Investigating the relationship between eye movements and situation awareness in weather forecasting.

Physiological indicators, including eye tracking measures, may provide insight into human decision making and cognition in many domains, including weather forecasting. Situation awareness (SA), a critical component of forecast decision making, is commonly conceptualized as the degree to which information is perceived, understood, and projected into a future context. Drawing upon recent applications of eye tracking in the study of forecaster decision making, we investigate the relationship among eye movement measures, automation, and SA assessed through a freeze probe assessment method. In addition, we explore the relationship between an automated forecasting decision aid use and information seeking behavior. In this study, a sample of professional weather forecasters completed a series of tasks, informed by a set of forecasting decision aids, and with variable access to an experimental automated tool, while an eye tracking system captured data related to eye movements and information usage. At the end of each forecasting task, participants responded to a set of questions related to the environmental situation in the framework of a survey-based assessment technique in order to assess their level of situation awareness. Regression analysis revealed a moderate relationship between the SA measure and eye tracking metrics, supporting the hypothesis that eye tracking may have utility in assessing SA. The results support the use of eye tracking in the assessment of specific and measurable attributes of the decision-making process in weather forecasting. The findings are discussed in light of potential benefits that eye tracking could bring to human performance assessment as well as decision-making research in the forecasting domain.

Designing and evaluating a STEM teacher learning opportunity in the research university.

This study examines the design and evaluation strategies for a year-long teacher learning and development experience, including their effectiveness, efficiency and recommendations for strategic redesign. Design characteristics include programmatic features and outcomes: cognitive, affective and motivational processes; interpersonal and social development; and performance activities. Program participants were secondary math and science teachers, partnered with engineering faculty mentors, in a research university-based education and support program. Data from multiple sources demonstrated strengths and weaknesses in design of the program's learning environment, including: face-to-face and via digital tools; on-site and distance community interactions; and strategic evaluation tools and systems. Implications are considered for the strategic design and evaluation of similar grant-funded research experiences intended to support teacher learning, development and transfer.

Effects of age and psychomotor ability on kinematics of mouse-mediated aiming movement.

The objective of this research is to understand the influence of age and age-related psychomotor ability on the process of mouse-mediated aiming movement. It is premised on the notions that (1) mouse-mediated aiming movements can be better understood via studying its kinematics and (2) age is a surrogate variable in kinematic differences, and that age-influenced fundamental factors such as psychomotor ability may have a more direct effect. As expected, age kinematic differences were detected. However, when comparing with age, age-influenced psychomotor ability (i.e. manual dexterity) contributed more substantially to the variances of kinematics in the ballistic phase. For homing phase, in addition to manual dexterity, age-influenced wrist-finger speed was also a significant contributor. In future studies, it is suggested that components of visual processing should be included for better understanding of its role as an age-influenced fundamental ability in aiming movements. Applications of this research are discussed. PRACTITIONER SUMMARY: This paper presents empirical data showing age effects in movement kinematics are chiefly mediated by age-related changes in psychomotor ability. Our findings provide additional data for existing and newer performance enhancement solutions, especially for those targeting older adults.

Effects of a 6-week periodized squat training with or without whole-body vibration upon short-term adaptations in squat strength and body composition.

