Representation And Mechanism Of Natural Objects In The Ventral Visual Cortex

Objective:The ventral visual pathway of the human brain is considered to be the core brain area for object recognition,classification and processing.Previous studies have shown that vitality and real-world size information dimensions can visually classify objects,and show differences in neural activation representations of animals,large inanimate objects,and small inanimate objects in the ventral visual pathway;but in the inanimate objects category,the difference in neural activation representations of natural objects and manmade objects on the ventral visual pathway is still unclear.This experiment uses brain functional magnetic resonance(Function Magnetic Resonance Imaging,fMRI)scanning technology to study the differences in neural activation representations of natural objects,animals,and man-made objects in the ventral visual pathway.Methods:In this experiment,a total of 24 healthy people were recruited as subjects and participated in the fMRI scan experiment,including 12 male and female subjects,ranging in age from 19 to 28 years old,with an average age of 23.3 years old.We use neuroimaging AFNI software to analyze the whole brain activation of the scanned fMRI data,and select the region of interest(ROI)through the functional positioning scan data.Based on the ROI analysis,we extracted 3 categories in a single individual ROI.The activation β value of the object picture is used as the activation level of different types of object pictures in the ROI,and then we will extract the activation β value at the group level to repeatedly measure the variance distribution to compare the three categories of objects in the same ROI(animal,The activation distribution difference between plants and man-made objects)and objects in the three categories(large and small animals,large and small natural objects,and large and small man-made objects).Results:1.Whole brain activation analysis results:(1)There are significant differences in the activation distribution of animal pictures and manamde object pictures,manmade object pictures and natural object pictures,animal pictures and natural object pictures in the ventral visual pathway.(2)The ventral visual pathway shows significant activation of small animals,but there is no activation area for large animals;pictures of natural objects and pictures of manmade objects show a difference in the real-world size of activation.Images of large natural objects and images of large manmade objects are preferentially activated in the medial region of the ventral temporal cortex(VTC),small natural objects are preferentially activated in the posterior area of the VTC,and small artificial objects are preferentially activated in the lateral area of the VTC.And the lateral occipital cortex(LOC)near the brain area.2.Based on the results of ROI analysis:(1)In the parahippocampal place area(PPA)of the bilateral parahippocampal place area,there is a difference between the activation induced by artificial object pictures and the activation induced by natural object pictures and animal pictures.Significant differences,and this brain area shows preferential activation of pictures of large artificial objects and large natural objects;(2)In the face-selective brain area(FFA)of the bilateral fusiform gyrus,there are differences among the activations induced by the pictures of artificial objects and natural objects and animals,while the activations induced by the pictures of artificial objects and natural objects in this brain area show no obvious difference.(3)In the Occipital face area(OFA)of the bilateral occipital cortex,there is a significant difference among the activation induced by animal pictures and artificial object pictures and natural object pictures.This brain area shows preferential activation of pictures of small artificial objects,small animals,and small natural objects.(4)There is a significant difference among the activation of bilateral LOC induced by animal pictures,artificial object pictures,and natural object pictures.This brain area shows preferential activation only for pictures of small artificial objects.Conclusion:There are different neural representations of natural objects and artificial objects in the ventral visual pathway,and show activation of the real size information of natural objects,but the category difference between natural and artificial objects in the ventral visual pathway cannot be based on vitality.The dimensional information is distinguished.The neural representation of visual objects in the ventral visual pathway is the integration of visual information of multiple objects.Natural objects may be "intermediate objects" independent of animals and artificial objects,connecting the VTC from the lateral(animals)to the medial(inanimate objects)transition.