Individual differences in habituation rates and object concept performance.

The scores from object concept tasks for 15 infants at 14 months of age were analyzed with respect to their habituation rates at 4 months of age. Partitioning of the data according to subjects categorized as fast and slow habituators brought some organization consistent with the notion that the former are more advanced than the latter. Statistical differences between groups did not obtain, but a significant correlation between ranked task scores and habituation ratios offers some support to the interpretation. The possibility of using habituation rates or ratios as an index of differences in processing, perhaps with some predictive value, may be considered if further evidence of relations to later cognitive performanceis found.     

Characteristics of the population of deaf and hard of hearing students with emotional disturbance in Illinois

The study summarizes a database for the years 1994-1999 on deaf and hard of hearing students in Illinois with a diagnosis of emotional disturbance (N = 115). Data are reported on the group's demographic, domestic, etiologic, communication-related, and intervention-related characteristics. These dually diagnosed students differed from Illinois's general population of deaf and hard of hearing students in many ways, including higher incidences of prematurity, prenatal trauma, and perinatal trauma. They were more likely to have had a later onset of hearing loss, to live in single-parent homes, to belong to an ethnic minority, to live in an urban or suburban area, and to qualify for low-income health care. Many had histories of abuse, 50% were regularly medicated, and 15% were assigned to surrogate parents.     

Utility of a novel perceptual-motor control test for identification of sport-related concussion beyond current clinical assessments

ABSTRACT

Clinically feasible metrics, that can inform the concussion recovery decision making process by evaluating a unique domain beyond current testing domains (e.g., balance, neurocognition, symptoms, vestibular/ocular function) are still in need. The purpose of this study was to compare perceptual-motor control in adolescent athletes ≤21 days of sport-related concussion and healthy controls and evaluate the association of perceptual-motor control to the outcomes of commonly-used sport-related concussion clinical assessments. Athletes (age: 12-18 years) with sport-related concussion (n = 48) and healthy controls (n = 24) completed the Perception-Action Coupling Task (PACT), whose outcomes are mean reaction, movement, initiation, response time, and accuracy. ImPACT outcomes are verbal/visual memory scores, motor processing speed, and reaction time. Vestibular-Ocular Motor Screen (VOMS) outcomes are symptoms from: smooth pursuit, horizontal/vertical saccades, near-point of convergence, horizontal/vestibular ocular-reflex, and visual motion sensitivity. CONCUSSED demonstrated ~5% deficit in overall perceptual-motor accuracy during PACT compared to CONTROLS (p = 0.03). PACT accuracy negatively correlated with smooth pursuits(r = -0.29), and horizontal (r = -0.35)/vertical (r = -0.30) saccades. The C5.0 decision tree determined PACT accuracy was the most relevant predictor of sport-related concussion when no visual motion sensitivity symptoms were reported and Visual Memory was >66. Perceptual-motor control tests may complement current sport-related concussion assessments when neurocognition and vestibular/ocular motor system are not grossly impaired.     

Serial habituation in two-, three-, and four-month-old infants.

Serial habituation of visual fixations in 2-, 3-, and 4-month-old infants was investigated through a design permitting cross-sectional, within-subject longitudinal, cohort longitudinal, and time-lag analyses. The components of the standard stimulus were displayed individually before and after successive exposures of the standard for familiarization. Relative saliencies of the components for each child were indexed by magnitude of responding to these parts in the initial presentation. Comparisons of the pre- and postexposure fixation times suggest that for all ages habituation was under way to the parts of the stimulus in orders of the relative saliencies. The nature of the data in general did not appear to be influenced significantly by any 1 methodology.     

Effective force and economy of triathletes and cyclists

The effective force applied on the crank, the index of pedalling effectiveness, and the economy of movement at 60, 75, 90, and 105 rev/min cadences were examined in nine cyclists and eight triathletes. Tests were performed on two days. Maximal oxygen uptake was measured and the second ventilatory threshold was estimated on day 1 using a stationary bicycle. On day 2, the four different cadences were tested at about 5% below the second ventilatory threshold. A strain gauge instrumented clip-less pedal mounted on the bicycle enabled us to measure the normal and tangential forces exerted on the pedal, while the pedal and crank angles were monitored with the aid of a video system. Based on this information, the effective force and the index of pedalling effectiveness were calculated. Cyclists produced significantly more effective force and a higher index of pedalling effectiveness at 60 and 75 rev/min and were significantly more economic at all cadences than triathletes. The significant and positive correlation between effective force and economy at all cadences suggests that improvement of the effective force would reflect on economy.