The purpose of this study was to examine the effects of a 6-week, periodized squat training program, with or without whole-body low-frequency vibration (WBLFV), applied before and between sets to 1RM squat strength and body composition. Thirty men aged between 20 and 30 years with at least 6 months of recreational weight training experience completed the study. Subjects were randomly assigned to either 1 of 2 training groups or to an active control group (CON). Group 1 (CON; n = 6) did not participate in the training protocol but participated only in testing sessions. Group 2 (SQTV, n = 13) performed 6 weeks of squat training while receiving WBLFV (50 Hz), before, and in-between sets. The third group (SQT, n = 11) performed 6 weeks of squat training only. Subjects completed 12 workouts with variable loads (55-90% one repetition maximum [1RM]) and sets (), performing squats twice weekly separated by 72 hours. The RM measures were recorded on weeks (W) 1, 3, and 7. During the second workout of a week, the load was reduced by 10-15%, with "speed squats" performed during the final 3 weeks. Rest periods in between sets were set at 240 seconds. The WBLFV was applied while subjects stood on a WBLFV platform holding an isometric quarter squat position (knee angle 135 ± 5°). Initially, WBLFV was applied at 50 Hz for 30 seconds at low amplitude (peak-peak 2-4 mm). A rest period of 180 seconds followed WBLFV exposure before the first set of squats. The WBLFV was then applied intermittently (3 × 10 seconds) at 50 Hz, high amplitude (peak-peak, 4-6 mm) at time points, 60, 120, and 180 seconds into the 240-second rest period. Total body dual x-ray absorptiometry scans were performed at W0 (week before training) and W7 (week after training). Measures recorded included total body mass (kg), total body lean mass (TLBM, kg), trunk lean mass (kg), leg lean mass (kg), total body fat percentage, trunk fat percentage, and leg fat percentage (LF%). Repeated-measures analysis of variance and analysis of covariance revealed 1RM increased significantly between W1-W3, W3-W7, and W1-W7 for both experimental groups but not for control (p = 0.001, effect size [ES] = 0.237, 1 - ß = 0.947). No significant differences were seen for %Δ (p > 0.05). Significant group by trial and group effects were seen for TLBM, SQTV > CON at W7 (p = 0.044). A significant main effect for time was seen for LF%, W0 vs. W7 (p = 0.047). No other significant differences were seen (p > 0.05). "Practical trends" were seen favoring "short-term" neuromuscular adaptations for the SQTV group during the first 3 weeks (p = 0.10, ES = 0.157, 1 - ß = 0.443, mean diff; SQTV week 3 4.72 kg > CON and 2.53 kg > SQT). Differences in motor unit activation patterns, hypertrophic responses, and dietary intake during the training period could account for the trends seen.

The acute effect of whole-body low-frequency vibration on countermovement vertical jump performance in college-aged men.

The purpose of this study was to examine the acute effects of whole-body vibration on jump performance. A total of 21 college-aged men, 18-30 years, recreationally resistance trained, were exposed to a total of 4 different acute whole-body low-frequency vibration (WBLFV) protocols (conditions 1-4), performing 2 protocols per testing session in random order. Exposures were all performed using high-amplitude (peak-peak 4-6 mm) and either 30 or 50 Hz for 30 continuous seconds, or 3 exposures of 10 seconds with 1 minute between exposures. Three countermovement vertical jumps (CMVJs) were performed before vibration (testing phase 1 or Tp1 and J1 the highest of 3 attempts) and at 3 separate time points postvibration (Tp2-4). Jump height (cm), peak power (Pmax), peak power per kilogram of body mass (Pmax kg), mean power (Pav), and mean velocity (Vav) were recorded. Repeated measures analysis of variance and analysis of covariance revealed no significant condition (C) or jump (J) differences for CMVJ height (cm) (p > 0.05). Analysis of percent change (Δ%) for CMVJ height (cm) revealed a significant Condition × Jump interaction, C4, J3 > C1, J3 (p = 0.009, mean diff 4.12%). Analysis of Pmax and Pmax kg revealed no significant Condition, Jump, or Condition × Jump interaction for the raw data or percent change (p > 0.05). Analysis of Pav (W) revealed significant differences for Condition (p = 0.031) but not for Jump (p = 0.226). There was a strong trend toward significance for Condition × Jump interaction (p = 0.059). C4 > C3 (p = 0.043, mean diff 23.78 W) and C1 (p = 0.038, mean diff 32.03 W). Analysis of Vav (m·s) revealed no significant main effects for Condition or Jump (p > 0.05) but found a significant Condition × Jump interaction (p = 0.007). C4, J6 > C2, J6 (p = 0.014, mean diff 0.05 m·s), and C3, J6 (p = 0.020, 0.05 m·s). WBLFV applied intermittently using 50 Hz appears to be more effective than other protocols using 30 and 50 Hz in facilitating select measures of CMVJ performance over a 17-minute time period post-WBLFV exposure. Practical manipulation of such a WBLFV "dose" may be beneficial to strength and conditioning practitioners wanting to acutely facilitate CMVJ and slow stretch shortening cycle performance while minimizing exposure time.

