Central Executive Network

What is the central executive network?

Responsible for tasks and decision making, the central executive network (CEN) acts as “the external mind.”

As one of the dominant control networks in the brain, the CEN performs high-level cognitive tasks, and works alongside or in anticorrelation with the other six main brain networks.

The CEN engages in:

    • Active tasks and external thinking involving working memory1
    • Controlled processing of information2
    • Integration of information from the other brain networks3
    • Rule-based problem solving and decision making4
    • Consideration of multiple, independent stimuli and independent factors5,6
    • Organizing behavior based on internal drives, subjective preferences, and choices7
    • Reinforce visually learned behaviors

With the ability to designate actions as one of dominant control networks, the CEN plays a critical role in the brain.

CEN_new

Role of the CEN

 

The central executive network exists as a superordinate control network.8 It uses input from other networks for task selection and executive function. By integrating with the other brain networks, the CEN processes a varied set of information, such as flexibility, working memory, initiation, and inhibition,8 all of which had previously been thought to be separate processes.

The CEN as the brain’s external mind

 

As the dominant control network for task selection and behavior, the CEN’s actions do not exist in a vacuum. It uses input from other brain networks to evaluate internal drives and personal preferences to ultimately guide an individual’s choices.7

When your stomach starts to feel hungry and you think about grabbing a tasty snack before dinner, your sensorimotor network and limbic system are processing these base sensations.

They lead you to think, “I want food,” and the CEN then sets the drive to get up and search for a bite to eat. As the CEN executes this internal drive, it is also responsible for your subjective preferences and choices.

When you arrive in the kitchen, you see a bowl of apples and a jar of cookies. You may think to yourself, “I prefer cookies,” because they would be your preference.7 However, after weighing your options, you ultimately decide, “I choose the apple,” because you opted to make a healthier choice.7

While this is an over-simplified example, the CEN is capable of processing drives, preferences, and choices ranging from the uncomplicated (apples versus cookies) to the complex (predicting moves in a game of chess or analyzing the stock market).7

It’s also worth noting that while other networks — like the sensorimotor network and limbic system — process external inputs and stimuli based on raw input and emotions. The CEN then has the agency to consider these instinctual inputs, independent variables, or stimuli8 to make choices and direct further action.

Discovery of the CEN

 

At the turn of the century, neuroscientists were looking to better understand the difference between the internal and external mind.

Studies began to evaluate the brain’s activation during resting states and self-referential processing.9 By measuring the brain’s activity when it was not engaged in attention-based tasks, Raichle et al. identified the brain’s default mode network (DMN)9 in 2001.

Later studies then examined the brain’s attention and executive control10 to identify areas engaged during task processing. Whilst the prefrontal cortex (PFC) had previously been implicated in cognitive control,11 the intricate mechanisms underpinning this role of the PFC were limited.12 In 2006, Dosenbach and colleagues extended our understanding by discovering that localized brain areas within the frontal lobe were consistently activated during nearly all specified tasks.13 These areas were later grouped as part of the dorsal attention network (DAN).

However, the picture was still incomplete.

As neuroscientists analyzed the difference between these two external- and internal-focused networks, it became apparent that a third network was also in play.6

The 2006 Dosenbach and colleagues study also identified additional areas for task control in the prefrontal region13 spatially positioned between the DMN and DAN.6 These areas were less consistently activated during task control, indicating they may have different functions. Subsequent studies began to delineate these functional areas by splitting them into two distinct attention- and control-focused networks.2,6,14

The key areas for task control are now considered constituents of the CEN.

Location of the central executive network in the brain

 

Since its initial discovery in the anterior frontal lobe,15 the central executive network has been found to be functionally connected (see Connectomics) to regions in the anterior cingulate cortex,15 the inferior parietal lobe,6 and the posterior most portions of the middle and inferior temporal gyri. 16,17

CEN_AXI AXIAL VIEW
CEN_SAG SAGITTAL VIEW
CEN_COR CORONAL VIEW

Asymmetry

 

The CEN also contains one of the few asymmetries in the brain’s connectome. Functional areas 8va in the frontal lobe and PGs in the parietal lobe are present only in the right hemisphere of the CEN. In the left hemisphere, these areas are functionally connected to the default mode network.

