@article{HeinzelRiemerSchulteetal.2014,
  author    = {Heinzel, Stephan and Riemer, Thomas G. and Schulte, Stefanie and Onken, Johanna and Heinz, Andreas and Rapp, Michael Armin},
  title     = {Catechol-O-methyltransferase (COMT) genotype affects age-related changes in plasticity in working memory: a pilot study},
  series = {BioMed research international},
  journal   = {BioMed research international},
  publisher = {Hindawi Publishing Corp.},
  address   = {New York},
  issn      = {2314-6133},
  doi       = {10.1155/2014/414351},
  pages     = {7},
  year      = {2014},
  abstract  = {Objectives. Recent work suggests that a genetic variation associated with increased dopamine metabolism in the prefrontal cortex (catechol-O-methyltransferase Val158Met; COMT) amplifies age-related changes in working memory performance. Research on younger adults indicates that the influence of dopamine-related genetic polymorphisms on working memory performance increases when testing the cognitive limits through training. To date, this has not been studied in older adults. Method. Here we investigate the effect of COMT genotype on plasticity in working memory in a sample of 14 younger (aged 24-30 years) and 25 older (aged 60-75 years) healthy adults. Participants underwent adaptive training in the n-back working memory task over 12 sessions under increasing difficulty conditions. Results. Both younger and older adults exhibited sizeable behavioral plasticity through training (P < .001), which was larger in younger as compared to older adults (P < .001). Age-related differences were qualified by an interaction with COMT genotype (P < .001), and this interaction was due to decreased behavioral plasticity in older adults carrying the Val/Val genotype, while there was no effect of genotype in younger adults. Discussion. Our findings indicate that age-related changes in plasticity in working memory are critically affected by genetic variation in prefrontal dopamine metabolism.},
  language  = {en}
}
@article{HeinzelLorenzBrockhausetal.2014,
  author    = {Heinzel, Stephan and Lorenz, Robert C. and Brockhaus, Wolf-Ruediger and Wuestenberg, Torsten and Kathmann, Norbert and Heinz, Andreas and Rapp, Michael Armin},
  title     = {Working memory load-dependent brain response predicts behavioral training gains in older adults},
  series = {The journal of neuroscience},
  volume    = {34},
  journal   = {The journal of neuroscience},
  number    = {4},
  publisher = {Society for Neuroscience},
  address   = {Washington},
  issn      = {0270-6474},
  doi       = {10.1523/JNEUROSCI.2463-13.2014},
  pages     = {1224 -- 1233},
  year      = {2014},
  abstract  = {In the domain of working memory (WM), a sigmoid-shaped relationship between WM load and brain activation patterns has been demonstrated in younger adults. It has been suggested that age-related alterations of this pattern are associated with changes in neural efficiency and capacity. At the same time, WM training studies have shown that some older adults are able to increase their WM performance through training. In this study, functional magnetic resonance imaging during an n-back WM task at different WM load levels was applied to compare blood oxygen level-dependent (BOLD) responses between younger and older participants and to predict gains in WM performance after a subsequent 12-session WM training procedure in older adults. We show that increased neural efficiency and capacity, as reflected by more "youth-like" brain response patterns in regions of interest of the frontoparietal WM network, were associated with better behavioral training outcome beyond the effects of age, sex, education, gray matter volume, and baseline WM performance. Furthermore, at low difficulty levels, decreases in BOLD response were found after WM training. Results indicate that both neural efficiency (i. e., decreased activation at comparable performance levels) and capacity (i. e., increasing activation with increasing WM load) of a WM-related network predict plasticity of the WM system, whereas WM training may specifically increase neural efficiency in older adults.},
  language  = {en}
}
@article{HeinzelLawrenceKalliesetal.2015,
  author    = {Heinzel, Stephan and Lawrence, Jimmy B. and Kallies, Gunnar and Rapp, Michael Armin and Heissel, Andreas},
  title     = {Using Exercise to Fight Depression in Older Adults},
  series = {GeroPsych : the journal of gerontopsychology and geriatric psychiatry},
  volume    = {28},
  journal   = {GeroPsych : the journal of gerontopsychology and geriatric psychiatry},
  publisher = {Hogrefe},
  address   = {Cambridge, Mass. ; G{\"o}ttingen [u.a.]},