Effects of adding whole body vibration to squat training on isometric force/time characteristics.

Resistance training interventions aimed at increasing lower-body power and rates of force development have produced varying results. Recent studies have suggested that whole-body low-frequency vibration (WBLFV) may elicit an acute postactivation potentiation response, leading to acute improvements in power and force development. Potentially, the use of WBLFV between sets of resistance training rather than during training itself may lead to increased recruitment and synchronization of high-threshold motor units, minimize fatigue potential, and facilitate the chronic adaptation to resistance exercise. The purpose of this study was to determine the effects of applying TriPlaner, WBLFV, prior to and then intermittently between sets of Smith machine squats on short-term adaptations in explosive isometric force expression. Thirty recreationally resistance trained men aged 18-30 were randomly assigned to 1 of 3 groups: resistance training only (SQT, n = 11), resistance plus whole-body vibration (SQTV, n = 13), or active control (CON, n = 6). An isometric squat test was performed prior to and following a 6-week periodized Smith machine squat program. Whole-body low-frequency vibration was applied 180 seconds prior to the first work set (50 Hz, 2-4 mm, 30 seconds) and intermittently (50 Hz, 4-6 mm, 3 x 10 seconds, 60 seconds between exposures) within a 240-second interset rest period. Subjects were instructed to assume a quarter squat posture while positioning their feet directly under their center of mass, which was modified using a handheld goniometer to a knee angle of 135 +/- 5 degrees . Instructions were given to subjects to apply force as fast and as hard as possible for 3.5 seconds. Isometric force (N) and rates of force development (N.s(-1)) were recorded from the onset of contraction (F(0)) to time points corresponding to 30, 50, 80, 100, 150, and 250 milliseconds, as well as the peak isometric rate of force development (PISORFD), and rate of force development to initial peak in force (RFDinitial). Repeated measures analysis of variance and analysis of covariance revealed no significant group by trial interactions for isometric rate of force development (ISORFD) between 0-30, 0-50, 0-80, 0-100, 0-150, and 0-250 milliseconds and PISORFD (p > 0.05). A significant group x trial interaction was seen for RFDinitial with SQTV >CG (p = 0.04, mean difference 997.2 N.s(-1)) and SQTV >SQT (p = 0.04, mean difference 1,994.22 N.s(-1)). Significant trial by covariate interactions (week one measures for ISORFD) and main effects for trial were observed for ISORFD between 0-80, 0-100, 0-and 150 milliseconds; PISORFD; and RFDinitial (p < 0.01). A significant trial effect was seen for Finitial (%) when expressed as a relative percentage of maximal voluntary contraction (MVC) (MVC = 100%) (p = 0.015; week 1 > week 7, mean difference, 5.82%). No significant differences were seen for any other force variables from the onset of contraction to MVC between weeks 1 and 7 (p > 0.05). The data suggest that there was a significant benefit afforded by adding WBLFV to a short-term resistance training protocol with regard to "explosive" strength expression. The addition of vibration prior to and between sets of resistance exercise may be a viable alternative to vibration applied during resistance exercise when trying to improve "explosive" isometric strength.

Effects of a 6-week periodized squat training program with or without whole-body vibration on jump height and power output following acute vibration exposure.

