Is obesity associated with impaired reaction time in youth?

Distractive Tasks and the Influence of Driver Attributes

Driver distraction is a major problem nowadays, contributing to many deaths, injuries, and economic losses. Despite the effort that has been made to minimize these impacts, considering the technological evolution, distraction at the wheel has tended to increase. Not only tech-related tasks but every task that captures a driver’s attention has impacts on road safety. Moreover, driver behavior and characteristics are known to be heterogeneous, leading to a distinct driving performance, which is a challenge in the road safety perspective. This study aimed to capture the effects of drivers’ personal aspects and habits on their distraction behavior. Following a within-subjects approach, a convenience sample of 50 drivers was exposed to three unexpected events reproduced in a driving simulator. Drivers’ reactions were evaluated through three distinct models: a Lognormal Model to make analyze the visual distraction, a Binary Logit Model to explore the adopted type of reaction, and a Parametric Survival Model to study the reaction times. The research outcomes revealed that drivers’ behavior and perceived workload were distinct when they were engaged in specific secondary tasks and for distinct drivers’ personal attributes and habits. Age and type of distraction showed statistical significance regarding the visual behavior. Moreover, reaction times were consistently related to gender, BMI, sleep patterns, speed, habits while driving, and type of distraction. The habit of engaging in secondary tasks while driving resulted in a cumulative better performance.

Impact of obesity on central processing time rather than overall reaction time in young adult men

BACKGROUND AND PURPOSE

The association between weight status with simple cognitive tasks such as reaction time (RT) may not be observed in young people as cognitive functioning development has reached its peak. In the present study, we aimed to examine the association between overall and central adiposity with overall and central processing of RT in a sample of young adult men with different weight status from Ardabil, Iran.

METHODS

Eighty-six young males between June-July 2018 completed RT tests as well as premotor time (PMT) using surface electromyography changes in isometric contraction response to an audio stimulus.

RESULTS

No significant associations were observed between RT and PMT and different body mass index categories (underweight, normal weight, overweight and obese), as well as fat mass and fat to skeletal muscle mass ratio quartiles (Q). However, participants with greater waist to height ratio (WHtR) had longer PMT (but not RT) than their peers with lower WHtR (Q3 than Q2 and Q1 groups; p < 0.05, d = 1.23). Participants in the skeletal muscle mass quartile Q2 tended to have longer RT than participants in Q3 in an adjusted comparison model (p = 0.05, d = 0.72).

CONCLUSIONS

Although the association between weight status and RT might be elusive in young adults, our results show that higher central adiposity is negatively associated with PMT in young adults. Longitudinal studies are needed to explore the changes in obesity indexes and process speed in longer terms.

LEVEL OF EVIDENCE

Level I, experimental study.