 

8Av_a
8Av_a

Left to right: Areas 8va and PGs - connected to the DMN on the left hemisphere of the brain.

Integration with other networks

 

As one of the brain’s dominant control networks, the central executive network works closely with each of the brain’s other main networks.

Like previously mentioned, the CEN correlates with the DAN for attention processing, as well as visual spatial planning.8

The CEN’s external mind is also anticorrelated with the DMN’s internal mind, which focuses on reflective, task-negative processes.18,19In healthy brains, the CEN and DMN have been shown to specifically alternate activity, forming a pair of anticorrelated networks.3 When the CEN is active, such as when processing visual or sensory inputs for task selection, the DMN is inactive; conversely, when the DMN is activated, such as during contemplation or daydreaming, the CEN is deactivated.20

The salience network (SN) is responsible for the switch between the CEN and DMN for external and internal processing.21

To return to our kitchen analogy, if you were hungry but decided you were not interested in eating either an apple or cookies, you could make a sandwich. The CEN begins issuing directives to locate the items you would need: a plate, bread, deli meat, and condiments.

Once you have assembled the sandwich and started eating, active task processing is no longer required. Your mind can then start to wander. If you begin thinking about your plans for the weekend or recalling something that happened earlier in the day, the salience network has imperceptibly switched your brain’s dominant control from the CEN to the DMN.

In addition to its relationship with the SN and DMN, the central executive network also integrates with each of the other networks as needed for task processing. The CEN:

  • Receives visual inputs from the visual network
  • Evaluates auditory inputs from the auditory network
  • Receives sensory inputs from the sensorimotor network while also sending back task directives8
  • Processes stimuli and motivational signals from the limbic system

 

Challenges for the central executive network

 

As the external mind, the CEN is in charge of receiving inputs and setting tasks. This occurs by forming top-down selection processes7 to achieve certain goals. Yet, since the CEN is designed to focus on individual actions, it may be physically incapable of multitasking.

It’s a common school of thought in education and business that multitasking is worse for a person’s productivity.22,23 However, studies have only recently begun to look at how multitasking may be difficult neurologically.24

A 2006 study demonstrated that functional areas of the CEN in the lateral prefrontal cortex may follow a “serial principle”25 to guide individual action and task selection.25 By using “task queuing,”25 the CEN is thought to sequence tasks to be executed one after the other.25

It has been speculated that the frontopolar prefrontal cortex could overcome the difficulty in processing multiple tasks with joint consideration7 or by transferring information between different brain networks to aid in simultaneous processing.6,12 However, it is possible there would still be a task delay when attempting to perform two tasks at once. This delay then would lead to one of the two tasks being relegated to a secondary process.25

Though it may struggle with multitasking, in healthy brains the CEN can still quickly and efficiently execute numerous tasks as needed.

That being said, when the CEN or one of its closely correlated or anticorrelated networks acts irregularly, processing changes can manifest in many types of mental illnesses.

CEN's impact on pathology and medicine

 

Since the CEN interacts so closely with other large-scale brain networks, it has been implicated in many neuropsychiatric disorders.

Aberrant switching between the CEN and DMN as a result of an over- or underactive salience network has been demonstrated as a symptom of schizophrenia26 and post-traumatic stress disorder (PTSD).27

A 2018 study further demonstrated that impaired functional connectivity between the cerebellum and the CEN may be a symptom of bipolar II depression, due to difficulty maintaining cognitive and emotional control.28

Similarly, if the CEN becomes overactive, it may possibly be implicated in obsessive-compulsive disorder when it cannot adequately control response inhibition or planning.29 Likewise, reduced functional connectivity with the amygdala may contribute to generalized anxiety disorder,30 as well as problems with cognitive control of social anxiety.31

Changes in the large-scale, dominant control networks may also contribute to attention-deficit/hyperactivity disorder (ADHD). There may be weaker connectivity between-network and less persistent cross-network interactions,32 which could lead to inattention or overactivity.

Interestingly, since irregularities in the CEN may correlate with lack of focus or abnormal levels of reaction, it has also been speculated that trait mindfulness activities used in meditation may correlate with an increase or strengthening in the functional connectivity of the CEN.33

Since the CEN is still a fairly recent discovery, there is much to be studied about how changes within this network can impact the brain, as well as possible opportunities for treatment. Due to the brain’s plasticity and ability to change, continuing study of the CEN and its relationships with other brain networks offer promising opportunities for change.

