Auditory Virtual Reality for Insect Phonotaxis

Insects have a sophisticated ability to navigate real environments. Virtual reality (VR) is a powerful tool for analyzing animal navigation in laboratory studies and is the most successful when used in the study of visually guided behaviors. However, the use of VR with non-visual sensory information, such as sound, on which nocturnal insects rely, for analyzing animal navigation has not been fully studied. We developed an auditory VR for the study of auditory navigation in crickets, Gryllus bimaculatus. The system consisted of a spherical treadmill on which a tethered female cricket walked. Sixteen speakers were placed around the cricket for auditory stimuli. The two optical mice attached to the treadmill measured the cricket’s locomotion, and the sound pressure and direction of the auditory stimuli were controlled at 100 Hz based on the position and heading of the cricket relative to a sound source in a virtual arena. We demonstrated that tethered female crickets selectively responded to the conspecific male calling song and localized the sound source in a virtual arena, which was similar to the behavior of freely walking crickets. Further combinations of our system with neurophysiological techniques will help understand the neural mechanisms for insect auditory navigation.

Concussion in cricket: Clinical findings using Sport Concussion Assessment Tool and recovery timeframes

Objectives To retrospectively review data of concussed and non-concussed elite cricket athletes following head impact to describe which clinical features on the day of injury are associated with concussion diagnosis. A secondary aim was to describe the recovery time of concussed athletes. Design Retrospective cohort study. Methods This study reviewed five seasons of Sport Concussion Assessment Tool (SCAT) data and clinical records for elite male and female cricket athletes who sustained a head impact during a cricket match or training. Results Data from 30 concussed and 37 non-concussed athletes were compared. Symptoms of ‘don’t feel right’ and ‘feeling slowed down’ had the strongest clinical utility for a concussion diagnosis post head impact. Concussed athletes reported a significantly lower ‘percent of normal’ (median 60%, IQR 60–90%) compared to athletes who sustained a non-concussive head impact (median 99%, IQR 95–100%, p = 0.003). No other component of the SCAT distinguished concussed from non-concussed athletes on day of injury. Concussed athletes typically experienced symptom resolution within 2–8 days and completed a graded return to play protocol within 4–14 days. No differences in SCAT findings or recovery times were observed between genders. Conclusion The SCAT may be used as a clinical tool to assist in diagnosis of concussionin elite cricket athletes. The components of the SCAT with the greatest clinical utility on day of injury were athlete-reported symptoms and ‘percent of normal’. Concussed cricket athletes typically complete their graded return to play protocol within 14 days however individualised management is paramount.

Previous flight facilitates partner finding in female crickets

In the cricket Gryllus bimaculatus, flying occurs soon after the last imaginal molt and precedes the mating behavior in natural conditions. Here, we tested the hypothesis that flying may improve subsequent behavioral performance in a novel environment in female crickets. We developed a behavioral set-up to test female cricket responsiveness to male calling song as well as their ability to locate and find the source of the song. The male song was produced by a loudspeaker hidden behind the fabric wall of a spacious square arena. Forced flight prior to the test promoted female sexual searching behavior in the novel environment. After the flight, more females reached the hidden source zone, spent more time near the source and finally more of them climbed over the wall section immediately in front of the hidden loudspeaker. At the same time, their behavior in the arena did not differ from the control group when the calling song was not delivered, suggesting that flight exerts its behavioral effects by influencing sexual motivation. Our results support the suggestion that preceding intense locomotion facilitates sexual searching behavior of females in a novel environment.

Modification of Cooper’s 12-min Run Test to Predict Maximum Oxygen Uptake in Indian Cricketers

Cooper’s 12-minute run test (CRT) for prediction of maximum oxygen uptake (VO2max) has not yet been explored in Indian sportspersons. Present investigation was conducted to evaluate the applicability of CRT in Indian cricketers. 75 male and 45 female cricket players were randomly recruited from reputed cricket academies of Kolkata, India and were randomly assigned into the study group (male = 45, female = 25) and confirmatory group (male = 30, female = 20). Incremental cycle ergometer exercise was used for direct estimation of VO2max by expired gas analysis and the indirect prediction of VO2max (PVO2max) was performed by CRT method. The current protocol of CRT was found to be inapplicable in both the genders of Cricketers due to a significant difference between PVO2max and VO2max and a large limit of agreement between PVO2max and VO2max in the study groups. A significant correlation (r = 0.76 in males and r = 0.79 in females, p<0.001) was depicted between VO2max and distance covered in CRT. Regression equations were computed based on the significant correlation. The application of these equations in the confirmatory groups revealed an insignificant difference between PVO2max and VO2max and narrow limits of agreement. Standard errors of the estimate of the regression norms were also minimal. Therefore, modified equations are recommended for CRT application for valid and precise evaluation of cardiorespiratory fitness in terms of VO2max in male and female Indian cricketers.