Synchronization of Independent Neural Ensembles in Human EEG during Choice Tasks.

During behavioral experiments, humans placed in a situation of having to choose between a more valuable but risky reward and a less valuable but guaranteed reward make their decisions in accordance with external situational factors and individual characteristics, such as inclination to risk or caution. In such situations, humans can be divided into "risk-inclined" and "risk-averse" (or "cautious") subjects. In this work, characteristics of EEG rhythms, such as phase-phase relationships and time lags between rhythms, were studied in pairs of alpha-beta and theta-beta rhythms.

[Impulsive Choice Improves the Cue Memory at an 8-arms Radial Maze Learning in Rats].

At the process of learning in an 8-arm radial maze the impulsive animals found the reinforced arms and ate the pellets faster, than self-control and ambivalent rats. They committed less working memory errors at the cue memory task, though there was no difference in the rate of learning and a number of errors of reference memory in animals of different groups. During reversion learning at the change of reinforced arms on unre- inforced, and vice versa, the impulsive animals spent less time to enter into the reinforced arms compared to other groups.

[Does Impulsivity Affect a Long-term and Working Memory in rats?].

In the present paper usingthe method of delay discounting three groups of animals were discovered: a) those that at choice between immediate weak and delayed strong rewards have chosen an immediate reinforcement (high impulsive rats); b) those that were able to inhibit its own behavior and get the delayed reinforcement (low impulsive rats); and c) the rats with both types of reactions. In the water maze the different groups of rats did find a hidden platform for different time, swum various distance and with different speed. The differences however were significant only at overall comparison (for all days and trials) of the above mentioned parameters of the water maze learning.

[Effect of Agonists and Antagonists of α2 Adrenergic Receptors on Choice of Reinforcement Value in Rats with Different Levels of Impulsivity].

The influence of drugs, agonist (clonidine) and antagonist (yohimbine) of α2-adrenergic receptors 5-HT2 on the behavior of rats tested by the method of choice to the value of reinforcement was investigated. Based on the selection of a rat the pedal for immediate poor and delayed valuable reinforcement rats were divided into 3 groups. Rats, in most cases, choosing valuable delayed reinforcements were classified as low-impulsive, those who mainly chosen poor immediate reinforcement to the high-impulsive group.

[Single and Network Neuron Activity of Subthalamic Nucleus at Impulsive and Delayed (Self-Control) Reactions in Choice Behavior].

During our experiments on cats was investigated the subthalamic neuron activity at different types of behavior in case of reinforcement choice depending on its value and availability. In chronic experiences the multiunit activity in subthalamic nucleus (STN) and orbitofrontal cortex (FC) has been recorded. Multiunit activity was analyzed over frequency and network properties of spikes.