Lifelong Connectivity: Neuroplasticity

• Related post: Wake up your neuroplasticity

The brain’s ability to strengthen, restore and, to some extent, rewire itself to compensate for developmental learning and traumatic brain deficits

Neuroplasticity refers to the brain’s ability to strengthen and restore itself and, to some extent, rewire itself to support developmental learning and compensate for traumatic brain deficits. Evidence was once presented that brain plasticity might be limited to early development, but it is now being explored much more broadly as an experience-dependent feature of adults. Neuroplasticity is perhaps one of the most meaningful findings of neuroimaging research, given its potential clinical usefulness. In other words, “the most important recent finding of MRI-based morphometry is the discovery of the brain’s ability to change its shape within weeks, reflecting structural adaptation to physical and mental activity.” Greater use of the brain increases dendritic and synaptic activity, thickens the brain’s gray matter, and the heavier brain in turn increases neural activity. In older adults, aerobic exercise reduces the normal cortical decline of aging while increasing brain volume and function. Cognitive behavioral therapy also modifies neural circuit function, and changing the way people think about others triggers changes that affect brain function.

Medical students in their mid-twenties studying for exams show significant, neuroimaging-based increases in gray matter (unmyelinated neurons) in the posterior hippocampus and the bilateral posterior and lateral parietal cortex. Scans three months later revealed that the structural changes persisted in each of these areas, and that the increase in the posterior hippocampus was in fact continuing. The hippocampus, which handles acquiring new information, holds it as short-term memory for about two years before engraving it for the long term. A 1998 study found that adult neurons can also regenerate in the hippocampus, the seahorse-shaped structure in the brain’s limbic system responsible for learning and memory. Hippocampal neurogenesis occurs during physical exercise in an enriched environment (one that gives the body plenty of stimulation) and while learning tasks that depend on new memory. Hippocampal neurons respond weakly to prolonged chronic stress, but hippocampal neurogenesis can be successfully strengthened through pharmacological and non-pharmacological treatments for depression, which also help treat mood disorders.

At the core of mood disorders such as depression and anxiety is a problem of emotional regulation. From infancy throughout life, the social brain is governed by the ability to express and self-regulate emotional experience. Emotional regulation is a functional expression of the coupling between subcortical and limbic activity and cortical brain activity. The brain’s circuits integrate the limbic system’s bottom-up expression of emotion with the cortex’s top-down regulation.

Understanding how the brain evolves and organizes itself reveals when and how strong emotional reactions drive a person to act. The ascending sequence of the brainstem, from the midbrain to the right hemisphere and then across to the left hemisphere, is associated with the increased integration of cognition and emotion that underlies complex social functioning. By contrast, midbrain areas closely linked to limbic function are associated with survival-based emotions. In times of danger, by coupling more strongly, function reverts to the brain’s older regions, and the strong neural coupling between the limbic system and the cerebellar motor areas is accompanied by weaker neural coupling toward the cortical areas. As a result, fear and anger under stress drive more complex emotions and cortical cognition.

The basic core emotions related to pleasure and pain are happiness, surprise, fear, anger, disgust and sadness. Basic emotions tell a person whether their environment is beneficial or harmful, rewarding or threatening, and whether it calls for acceptance or rejection, categorizing it as unpleasant or pleasant. Arousal from displeasure or pleasure is built by autonomic reflexes mediated by the brainstem and the basal ganglia, which affect brainstem motor activation. The innate human tendency to return to emotion is expressed in the brain’s organization. The structure of a hierarchically organized brain model is expressed functionally through bottom-up and top-down neural pathways.

Emotional regulation and integration

Affective neuroscience emphasizes the importance of limbic emotion connected with right frontal cortical communication. According to neuroimaging studies, the area commonly important for activating both core emotions and social emotions is the orbitofrontal cortex (OFC). The OFC, the lower part of the prefrontal cortex, sits above the eyes and behind the forehead. The OFC is known as the summit of emotional processing. Its location, just above the central brain, is crucial for limbic emotion connecting with the frontal cortex.

Relational empathic expression and mindfulness

Humans can learn through empathic imitation and by observing other people’s actions, and mirror neurons help us observe and recognize that someone else’s action is something we can do too. Mirror neurons, first discovered in the brains of macaque monkeys, fire not only in response to their perceptions or when anticipating intentional, successful actions performed by others, but also when they intentionally move their own hands and feet.

• #neuroplasticity
• #plasticity
• #brain
• #art
• #therapy
• #neuroscience