DGIST Department of Brain & Cognitive Sciences Hyeon-Ae Jeon Hierarchical processing in the brain : The role of automaticity DGIST Department of Brain & Cognitive Sciences Hyeon-Ae Jeon 1

Definition of hierarchical processing Superordinate levels, operating over longer time scales, modulate subordinate processing (Broadbent, 1977; Newell, 1990). Mathematics Action Music Language 2

Why is hierarchical processing important? “The human architecture is built up of a hierarchy of multiple system levels and it cannot be otherwise structured.” (Allen Newell, 1994, Unified Theories of Cognition, p. 117). Human cognitive architecture is generally known as a complex system composed of substructures as in hierarchical processing. 3

Research questions Functional Connectivity Localization Structural The role of automaticity in hierarchical processing in language (first & second) and non-language Psycho-physiological interactions in hierarchical processing White matter tracks depending on the levels of automaticity in hierarchical processing 4

New approach to the hierarchical process Controlled Process Controlled Process Automatic Process Second language Non-language (a visual sequence process) First language Low Medium High Low Medium High High Language vs. Non-Language Controlled vs. Automatic 5

Posterior to anterior system for the controlled process Levels of Hierarchy Low High P<0.05 Posterior Anterior Low, L2 Medium, L2 Medium, NL High, L2 High, NL L2 (2nd language ) NL (Non-language) P<0.001 Gradient pattern (posterior to anterior) depending on the levels of hierarchy Jeon & Friederici, 2013 6

Hierarchical process & Degree of Automaticity Cognitive Control Hierarchical process & Degree of Automaticity Controlled Process Controlled Process Automatic Process Second language Non-language (a visual sequence process) First language Low Medium High Low Medium High High Controlled vs. Automatic Language vs. Non-Language → Gradient pattern (posterior to anterior) depending on the levels of hierarchy 7

Posterior confined system for the automatic process High Low Posterior region for the automatic process (L1) (NL) (L2) Anterior region for the controlled process High Low High Low Jeon & Friederici, 2015 8

Controlled Hierarchy Automatic Hierarchy Posterior to anterior gradient system as the level of hierarchy becomes higher Posterior confined system for automatic hierarchical processing Jeon & Friederici, 2015 9

Research questions Functional Connectivity Localization Structural The important role of automaticity in hierarchical processing Psycho-physiological interactions in the hierarchical process in mathematics Hierarchy 10

Mathematical hierarchy within the prefrotal cortex Mathematician with high automaticity Precentral Gyrus (posterior) Non-mathematician with low automaticity Pars Triangularis (anterior) Jeon & Friederici, 2016 11

Functional connectivity in mathematical hierarchy Precentral gyrus Superior parietal lobe Connectivity strength r= 0.469* Math Scores Precentral gyrus Low High Seed regions L R Math Scores r= -0.465* Connectivity strength Math Scores r= -0.507* Connectivity strength Low High Low High Putamen Caudate nucleus (*P < 0.05) Jeon & Friederici, 2016 12

Research questions Functional Connectivity Localization Structural The important role of automaticity in hierarchical processing Different functional connections depending on the levels of mathematical competence White matter tracks depending on the levels of automaticity 13

L1 hierarchical processing Positive correlation between mathematical automaticity and number of streamlines along the arcuate fasciculus L1 hierarchical processing The level of automaticity of hierarchical structures in mathematics is reflected even in the structural connectivity.

Research questions Functional Connectivity Localization Structural The importance of automaticity in hierarchical processing (Posterior to anterior vs. posterior confined) Different functional connections depending on the levels of mathematical competence Automaticity is reflected by the structural connectivity. 15

Future directions in other domains Hierarchies Changes With learning Regional interactions Changes from the anterior to posterior region with learning Hierarchical processing in other domains: actions or music Functional connectivity using resting state fMRI 16

jeonha@dgist.ac.kr cogneuro.dgist.ac.kr Thank you. jeonha@dgist.ac.kr cogneuro.dgist.ac.kr