The impact of emotions and predominant emotion regulation technique on driving performance.

Emotion-provoking stimuli abound on modern roadways. Driving measures, of both longitudinal and lateral control of the vehicle, have been shown to vary based on affective influences. Research, however, has yet to address how drivers' individual techniques to mitigate emotional reactions influence driving performance. To address this issue, the present study featured a dual-task protocol involving simulated driving together with processing of emotionally-valenced images with a focus on different Predominant Emotion Regulation Techniques (PERT): one adaptive strategy (task-focused coping) and one maladaptive style (emotion-focused coping). Dependent measures included mean driving speed and number of lane excursions. Results indicated that pleasant images degraded longitudinal control to the greatest extent, while unpleasant images produced the greatest detriment in lateral control. Additionally, individuals' PERT played a major interactive role in drivers' longitudinal control leading task-focused females and emotion-focused males to adhere more closely to the speed limit; yet, it did not affect their lateral control. Results hold important potential implications for the amount or variety of training necessary for driver licensure to promote and sustain safe vehicle control.

The impact of emotions and predominant emotion regulation technique on driving performance.

Emotion-provoking stimuli abound on modern roadways. Driving measures, of both longitudinal and lateral control of the vehicle, have been shown to vary based on affective influences. Research, however, has yet to address how drivers' individual techniques to mitigate emotional reactions influence driving performance. To address this issue, the present study featured a dual-task protocol involving simulated driving together with processing of emotionally-valenced images with a focus on different Predominant Emotion Regulation Techniques (PERT): one adaptive strategy (task-focused coping) and one maladaptive style (emotion-focused coping). Dependent measures included mean driving speed and number of lane excursions. Results indicated that pleasant images degraded longitudinal control to the greatest extent, while unpleasant images produced the greatest detriment in lateral control. Additionally, individuals' PERT played a major interactive role in drivers' longitudinal control leading task-focused females and emotion-focused males to adhere more closely to the speed limit; yet, it did not affect their lateral control. Results hold important potential implications for the amount or variety of training necessary for driver licensure to promote and sustain safe vehicle control.

Determination of the pattern of acetylation of low-molecular-weight chitosan used in biomedical applications.

The microstructure of chitosan, a linear copolymer of glucosamine and N-acetylglucosamine units widely used in biomedical applications, is closely dependent on the conditions of its preparation. Knowledge of the structural differences between chitosan preparations is very important in determining the properties of chitosan and essential for structure-activity analysis where biological systems are concerned. Determination of the pattern of acetylation of chitosan samples (P(A) parameter) by (13)C NMR spectroscopy hitherto required depolymerization of the native chitosans. The present study has demonstrated that this step is not necessary for determining P(A) of low-molecular-weight chitosan samples.

Event-related potential evidence for the processing efficiency theory.

The purpose of this study was to examine the central tenets of the processing efficiency theory using psychophysiological measures of attention and effort. Twenty-eight participants were divided equally into either a high or low trait anxiety group. They were then required to perform a simulated driving task while responding to one of four target light-emitting diodes. Cortical activity and dual task performance were recorded under two conditions -- baseline and competition -- with cognitive anxiety being elevated in the competitive session by an instructional set. Although driving speed was similar across sessions, a reduction in P3 amplitude to cue onset in the light detection task occurred for both groups during the competitive session, suggesting a reduction in processing efficiency as participants became more state anxious. Our findings provide more comprehensive and mechanistic evidence for processing efficiency theory, and confirm that increases in cognitive anxiety can result in a reduction of processing efficiency with little change in performance effectiveness.

A visual search examination of attentional biases among individuals with high and low drive for thinness.

The purpose of this study was to examine attentional biases through visual search patterns of 40 females with high (high-risk for eating disorders) or low (low-risk for eating disorders) levels of drive for thinness and body dissatisfaction while viewing slides depicting ectomorphic, mesomorphic, and endomorphic female body shapes. Participants were outfitted in an eye tracking system, which was used to collect gaze behavior data while viewing the slides. Fixation frequency and duration to five body locations were analyzed through the use of ASL EYENAL software. For the mesomorphic, ectomorphic, and endomorphic slides, the low-risk group looked significantly more often at the leg region than the high-risk group. The low-risk group also gazed significantly longer at the leg region than the high-risk group when viewing the mesomorphic and ectomorphic slides. For the endomorphic slides, the low-risk group focused significantly longer on the midsection than did the high-risk group. The findings suggest avoidance behaviors among the high-risk group that are reflected in their locus of attention, and indicate that negative affect among high-risk individuals may be induced by selective attention to particular environmental cues. An integrative theoretical account emanating from cognitive, social, and behaviorist approaches to understanding attentional biases in body disturbance is used to explain the findings.

