Excellent overview here (1) of how the emotional brain is altered due to the effects of insecure attachment to primary caregivers and the consequences this may have on later emotion processing and regulation.
This overview will be in thee parts.
“Neuronal circuits are wired through a combination of nature and nurture, genetics and experience. The kind of parenting we receive as children, the nature of our relationships throughout life, and the experience of therapy all change the brain by changing synaptic connections and circuits. ‘‘Human connections create neuronal connections’’ (Siegel, 1999, p. 85).
Because of the impact that social relationships have on our brains, Siegel has suggested that ‘‘the brain [is] the social organ of the body’’ (Siegel & Hartzell, 2003, p. 97). It is clear from neuroscience that nature and nurture are mutually recursive. ‘‘Experience shapes the brain throughout life by altering the connections among neurons. . . . Experience is biology’’ (Siegel & Hartzell, pp. 33–34).
These observations are not mere metaphors; they are based on extensive and compelling research on the human brain, development, and relationships. Beyond affecting synaptic connections, experience, especially early parent-child experience, can modify the actual activity of genes (Begley, 2007).
The structure and wiring of our brains require the attunement and attentiveness of others. As Cozolino (2006) puts it, ‘‘The brain is an organ of adaptation that builds its structures through interactions with others. . . . There are no single brains ’’ (p. 6).
‘‘The individual neuron or single human brain does not exist in nature. Without mutually stimulating interactions, people and neurons wither and die’’ (p. 11). Indeed, the failure to thrive and deaths of babies left unattended and unattached in orphanages, so poignantly described by infant specialists, bears out the literal truth of this statement.
…our actual brain structure, the neuronal connections and networks that determine our preferences, personalities, and survival strategies, is wired early and becomes hard to change. The frequently cited mechanism for this is Hebb’s law: ‘‘Neurons that fire together wire together’’ (Siegel, 1999, p. 26); that is, the neurochemical linking of two neurons makes it more likely that they will be linked in the future. Scientists have located the biochemical process by which this wiring occurs; it is responsible for our habits and can be resistant to change at the synaptic level. On the other hand, change is possible; neurogenesis and neuroplasticity, the creation of new neurons and new neuronal connections continue throughout our life spans. Experience alters the brain, even as we age. Whenever we learn something new, including new attitudes, perspectives, or behaviors, we are changing the physical structure of the brain…
…The human brain is roughly organized in three interconnected layers, with increasing levels of complexity. The brain stem, the most basic brain area, regulates breathing, heart rate, and general alertness. The limbic system, developed in mammals, includes the amygdala, anterior cingulate, and hippocampus; much of our emotional processing occurs in the limbic area.
The neocortex, especially the prefrontal cortex, is most developed in humans and is responsible for higher thought and executive functioning. The interconnections among brain stem, limbic, and neocortical areas are numerous and often bidirectional, with emotion, thought, and body processes all affecting each other. We share with all animals the instinct for self-preservation. ‘‘The fundamental behavioral tendency of all organisms is to approach what is life sustaining and avoid that which is dangerous’’ (Cozolino, 2006, p. 28). The amygdala, ‘‘fear central’’ (LeDoux, 1996, cited in Goleman, 2006, p. 78), is particularly alert to danger and sends alarms throughout the body in threat situations…
This instinctive survival process often leads to grief in human relationships. When we feel threatened interpersonally, the amygdala leads us to fight or flee. The paradox underlying much of the push-pull ambivalence in human relationships is that we are wired both for self-protection and for connection (Atkinson, 2005). The evolutionary importance of connection for human survival is emphasized throughout the neuroscience literature. ‘‘Our social brains have been shaped by natural selection because being social enhances survival’’ (Cozolino, 2006, p. 12). It has been noted that the size of the neocortex has grown in primates in proportion to the growth of the size of social groups. Much of the elaborate circuitry of the human brain is devoted to reading and decoding social cues. ‘‘Given our dependence on groups for our very survival, primates have evolved elaborate neural networks for interacting with others as well as reading their minds and predicting their intentions. . . .
These systems of attaching, predicting, and communicating are all functions of the social brain’’ (Cozolino, p. 21). Social connections facilitate survival in primates. Sociable baboon mothers who spend the most time grooming and socializing with other females are more relaxed, are better mothers, and have infants most likely to survive (Goleman, 2006). Taylor (2002) has identified the ‘‘tend and befriend’’ response in female primates and humans in response to threat, a counterbalance to fight or flight. Studies of humans of both genders point to the positive impact of nurturing relationships on physical and emotional health (Goleman, 2006). Conversely, social rejection in humans activates the same part of the brain as does physical pain, prompting speculation that ‘‘exclusion could be a death sentence’’ in human prehistory, so important was the group for survival (Goleman, 2006, p. 113).
THE EMOTIONAL BRAIN: A TALE OF TWO ROADS
Human emotions are not located in a single brain site; rather, they involve interconnected brain circuits. Most of our emotional life is processed nonconsciously and subcortically. We are often unaware that we are even having an emotion until after the fact, when our higher cortical processes kick into gear and consider the information from the limbic system and the rest of the body.
Neuroscientists differentiate between emotions and feelings. Emotions are considered evolutionary adaptations, nonconscious, and embodied. As LeDoux (1996) vividly notes, ‘‘Our emotions are full of blood, sweat, and tears’’ (p. 42). Panksepp (1998) identifies seven different emotional operating systems with different neural pathways and different evolutionary purposes: fear, care, lust, panic, seeking, play, and rage. Other authors note several universal human emotions, conveyed in facial expressions recognized across cultures: disgust, fear, happiness, sadness, and anger (Damasio, 1994).
