Development of Cognitive Control

Overview

• Brain systems change dynamically at cellular, circuit, and systems levels, which underlies the shift to adult cognitive control.
• Examines existing data to present a new framework for understanding the brain's role in cognitive control development.
• Cognitive control is often better in adulthood through flexible combination of component processes like:
  • Inhibitory control.
  • Performance monitoring.
  • Working memory.
• Brain structure matures because of interactions of dopaminergic and GABAergic systems that contribute to:
  • Enhanced network synchronization
  • Improved signal-to-noise ratio.
• Specialization and strengthened connectivity in networks promote the shift to adult cognitive control.
• Adolescence is an adaptive period of heightened experience-seeking that allows for brain specialization that support cognitive control.

Keywords

• Development
• Cognitive control
• Networks
• Dopamine
• GABA
• Inhibition
• Working memory
• Performance monitoring

Introduction

• Describes cognitive control as the ability to coordinate behavior in a flexible, voluntary, and adaptive manner to achieve internal goals in a noisy and changing environment.
• Cognitive control relies on separate but interacting components:
  • Task-set switching
  • Task-set maintenance
  • Adaptive gating
  • Working memory
  • Response selection
  • Response inhibition
• Flexible integration of processes supporting online maintenance of goal-relevant information (working memory).
• These processes include suppression of competing, goal-irrelevant information (inhibitory control), and continuous evaluation of selected actions (performance monitoring).

Availability and Cognitive Control

• Cognitive control is present early in development, with implementation improving into adulthood.
• Development does not mean a new ability emerges, but that an existing set of cognitive functions continue to refine.
• This is supported by improved accuracy rates into adulthood on cognitive control tasks.
• Adolescents show dramatic improvements, but control is more variable than in adults.
• The shift to adult control is specifically interesting for understanding healthy and impaired cognitive development.
• Adolescence often happens between 10-16 years commonly.
• Puberty includes increased sensation and novelty seeking tendencies driven by desire for short-term rewards.
• The sensation and novelty behavior can lead to risk-taking and increased mortality rates, along with having implications for juvenile law.
• Major psychopathology can impair cognitive control.
• Limitations in cognitive control are thought to play a role in:
  • Adolescent risk-taking.
  • Emergence of psychopathology.
• Integration of component processes like inhibitory control, working memory, and performance monitoring, as well as modulation by motivational systems supports cognitive control.
• Researchers have studied these independently
• Neuroimaging has built a framework to look at relationships between brain systems supporting components of cognitive control.
• Development of individual component processes of cognitive control and maturation of associated brain networks are presented.
• There is evidence for an interactive component model of cognitive control.
• Brain systems-level change mechanisms extend understanding of the interplay between control and motivational systems in adolescence.
• Changes in dopaminergic signaling during adolescence, help improve the integration and maturation of cognitive control components.

Inhibitory Control

• Describes inhibitory control as the capacity to suppress a dominant, goal-incompatible response in favor of a planned, goal-directed response
• Even in infancy, children can exert inhibitory control.
• Throughout childhood and adolescence, inhibitory error rates decline
• fMRI studies have focused predominantly on the prefrontal cortex's function when characterizing age-related changes in core inhibitory control circuitry activation.
• Studies have found developmental increases and decreases in recruitment of prefrontal regions
• The effect of changes in how prefrontal systems impact the development of inhibitory control is unknown.
• More recent studies have found decreased prefrontal engagement with age correlating to improved performance
• Task-related prefrontal engagement decreased from childhood to adolescence in a longitudinal fMRI study investigating the performance of inhibitory control
• It can reflect reduced effort with age, paralleling adults under higher cognitive load
• Improved synchronization among relevant prefrontal systems may lessen local processing needs, which could lessen BOLD response.
• Activation increases with the dorsal anterior cingulate cortex (dACC).
• These results suggest that inhibitory control during adolescence increases from performance monitoring in the dACC.
• This is consistent with cross-sectional fMRI and extensive EEG studies.
• The ACC shows increased involvement as humans age when doing inhibitory control tasks, underlining how important integration is between component processes of cognitive control.

Performance Monitoring

• Performance monitoring focuses on the ability to supervise actions and their consequences.
• Conflict and error processing which rely on the ACC are needed.
• dACC assists inhibitory control through supervisory processing.
• Dorsal regions of the ACC connect strongly with premotor, supplementary motor & primary motor regions; insula; nucleus accumbens; dorsal striatum; lateral basal nucleus of the amygdala.
• Nociceptive data is received from the spinothalamic tract, and the dACC becomes an anatomical hub that combines data about pain, negative affect, and performance monitoring
• This may serve as a central data hub for networks that potentially show drawn-out development through adolescence.
• Increased ability to monitor performance is considered a key aspect of development.
• Increased dACC recruitment has been found in many studies.
• Electrophysiological data demonstrates an increased capability to monitor performance throughout adolescence via increased error-related negativity when errors occur.
• Due to the supervisory role of the performance monitoring system, developmental improvements are likely to help development for other components of cognitive control.

Working Memory

• The ability to maintain a representation online to guide goal-directed behavior.
• Frontoparietal and sensory regions maintain organization, supervision, and mnemonic qualities
• accuracy improves from childhood into late adolescence
• Overall accuracy appeared adult-like by adolescence in an oculomotor spatial working memory task.
• FMRI studies indicate that prefrontal-parietal cortical circuitry is utilized by children and adults alike
• Enhancements are related to enhancement of the recruitment of this circuitry.
• Improvements were related to increased activation of executive network regions and deactivation of default mode network regions.
• Developmental differences are greatest when manipulation or distraction suppression is needed.
• Integration of inhibitory control processes supports mature working memory.

