Biopsych 1/22

Emotional Decision Making and Neuroscience

  • Introductory Concepts:

    • Discussion on the impact of emotional responses on decision-making.

    • Neurons have the capacity to signal emotional responses but can also engage mechanisms for calmness and logical thought.

  • Emotional Control:

    • Variances in emotional control among individuals due to early life experiences.

    • Some individuals learn to suppress emotional expression, leading to strong neural pathways that inhibit emotional engagement.

  • Influence of Trauma:

    • Impact of both 'big T' and 'little t' trauma on emotional regulation and neural pathways.

Neural Pathways and Myelination

  • Neurons and Connectivity:

    • Importance of strengthening connections between decision-making (logical) areas and emotional areas of the brain.

  • Myelin:

    • Definition: Myelin is an insulating substance that surrounds neuronal axons, facilitating the efficient transmission of electrical signals.

    • Myelination enhances communication between neurons, and its development is pivotal during neural development.

    • The ongoing development of myelination in the prefrontal cortex and emotional regions continues into adulthood.

Brain Development

  • Development Status of Neural Pathways:

    • Concept that 'your brain is not fully developed' based on incomplete myelination and connectivity of neuronal pathways.

    • Discussion of neuroplasticity and how it contrasts with previous beliefs of fixed personality and neuron pathways established early in life.

  • Neurogenesis:

    • Definition: Neurogenesis is the process of creating new neurons; it can occur throughout life but is notably more robust during developmental stages.

    • Analogy: Pruning is akin to maintaining a fruit tree by cutting off weaker branches to strengthen the healthier ones, decisively focusing brain energy on stronger neuronal connections.

Pruning in Neuronal Communication

  • Pruning Process:

    • Definition: Pruning in neuroscience is the process by which neurons eliminate unnecessary connections to strengthen important pathways and optimize efficiency.

    • Examples:

    • Communication with fewer, stronger connections is favored, much like pruning weak branches on a fruit tree can boost fruit production.

  • Application in Learning:

    • Critical windows in childhood development, such as language acquisition, illustrate how multiple connections can help in learning new languages.

    • As individuals age, they prune away excessive connections, which can reduce their ability to associate multiple ideas with a single concept (e.g., the word "purple").

Neuroplasticity and Synaptogenesis

  • Neuroplasticity:

    • Definition: Neuroplasticity refers to the brain's capacity to reorganize itself by forming new neural connections throughout life.

    • Example: The process of synaptogenesis, which is the formation of new synapses between neurons, can occur in response to learning through intentional effort.

  • Synaptic Use and Synaptic Strength:

    • Discussion of how active synapses allocate more resources and space, while those that are not frequently used may diminish in size and strength.

Case Study: Phantom Limb Syndrome

  • Introduction to Phantom Limb Syndrome:

    • Overview of the phenomenon where amputees continue to feel sensations in missing limbs.

  • Derek Steen's Experience:

    • Anecdote detailing Derek's motorcycle accident and subsequent phantom sensations of his missing arm, leading him to Ramachandran.

  • Research Questions:

    • Investigating why Derek felt sensations in his phantom fingers when his face was touched, leading to a deeper understanding of body representation in the brain.

  • Somatosensory Cortex Mapping:

    • Explanation that the brain has a map of the body on the somatosensory cortex, with adjacent areas mapped for different body parts.

    • Upon amputation of a limb, adjacent areas (e.g., face) could begin to activate the area of the brain corresponding to the missing limb due to lack of incoming sensory signals from the amputation site, leading to misinterpretation of sensations.

Scientific Validity

  • Skepticism and Evidence:

    • Initial skepticism about the theory concerning neural pathways' flexibility challenged traditional beliefs that early-created links could not change.

  • Brain Scan Studies:

    • Proposal for using brain scans to validate the hypothesis of reorganization of brain pathways and sensory input after amputation.

  • Conclusion about Complexity:

    • The complexity of the brain's neuronal communication surpasses other biological systems, illustrating the intricate nature of brain functionality and mapping.