Relationship Between Dopamine Based On Spontaneous Eye Blink Rate And Positive And Negative Learning

Dopamine function as an important neurotransmitter,includes several distinct dopamine pathways,one of which plays a major role in reward-motivated behavior,other brain dopamine pathways are involved in motor control.Numbers of researches indicated that EBR correlate with striatal DA closely.EBR is positively correlate with resting DA activity.A lot of researches proved DA increase or decrease due to psychinosis pharyngeus or medicine used correspond with high EBR and low EBR levels of individuals.In view of dopamine plays an important role on individuals' cognitive activity,some researchers come up with a “basal ganglia neural network model” to explain how dopamine modulate cognitive activity.Basal ganglia includes two types of DA receptors,these receptor systems interact to form a DA-modulated decision threshold for selecting responses and updating representations in the cortex.Specifically,a D1-rich direct pathway in the basal ganglia provides a‘Go' signal that facilitates updating of representations and selection of the response under consideration in the cortex,while a D2-rich indirect pathway provides a ‘No Go' signal that suppresses competing responses and representations.Importantly,whereas DA has excitatory effects on D1-driven Go signals,it is inhibitory on D2-driven No Go signals.As such,higher levels of DA(e.g.due to positive prediction errors)lower the decision threshold and promote gating by facilitating D1-driven Go signals and inhibiting the D2-driven No Go pathway,whereas at lower levels(e.g.due to negative prediction errors)it reduces inhibition of D2-driven No Go signals and thus facilitates response suppression and stability of cortical representations.Some researches prove that reinforcement learning ability of individuals who suffer form dopaminergic diseases accord with basal ganglia neural network model.However,there are some researches have paradoxical results.Previous studies applied different reward and punishment conditions,moreover,they have different subjects group.There are no such research investigate how dopamine modulate reinforcement learning fully at present,so it's meaningful to made further investigation about it.Three behavioral experiments were run by manipulating different reward and punishment conditions in our study.Experiment 1 used the probabilistic selection task to explore the role of dopamine modulate reinforcement learning of three different reward and punishment conditions:less reward and less punish(reward : punishment = 1:1),much reward and less punishment(reward :punishment = 5:1),less reward and much punishment(reward : punishment = 1:5).One hundred participants joined the experiment(including 83 females and 17 males),we recorded each participants EBR before the task,and each participant executed one experimental conditions only:three kinds of task condition.We recorded their response time and the error rate.The results of correlation analysis showed that: on condition of less reward and lesspunishment,individual's EBR follow an inverted-u-shaped association with positive learning;on condition of much reward and less punishment and of less reward and much punishment,individual's EBR had no significant relationship with positive learning or negative learning.Based on the results of experiment1,experiment 2 used the same task of experiment 1 with the same reward and punishment but increase reward and punishment value to verify the inverted-u-shaped between EBR and positive learning which find in experiment 1.Thirty-two participants joined the experiment(including 28 females and 4 males)and the result prove it is right.Based on the results of experiment1,experiment 3 used the same task of experiment 1 with different reward and punishment condition: much reward and less punishment(reward : punishment = 100:1),less reward and much punishment(reward : punishment = 1:100),fifty-two participants joined the experiment(including44 females and 8 males)and result show on condition of both,individual's EBR follow a nearly U shape association with negative learning(but not significant).In summary,whether reward and punishment consistent affect the role of dopamine plays on reinforcement learning.On condition of the same reward and punishment,individual's EBR follow an inverted-u-shaped association with positive learning,which reflect D1 receptor modulate positive learning and cognitive flexibility;on condition of much reward and less punishment(reward and punishment = 100:1),less reward and much punishment(reward and punishment = 1:100),individual's EBR follow a nearly U shape association with negative learning,which reflect D2 receptor modulate negative learning and cognitive stability.Dopamine via basal ganglion neural network model and dopamine self-regulation system modulate reinforcement learning.Our results presented here nicely complement researches on the role of dopamine modulate reinforcement learning.