Motivation and emotion/Book/2023/Default mode network and the self

Overview


The Default mode network (DMN) refers to the regions of the brain that are active while a person is not focused on any outside stimulus, this has been measured through it's metabolic activity while at rest (Raichle, 2015). It is a set of brain regions that is most active during a resting state and is activated when individuals are focused on emotional processing, self-referential activity, recollection of prior experiences, and imagining of future events (Raichle, 2015). Current research shows significant links to a sense of self and major disruptive effects when a psychedelic is administered leading to possible therapeutic uses. (Carhart-Harris et al., 2014).

The DMN is made up of numerous different anatomical structures with various functions (see Table 1), however this chapter will explore the relationship between the DMN, two theories of self, and the effect psychedelics have on each respectively.

Table 1.

Focus questions:
 * What is the Default Mode Network?
 * What is the self?
 * What is the role of the Default Mode Network in the sense of self
 * What is the role of psychedelics?

Self-concept theory
There are many different philosophical and psychological theories of what the "self" is. One prominent theory was proposed by Carl Rogers, it is called the Self-Concept Theory. Rogers was a humanistic psychologist who believed that individuals have an "ideal self" and a "perceived self" and motivation and personality is derived from the desire to align the real self with the perceived self (Ho and Mcleod, 2008). Rogers believed that someone's Self-Concept was influenced by three factors (Ho and Mcleod, 2008):
 * 1) The view you have of yourself (Self image)
 * 2) How much value you place on yourself (Self worth)
 * 3) What you wish you were really like (Ideal self)

Rogers developed this theory due to his work with patients suffering from emotional disorders, Rogers believed that the negative feelings his patients had regarding themselves were because of the inaccurate beliefs that they held about themselves,  often times Rogers found that these beliefs were reinforced by their parents (Rosenberg, 1989). The Self-Concept Theory of Carl Rogers provides a framework for understanding an individual's perception of self, the intrinsic values they associate with their identity, and their aspirations towards an ideal self. These interconnected dimensions of self-image, self-worth, and the ideal self are shaped by personal experiences and external influences, notably parental reinforcement.


 * Picture this



Imagine you are a young teenager who feels as if you have less value than your peers because they are successful at basketball and you can't get the hang of it. Imagine your parents reinforce this belief by saying you're too small to play basketball. If you accept this belief you'll experience negative emotions and feel poorly about your self, however if you challenge this belief and ask yourself positive reflective questions you can address the negativity in a constructive way. After all, professional NBA player Muggsy Bogues was 5'3 and had a long and successful career within the NBA.

How does the default mode network apply to self-concept theory?
The DMN is involved in processes related to self-awareness and self-referential thoughts (Qin and Northoff, 2011). According to Self-Concept Theory, an individual's self-identity is molded by their perceptions and thoughts about themselves. This theory underscores the role of self-reflection in shaping one's sense of self. Consistently, the DMN is actively engaged during introspective activities, such as when someone reflects on their attributes, assesses their self-worth, or processes their feelings. (Raichle, 2015).

Additionally, the DMN aids in accessing episodic personal memories, primarily through regions like the Dorsal medial prefrontal cortex and Precuneus (Sestieri et al., 2011). Recognizing the importance of past experiences and parental influences in shaping self-concept, it's possible that the DMN facilitates the recall of these memories and experiences, integrating them into an individual's self-concept.

Self-Concept Theory argues that our sense of self is defined by our introspection and how we perceive ourselves across different dimensions. Given the DMN's integral role in self-reflection, memory retrieval, and the assimilation of external influences, it is tied to the foundational principles of Self-Concept Theory.

Quiz - self-concept theory and the DMN
{The DMN plays a role in which: + Self-referential thinking - Emotional regulation
 * type=""}

{Which of the following is a role the DMN plays in Rogers theory of self? + Facilitating mental processes for self referential thinking - Providing a base sense of self when an individual wakes up
 * type=""}

Narrative identity
The Narrative Identity Theory focuses on the idea that individuals construct their identities through storytelling, individuals create a sense of self by organizing their life experiences into a constantly evolving narrative experience (Schechtman, 2011). These narratives help someone make sense of their past, present and future, and provide them with a sense of unity and purpose in their life (McAdams, 2001). Depending on how a person perceives their own personal story their experiences can vary wildly. For example, high school students who were able to identify a positive outcome from a negative adolescent experience had higher levels of well-being than students who could not find a silver lining (McAdams and Mclean, 2013).

Key components of Narrative Identity Theory include (McAdams and Mclean, 2013).:


 * Identity Construction: Narrative Identity Theory posits that we create our sense of self by constructing and maintaining personal narratives. These narratives include elements like personal goals, values, and the interpretation of significant life events.
 * Life Storytelling: Individuals continually shape and revise their life stories as they gain new experiences and insights. These stories are not just chronological accounts but also include interpretations and emotional reactions to events.
 * Coherence and Meaning: A well-developed narrative self provides coherence and meaning to an individual's life. It helps answer questions like "Who am I?" and "What is the purpose of my life?" These answers contribute to a sense of identity.

