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How The Brain Works: A Constructionist Approach to Mind-Brain Correspondence (Part 2)

article how the brain works

  October 17, 2024

Intrinsic Brain Architecture

The human brain is a remarkable system that relies on several interconnected networks to support perception, cognition, action, and emotion. These intrinsic brain networks serve as the foundation for both everyday activities and complex cognitive processes. Here, we explore the seven key brain networks based on the Yeo et al. (2011) model: Visual Network, Somatomotor Network, Dorsal Attention Network, Ventral Attention Network, Limbic Network, Frontoparietal Network, and Default Network. Each plays a unique role in supporting our interactions with the world, spanning sensory perception to introspective thought.

Before diving into the specific functions of each network, it's important to understand the constructionist view of brain function. This approach posits that the brain's functions are not rigidly localized but rather emerge from the dynamic interplay of different networks working in tandem. According to this view, cognitive and emotional functions are constructed from combinations of basic psychological processes distributed across multiple networks. This concept challenges the traditional view that specific brain regions or networks are solely responsible for discrete mental functions (Barrett, 2017).

This constructionist approach helps us appreciate how different networks collaborate in varying configurations depending on the context and task demands. For instance, the Frontoparietal Network may work in conjunction with the Default Network during introspective decision-making, illustrating how the brain flexibly adapts its resources to meet situational requirements. Let’s explore this mind-brain correspondence for each of the seven networks:

1. Visual Network (VN)

The Visual Network is primarily involved in processing visual stimuli and is located in the occipital lobe of the brain. It integrates information from the eyes to create coherent visual perception, including the recognition of shapes, colors, and motion. This network's activity is central during tasks that require high visual acuity, such as reading, facial recognition, and navigation through visual environments (Gazzaniga et al., 2018).

Task Domains: Visual perception, pattern recognition, and reading.

The VN provides us with the ability to interpret our surroundings, helping us understand where we are and what we see, thereby contributing to situational awareness.

2. Somatomotor Network (SMN)

The Somatomotor Network coordinates voluntary motor activities and processes sensory information related to touch. It encompasses regions such as the primary motor cortex and somatosensory cortex. The SMN allows for precise body movements and integrates sensory input to guide actions (Penfield & Boldrey, 1937).

Task Domains: Motor coordination, sensory integration, and proprioception.

The SMN supports our capacity to interact physically with the environment, providing feedback for our actions and allowing us to adapt our movements based on sensory information.

3. Dorsal Attention Network (DAN)

The Dorsal Attention Network is crucial for maintaining focus on specific tasks and processing spatial information. This network involves regions of the parietal and frontal cortex and plays a key role in goal-directed attention (Corbetta & Shulman, 2002). When we intentionally focus on a particular object or area, the DAN is activated, helping us ignore distractions.

Task Domains: Visual-spatial attention, goal-directed actions, and focused concentration.

The DAN enables us to stay on track during tasks, filter out irrelevant information, and maintain awareness of spatial relationships, which is particularly useful in activities like driving or playing sports.

4. Ventral Attention Network (VAN)

The Ventral Attention Network is involved in detecting unexpected, salient stimuli and directing attention to them. It includes regions such as the temporoparietal junction and ventral frontal cortex. The VAN is often activated in response to novel or behaviorally relevant stimuli that demand attention (Corbetta et al., 2008).

Task Domains: Stimulus-driven attention, reorienting to salient stimuli, and novelty detection.

The VAN allows us to rapidly reorient our focus to unexpected changes in the environment, such as a sudden movement or an unfamiliar sound, ensuring that we can respond appropriately to new information.

5. Limbic Network (LN)

The Limbic Network is involved in emotions, motivation, and memory. Key structures within this network include the amygdala, hippocampus, and parts of the prefrontal cortex. The LN is responsible for emotional experiences, memory consolidation, and the formation of affective responses (Phelps, 2004).

Task Domains: Core affect generation, reward processing, and memory encoding.

The Limbic Network shapes our emotional world, helping us evaluate experiences as rewarding or threatening, which in turn guides our behavior and decision-making processes.

6. Frontoparietal Network (FPN)

The Frontoparietal Network, also known as the Executive Control Network, is central to executive functions like problem-solving, decision-making, and working memory. It connects regions of the frontal and parietal cortex, allowing for flexible control of thoughts and actions (Miller & Cohen, 2001).

Task Domains: Cognitive flexibility, planning, and decision-making.

The FPN is what allows us to make plans, weigh options, and make decisions. It supports adaptive behavior, especially in novel situations where we need to exert conscious control over our actions.

7. Default Network (DN)

The Default Network, also known as the Default Mode Network, is most active when the brain is at rest and not engaged in specific tasks. It includes the medial prefrontal cortex, posterior cingulate cortex, and angular gyrus and is associated with self-referential thinking, mind-wandering, and memory retrieval (Raichle et al., 2001).

Task Domains: Self-reflection, autobiographical memory, and imagination.

The DN allows us to reflect on past experiences, imagine future scenarios, and form an understanding of ourselves and others. It plays a vital role in maintaining our sense of identity and processing social information.

Summary

The seven intrinsic brain networks operate in concert to support an array of cognitive, emotional, and sensory functions. These functions are not localized within single networks but rather emerge from the flexible interactions among multiple networks. Each network contributes uniquely to our experience, from perceiving the external environment to navigating complex social landscapes and forming our inner world. Understanding these networks helps to explain how different aspects of our behavior and cognition emerge from the coordinated activity of distinct brain regions.

- Ramon D.
Founder, BrainFrst Inc.

References
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