The purpose of this study was to examine whether variability in gaze behavior and cortical activation would differentiate expert (n = 12) and nonexpert (n = 13) small-bore rifle shooters. Spectral-activity and eye-movement data were collected concurrently during the course of a regulation indoor sequence of 40 shots from the standing position. Experts exhibited significantly superior shooting performance, as well as a significantly longer quiet eye period preceding shot execution than did nonexperts. Additionally, expertise interacted with hemispheric activation levels: Experts demonstrated a significant increase in left-hemisphere alpha and beta power, accompanied by a reduction in right-hemisphere alpha and beta power, during the preparatory period just prior to the shot. Nonexperts exhibited similar hemispheric asymmetry, but to a lesser extent than did experts. Findings suggest systematic expertise-related differences in ocular and cortical activity during the preparatory phase leading up to the trigger pull that reflects more optimal organization of the neural structures needed to achieve high-level performance.

No abstract

Fatigue contributes to driving-related accidents and fatalities. Cardiovascular measures such as heart rate and heart rate variability may serve as early indicators of fatigue. In the current investigation, 24 professional truck drivers drove three truck configurations: single trailer, triple trailer A-dolly, and triple trailer C-dolly on a standard route that lasted between 8 and 10 h. During the driving session, continuous measures of heart rate were quantified on-line. In addition to heart rate, two measures of heart rate variability (i.e. respiratory sinus arrhythmia and the Traube-Hering-Mayer wave or 0.1 Hz oscillation) were derived from the beat-to-beat heart rate. Independent of configuration, heart rate increased and the measures of heart rate variability decreased during the driving route. Only heart rate statistically differed among the configurations. Since heart rate is physiologically linked to metabolic output, the results suggest that the observed effect may be due to the physical demands required to drive each truck configuration. In support of this conclusion, the heart rate effect was consistent with the subjective report of task demand. The slowest heart rates were observed while driving the least demanding configuration (i.e. single trailer). The fastest heart rates were observed while driving the most demanding configuration (i.e. triple trailer A-dolly).

Identification of the necessary stimulus properties to elicit the stimulus preceding negativity (SPN) has been the impetus for numerous research studies. The current study was conducted to explore the possibility that the SPN is an index of cognitive resource allocation. An auditory warning stimulus (S1) indicated whether an easy or difficult discrimination would occur at S2. The SPN was collected before a nonmotor discrimination task (S2) that consisted of identifying the higher of two bars. To eliminate the influence of motor processing prior to S2, a button press on the side of the higher bar was held until perception of a response cue (S3). Additionally, P3, contingent negative variation (CNV), and behavioral measures were collected to assist in assessing the SPN. Results indicated that although the SPN exhibited increased negativity, no differences were observed based on task difficulty. However, task difficulty did affect P3 data for both the warning tone and the discrimination task, an effect not observed for the CNV. Overall, the data did not support that hypothesis that the SPN provides an index of cognitive demand.

Latencies and peak-to-peak amplitudes of pattern-reversal evoked-potential (PREP) components of active and inactive community-dwelling healthy 61- to 77-year-olds were compared with those of active and inactive 18- to 31-year-olds to determine whether long-term physical activity involvement was associated with attenuation of age-related changes in sensory processes. Binocular PREPs were derived for each of 2 check sizes (22 × 15 ft and 41 × 30 ft of visual angle) to provide increasing challenge of spatial resolution. Analyses of the latencies revealed significant effects for age, gender, and check size such that latencies were longer for older than for young participants, men than for women, and small than for larger check sizes. Amplitudes were larger in older adults for the P100-N150 peak-to-peak difference, but physical activity history was not associated with reduction of the observed age-related increases in component latencies and amplitude. As such, physical activity does not appear to attenuate age-related decline in visual sensory processing.