Motivation via Rewards

• Importantly, cognitive control depends on interactions with reward circuitry given the presence of incentives.
• Inhibitory management improves to adult like levels when correct responses are rewarded during adolescence.
• In addition to increased activation of motivational systems(ex: ventral striatum), adolescents recruit control regions to a greater extent than adults when paired with a reward contingency.
• Motivational structures may boost behaviors to collect a reward, including cognitive management skills.

Network Development

• Cognitive control is driven by specialized networks
• Improvements are increasingly due to functional collaboration among specialized networks.
• Graph theoretical approaches allow researchers to define regional interactions from the temporal signature of spontaneous brain activity.
• Further this can be used to describe/understand how these interactions change with development.
• Structural networks are white matter pathways connecting localized brain regions and give a base for functional integration.
• The predisposition for brain regions to modulate activation with similar temporal dynamics at rest or during a task is refered to as functional networks
• Structural and functional networks are related, but function modulates structure.
• Basic aspects of structural and functional network are there before birth
• Throughout live they support greater systems-level integration among increasingly specialized networks by going through developmental modifications
• Body, brain, and environment interactions have an affect
• Plasticity facilitates specialization in which adolescence is notable as a period
• Developmental changes are measured by graph theoretical measurements that include:
  • Small-worldness.
  • Community structure.
  • Hubness.
  • Rich-clubness.
• Small-world architecture promotes efficient local and global information processing though highly clustered subnetworks Network segregation is the clustering of densely intraconnected processing brain regions that are specialized.
• Network integration relates to combining specialized data from distributed brain regions and networks.
• Both have key roles during development.
• Critical brain regions for network integration are refered to as hubs.
• Hubs make an intraconnected network between themselves.
• The intraconnected network supports global brain communication and interconnectivity.

Network Development in Adolescence

• Core components of structural network topology are evident by infancy
• Structural network segregation decreases from 12 to 30
• Network integration increases in adolescence
• Rich clubs become evident by 30 weeks gestation
• There is a proliferation of connections until childhood
• Aspects of rich club organization stabilize by childhood
• With adolescence additional nodes are integrated
• Canonical adult functional networks are observable by age two
• Small-worldness is present throughout childhood
• Hubs localize from the sensory cortices to the association cortices, changing in childhood
• Organization, number, and connectivity of the hub architecture become adult like in adolescence
• Functional rich-club organization becomes evident with slight increases in participating nodes in adulthood
• Foundational architecture provides a backbone for network specialization and integration with its early stabilization hub
• Increased integration is seen in connectivity between prefrontal hub regions and increased white matter integrity of frontoparietal tracts.
• Cognitive control supported by module integration of segregated parts of processes.
• Findings that children/adults show shift in prominence of local to distributed connectivity engagement that indicate changes were underminded from spurious effect.
• Modular organization has to be defined by the network's structure, rather than distance - Then integration/segregation defined by analytical ways sensitive to network structure

Neural Correlations and Ability for Cognitive Control

• Prolonged maturation of cognitive control ability happens with neural correlates
• Functional/structural network architecture in the brain supports interregional integration.
• Integration critical for mature cognitive management Integration of frontoparietal and cingulo-opercular improves with working memory
• Performance is associated with interaction between default mode network and those networks.
• Interactive component model based on dynamic interoperation of systems which underlie cognitive management (working memory, inhibitory control, monitoring).
• Components include distinct/overlapping brain regions that compliment and are integrated with other.
• Pairwise relation/regions bring connectivity weight that are current on task/set
• Connectivity patterns that facilitate task achievement reinforce it.
• DA Hebbian increases signal to noise/synchrony, which refines brain network structure
• During development these parts reinforce the ability for components to be timely/flexible. This is because of reduced reaction times.

Cognitive Control Development: Specialization of Cognitive Control

System level

• The brain shows alteration at molecular levels, gray matter reduction, and synaptic pruning
• Gray matter shows development through neocortex/subcortical, which includes striatum & thalamus' Enhancement of signal-noise ratio by pruning excess connections supporting complex cognitive control
• White matter pathways demonstrates linear increases (occipital-parietal)
• Integrity and speed significantly increases from myelination
• Positively correlated white matter integrity relates to cognitive performance + working memory.

Conclusion

• Findings suggest adolescent brain starting to reach stability in gray matter thinning, pruning, and increased myelination
• Changes facilitate new ability to function as an adult, though it's unreliable:excess synapses with poor neuronal may limit function.

Cellular - Level Changes

• Interactions between dopaminergic and reward control function with (GABA)ergic system network shaping
• Age shows changes in dopaminergic and (GABA)ergic systems changes by way of plasticity.
• Substantive change within systems are present throughout life, but specifically in adolescence
• Cortical GABA neurons set synchronized frequency while excitatory helps cognitive function (Gonzalez/lewis)
• Neocortical (GABA)ergic changes over development + synpatic markers improving too
• PV cells inhibitory that synapse post pyramidal
• Inhibitory pyramidal function has cellular mechanism underlying increased synchrony and peradolescence
• Increased (GABA) expression is in adolescence = higher synchrony through Hebbian to develop (EEG Uhthaas).
• Neuronal transitions are favored with external signals, like vision functions.
• DA function undergoes changes by impacting striatum and influence reward/emotions with limb cortex/executive (haber) Processing cognition/rewards also come because of this
• Expression synth receptors peaks during teen age/adolescence
• Cortical increase throughout (DLPFC and dACC) for activity. The peaks are unique to development of the teens