Psychology Chapter 2; Part 2: 1/29/25

Split Brain Overview

• Brain Wiring: Information from the left visual field goes to the right hemisphere of the brain, and vice versa.

• Importance: Understanding this wiring can help comprehend conditions such as epilepsy where excessive electrical activity occurs.

Epilepsy and Its Treatment

• Electrical Activity: In people with epilepsy, random bursts of electrical activity often start in the same brain region and can spread through the corpus callosum.

• Corpus Callosum: This is a bundle of nerves connecting the left and right hemispheres; it allows electrical activity to transfer between them.

• Seizure Types: The spread of electrical activity can cause generalized seizures, such as grand mal seizures.

• Historical Treatments: In the past, medications to control seizures could be toxic, leading to severe consequences.

• Surgical Intervention: Cutting the corpus callosum can isolate seizure activity, reducing the amount of medication needed for treatment.

Research on Hemispheric Specialization

• Studying Split Brain Patients: Research has revealed different functions of each hemisphere.

• Experimental Setup: By flashing images only to one side of the visual field, researchers can determine which hemisphere processes the information:

  • Example 1: Image of an apple flashed on the right side goes to the left brain; patient can verbally identify it.

  • Example 2: Image flashed on the left side goes to the right brain; patient cannot verbally identify it but can pick it up with the left hand.

• Language Processing: The left hemisphere is primarily responsible for language for most right-handed individuals.

Functional Differences Between Hemispheres

• Right Hemisphere Abilities: Involved in pattern recognition and emotional processing.

  • Example: When shown an image made of books forming a face, the right hemisphere recognizes the face while the left identifies the books.

• Right-Brain Damage: Can lead to face recognition issues after injuries or strokes.

Anatomical Differences in Gender

• Brain Size: On average, male brains are heavier, but female brains may have more cortical surface area due to more gyri and sulci.

• Debate Over Differences: Discussions about how these differences affect mental functions continue, but research emphasizes that:

  • There are overlaps between the genders with more similarities than differences.

• Gender Stereotypes: Societal beliefs often misrepresent capabilities, particularly in fields like STEM.

  • Example: Historical context shows women excelled as "human computers" at NASA.

Performance Differences in Tasks

• Spatial Navigation: Studies indicate biological males often outperform females in spatial tasks, but the root cause—whether biological or social—is debated.

• Performance Distribution: Statistical analyses show similarities in performance ranges between genders but note average differences.

Emotional and Relationship Implications

• Socialization Influences: Societal expectations about emotional expression can affect interpersonal relationships and communication:

  • Males might not express emotions like sadness, leading to misunderstandings in relationships.

• Understanding emotional processing is crucial for men’s mental health, addressing the high rates of suicide and emotional distress.

Neuroplasticity

• Definition: The brain's ability to adapt and reorganize itself when faced with changes or damage.

• Example Case: Joanie Miller’s surgery to remove half her brain successfully illustrated neuroplasticity as her left hemisphere compensated.

• Research Directions: Current studies explore how neuroplasticity can be harnessed for treating conditions like Alzheimer's.

Summary of Key Themes and Questions

• Differences and Similarities: There are clear differences between male and female brain anatomy, but much overlap exists in function.

• Research Applications: Understanding brain differences helps in diagnosing and treating psychological disorders, tailoring therapies to individuals.

• Future Implications: Continued research aims to deepen knowledge about brain functions and their links to behavioral outcomes.