Cognitive Mechanisms Of Average Representation

Statistical summary representation,also known as set coding,refers to the use of statistical indicators to characterize a set of similar sets of phenomena,and the statistical summary representation that has received the most attention from researchers is the average representation.The revelation of the cognitive mechanisms of statistical summary representations has attracted the interest of a large number of researchers.The inverse hierarchy theory can be used to explain the cognitive mechanisms of overall processing,including the cognitive mechanisms of statistical summary representations.According to this theory,(1)average representation is first a bottom-up feedforward process,where neural signals encoding members are pooled upward to form an overall representation.The result of the representation-the overall representation-is conscious,while the member representations that make up the whole are unconscious;(2)after the feedforward process,there is a top-down feedback process,which can help the recognition of member representations into consciousness after the formation of the overall representation.Direct validation of the inverse hierarchy theory is currently lacking in the field of average representation,such as what is the relationship between average representation and consciousness? Does mean representation require feedback?This dissertation examines whether average representations are consistent with the inverse hierarchy theory through two studies,Study 1 examines the relationship between average representations and member representations and consciousness,and Study 2 examines whether average representations and member representations require feedback.The continuous flicker breakthrough inhibition paradigm is an important means of investigating whether visual information processing requires awareness.In the continuous flicker breakthrough inhibition paradigm,researchers often disrupt the overall pattern of a stimulus by disrupting processing(scramble)while preserving lowlevel visual attributes such as luminance and contrast,and observe its effect on the time required to breakthrough inhibition into consciousness;if the time to breakthrough inhibition is shorter without disruption compared to disruption,then this visual stimulus can be processed under unconscious conditions.Study 1 used the continuous flicker breakthrough inhibition paradigm to test whether the average representation is consistent with the inverse hierarchy theory,i.e.,whether the average representation versus the member representation requires consciousness.A total of 3 experiments were included.Experiment 1 examined whether overall representations and member representations could be processed unconsciously by disrupting the overall pattern versus disrupting the member pattern.The results only revealed the disruption main effect of membership and not the disruption main effect of the whole,indicating that member representations can be formed unconsciously while whole representations cannot be formed unconsciously.Experiment 2 found that different types of the whole(homogeneous and heterogeneous)do not have an effect on the time of stimulus breakthrough inhibition,further indicating that the whole representation of the set cannot be formed unconsciously.Experiment 3 found no significant change in the amount of disruptive effects by varying the number of stimuli from the member-only mode to both member and whole modes,indicating that the whole mode has no effect on the amount of disruptive effects,further suggesting that the whole mode cannot be characterized under unconscious conditions.The results of Study I support the reverse hierarchy theory view that membership representations are unconscious,while holistic representations require consciousness.The purpose of Study II was to explore whether average representation relies on top-down feedback.Previously,in addition to the functional connectivity of TMS and brain imaging that can reveal whether there is feedback regulation of neural activity,behavioral studies can interfere with the feedback signal by postmasking(it is important to note that because the presentation of masked visual stimuli is not brief,visual stimuli can still enter consciousness and simply interfere with the feedback process of the neural signal)and observe whether behavioral performance is affected,and if an effect is found,it would indicate that this mental process relies on top-down feedback.In Study 2,by manipulating postmasking to interfere with the feedback process of neural signals,Experiment 4 found that mean representations were more correct in the unmasked condition compared to the masked condition,while performance on member representations was unaffected by postmasking,indicating that mean representations are feedback dependent,while member representations are not.Experiment 5 found that heterogeneous sets requiring average representation were affected by postmasking,while homogeneous sets not requiring average representation were not affected by postmasking,further indicating that average representation relies on top-down feedback.The present study concludes that(1)averaging representations is a processing process that requires consciousness,whereas membership representations do not require consciousness,which is consistent with the reverse hierarchy theory;and(2)averaging representations relies on top-down feedback,which is inconsistent with the reverse hierarchy theory.In conclusion,our findings partially support the reverse hierarchy theory.