Discover the key roles of other brain networks as they function alongside the central executive network.

Reference list

 

  1. Dosenbach NU, Fair DA, Miezin FM, et al. Distinct brain networks for adaptive and stable task control in humans. Proc Natl Acad Sci U S A. 2007;104(26):11073-11078. doi:10.1073/pnas.0704320104
  2. Dosenbach NU, Fair DA, Miezin FM, et al. Distinct brain networks for adaptive and stable task control in humans. Proc Natl Acad Sci U S A. 2007;104(26):11073-11078. doi:10.1073/pnas.0704320104
  3. Baker CM, Burks JD, Briggs RG, et al. A connectomic atlas of the human cerebrum—Chapter 7: The lateral parietal. In: A Connectomic Atlas of the Human Cerebrum Supplement. Oper Neurosurg. 2018;15:S295-S349. doi:10.1093/ons/opy261
  4. Menon V. Large-scale brain networks and psychopathology: a unifying triple network model. Trends Cogn Sci. 2011;15(10):483-506. doi:10.1016/j.tics.2011.08.003

  5. Kroger JK, Sabb FW, Fales CL, Bookheimer SW, Cohen MS, Holyoak KJ. Recruitment of anterior dorsolateral prefrontal cortex in human reasoning: a Parametric study of relational complexity. Cerebral Cortex. 2002;12(5):477-485. doi.org/10.1093/cercor/12.5.477
  6. Vincent JL, Kahn I, Snyder AZ, Raichle ME, Buckner RL. Evidence for a frontoparietal control system revealed by intrinsic functional connectivity [published correction appears in J Neurophysiol 2011 Mar;105(3):1427]. J Neurophysiol. 2008;100(6):3328-3342. doi:10.1152/jn.90355.2008
  7. Koechlin, E. Architecture of central executive functions in the human prefrontal cortex. 2007. https://www.princeton.edu/~yael/NIPSWorkshop/KoechlinAbstract.pdf. Accessed January 28, 2021.
  8. Niendam TA, Laird AR, Ray KL, Dean YM, Glahn DC, Carter CS. et al. Meta-analytic evidence for a superordinate cognitive control network subserving diverse executive functions. Cogn Affect Behav Neurosci. 2012;12:241-268. doi.org/10.3758/s13415-011-0083-5
  9. Raichle ME, MacLeod AM, Snyder AZ, Powers WJ, Gusnard DA, Shulman GL. A default mode of brain function. Proc Natl Acad Sci U S A. 2001;98(2):676-682. doi.org/10.1073/pnas.98.2.676
  10. Fan J, McCandliss BD, Fossella J, Flombaum JI, Posner MI. The activation of attentional networks. Neuroimage. 2005;26(2):471-479. doi.org/10.1016/j.neuroimage.2005.02.004
  11. Miller EK. The prefrontal cortex and cognitive control. Nat Rev Neurosci. 2000;1(1):59-65. doi:10.1038/35036228
  12.  Koechlin E, Basso G, Pietrini P, Panzer S, Grafman J. The role of the anterior prefrontal cortex in human cognition. Nature. 1999;399(6732):148-151. doi:10.1038/20178
  13. Dosenbach NU, Visscher KM, Palmer ED, et al. A core system for the implementation of task sets. Neuron. 2006;50(5):799-812. doi:10.1016/j.neuron.2006.04.031
  14. Dosenbach NU, Fair DA, Cohen AL, Schlaggar BL, Petersen SE. A dual-networks architecture of top-down control. Trends Cogn Sci. 2008;12(3):99-105. doi:10.1016/j.tics.2008.01.001
  15. Boschin EA, Piekema C, Buckley MJ. Essential functions of primate frontopolar cortex. [published correction appears in Proc Natl Acad Sci U S A 2015;112(13):E1690]. Proc Natl Acad Sci U S A. 2015;112(9):E1020-E1027. doi:10.1073/pnas.1419649112
  16. Bilevicius E, Kolesar TA, Smith SD, Trapnell PD, Kornelsen J. Trait emotional empathy and resting state functional connectivity in default mode, salience, and central executive networks. Brain Sci. 2018;8(7):128. doi.org/10.3390/brainsci8070128
  17. O'Neill A, Mechelli A, Bhattacharyya S. Dysconnectivity of large-scale functional networks in early psychosis: A meta-analysis. Schizophr Bull. 2019 Apr;45(3):579-590. doi:10.1093/schbul/sby094