Narrative Identity suggests that our sense of self is inherently linked with our personal life story and how we perceive it, the DMN plays a crucial role in this process through supporting self-reflective thinking and episodic memory retrieval.

How does the default mode network apply to the narrative identity theory?
The Narrative Identity Theory utilizes various functions of the Default Mode Network (DMN) to explain a sense of self, the DMN is highly active during self-reflective and introspective activities (Raichle, 2015). When individuals engage in constructing and reflecting on their life stories, the DMN is likely involved in processing and integrating these self-relevant thoughts. Constructing a narrative identity involves recalling personal memories and envisioning the future, the DMN plays a crucial role in both autobiographical memory retrieval and prospective thinking, which are essential components of creating a life narrative (Mazoyer, et.al., 2001).

The Narrative Identity Theory provides an explanation of the way in which humans construct their identity, focusing on the process of storytelling that ties together past experiences, present reflections, and future aspirations into a holistic narrative. This construction is not a passive process but an active one that continually evolves, adding depth to an individuals sense of self. Components such as identity construction, life storytelling, and coherence underline the mechanisms by which individuals find meaning and purpose in their lives. The DMN is a neurological underpinning of this theory by facilitating self-reflection and memory retrieval. The DMN bridges the gap between narrative identity construction and its neurological basis.

Quiz - narrative identity and the DMN
{The DMN facilitates the Narrative Identity Theory through which functions: + Self-reflection, memory retrieval, mind-wandering - Self-reflection, identity construction, providing coherence
 * type=""}

{Narrative Identity Theory posits which of the following: + Individuals sense of self is created by forming a narrative of their life - Individuals sense of self is created by reading novels and integrating these lessons into their behaviour
 * type=""}

Psychedelic effects on the DMN
Psychedelics are a class of drug that produce vivid hallucinations and mystical experiences through acting on serotonin receptors within the brain, substances include psilocybin and LSD. Both have been shown to significantly influence brain activity, particularly within the DMN (Gattuso, et.al., 2022). Under the influence of psychedelics, there's a marked decrease in DMN activity and connectivity. This disruption is believed to be responsible for many of the characteristic effects of these substances, including the dissolution of ego, heightened feelings of interconnectedness, and altered patterns of thought (Speth, et.al., 2016). Interestingly, this modulation of the DMN may offer therapeutic potential, with research suggesting that the temporary "reset" of this network can help individuals reconstruct a sense of self (Carhart-Harris et al., 2014).



Psychedelic effects on the self
The DMN is associated with self-referential thinking and the construction and maintenance of our sense of personal identity. Within this network, various brain regions work in tandem to consolidate memories, process emotions, and create narratives about who we are based on our past experiences and future expectations. When psychedelics are ingested, they significantly decrease the activity and connectivity within the DMN (Soares, et.al., 2023). This leads to a temporary disintegration of the structures that maintain our usual sense of self. Users often report feelings of ego dissolution, where the boundary between the self and the external world becomes blurred (Stoliker, et.al., 2022). This can manifest as a sense of oneness with the universe, a feeling of interconnectedness with all things, or the sensation that the individual ego or "self" has temporarily disappeared. These experiences challenge and redefine our conventional understanding of the self, and can lead to profound personal insights and shifts in perspective (Ko, et.al., 2023). By disrupting the DMN's regular functioning, psychedelics can facilitate a break from entrenched self-narratives, potentially offering therapeutic avenues for conditions deeply tied to one's sense of self, such as depression, anxiety, and PTSD (Carhart-Harris et al., 2014).

Conclusion
The Default Mode Network (DMN) plays a pivotal role in constructing a sense of self, a concept that has has various theories and no grand answer. By shedding light on the neural processes of self-awareness, introspection, and autobiographical memories, the DMN underscores the depth and fluidity of our identity and how it could be constructed. Two primary theories, the Self-Concept theory and the Narrative Identity Theory, tap into this neurological framework. The Self-Concept Theory, championed by Carl Rogers, delves into our self-image, self-worth, and ideal self, emphasizing that our internal beliefs shaped by external reinforcement form our identity. The DMN deals with the processes mentioned in this theory, reinforcing the integration of past experiences and introspective evaluations that mold our self-concept.

On the other hand, the Narrative Identity Theory posits that individuals create a sense of self through chronicling their lives, weaving the past, present, and future into a continuous evolving narrative. It proposes that our sense of self is a tapestry of experiences and reflections, ever-evolving with each new chapter of our life. The DMN underpins this theory by processing these narratives, from introspective ruminations to the retrieval of past memories, culminating in a cohesive sense of self.

The DMN offers a neural perspective to the multifaceted nature of self-awareness and identity. With the DMN as a focal point, the potential for research in the realms of psychology is extensive. Exploring the DMN's connections further could be an avenue of research into the nature of the self and though our understanding of psychedelic treatment is nascent, it also offer implications for therapeutic interventions and enhancing mental well-being through psychedelic treatments.