What fMRI analysis of the Default Mode Network
can reveal about the impact of Stories on the Human Brain
Introduction
Narratives are increasingly being used in neuroscience as naturalistic stimuli for studies employing Functional Magnetic Resonance Imaging (fMRI) analysis to examine the regions of the brain collectively known as the Default Mode Network (DMN). Using naturalistic stimuli ensures these studies have sound ecological validity, and fMRI analysis provides robust quantitative evidence validating the importance of narratives in healthy socioemotional development – a bond that has previously been largely demonstrated using qualitative studies. Thus results from these studies provide an untapped pool of empirical evidence demonstrating the relationship between narratives and social and emotional development.
When taken together these studies suggest that the role of narratives in this relationship is not incidental; rather that narratives, language, and self- and social-awareness are interdependent and have developed as an evolutionary triptych, central to the evolution of the human DMN and its role in the unique ability of humans to accumulate and share knowledge. Reinterpreting studies of narratives in neuroscience through an educational lens reveals the potential for stories to enhance self-actualisation in children and adolescents, especially in reading programs such as those encompassing Developmental Bibliotherapy. This novel approach provides a framework by which existing fMRI analysis can provide a source of empirical evidence for a broader investigation into the importance of narratives in adolescent wellbeing and education. [GO BACK]
Stories and Personality
Storytellers and their audiences know how stories can influence and change our view of ourselves, others and the world. Stories, or narratives, reveal how interrelated events, unfolding over time affect the fortunes and relationships in the lives of the story’s characters. Narratives often contain moral or didactic messages embellished with richness in meaning and emotional content which encourages engagement and transportation into characters’ minds, and ensures these messages are understood and remembered. Readers are swayed, challenged and persuaded, and engage in simulation, prospection and prediction.
Immersion in a story can induce a flow state, where time can be distorted, and where our brains reject external sensory stimuli in preference to the adventures within our imagination as it engages with the perspectives of other lives and the possibilities of other worlds. For some, this is the purpose of narratives – one enters into the contract of story, not only fully aware that narratives require emotional commitment, but eagerly anticipating the experience.
Transportation into fictional lives and locations can be so complete that readers’ mirror neurons respond as if they were physically experiencing the world of the story. Emotions are experienced vicariously as the story’s protagonists exhibit character attributes of core confidence – such as hope, efficacy, resilience and optimism – and develop a growth mindset where new experiences are reframed as adventures, feedback from trusted allies is acknowledged and accepted, and failure is met with resilience and regarded as learning opportunity.
When Campbell’s hero of the didactic Bildungsroman genre returns home transformed, empowered and enlightened, by association so does the reader. Along the hero’s journey readers vicariously experience reward and pleasure as they proudly, albeit vicariously, enjoy the hero’s successes and learn from the hero’s failures. Stories help to clarify, explain, normalise and validate emotions and experiences in ways that enable the transformative power of catharsis. Stories can also become instruments of comfort; as the story’s audience becomes aligned with the protagonists they feel less isolated and alone; and by enabling them to experience protagonists’ viewpoints, audience members become aware of others’ perspectives and also become more aware of their own.
Fictional narratives can promote creativity and provide intellectual opportunities, stimulating the imagination with problems or mysteries, and augmenting knowledge. Audiences, given insights into protagonists’ motives and intentions, are able to view the same events from multiple perspectives, broadening their own emotional experiences. Escapism, using the “novel as a therapeutic experience”, and vicarious learning opportunities can be significant intellectual responses. Our intellectual flexibility is challenged by narratives which reveal conundrums, surprises and secrets, introduce fallible heroes, present uncomfortable truths or use humour to shock and surprise. Engagement with narratives can inspire, motivate, guide self-reflection, enhance wellbeing and nurture self-actualisation.