  18. Greicius MD, Menon V. Default-mode activity during a passive sensory task: Uncoupled from deactivation but impacting activation. J Cogn Neurosci. 2004;16(9):1484-1492. doi.org/10.1162/0898929042568532
  19. Chand GB, Hajjar I, Qiu D. Disrupted interactions among the hippocampal, dorsal attention, and central-executive networks in amnestic mild cognitive impairment. Hum Brain Mapp. 2018;39:4987-4997. doi.org/10.1002/hbm.24339.
  20. Goulden M, Khusnulina A, et al.The salience network is responsible for switching between the default mode network and the central executive network: Replication from DCM.
    NeuroImage. 2014;99:180-190. doi.org/10.1016/j.neuroimage.2014.05.052
  21. Seeley WW. The salience network: a neural system for perceiving and responding to homeostatic demands. J Neurosci. 2019;39(50):9878-9882. doi.org/10.1523/jneurosci.1138-17.2019
  22. Bradberry T. Why smart people don’t multitask. Entrepreneur website. https://www.entrepreneur.com/article/288829. Published February 7, 2017. Accessed February 1, 2019.
  23. Ophir E, Nass C, Wagner AD. Cognitive control in media multitaskers. Proc Natl Acad Sci U S A. 2009;106(37):15583-15587. doi:10.1073/pnas.0903620106
  24. Uncapher MR, Wagner AD. Media multitasking, mind, and brain. Proc Natl Acad Sci U S A. 2018;115(40):9889-9896. doi:10.1073/pnas.1611612115
  25. Dux PE, Ivanoff J, Asplund CL, Marois R. Isolation of a central bottleneck of information processing with time-resolved FMRI. Neuron. 2006;52:1109-1120. doi:10.1016/j.neuron.2006.11.009
  26. Dong D, Wang Y, Chang X, Luo C, Yao L. Dysfunction of large-scale brain networks in schizophrenia: A meta-analysis of resting-state functional connectivity. Schizophr Bull. 2018;44(1):168-181. doi.org/10.1093/schbul/sbx034
  27. Daniels JK, McFarlane AC, Bluhm RL, et al. Switching between executive and default mode networks in posttraumatic stress disorder: alterations in functional connectivity. J Psychiatry Neurosci. 2010;35(4):258-266. doi:10.1503/jpn.090175
  28. Luo X, Chen G, Jia Y, et al. Disrupted cerebellar connectivity with the central executive network and the default-mode network in unmedicated bipolar II disorder. Front Psychiatry. 2018;9:705. doi:10.3389/fpsyt.2018.00705
  29. Chen Y, Meng X, Hu Q. Altered resting‐state functional organization within the central executive network in obsessive-compulsive disorder. Psychiatry Clin Neurosci. 2016;70:448-456. doi.org/10.1111/pcn.12419
  30. Kolesar TA, Bilevicius E, Wilson AD, Kornelsen J. Systematic review and meta-analyses of neural structural and functional differences in generalized anxiety disorder and healthy controls using magnetic resonance imaging. Neuroimage Clin. 2019;24:102016. doi.org/10.1016/j.nicl.2019.102016
  31. Qiu C, Liao W, Ding J. Regional homogeneity changes in social anxiety disorder: A resting-state fMRI study. Psychiatry Res Neuroimaging. 2011;194(1):47-53. doi.org/10.1016/j.pscychresns.2011.01.010
  32. Cai W, Chen T, Szegletes L, Supekar K, Menon V. Aberrant time-varying cross-network interactions in children with attention-deficit/hyperactivity disorder and the relation to attention deficits. Biol Psychiatry Cogn Neurosci Neuroimaging. 2018;3(3):263-273. doi.org/10.1016/j.bpsc.2017.10.005
  33. Doll A, Hölzel BK, Boucard CC, Wohlschläger AM, Sorg C. Mindfulness is associated with intrinsic functional connectivity between default mode and salience networks. Front Hum Neurosci. 2015;9:461. doi:10.3389/fnhum.2015.00461