The effects of acute exercise intensity on episodic and false memory among young adult college students

© 2019 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License Background: Previous experimental work demonstrates that acute exercise may enhance episodic memory performance. However, limited research has examined the extent to which acute exercise influences false episodic memory production, and no studies, to date, have examined whether there is an intensity-specific effect of acute exercise on both true episodic and false episodic memories. Thus, the present experiment evaluated the effects of intensity-specific acute exercise on episodic memory and false episodic memory. Methods: A three-arm, parallel, between-group randomized controlled trial was employed in University setting, with participants (N=60; Mage = 20.8 years) randomized into a moderate-intensity exercise group (15-minute bout of treadmill exercise at 50% heart rate reserve), a high-intensity exercise group (15-minute bout of treadmill exercise at 80% heart rate reserve), or a control group (time-matched period of sitting).True episodic and false episodic memory were both assessed using 6 word-lists from the Deese-Roediger-McDermott (DRM) paradigm, including both a short-term recall and a delayed memory recognition assessment. Results: For the number of words recalled across each of the 6 lists, there was a significant main effect for list (P\u3c0.001, η2p=0.15), marginally significant main effect for group (P=0.07, η2p=0.09), but no list by group interaction effect (P=0.44, η2p=0.03). Those in the high-intensity exercise group recalled significantly (P\u3c0.05) more words than the control group. For the false episodic word recall, across various lists, high-intensity acute exercise was associated with a greater rate of false episodic memories. For the memory recognition task, there was no main effect for word type (P=0.46, η2p=0.01), group (P=0.4443, η2p=.03), word type by group interaction (P=0.44, η2p=0.03), recall by group interaction (P=0.4441, η2p=0.04), or word type by recall by group interaction (P=0.32, η2p=0.04). However, there was a main effect for recall (P\u3c0.001, η2p=.54) and a word type by recall interaction (P\u3c0.001, η2p=0.77). Conclusion: These findings suggest that acute high-intensity exercise may enhance true episodic memories, and, possibly, also increase the rate of false episodic memories. We discuss these findings in the context of how different acute exercise intensities may have unique and differential effects on underlying mechanistic processes related to true and false episodic memory

Mental imagery and acute exercise on episodic memory function

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Mental imagery is used extensively in the sporting domain. It is used for performance-enhancement purposes, arousal regulation, affective and cognitive modification, and rehabilitation purposes. The purpose of this experiment was to evaluate whether acute exercise and mental imagery of acute exercise have similar effects on cognitive performance, specifically memory function. A within-subject randomized controlled experiment was employed. Participants (N = 24; Mage = 21.5 years) completed two exercise-related visits (i.e., actual exercise and mental imagery of exercise), in a counterbalanced order. The acute-exercise session involved 10 min of intermittent sprints. The mental-imagery session involved a time-matched period of mental imagery. After each manipulation (i.e., acute exercise or mental imagery of acute exercise), memory was evaluated from a paired-associative learning task and a comprehensive evaluation of memory, involving spatial–temporal integration (i.e., what, where, and when aspects of memory). Bayesian analyses were computed to evaluate the effects of actual exercise and mental imagery of exercise on memory function. For the paired-associative learning task, there was moderate evidence in favor of the null hypothesis for a main effect for condition (BF01 = 2.85) and time by condition interaction (BF01 = 3.30). Similarly, there was moderate evidence in favor of the null hypothesis for overall (what-where-when) memory integration (BF01 = 3.37), what-loop (BF01 = 2.34), where-loop (BF01 = 3.45), and when-loop (BF01 = 3.46). This experiment provides moderate evidence in support of the null hypothesis. That is, there was moderate evidence to support a non-differential effect of acute exercise and mental imagery of acute exercise on memory function

Determination of focal mechanism solutions of the earthquakes with M≥4.0 occurred in the mainland of China during August to October 2023

In this paper，the regional full waveform inversion using the broadband waveforms recorded by China Seismic Network were conducted, and the focal mechanism solutions of the 26 earthquakes with M≥4.0 occurred in the mainland of China during August to October 2023 were obtained. The types of these focal mechanism solutions show 9 reverse faulting, 14 strike-slip faulting and 3 normal faulting

