Application of Imagery Theory to Sport Psychology: Some Preliminary Findings

Bioinformational theory has been proposed by Lang (1979a), who suggests that mental images can be understood as products of the brain's information processing capacity. Imagery involves activation of a network of propositionally coded information stored in long-term memory. Propositions concerning physiological and behavioral responses provide a prototype for overt behavior. Processing of response information is associated with somatovisceral arousal. The theory has implications for imagery rehearsal in sport psychology and can account for a variety of findings in the mental practice literature. Hypotheses drawn from bioinformational theory were tested. College athletes imagined four scenes during which their heart rates were recorded. Subjects tended to show increases in heart rate when imagining scenes with which they had personal experience and which would involve cardiovascular activation if experienced in real life. Nonsignificant heart rate changes were found when the scene involved activation but was one with which subjects did not have personal experience.

Multi-Decadal Record of Ice Dynamics on Daugaard Jensen Gletscher, East Greenland, from Satellite Imagery and Terrestrial Measurements

The history of ice velocity and calving front position of Daugaard Jensen Gletscher, a large outlet glacier in East Greenland, is reconstructed from field measurements, aerial photography and satellite imagery for the period 1950-2001. The calving terminus of the glacier has remained in approximately the same position over the past similar to 50 years. There is no evidence of a change in ice motion between 1968 and 2001, based on a comparison of velocities derived from terrestrial surveying and feature tracking using sequential satellite images. Estimates of flux near the entrance to the fjord vs snow accumulation in the interior catchment show that Daugaard Jensen Gletscher has a small negative mass balance. This result is consistent with other mass-balance estimates for the inland region of the glacier.

A New Velocity Map for Byrd Glacier, East Antarctica, from Sequential Aster Satellite Imagery

New ice-velocity measurements are obtained for the main trunk of Byrd Glacier, East Antarctica, using recently acquired Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery. The velocities are derived from the application of a cross-correlation technique to sequential images acquired in 2000 and 2001. Images were co-registered and ortho-rectified with the aid of a digital elevation model (DEM) generated from ASTER stereo imagery. This paper outlines the process of DEM generation, image co-registration and correction, and the application of the cross-correlation technique to obtain ice velocities. Comparison of the new velocity map with earlier measurements of velocity from 1978 indicates that the glacier has undergone a substantial deceleration between observations. Portions of the glacier flowing at speeds of similar to 850 m a(-1) in 1978/79 were flowing at similar to 650 m a(-1) in 2000/01. The cause of this change in ice dynamics is not known, but the observation shows that East Antarctic outlet glaciers can undergo substantial changes on relatively short timescales.

Rapid Volume Loss from Two East Greenland Outlet Glaciers Quantified Using Repeat Stereo Satellite Imagery

The coastal portions of Kangerdlugssuaq and Helheim glaciers in southeast Greenland lost at least 51 +/- 8 km(-3) yr(-1) of ice between 2001-2006 due to thinning and retreat, according to an analysis of sequential digital elevation models (DEMs) derived from stereo ASTER satellite imagery. The dominant contribution to this ice loss was dynamic thinning caused by the acceleration in flow of both glaciers. Peak rates of change, including thinning rates of similar to 90 m yr(-1), coincided with the rapid increases in flow speed. Extrapolation of the measured data to the ice divides yields an estimated combined catchment volume loss of similar to 122 +/- 30 km(-3) yr(-1), which accounts for half the total mass loss from the ice sheet reported in recent studies. These catchment-wide volume losses contributed similar to 0.31 +/- 0.07 mm yr(-1) to global sea level rise over the 5-year observation period with the coastal regions alone contributing at least 0.1 +/- 0.02 mm yr(-1).

The Adaptation Effect in Bilingual People who Stutter: An Examination of the Oral-Motor Rehearsal Theory

The present study provided further information about stuttering among bilingual populations and attempted to assess the significance of repeated oral-motor movements during an adaptation task in two bilingual adults. This was accomplished by requesting that bilingual people who stutter to complete an adaptation task of the same written passage in two different languages. Explored was the following research question: In bilingual speakers who stutter, what is the effect of altering the oral-motor movements by changing the language of the passage read during an adaptation task? Two bilingual adults were each requested to complete an adaptation task consisting of 10 readings in two separate conditions. Participants 1 and 2 completed two conditions, each of which contained a separate passage. Condition B consisted of an adaptation procedure in which the participants read five successive readings in English followed by five additional successive readings in Language 1 (L1). Following the completion of the first randomly assigned condition, the participant was given a rest period of 30 minutes before beginning the remaining condition and passage. Condition A consisted of an adaptation procedure in which the participants read five successive readings in L1 followed by five additional successive readings in English. Results across participants, conditions, and languages indicated an atypical adaptation curve over 10 readings characterized by a dramatic increase in stuttering following a change of language. Closer examination of individual participants revealed differences in stuttering and adaptation among languages and conditions. Participants 1 and 2 demonstrated differences in adaptation and stuttering among languages. Participant 1 demonstrated an increase in stuttering following a change in language read in Condition B and a decrease in stuttering following a change in language read in Condition A. It is speculated that language proficiency contributed to the observed differences in stuttering following a change of language. Participant 2 demonstrated an increase in stuttering following a change in language read in Condition A and a minimal increase in stuttering following a change in language read in Condition B. It is speculated that a change in the oral-motor plan contributed to the increase in stuttering in Condition A. Collectively, findings from this exploratory study lend support to an interactive effect between language proficiency and a change in the oral-motor plan contributing to increased stuttering following a change of language during an adaptation task.