examined lexical syntactic and semantic constraints on verb-argument relations. An off-line version of the second experiment was also carried out. There were two major findings. First, the patient could construct a semantic, but not syntactic, representation of an utterance. Second, he was much more dependent than normal upon pragmatic information. These results are discussed with respect to current claims about the nature of agrammatic comprehension deficits.     

SUPERORDINATE IDENTIFICATION, SUBGROUP IDENTIFICATION, AND JUSTICE CONCERNS:

Abstract— The diversity of American society raises concerns about whether authorities can maintain social cohesion amid competing interests and values The group-value model of justice suggests that authorities function more effectively when they are perceived as fair (e g, benevolent, neutral, and respectful) However, such relational evaluations may be effective only if authorities represent a group with which people identify In a diverse society, subgroup memberships may assume special importance People who identify predominantly with a subgroup may focus on instrumental issues when evaluating a superordinate-group authority, and conflicts with that authority may escalate if those people do not receive favorable outcomes Results indicate that subgroup identification creates problems for authorities only when people have strong subgroup subgroup identification and weak superordinate-group identification As long as people identify strongly with the superordinate group, even if they also identify strongly with their subgroup, relational issues will dominate reactions to authorities     

Tactual picture identification by blind and sighted people: Effects of providing categorical information

Four experiments examined the influence of categorical information and visual experience on the identification of tangible pictures, produced with a raised-line drawing kit. In Experiment 1, prior categorical information aided the accuracy and speed of picture identification. In a second experiment, categorical information helped subjects when given after the examination of each picture, but before any attempt at identification. The benefits of categorical information were also obtained in another group of subjects, when the superordinate categories were named at the start of the experiment. In a third experiment, a multiple-choice picture recognition task was used to eliminate the difficulty of naming from the picture-identification task. The multiple-choice data showed higher accuracy and shorter latencies when compared with identification tasks. A fourth experiment evaluated picture identification in blindfolded sighted, early, and late blind participants. Congenitally blind subjects showed lower performance than did the other groups, despite the availability of prior categorical information. The data were consistent with theories that assume that visual imagery aids tactual perception in naming raised line drawings. It was proposed that part of the difficulty in identification of raised line pictures may derive from problems in locating picture categories or names, and not merely in perception of the patterns.     

Holland's theory and non-college-degreed working black and white women

The main concern of this study was to investigate differences between black and white American women employed in traditional female occupations who took the Vocational Preference Inventory (VPI) and the Self-Directed Search (SDS). The VPI and the SDS were administered to 110 black and white non-college-degreed workers in three occupations (laboratory technicians, sales clerks, and clerk-typists) corresponding to three of Holland's environmental categories (Investigative, Enterprising, and Conventional). In general, the findings for the three VPI and SDS scales and for these six occupational groups are mixed. On the SDS scales, findings indicate that black and white women in the same occupation seem to be far more similar than different. On the scales of the VPI, however, white and black women in the same occupation seem to be more different than similar.     

Temporal characteristics in apparent movement: Omega movement vs. PHI movement

A vertical line stimulus was presented alternately at two positions on an oscillo scope face, with no interstimulus interval. Observation of this stimulus produced haphazard alternation between a number of movement percepts, which were divided into four categories: phi, omega and partial movement, and no movement. Attention to one category did not increase the proportion of time movement in that category it was reported. Proportion of time reported for each category varied differentially as a function of alternation frequency. Upper and lower displacement amplitude limits were measured as a function of frequency for phi and omega movement. Both limits for omega movement differed from those for phi movement. The results imply that phi and omega movement involve separate processing stages in the visual system.