The Temporal and Spatial Evolution of Marathons in China from 2010 to 2018

The purpose of this study is to explore the spatial distribution pattern and influencing factors of the Chinese marathon. Geographic Information System (GIS) related spatial analysis tools were used to calculate the following: averaged nearest neighbor index, nuclear density analysis, and hot spot analysis amongst others. The spatial distribution evolution characteristics & influencing factors of 18 Chinese marathon events in year 2010, 129 in year 2015 and 342 in year 2018 were analyzed. The results show that: (a) In year 2010 Nearest neighbor ratio was 1.164714, Moran’s I was −0.010165 (type: Random), year 2015 was 0.502146, Moran’s I was 0.066267 (type: Clustered), and year 2018 was 0.531149, Moran’s I was 0.083485 (type: Clustered) ; (b) In year 2010 there was a 333.6 km search radius, The core circle of the Yangtze River Delta was adopted. In 2015 and 2018, the search radius of 556 km was adopted, which was respectively obtained from the core circle of the Yangtze River Delta, the core circle of Beijing-Tianjin-Hebei and the core circle of East China; (c) According to the Z value data, East China and North China in 2015 passed 95% of the confidence in 5 provinces and municipal hot spots, passed 90% of the confidence in 3 hot spots, and passed 95% of the confidence in Chongqing Cold Point. In 2018, East China, North China, Central Region and other eight provinces and cities hot spots passed 95% of the confidence, 4 hot spots passed 90% of the confidence, Tibet Autonomous Region cold spot passed 90% of the confidence. Conclusion: The overall distribution of marathon events is greater in the eastern region than the western region, greater in the southern region than the northern region, and greater in coastal regions than the inland regions; the nuclear density distribution has spread from the Yangtze River Delta mononuclear circle in 2010 to the core circle of the entire East China region. Moreover, it spread to North China, Central China, and South China; the distribution of hot spots spread from Shanghai, Jiangsu, and Zhejiang to the entire North China and East China regions. During the past 38 years of development of the Chinese marathon, it has been divided into three stages due to different political, economic and social environments

Pn wave velocity and anisotropy underneath the central segment of the North-South Seismic Belt in China

We present a Pn wave velocity and anisotropy model of the central segment of the North-South Seismic Belt in China, where there are numerous stable basins and active faults, making this segment attractive for extensive studies. The model was obtained by a tomographic analysis of 49,973 Pn wave phase readings collected by the China Earthquake Networks Center and temporary stations in Yunnan and Sichuan. The tomographic velocity model shows that the average Pn wave velocity is 8.06km/s; prominent high-velocity (high-V) anomalies are visible under the Sichuan Basin, the Zoige Basin and the Ordos block, which clearly outline their tectonic mar- gins. A pronounced low-velocity (low-V) zone is observed from the Songpan-Ganzi block to the Chuan-Dian and Daliangshan blocks, suggesting the presence of hot material upwelling. The station delay data show a gradual variation from negative to positive values, possibly reflecting a crustal thickness variation from the southwest to the northeast of the study area. A correlation between the Pn wave anisotropy and the distribution of velocity anomalies is observed: anisotropy is relatively weaker in the high-V anomaly zones beneath stable basins, while it is stronger in the low-V anomaly zones and the high-to-low-V anomaly transition zones. The high-resolution velocity and anisotropy tomographic model that we obtained could also provide a better understanding of the study area seismicity, since the occurrence of strong earthquakes seems to be related to the presence and strength of lateral heterogeneities at the uppermost mantle level

The effects of high-intensity interval exercise and hypoxia on cognition in sedentary young adults

