TY - CHAP A1 - Heinz, A. A1 - Kluge, U. A1 - Schouler-Ocak, M. A1 - Rapp, Michael A. T1 - Biological Effects of Social Exclusion T2 - European psychiatry : the journal of the Association of European Psychiatrists N2 - Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is similar to 17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern straptoothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates. Y1 - 2015 SN - 0924-9338 SN - 1778-3585 VL - 30 PB - Elsevier CY - Paris ER - TY - GEN A1 - Liu, S. A1 - Kuschpel, M. S. A1 - Schad, Daniel A1 - Heinzel, Stephan A1 - Rapp, Michael A. A1 - Heinz, A. T1 - Effects of rest on learning processes T2 - European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology Y1 - 2018 U6 - https://doi.org/10.1016/j.euroneuro.2017.12.099 SN - 0924-977X SN - 1873-7862 VL - 28 SP - S67 EP - S68 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sebold, Miriam Hannah A1 - Garbusow, Maria A1 - Jetzschmann, P. A1 - Schad, Daniel A1 - Nebe, S. A1 - Schlagenhauf, Florian A1 - Heinz, A. A1 - Rapp, Michael A. A1 - Romanczuk-Seiferth, Nina T1 - Reward and avoidance learning in the context of aversive environments and possible implications for depressive symptoms JF - Psychopharmacology N2 - Background Aversive stimuli in the environment influence human actions. This includes valence-dependent influences on action selection, e.g., increased avoidance but decreased approach behavior. However, it is yet unclear how aversive stimuli interact with complex learning and decision-making in the reward and avoidance domain. Moreover, the underlying computational mechanisms of these decision-making biases are unknown. Methods To elucidate these mechanisms, 54 healthy young male subjects performed a two-step sequential decision-making task, which allows to computationally model different aspects of learning, e.g., model-free, habitual, and model-based, goal-directed learning. We used a within-subject design, crossing task valence (reward vs. punishment learning) with emotional context (aversive vs. neutral background stimuli). We analyzed choice data, applied a computational model, and performed simulations. Results Whereas model-based learning was not affected, aversive stimuli interacted with model-free learning in a way that depended on task valence. Thus, aversive stimuli increased model-free avoidance learning but decreased model-free reward learning. The computational model confirmed this effect: the parameter lambda that indicates the influence of reward prediction errors on decision values was increased in the punishment condition but decreased in the reward condition when aversive stimuli were present. Further, by using the inferred computational parameters to simulate choice data, our effects were captured. Exploratory analyses revealed that the observed biases were associated with subclinical depressive symptoms. Conclusion Our data show that aversive environmental stimuli affect complex learning and decision-making, which depends on task valence. Further, we provide a model of the underlying computations of this affective modulation. Finally, our finding of increased decision-making biases in subjects reporting subclinical depressive symptoms matches recent reports of amplified Pavlovian influences on action selection in depression and suggests a potential vulnerability factor for mood disorders. We discuss our findings in the light of the involvement of the neuromodulators serotonin and dopamine. KW - Reward learning KW - Avoidance learning KW - Reinforcement learning KW - Computational psychiatry KW - Decision-making KW - Affective modulation KW - Depression symptoms Y1 - 2019 U6 - https://doi.org/10.1007/s00213-019-05299-9 SN - 0033-3158 SN - 1432-2072 VL - 236 IS - 8 SP - 2437 EP - 2449 PB - Springer CY - New York ER - TY - JOUR A1 - Sebold, Miriam Hannah A1 - Spitta, G. A1 - Gleich, T. A1 - Dembler-Stamm, T. A1 - Butler, Oisin A1 - Zacharias, Kristin A1 - Aydin, S. A1 - Garbusow, Maria A1 - Rapp, Michael A. A1 - Schubert, Florian A1 - Buchert, Ralph A1 - Gallinat, Jürgen A1 - Heinz, A. T1 - Stressful life events are associated with striatal dopamine receptor availability in alcohol dependence JF - Journal of neural transmission N2 - Stress plays a key role in modulating addictive behavior and can cause relapse following periods of abstinence. Common effects of stress and alcohol on the dopaminergic system have been suggested, although the precise mechanisms are unclear. Here, we investigated 20 detoxified alcohol-dependent patients and 19 matched healthy controls and assessed striatal D2/D3 availability using [F-18]-fallypride positron emission tomography and stressful life events. We found a strong association between striatal D2/D3 availability and stress in patients, but not in healthy controls. Interestingly, we found increased D2/D3 receptor availability in patients with higher stress levels. This mirrors complex interactions between stress and alcohol intake in animal studies and emphasizes the importance to investigate stress exposure in neurobiological studies of addiction. KW - Stressful life events KW - Dopamine D2 KW - D3 receptor KW - Positron emission tomography KW - Striatum KW - Alcohol dependence Y1 - 2019 U6 - https://doi.org/10.1007/s00702-019-01985-2 SN - 0300-9564 SN - 1435-1463 VL - 126 IS - 9 SP - 1127 EP - 1134 PB - Springer CY - Wien ER -