Effect of a short rest period on associative and relational memory performance: A Virtual Reality study

Virtual reality immerses individuals in 3D environments where spatial properties are similar to those of real life. Virtual reality can therefore be effective and relevant in the study of memory processing, especially when spatial properties are involved. We studied the effect of a 20-minute rest period on memory performance for associative and relational learnings. Eighty-one participants were placed in a virtual environment in which they learned 24 associations implicating objects and their respective precise location. As expected, the performance of associative memory was improved by a rest period between study and test phases. We discuss these results and the benefits of using an immersive virtual environment for such memory investigation. In addition, elaborating our environment was highly informative and led to several recommendations that we believe could be useful for researchers who would like to rely on virtual reality for investigating memory.

Influence of very short rest period lengths on repeated one maximun repetition bench press performance

Objective: The purpose of this investigation was to compare different rest period lengths between consecutive one maximum repetition bench press attempts on performance and ratings of perceived exertion. Method: Eighteen trained men (27.95 ± 4.25 years; 81.00 ± 9.21 kg; 174.62 ± 3.34 cm; bench press relative strength 1.33 ± 0.11 kg/kg of body mass) participated in three randomly ordered sessions that required two consecutive one maximum repetition bench press attempts with 20, 40, or 60-s rest between attempts. Results: The Cochran Q analysis showed no significant differences in the ability to successfully perform a second one maximum repetition attempt with 20, 40, or 60-s rest between attempts (p = 0.882). Specifically, no significant differences were found in the successful completion of the first and second attempts for the 20-s (p = 0.317), 40-s (p = 0.083), and 60-s (p = 0.157) trials, respectively. Briefly, for both 20 and 60-s rest conditions Δ% = 88.88% of subjects successfully performed the second attempt and, for the 40-s protocol, only Δ% = 83.33% completed. For the pre and post-set ratings of perceived exertion, the shorter rest period (20-s) promoted significantly higher values compared to the longer rest periods (pre-set ratings of perceived exertion, p = 0.04; post-set ratings of perceived exertion, p = 0.023). Conclusions: The results of this study can be applied to recreationally trained individuals with the intent of generating a time-efficient process for conducting a valid and reliable one maximum repetition bench press assessment.

Evidence for Reliable Individual Differences in Intra-Individual Variability

In reliability theory, the deviations in an individual's performance from his own mean score are referred to as error and the assumption is made that error scores in a series of repeated tests will be uncorrected. To test this assumption, 24 college males were given 175 RT trials a day for 5 days (the first day served as a warm-up session and was not used in the analyses). Within each test day, a short rest period was given following every block of 35 trials. When data were examined on a day-to-day basis, i.e., the total 175 trials per day were used, the reliability coefficients were high (.811 to .866); on a block-to-block within-days basis, i.e., the total 175 trials per day were subdivided into 5 blocks of 35 trials, the coefficients were lower but statistically significant (the average block-to-block correlations for test Days 1, 2, 3 and 4 were .639, .704, .734 and .646 respectively). Re-evaluation of reliability theory and its assumption that an individual's deviations from his own mean ability represent error is needed. Present data suggest these deviations from mean ability in a motor skill actually reflect a biological variability and, as such, should be referred to as intra-individual variability.