During childhood fictional narratives can provide safe play spaces where key life skills can be shaped, tested and refined. These fictional play spaces can help to frame personal narratives, shape personalities, enhance confidence, and help to identify, clarify and define personal identity including values and beliefs. Stories become a pathway for young readers to form personal identities as they begin to identify and name themselves in the context of the world. [GO BACK]
Reading and wellbeing
Although fairy tales, folk tales, myths, anecdotes, novels, chronicles, biographies, legends, falsehoods, descriptions of news items and yarns can all be considered narratives, fiction provides the greatest opportunity for personal transformation and thus the greatest potential to enhance wellbeing. Comprehension and self-reflection is associated with engagement with a narrative’s content. Engagement with a narrative is a personal relationship which occurs regardless of either reading proficiency or literary content of the narrative, and is also associated with reading for pleasure. Engagement with a hero who is validated, enabled, enlightened and returns home triumphant in a future which is always positive has the potential to promote wellbeing by stimulating the reader’s dopaminergic system.
Studies linking narratives with benefits to social and emotional development in the developmental stages of childhood and adolescence are not difficult to find. And yet schools are divesting resources from school libraries, and the numbers of qualified school librarians is dwindling. Prior to 21st century, research documenting the relationship between narratives and wellbeing has been limited to findings derived from studies which rely on qualitative, subjective, anecdotal and intuitive data. However, the relationship between stories and socio-emotional development and wellbeing is a relationship that has also been difficult to prove using scientific methods: each person’s interpretation of a narrative is individual, personal, and unique, influenced by memories, inferences, experiences, and reading styles that are infinitely varied. [GO BACK]
Decoding the Default Mode Network
The Default Mode Network (DMN) is an interconnected group of regions within the human brain. DMN was initially identified in 2001 as the regions of the brain most active when the brain is in a wakeful but resting state. DMN is now recognised as being the brain’s centre for personality, and self-referential mental activity including the processing of emotions and memories. It is active during spontaneous cognition, including mental time travel (MTT) and REM sleep. DMN begins to develop from early infancy and is shaped by both personal and vicarious experiences.
Functional Magnetic Resonance Imaging (fMRI) is a non-invasive method used to observe DMN responses to external stimuli. Studies using fMRI analysis are beginning to reveal the significant role of the human DMN as the brain’s primary network for personality, memory, imagination, forethought, intuition, moral judgment, mentalising and all other self-referential thoughts and behaviours. FMRI also reveals how DMN interacts – its functional connectivity (FC) – with other regions in the brain. FC between the DMN and the executive control and salience brain networks suggests that these other networks act to monitor and evaluate the feasibility and reasonableness of ideas, plans and memories during MTT. FMRI studies show that FC between DMN and other regions of the brain is strengthened by reading fiction, and also that increased FC in the brain is associated with increased resilience in the face of setbacks. The dopaminergic system, which registers emotions associated with reward, such as pleasure, also has FC with DMN. Delusion, depression, Alzheimer’s, schizophrenia, OCD, ASD and ADHD have been associated with changes in DMN and its FC with other regions of the brain, especially the executive control and salience networks.
Speculation of the role of the DMN, especially during MTT and REM, varies from it being a sentinel keeping watch for dangers from the external environment, to a process which maintains the brain in an autopilot role during otherwise boring activities, to the essential feature of the human brain which distinguishes us from other animals. Egocentric sensory information such as pain is also monitored by DMN, even during REM sleep.
DMN is central in the processing of memory, emotion, language, imagination, simulation, planning, prediction, navigation, and thinking from others’ perspectives (known as Theory of Mind (TOM) or mentalising). DMN is also closely associated with vicarious learning, curiosity, intuition, and creative insight – sometimes referred to as the AHA! Moment. Humour and literary elements such as metaphor and simile are also processed in DMN. This close alignment between the complex processes associated with language independent comprehension and the processing responsibilities associated with DMN suggested the use of naturalistic stimuli in empirical studies of social behaviour in humans.
