The human reward system has been shown to be activated by a wide range of reinforcers, including food, money, sex, drugs, and beauty. Now, a recent fMRI study has found mesolimbic reward activation associated with humorous cartoons, providing a neurobiological link between theories of humour and hedonic processes in the brain.

Recent studies have reported inconsistent results regarding the loss of reward sensitivity in the aging brain. Although such an age effect might be due to a decline of physiological processes, it may also be a consequence of age-related changes in motivational preference for different rewards. Here, we examined whether the age effects on neural correlates of reward anticipation are modulated by...

In this paper, we propose a single sample path based algorithm with state aggregation to optimize the average rewards of singularly perturbed Markov reward processes (SPMRPs) with a large scale state spaces. It is assumed that such a reward process depend on a set of parameters. Differing from the other kinds of Markov chain, SPMRPs have their own hierarchical structure. Based on this special s...

This paper proposes a new heuristic algorithm suitable for real-time applications using partially observable Markov decision processes (POMDP). The algorithm is based in a reward shaping strategy which includes entropy information in the reward structure of a fully observable Markov decision process (MDP). This strategy, as illustrated by the presented results, exhibits near-optimal performance...

Considered are infinite horizon semi-Markov decision processes (SMDPs) with finite state and action spaces. Total expected discounted reward and long-run average expected reward optimality criteria are reviewed. Solution methodology for each criterion is given, constraints and variance sensitivity are also discussed.

The alternating renewal process is one of the renewal processes in renewal theory. It is widely used in inventory systems and queueing systems. In classical alternating renewal processes, one of the assumptions is that the on times and off times are independent random variables. The notion of a fuzzy set was introduced by Zadeh [1] who defined it as a generalized characteristic function. Recent...

Motivational signals influence a wide variety of cognitive processes and components of behavioral performance. Cognitive dysfunction in patients with childhood chronic fatigue syndrome (CCFS) may be closely associated with a low motivation to learn induced by impaired neural reward processing. However, the extent to which reward processing is impaired in CCFS patients is unclear. The aim of the...

Rats can learn to forage among olfactory cues to associate one with reward in only 3 massed trials. The learning is achieved in less than 10 min and results in a memory trace lasting at least 1wk week. To study the neuro-anatomical circuits involved in the memory formation we used immunoreactivity to the immediate early gene c-fos as a marker for neuronal activity induced by the learning. The p...