Research On Brain Mechanism Of Visual Task Cognitive Decision Process With Different Difficulties

For cognitive decision-making of different task difficulties,a series of complex cognitive processing processes are implied before the decision is executed.Exploring the mechanism of brain activity in the visual cognitive decision-making process of different task difficulties is of great significance for us to understand and use the brain and develop brain-like artificial intelligence.However,the current studies on the brain mechanism in the cognitive decision-making process are less.There is a lack of a unified conclusion on the endogenous brain activity of the cognitive decision-making process,and also a lack of understanding of the interaction of information between the active brain regions.In response to the above two problems,this paper designed the experimental paradigm of cognitive decision-making under different task difficulty,and the scalp EEG signals of 15 healthy subjects during the experimental process were collected.Locate the EEG sources of the collected signals and build a dynamic causal network,so as to explore the changes in the brain's endogenous distribution during cognitive decision and the flow of information between active brain regions over time.The main work completed and results achieved in this paper are:(1)Design of experimental paradigm.The blurring of different definitions of the picture is realized,the recognition of the different definitions of the picture is defined as the task difficulty,and the button is used as the decision-making execution response.(2)Event-related potential(ERP)analysis of the cognitive decision-making process of different task difficulties.Through the behavioral recognition of decisionmaking reaction time and accuracy,the definition of pictures with significant differences in difficulty was determined.The EEG data of all subjects were superimposed average to obtain ERP,the N1 component representing the perception process in the early stage of the cognitive process,the D220 component representing the difficulty in the cognitive stage and the N300 component reflecting cognition are determined.(3)EEG source location of cognitive decision-making process under different task difficulties.The resource analysis of the ERP cognitive components in different stages shows that there is no obvious difference in the activated brain regions when cognitive decisions are made with different definitions of the pictures,but there are differences in time.The greater the difficulty of the task,the cognitive and decision-making stages the longer the time.In the early stage of cognition,the BA19 area of the occipital lobe(visual joint cortex)is activated to make a preliminary understanding of things;In the mid-stage of cognition,it is mainly the BA9 area of the frontal lobe(cognitive area)and the BA19 of the occipital lobe are performing cognitive functions,remembering,analyzing and discriminating the characteristics of things;After the end of the cognitive process and in the early stage of decision-making,the BA6(auxiliary sports area)and BA5 and BA7 areas(somatosensory joint area)exercise coordinate and plan to prepare for key movements according to the cognitive results.(4)Construction and analysis of dynamic causal networks.Based on the source location results,ADTF dynamic causal networks are constructed to obtain the change of information flow between the active areas of the brain in continuous time.The results show that,at different stages of cognition,when the picture clarity is different,there is a different degree of information coupling between the sources.The difference is that when the picture clarity is low,there is information exchange between the left and right hemispheres of the occipital lobe.Only the right hemisphere of the occipital lobe interacts with other areas,while the left occipital lobe does not.