The use of narratives as stimuli for fMRI studies offers a number of advantages: narratives are engaging, and their use does not require training; narratives can be reproduced, selectively edited, and their presentation mode varied; and narratives can be independent of language. Naturalistic stimuli have demonstrated how the human DMN changes, and reconfigures when presented with unfolding, or conflicting story elements and a functional subdivision of the DMN has been identified – named the Chrono architecture – which updates the brain’s spatial and temporal information. Narratives in neuroscience have revealed how the DMN responses differ between character based and action based fiction, and between fiction and non-fiction. The use of narratives as naturalistic stimuli although nascent, is increasingly providing neuroscience with insights into how the human DMN processes real-life sensory experiences. [GO BACK]
An Evolutionary Triptych
It seems that the human DMN may have three interconnected roles: firstly, a concept building role, responsible for recognising, creating, recording, recalling and sharing concepts, and relationships between concepts, that facilitate communication via the development of language; secondly, a storyteller role to facilitate the transmission of information in a format that was easily comprehended and remembered, and which encouraged appropriate responses; and finally, a social awareness role which enabled early humans to consider another’s perspective, and set the foundations for social mores and customs. FMRI studies indicate that the human DMN possibly developed as an evolutionary triptych incorporating the Concept brain, the Story brain, and the Social brain in a mutually enriching and supporting scaffold for ongoing human development. [GO BACK]
The Concept Building Brain
DMN has the ability to build, maintain, augment and reject relationships and concepts giving rise to the notion of DMN as the Concept Building brain, Although independent of language, this ability to generate relationships and recognise patterns is fundamental for the development of language. These roles of DMN, particularly the relationship building role, also provides evidence of the mechanisms involved in learning, association, spontaneous thought, creativity, intuition and MTT. [GO BACK]
The Storytelling Brain
DMN has also been called the Storytelling Brain as fMRI analysis has revealed regions of DMN are activated during the high level processing of narratives; regions involved in memories, emotions, plot formation and scene building, navigation, and prospection have been identified using naturalistic stimuli including narratives. Furthermore, curiosity indicates that in the absence of stories the human DMN will try to find one in an attempt to make meaning. Narratives simulate real world situations by using just the essential elements necessary to efficiently transmit information, assist cognition and convey context; it has been suggested that the transfer of information between humans is the primarily role of stories. [GO BACK]
The Social Brain
DMN is the location of our personality and could be appropriately named the Social Brain. Narrative comprehension engages the neural mechanisms associated with personality, perspective taking and Theory of Mind (TOM), thereby supporting socio-emotional development and self-actualisation. FMRI has revealed how DMN engages memory and prior experiences during narrative comprehension, and how these memories and prior experiences can be projected into the future.
InterSubject Correlation (ISC) – a measure of the extent to which DMN activity patterns revealed by fMRI analysis are found to be similar within a group of participants – provides neurological examples of information being transferred between a storyteller and their audience, and the context of a narrative itself increasing ISC between listeners during the telling and into the future. Studies of ISC in DMN responses to both humour and suspense highlight how memory and culture are linked to emotional responses. ISC can be observed while DMN is stimulated using naturalistic data in written, auditory and audio-visual narratives, as well as music, and aesthetic performances, providing evidence of the variety of activities that produce this unifying response, in ways that are independent of language.
FMRI studies also demonstrate the actions of the Mirror Neuron System (MNS) which is responsible for a phenomenon whereby a set of neurons corresponding to the action of an individual is activated in an observer, unifying the execution of an action by one person with the perception of the action in another. The MNS enables people to experience and learn actions and emotions vicariously, including those associated with social situations. Narratives also promote positivity and vicarious pleasure in the dopaminergic system.
DMN activity was initially thought to be associated purely with task-negative activity since DMN activity is anticorrelated with the task-positive dorsal attention network (DAN). However, using narratives in neuroscience can demonstrate that DMN is functionally connected to regions of the brain necessary for wellbeing such as the executive control and salience networks. [GO BACK]
References for Narratives in Neuroscience Research Project
Part 2 – The Integrative Literature Review – Reflexive Thematic Analysis
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