Feelings are our conscious awareness of emotions (Damasio); ‘‘the body’s response lets us know how we feel’’ (Siegel, 1999, p. 146). Most of the action emotionally happens subconsciously; we may be driven by our emotions but unable to name our feelings. The neurological condition of alexithymia, the inability to identify or articulate one’s feelings, is the extreme version of this phenomenon. The extent to which our automatic emotional processes benefit or harm us is considered in the neuroscience literature.
Joseph LeDoux (1996) has labeled the quick, nonconscious, reactive system the ‘‘low road,’’ and the more considered, thoughtful system the ‘‘high road.’’ We are equipped by evolution for both; the low, limbic road allows us instinctively to assess danger and protect ourselves, whereas the high, neocortical road gives us more flexibility, thoughtfulness, and choice. The classic example, originating with LeDoux and described by Goleman (1995), is of a person encountering what looks like a snake in the forest. The information about the object enters the human brain through the optic nerve, which sends signals to the thalamus; one route from the thalamus goes directly to the amygdala, which assesses the object for danger and typically leads to a fight-or-flight response. The person in our vignette is wise to flee quickly from the putative snake. At the same time, but traveling more slowly because of the more complex synaptic journey, the signals go to the visual cortex and higher thinking processes; the person may consider, is this a snake, or a stick?
From a survival point of view, the quick, low-road amygdala response can be lifesaving. As LeDoux puts it, ‘‘It is better to have treated a stick as a snake than not to have responded to a possible snake’’ (p. 166). The price we pay for our evolutionary protection is overreactivity in our human relationships. When we feel threatened, now not by a snake but by our spouse, the low road of the amygdala kicks into gear, and we may respond irrationally and with intense emotion.
The high-road and low-road language at times sounds disparaging of our automatic, nonconscious responses. But our ability to assess and respond quickly the work of our ‘‘adaptive unconscious’’ (Gladwell, 2005) is vital to our survival and social functioning. Although the amygdala can get us into social trouble, it is also a key component in social attunement.
People with damaged amygdalas are impaired in empathy and in the capacity to judge the trustworthiness of others (Goleman, 2006). This limbic structure gives color to our emotional lives and, if paired with a functioning prefrontal cortex, helps guide our decision-making. The amygdala, along with other information from our bodies (e.g., the vagus nerve, which sends up ‘‘gut feelings’’ from the stomach to the brain, and the insula, which reads body states), helps us stay in tune with ourselves and others at a nonverbal level. Our emotional brain constantly appraises faces and other stimuli for positive or negative valence, for safety or danger.
Damasio (1994) emphasizes the crucial role of emotion in informing reason as we navigate through our social lives. The neocortex, or ‘‘high road,’’ allows us to pause and consider our options, to think before we react impulsively. The integration of prefrontal cortex with limbic system is necessary for emotional and relational well-being. When we encourage clients to observe their own reactivity, meditate, or take a time-out from a fight, we are helping them engage their higher brain functions, especially their ventromedial (middle) prefrontal cortex.
Part of this section, the orbitofrontal cortex (OFC), one synapse away from the limbic system, brain stem, and neocortex, serves as the brain’s emotion regulation system and ‘‘chief executive officer’’ (Siegel & Hartzell, 2003) of the social/ emotional brain. It functions at the interface of higher and lower brain regions, integrating neocortical and limbic functions.
The OFC calms down the amygdala and helps us make choices in keeping with our goals and values; it allows us to choose the high road. The OFC is active in processes of self-awareness, response flexibility, regulation of emotion, and empathy or ‘‘mindsight’’ (Siegel & Hartzell).
The OFC continues to develop throughout the life span; it is characterized by neuroplasticity, or the ability to change at the neural level. There are limits, however, to the orbitofrontal cortex’s ability to keep the amygdala in check. Early trauma, abuse, or neglect can impair the OFC’s functioning. Furthermore, the amygdala can overwhelm even a healthy prefrontal cortex: ‘‘The connections from the cortical areas to the amygdala are far weaker than the connections from the amygdala to the cortex.
This may explain why it is so easy for emotional information to invade our conscious thoughts, but so hard for us to gain conscious control over our emotions’’ (LeDoux, 1996, p. 265). A damaged OFC results in impairment in judgment, self-control, and emotional fluency.
On the other hand, an overactive OFC, stuck in the ‘‘on’’ mode, has been implicated in obsessive-compulsive disorder (Schwartz & Begley, 2002). Much interpersonal communication happens nonverbally, nonconsciously, right brain to right brain; as Goleman (2006) puts it, we communicate across the social synapse, at times not even aware that we are doing so. Sometimes this can be soothingas when in the presence of an attuned therapist, parent, or partner. At other times, it can be dysregulating.
Emotions tend to be ‘‘contagious’’ (Goleman, p. 13), and we can take on the agitation of another without knowing why or how we got there. ‘‘Like secondhand smoke, the leakage of emotions can make a bystander an innocent casualty of someone else’s toxic state’’ (p.14). Whether we benefit or are harmed by a particular interaction, we are wired to connect.
Neuroscience has discovered that our brain’s very design makes it sociable, inexorably drawn into an intimate brain-to-brain linkup whenever we engage with another person. That neural bridge lets us affect the brain and the body of everyone we interact with just as they do us. (p. 4) Young children are particularly vulnerable in this regard.
The infant’s amygdala is functioning at birth and comes to full maturity early on. Emotion processing occurs mostly in the right hemisphere, which is dominant in its growth during the first 3 years of life. The left hemisphere, responsible for linear, logical thinking and for verbal production, develops later. The baby’s right brain is wired in concert with the parent’s or caregiver’s right brain through nonverbal interaction (Schore, 2003). During the exuberant growth period of the infant’s right brain in the early years, there is a special sensitivity to the interpersonal environment that helps shape the child’s emotional brain.