  issn      = {1662-9647},
  doi       = {10.1024/1662-9647/a000133},
  pages     = {149 -- 162},
  year      = {2015},
  abstract  = {Depression is the most prevalent psychiatric disorder in the general population. Despite a large demand for efficient treatment options, the majority of older depressed adults does not receive adequate treatment: Additional low-threshold treatments are needed for this age group. Over the past two decades, a growing number of randomized controlled trials (RCT) have been conducted, testing the efficacy of physical exercise in the alleviation of depression in older adults. This meta-analysis systematically reviews and evaluates these studies; some subanalyses testing specific effects of different types of exercise and settings are also performed. In order to be included, exercise programs of the RCTs had to fulfill the criteria of exercise according to the American College of Sports Medicine, including a sample mean age of 60 or above and an increased level of depressive symptoms. Eighteen trials with 1,063 participants fulfilled our inclusion criteria. A comparison of the posttreatment depression scores between the exercise and control groups revealed a moderate effect size in favor of the exercise groups (standardized mean difference (SMD) of -0.68, p < .001). The effect was comparable to the results achieved when only the eleven trials with low risk of bias were included (SMD = -0.63, p < .001). The subanalyses showed significant effects for all types of exercise and for supervised interventions. The results of this meta-analysis suggest that physical exercise may serve as a feasible, additional intervention to fight depression in older adults. However, because of small sample sizes of the majority of individual trials and high statistical heterogeneity, results must be interpreted carefully.},
  language  = {en}
}
@misc{KuschpelLiuSchadetal.2015,
  author    = {Kuschpel, Maxim S. and Liu, Shuyan and Schad, Daniel and Heinzel, Stephan and Heinz, Andreas and Rapp, Michael Armin},
  title     = {Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85151},
  year      = {2015},
  abstract  = {The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game "Angry Birds" before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the "Angry Birds" video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity.},
  language  = {en}
}
@article{KuschpelLiuSchadetal.2015,
  author    = {Kuschpel, Maxim S. and Liu, Shuyan and Schad, Daniel and Heinzel, Stephan and Heinz, Andreas and Rapp, Michael Armin},
  title     = {Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task},
  series = {Frontiers in psychology},
  journal   = {Frontiers in psychology},
  number    = {6},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-1078},
  doi       = {10.3389/fpsyg.2015.01683},
  year      = {2015},
  abstract  = {The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game "Angry Birds" before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the "Angry Birds" video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity.},
  language  = {en}
}
@article{HeinzelLorenzPelzetal.2016,
  author    = {Heinzel, Stephan and Lorenz, Robert C. and Pelz, Patricia and Heinz, Andreas and Walter, Henrik and Kathmann, Norbert and Rapp, Michael Armin and Stelzel, Christine},
  title     = {Neural correlates of training and transfer effects in working memory in older adults},
  series = {NeuroImage : a journal of brain function},
  volume    = {134},
  journal   = {NeuroImage : a journal of brain function},
  publisher = {Elsevier},
  address   = {San Diego},
  issn      = {1053-8119},
  doi       = {10.1016/j.neuroimage.2016.03.068},
  pages     = {236 -- 249},
  year      = {2016},
  abstract  = {As indicated by previous research, aging is associated with a decline in working memory (WM) functioning, related to alterations in fronto-parietal neural activations. At the same time, previous studies showed that WM training in older adults may improve the performance in the trained task (training effect), and more importantly, also in untrained WM tasks (transfer effects). However, neural correlates of these transfer effects that would improve understanding of its underlying mechanisms, have not been shown in older participants as yet. In this study, we investigated blood-oxygen-level-dependent (BOLD) signal changes during n-back performance and an untrained delayed recognition (Sternberg) task following 12 sessions (45 min each) of adaptive n-back training in older adults. The Sternberg task used in this study allowed to test for neural training effects independent of specific task