The purpose of this study was to examine the effects of a 6-week, periodized squat training program with (SQTV) or without (SQT) whole-body low-frequency vibration (WBLFV) on acute improvements in jump height and power output over 3 separate testing occasions. Participants ranged in age from 18 to 30 years and were randomized into 1 of 3 groups (CG, or control group, n = 6; SQTV, n = 13; or SQT, n = 11). SQTV and SQT performed Smith machine back squat training twice per week with 3 to 5 sets of 55 90% of the 1-repetition maximum (1RM). The SQTV group also received WBLFV (50 Hz; 2-6-mm amplitude) during the 6-week training period before training (30 seconds, 2-4-mm amplitude) and between sets (3 bouts lasting 10 seconds each). Two 30-cm depth jumps and two 20-kg squat jumps were performed after an acute vibration protocol during weeks 1, 3, and 7. Jump height (cm), peak power (Pmax), peak power per kilogram of body mass (Pmax/kg), and mean power (Pav) were recorded for the depth and squat jumps. Although there were no group by trial interactions, percent change in Pmax for the squat jump was greater (p < 0.01) for the SQTV group than for the SQT group post WBLFV. In addition, the percent change scores for jump height and Pmax/kg for the depth jump were greater (p < 0.05) for SQTV than for SQT following WBLFV exposure. WBLFV during the 6-week squat training program resulted in greater acute improvements in power output and jump height for both jump conditions compared to SQT alone.

Effects of 6 weeks of periodized squat training with or without whole-body vibration on short-term adaptations in jump performance within recreationally resistance trained men.

The purpose of this study was to examine the effects of a 6-week, periodized squat training program, with or without whole-body low-frequency vibration (WBLFV), on jump performance. Males ranged in age from 20 to 30 years and were randomized into groups that did squat training with (SQTV, n = 13) or without (SQT, n = 11) vibration, or a control group (CG, n = 6). Measures of jump height (cm), peak power (Pmax), Pmax per kilogram of body mass (Pmax/kg), and mean power were recorded during 30-cm depth jumps and 20-kg squat jumps at weeks 1 (pretraining), 3 (midtraining), and 7 (posttraining). No significant group differences were seen for 30-cm depth jump height between weeks 1 and 7 (p > 0.05). Trial three (W7) measures were greater than those for trial two (W3) and trial one (W1) (p < 0.05). Significant group differences were seen for 20-kg squat jump height, with SQTV > SQT between weeks 1 and 7 (p < 0.05). Significant trial differences were seen, with W7 > W3 > W1 (p < 0.05) as well as for 30-cm depth jump Pmax percent change (W7 > W3 and W1 p < 0.05)). A significant trial effect was seen for 20-kg squat jump Pmax (W7 > W1, p < 0.05) and 20-kg squat jump Pmax/kg percent change (W7 > W3 > W1, p < 0.05). The addition of vibration to SQTV seemed to facilitate Pmax and mean power adaptation for depth jumps and Pmax for squat jumps, although not significantly (p > 0.05). Stretch reflex potentiation and increased motor unit synchronization and firing rates may account for the trends seen. Baseline squat strength, resistance training experience, and amplitude, frequency, and duration of application of WBLFV seem to be important factors that need to be controlled for.

Effects of age and ACL reconstruction on quadriceps gamma loop function.

BACKGROUND AND PURPOSE: Both aging and anterior cruciate ligament (ACL) reconstruction are associated with strength deficits, which can in turn influence performance of activities of daily living. Thus it is informative to understand mechanisms underlying strength deficits. Age-related declines in strength follow reductions in muscle fiber numbers and size, whereas strength deficits following ACL reconstruction may be caused by the loss of intraligamentous mechanoreceptors. A common link between these conditions is the gamma spindle system, or the gamma loop. Appropriately applied vibration can affect the gamma loop by causing disruption of afferent feedback to a muscle and result in decreased force capabilities. We investigated the effect of age and ACL reconstruction on gamma loop function. METHODS: Maximal isometric strength (MVC) and electromyography (EMG) of the quadriceps were quantified before and after vibration stimulation of the infrapatellar tendon of 3 groups: young healthy (n=4; mean age=23.8 yrs), young ACL reconstructed (n=7; mean age=22.4 yrs), and older healthy (n=4; mean age=66.1 yrs) individuals. RESULTS: The quadriceps MVC, vastus lateralis EMG, vastus medialis EMG, and rectus femoris EMG declined significantly in the young healthy group following vibration stimulation to the infrapatellar tendon, which indicated an intact gamma loop. There were no changes in these variables for the old healthy and ACL reconstructed groups. CONCLUSION: Gamma loop function was impaired in both the older and ACL reconstructed groups possibly due to either decreased muscle spindle sensitivity or the loss of mechanoreceptors.