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Introduction: Friedreich’s ataxia (FRDA) is an inherited ataxia with a range of progressive features including axonal degeneration of sensory nerves. The aim of this study was to investigate auditory perception in affected individuals. Methods: Fourteen subjects with genetically defined FRDA participated. Two control groups, one consisting of healthy, normally hearing individuals and another comprised of subjects with sensorineural hearing loss, were also assessed. Auditory processing was evaluated using structured tasks designed to reveal the listeners’ ability to perceive temporal and spectral cues. Findings were then correlated with open-set speech understanding. Results: Nine of 14 individuals with FRDA showed evidence of auditory processing disorder. Gap and amplitude modulation detection levels in these subjects were significantly elevated, indicating impaired encoding of rapid signal changes. Electrophysiologic findings (auditory brainstem response, ABR) also reflected disrupted neural activity. Speech understanding was significantly affected in these listeners and the degree of disruption was related to temporal processing ability. Speech analyses indicated that timing cues (notably consonant voice onset time and vowel duration) were most affected. Conclusion: The results suggest that auditory pathway abnormality is a relatively common consequence of FRDA. Regular auditory evaluation should therefore be part of the management regime for all affected individuals. This assessment should include both ABR testing, which can provide insights into the degree to which auditory neural activity is disrupted, and some functional measure of hearing capacity such as speech perception assessment, which can quantify the disorder and provide a basis for intervention.

Abstract. Driver distraction has become a major concern for transportation safety due to the increasing use of in-vehicle devices. To reduce safety risk, it is crucial to understand how fundamental aspects of distracting activities affect driver cognition in terms of roadway situation awareness. This study used a simulator-based experiment to investigate the effects of visual, cognitive and simultaneous distraction on operational and tactical control of vehicles. Twenty drivers participated in the study and drove in following or passing driving scenarios under four distraction conditions (without, with visual, with cognitive, and with simultaneous distraction). Results revealed visual distraction to affect all aspects of driver situation awareness. Cognitive distraction affected comprehension and projection of roadway and vehicle states. Correlation analyses revealed decrements in driver SA due to distraction to be associated with decreases in performance.

Is there an association between the proportion of the population that is young and national homicide rates, and when testing other theories cross-nationally is it necessary to control for this concept? To answer these questions, we carried out an extensive review of the empirical literature and then used data for the years 1999-2004 from a sample of 55 nations to test two predominant hypotheses: Percent young is significantly associated with homicide victimization rates across nations, and percent young accounts for a significant proportion of the overall variance in homicide victimization rates across nations. The results consistently indicated no significant association between percent young and homicide victimization rates across nations. Moreover, including percent young in models of cross-national homicide rates likely has negative ramifications for model fit. We situate these findings within the larger literature and provide a discussion of the implications for future cross-national homicide research.

Findings support the need to assess the impacts of in-vehicle distraction on different levels of driving control. Future study should investigate driver distraction under strategic control.