affordances of the trained task and to separate maintenance from updating processes. Thirty-two healthy older participants (60-75 years) were assigned either to an n-back training or a no-contact control group. Before (t1) and after (t2) training/waiting period, both the n-back task and the Sternberg task were conducted while BOLD signal was measured using functional Magnetic Resonance Imaging (fMRI) in all participants. In addition, neuropsychological tests were performed outside the scanner. WM performance improved with training and behavioral transfer to tests measuring executive functions, processing speed, and fluid intelligence was found. In the training group, BOLD signal in the right lateral middle frontal gyrus/caudal superior frontal sulcus (Brodmann area, BA 6/8) decreased in both the trained n-back and the updating condition of the untrained Sternberg task at t2, compared to the control group. fMRI findings indicate a training-related increase in processing efficiency of WM networks, potentially related to the process of WM updating. Performance gains in untrained tasks suggest that transfer to other cognitive tasks remains possible in aging. (C) 2016 Elsevier Inc. All rights reserved.},
  language  = {en}
}
@misc{ChaparroZechHeinzeletal.2017,
  author    = {Chaparro, Camilo G. A. Perez and Zech, Philipp A. and Heinzel, Stephan and Mayer, Frank and Wolfarth, Bernd and Rapp, Michael Armin and Heissel, Andreas},
  title     = {Effects Of Aerobic \& Resistance Training On Cardiorespiratory Fitness In People Living with HIV. A Meta-analysis},
  series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  volume    = {49},
  journal   = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {0195-9131},
  doi       = {10.1249/01.mss.0000519265.28705.86},
  pages     = {842 -- 842},
  year      = {2017},
  language  = {en}
}
@misc{ZechRappHeinzeletal.2017,
  author    = {Zech, Philipp A. and Rapp, Michael Armin and Heinzel, Stephan and Wolfarth, Bernd and Lawrence, Jimmy B. and Heissel, Andreas},
  title     = {Does Exercise Help People Living with HIV Improve Their Quality of Life? A meta-analysis.},
  series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  volume    = {49},
  journal   = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {0195-9131},
  doi       = {10.1249/01.mss.0000518177.22369.2f},
  pages     = {470 -- 470},
  year      = {2017},
  language  = {en}
}
@article{HeinzelLorenzQuynhLamDuongetal.2017,
  author    = {Heinzel, Stephan and Lorenz, Robert C. and Quynh-Lam Duong, and Rapp, Michael Armin and Deserno, Lorenz},
  title     = {Prefrontal-parietal effective connectivity during working memory in older adults},
  series = {Neurobiology of Aging},
  volume    = {57},
  journal   = {Neurobiology of Aging},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0197-4580},
  doi       = {10.1016/j.neurobiolaging.2017.05.005},
  pages     = {18 -- 27},
  year      = {2017},
  abstract  = {Theoretical models and preceding studies have described age-related alterations in neuronal activation of frontoparietal regions in a working memory (WM)load-dependent manner. However, to date, underlying neuronal mechanisms of these WM load-dependent activation changes in aging remain poorly understood. The aim of this study was to investigate these mechanisms in terms of effective connectivity by application of dynamic causal modeling with Bayesian Model Selection. Eighteen healthy younger (age: 20-32 years) and 32 older (60-75 years) participants performed an n-back task with 3 WM load levels during functional magnetic resonance imaging (fMRI). Behavioral and conventional fMRI results replicated age group by WM load interactions. Importantly, the analysis of effective connectivity derived from dynamic causal modeling, indicated an age-and performance-related reduction in WM load-dependent modulation of connectivity from dorsolateral prefrontal cortex to inferior parietal lobule. This finding provides evidence for the proposal that age-related WM decline manifests as deficient WM load-dependent modulation of neuronal top-down control and can integrate implications from theoretical models and previous studies of functional changes in the aging brain.},
  language  = {en}
}
@misc{HeinzelRimpelStelzeletal.2017,
  author    = {Heinzel, Stephan and Rimpel, J{\´e}r{\^o}me and Stelzel, Christine and Rapp, Michael Armin},
  title     = {Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-401921},
  pages     = {15},
  year      = {2017},
  abstract  = {Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60-72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination.},
  language  = {en}
}