Germán Gómez-Herrero⋆, Wei Wu, Kalle Rutanen⋆, Miguel C. Soriano§, Gordon Pipa, and Raul Vicent... more Germán Gómez-Herrero⋆, Wei Wu, Kalle Rutanen⋆, Miguel C. Soriano§, Gordon Pipa, and Raul Vicente ⋆Department of Signal Processing, Tampere University of Technology, PO 553, 33101 Tampere, Finland Max Planck Institute for Brain Research, 60528 Frankfurt ...
Neural plasticity plays an important role in learning and memory. Reward-modulation of plasticity... more Neural plasticity plays an important role in learning and memory. Reward-modulation of plasticity offers an explanation for the ability of the brain to adapt its neural activity to achieve a rewarded goal. Here, we define a neural network model that learns through the interaction of Intrinsic Plasticity (IP) and reward-modulated Spike-Timing-Dependent Plasticity (STDP). IP enables the network to explore possible output sequences and STDP, modulated by reward, reinforces the creation of the rewarded output sequences. The model is tested on tasks for prediction, recall, non-linear computation, pattern recognition, and sequence generation. It achieves performance comparable to networks trained with supervised learning, while using simple, biologically motivated plasticity rules, and rewarding strategies. The results confirm the importance of investigating the interaction of several plasticity rules in the context of reward-modulated learning and whether reward-modulated self-organization can explain the amazing capabilities of the brain.
To investigate neuronal processing during short-term memory, we analyzed behavior-related modulat... more To investigate neuronal processing during short-term memory, we analyzed behavior-related modulations of coupling between signals on two spatial scales: ¢rst, very local multiunit activity and second, local ¢eld potentials. Coupling was assessed by spike ¢eld coher- ence using a new approach to overcome limitations in cases of low ¢ring rates. We demonstrate the reliability of our approach with simulated data.
One of the key findings supporting,the assembly hypothesis was found in recordings from,the prima... more One of the key findings supporting,the assembly hypothesis was found in recordings from,the primary,motor,cortex of behaving monkeys involved in a delayed pointing task [A. Riehle, S. Gru¨ n, M. Diesmann, A. Aertsen, Spike synchronization and rate modulation differentially involved in motor cortical function, Science 278 (1997) 1950–1953]. Based on the unitary event (‘UE’) method, the authors have shown,that excess
We investigate the influence of spike timing dependent plasticity (STDP) on the prediction proper... more We investigate the influence of spike timing dependent plasticity (STDP) on the prediction properties of recurrent microcircuits. We use sparsely connected networks in which the synaptic modifications introduced by STDP are complemented by two homeostatic plasticity mechanisms: synaptic normalization and intrinsic plasticity. In the presence of structured external input, STDP changes the connectivity matrix of the network such that the
Based on the frameworks of dual-process theories, we examined the interplay between intuitive and... more Based on the frameworks of dual-process theories, we examined the interplay between intuitive and controlled cognitive processes related to moral and social judgments. In a virtual reality (VR) setting we performed an experiment investigating the progression from fast, automatic decisions towards more controlled decisions over multiple trials in the context of a sacrificing scenario. We repeatedly exposed participants to a modified ten-to-one version and to three one-to-one versions of the trolley dilemma in VR and varied avatar properties, such as their gender and ethnicity, and their orientation in space. We also investigated the influence of arousing music on decisions. Our experiment replicated the behavioral pattern observed in studies using text versions of the trolley dilemma, thereby validating the use of virtual environments in research on moral judgments. Additionally, we found a general tendency towards sacrificing male individuals which correlated with socially desirable...
Germán Gómez-Herrero⋆, Wei Wu, Kalle Rutanen⋆, Miguel C. Soriano§, Gordon Pipa, and Raul Vicent... more Germán Gómez-Herrero⋆, Wei Wu, Kalle Rutanen⋆, Miguel C. Soriano§, Gordon Pipa, and Raul Vicente ⋆Department of Signal Processing, Tampere University of Technology, PO 553, 33101 Tampere, Finland Max Planck Institute for Brain Research, 60528 Frankfurt ...
Neural plasticity plays an important role in learning and memory. Reward-modulation of plasticity... more Neural plasticity plays an important role in learning and memory. Reward-modulation of plasticity offers an explanation for the ability of the brain to adapt its neural activity to achieve a rewarded goal. Here, we define a neural network model that learns through the interaction of Intrinsic Plasticity (IP) and reward-modulated Spike-Timing-Dependent Plasticity (STDP). IP enables the network to explore possible output sequences and STDP, modulated by reward, reinforces the creation of the rewarded output sequences. The model is tested on tasks for prediction, recall, non-linear computation, pattern recognition, and sequence generation. It achieves performance comparable to networks trained with supervised learning, while using simple, biologically motivated plasticity rules, and rewarding strategies. The results confirm the importance of investigating the interaction of several plasticity rules in the context of reward-modulated learning and whether reward-modulated self-organization can explain the amazing capabilities of the brain.
To investigate neuronal processing during short-term memory, we analyzed behavior-related modulat... more To investigate neuronal processing during short-term memory, we analyzed behavior-related modulations of coupling between signals on two spatial scales: ¢rst, very local multiunit activity and second, local ¢eld potentials. Coupling was assessed by spike ¢eld coher- ence using a new approach to overcome limitations in cases of low ¢ring rates. We demonstrate the reliability of our approach with simulated data.
One of the key findings supporting,the assembly hypothesis was found in recordings from,the prima... more One of the key findings supporting,the assembly hypothesis was found in recordings from,the primary,motor,cortex of behaving monkeys involved in a delayed pointing task [A. Riehle, S. Gru¨ n, M. Diesmann, A. Aertsen, Spike synchronization and rate modulation differentially involved in motor cortical function, Science 278 (1997) 1950–1953]. Based on the unitary event (‘UE’) method, the authors have shown,that excess
We investigate the influence of spike timing dependent plasticity (STDP) on the prediction proper... more We investigate the influence of spike timing dependent plasticity (STDP) on the prediction properties of recurrent microcircuits. We use sparsely connected networks in which the synaptic modifications introduced by STDP are complemented by two homeostatic plasticity mechanisms: synaptic normalization and intrinsic plasticity. In the presence of structured external input, STDP changes the connectivity matrix of the network such that the
Based on the frameworks of dual-process theories, we examined the interplay between intuitive and... more Based on the frameworks of dual-process theories, we examined the interplay between intuitive and controlled cognitive processes related to moral and social judgments. In a virtual reality (VR) setting we performed an experiment investigating the progression from fast, automatic decisions towards more controlled decisions over multiple trials in the context of a sacrificing scenario. We repeatedly exposed participants to a modified ten-to-one version and to three one-to-one versions of the trolley dilemma in VR and varied avatar properties, such as their gender and ethnicity, and their orientation in space. We also investigated the influence of arousing music on decisions. Our experiment replicated the behavioral pattern observed in studies using text versions of the trolley dilemma, thereby validating the use of virtual environments in research on moral judgments. Additionally, we found a general tendency towards sacrificing male individuals which correlated with socially desirable...
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