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Background and Objectives: Limited research has evaluated the effects of acute exercise on cognition under different conditions of inspired oxygenation. Thus, the purpose of this study was to examine the effects of high-intensity interval exercise (HIE) under normoxia (inspired fraction of oxygen (FIO2): 0.209) and moderate hypoxia (FIO2: 0.154) on cognitive function. Design: A single-blinded cross-over design was used to observe the main effects of exercise and oxygen level, and interaction effects on cognitive task performance. Methods: Twenty inactive adults (10 males and 10 females, 19–27 years old) performed a cognitive task (i.e., the Go/No-Go task) before and immediately after an acute bout of HIE under normoxic and hypoxic conditions. The HIE comprised 10 repetitions of 6 s high-intensity cycling against 7.5% body weight interspersed with 30 s passive recovery. Heart rate, peripheral oxygen saturation (SpO2) and rating of perceived exertion were monitored. Results: The acute bout of HIE did not affect the reaction time (p = 0.204, η2 = 0.083) but the accuracy rate decreased significantly after HIE under both normoxic and hypoxic conditions (p = 0.001, η2 = 0.467). Moreover, moderate hypoxia had no influence either on reaction time (p = 0.782, η2 = 0.004) or response accuracy (p = 0.972, η2 \u3c 0.001). Conclusions: These results indicate that an acute session of HIE may impair response accuracy immediately post-HIE, without sacrificing reaction time. Meanwhile moderate hypoxia was found to have no adverse effect on cognitive function in inactive young adults, at least in the present study

Effects of acute exercise and learning strategy implementation on memory function

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Background and Objectives: Long-term potentiation (LTP), the functional connectivity among neurons, is considered a mechanism of episodic memory. Both acute exercise and learning are thought to influence memory via an LTP-related mechanism. Limited research has evaluated the individual and combined effects of acute exercise and learning strategy implementation (e.g., 3-R technique, cue-integration) on memory, which was the purpose of this study. Materials and Methods: For Experiment 1, participants (n = 80; Mage = 20.9 years) were randomized into one of four experimental groups, including Exercise + Learning (E + L), Learning Only (L), Exercise Only (E), and Control Group (C; no exercise and no learning strategy implementation). The exercise stimulus involved an acute 15-min bout of lower-intensity (60% of heart rate max) walking exercise and the learning strategy involved the implementation of the 3-R technique. Experiment 2 (n = 77; Mage = 21.1 years) replicated Experiment 1 but addressed limitations (e.g., exposure level of the memory task) from Experiment 1 and employed a higher-intensity bout of exercise (77% of heart rate max). Experiment 3 (n = 80; Mage = 21.0 years) evaluated these same four experimental conditions but employed a cue-integration learning strategy and a moderate-intensity bout of acute exercise (64% of heart rate max). Results: These three experiments demonstrate that both learning techniques were effective in enhancing memory and we also provided evidence of a main effect for acute exercise (Experiment 3). However, we did not observe consistent evidence of a learning by exercise interaction effect. Conclusions: We demonstrate that both acute exercise and different learning techniques are effective in enhancing long-term memory function

Severe hypoxia does not offset the benefits of exercise on cognitive function in sedentary young women

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Purpose: To examine the effect of acute moderate-intensity continuous exercise performed under normobaric severe hypoxia on cognition, compared to sea-level normoxia. Methods: Thirty healthy inactive women randomly performed two experimental trials separated by at least three days but at approximately the same time of day. Executive functions were measured during the follicular stage via an interference control task before (rest) and during exercise with 45% peak power output under normobaric normoxia (PIO 2 = 150 mmHg, FIO 2 = 0.21), and (2) hypoxia (PIO 2 = 87 mmHg, FIO 2 = 0.12, simulated at an altitude of 4000 m). Reaction time (RT), accuracy rate (AC), heart rate, ratings of perceived exertion, and peripheral oxygen saturation (SpO 2 ) were collected before and during exercise. Results: RT (p \u3c 0.05, η 2p = 0.203) decreased during moderate exercise when compared at rest, while a short bout of severe hypoxia improved RT (p \u3c 0.05, η 2p = 0.134). Exercise and hypoxia had no effects on AC (p \u3e 0.05). No significant associations were found between the changes of RT and SpO 2 under the conditions of normoxia and hypoxia (p \u3e 0.05). Conclusions: At the same phase of the menstrual cycle, a short bout of severe hypoxia simulated at 4000 m altitude caused no impairment at rest. RT during moderate exercise ameliorated in normoxia and severe hypoxia, suggesting that both exercise and short-term severe hypoxia have benefits on cognitive function in sedentary young women