Perceptual decision making for baseball pitch recognition: using P300 latency and amplitude to index attentional processing.

This study was designed to examine the perceptual and attentional processes associated with the effects of administering a cost-benefit precuing paradigm to intermediate and advance-level baseball batters. Psychophysiological and performance data obtained from 10 advanced and 10 intermediate-level players were compared. A total of 400 pitches (200 fastballs, 200 curveballs) was randomly presented via a large projection screen, and participants pressed one of two buttons to indicate the type of pitch thrown. Verbal precues were given for 300 of the pitches. Of those, 75% were valid, and 25% were invalid. Electroencephalographic data collected from the P location was used to assess the latency and amplitude of P300. Analysis of variance (Skill Level x Precue x Pitch) for P300 and reaction time (RT) indicated that intermediate batters produced shorter P300 latencies, larger P300 amplitudes, longer RTs, and less correct responses than the advanced batters; the effects were more pronounced for the curveballs. These results suggest that intermediate batters are less efficient in their perceptual decision-making processes due to greater limitations in attentional capacity when compared with advanced batters.

Minimizing error in measurement of error: a proposed method for calculation of error in a two-dimensional motor task.

Traditional one-dimensional error scores are still consistently used in research on motor learning to quantify two-dimensional error; however, the inherent differences in two-dimensional tasks render that application inappropriate and often misleading. Consequently, the purpose of this paper was to propose a novel method of presenting errors, which more precisely represents the accuracy, direction, and variability of error in two-dimensional settings. Although closely related to several alternatives for representing errors, the methodology used and the results obtained provide a more accurate procedure for pinpointing critical trends in what have been commonly referred to as AE (absolute error), VE (variable error), CE (constant error), and E (total variability). The proposed measurements of AVE (adjusted variable error), DE (directional error), TSE (total spread of error), and RE (radial error) provide composite error scores carrying a variety of information about performance on two-dimensional tasks. Formulas and examples are provided to facilitate computation and enhance understanding of the proposed scores.

An electrocortical comparison of executed and rejected shots in skilled marksmen.

Electroencephalographic (EEG) activity during the preshot period was investigated in seven skilled marksmen. Specifically, alpha and beta spectral power were obtained for the 4-s period prior to the execution or rejection of shots. Rejected shots were defined as those that resulted in the marksman's self-initiated decision to withdraw their rifle from the target rather than execute the shot. EEG activity during the preparatory period was contrasted between the executed and rejected shots to better understand the involved attentional processes associated with the preshot state. Results for rejected compared with executed shots revealed a progressive increase in alpha and beta power for rejected compared with executed shots, which increased across the preparatory period. Furthermore, increased spectral power was found in the left compared with the right hemisphere for both executed and rejected shots, and in the different regions of the scalp. Therefore, the decision to reject a shot seems to be characterized by inappropriate allocation of the neural resources associated with task execution.

Maximizing performance feedback effectiveness through videotape replay and a self-controlled learning environment.

This study was designed to examine whether participants who could control the schedule of performance feedback (KP) would learn differentially from those who received a rigid feedback schedule while learning a complex task. Participants (N = 48) were randomly assigned to self-controlled KP (SELF), summary KP (SUMMARY), yoked control (YOKE), or knowledge of results only (KR) conditions. Data collection consisted of an acquisition phase and a 4-day retention phase during which right-handed participants performed a left-handed ball throw. Overall, throwing form improved across trial blocks during acquisition, with the SUMMARY, SELF, and YOKE groups showing more improvement than the KR group. During retention, the SELF group retained a higher level of throwing form and accuracy in comparison to the other groups. Results suggest that when given the opportunity to control the feedback environment, learners require relatively less feedback to acquire skills and retain those skills at a level equivalent to or surpassing those who are given more feedback but receive it passively.

Subject-controlled performance feedback and learning of a closed motor skill.

Research on knowledge of results and knowledge of performance has been directed toward identification of the optimal schedule for administering feedback. The purpose of this investigation was to assess whether a schedule based on performance feedback controlled by the learner would be a more effective means of delivering feedback than any predetermined or random schedule. Participants were randomly assigned to one of five conditions: (a) control group receiving no performance feedback, (b) 50% relative performance feedback, (c) summary performance feedback, (d) subject-controlled performance feedback, and (e) yoked control group. Data were collected during an acquisition phase (four blocks of 10 trials) and a retention phase (two block of 10 trials) in which subjects performed an underhand ball toss. Repeated-measures analyses indicated significant main effects for the absolute error (AE). Participants in the subject-controlled performance feedback condition performed significantly better on both retention trials than the other groups. Analysis suggests that a feedback schedule which is controlled by the learner may be a more effective means of delivering augmented feedback than other schedules which have been examined.