Psych 100 brain pt 3
PSYC100 Study Notes
Introduction
Emphasis on retrieval practice; students encouraged to challenge their understanding.
Students are invited to review:
Advantages and disadvantages of using case studies.
The distinction among the three types of validity.
Reminder for students to participate in PollEv for interactive questions later in class.
Main Concepts
Main Point #1: Neuroplasticity
Definition: Neuroplasticity is a key concept in psychology that refers to the brain's ability to reorganize itself by forming new neural connections throughout life.
Example: When you learn to play a musical instrument, your brain creates and strengthens connections in areas related to motor skills, hearing, and memory. If you stop playing, some of these connections might weaken, but the potential for new ones remains.
Processes of Neuroplasticity: Encompasses various processes that facilitate learning and adaptation over one's lifetime.
Main Point #2: Dominance of Plasticity Types
Different Types of Plasticity:
Plasticity can be categorized into sensory, motor/language, and higher cognition.
Timeframes:
Certain types of plasticity are more prevalent during specific periods of development (e.g., childhood) and less during others.
Example: Learning new languages is significantly easier for young children (developmental plasticity) compared to adults, though adults can still learn (adaptive plasticity).
Main Point #3: Conditions of Neuroplasticity
Neuroplasticity occurs under two key conditions:
Developmental Plasticity: Refers to changes in the brain during critical periods of development.
Example: A baby's visual cortex developing and organizing itself in response to visual input from the environment.
Compensation for Loss: Involves the brain's ability to adapt to injuries or degeneration by reorganizing existing pathways or creating new ones.
Example: After a stroke, if an area of the brain responsible for arm movement is damaged, other areas might take over or new pathways might form to help restore some function.
Main Point #4: Environmental Influence on Plasticity
Environmental and Biological Interactions:
The environment plays a significant role alongside biological factors in shaping neuroplasticity.
This implies a dynamic interplay between genetic predispositions and environmental factors, leading to changes in brain structure and function.
Example: Children raised in enriched environments with lots of stimulation, learning opportunities, and social interaction tend to develop more complex neural networks than those in deprived environments.
Genetic Considerations
Human Genome Project
Human Genome Project reveals that humans possess approximately 20,000 genes.
Gene by Environment Interactions (GxE)
GxE Defined: Refers to the interaction between genetic predispositions and environmental factors that can influence behaviors and traits.
Study of Antisocial Behavior:
A composite index based on z-scores shows variance in antisocial behavior in relation to genetic activity levels (e.g., MAOA activity levels).
Example Data:
Low MAOA Activity: Sample size of 163.
High MAOA Activity: Sample size of 279.
The study demonstrates how early severe childhood maltreatment correlates with antisocial behavior differing by genetic factors.
Aggressive Responses Data
Statistical Findings:
Number of aggressive responses varies by gene activity level and exposure to severe childhood maltreatment:
Graphical representation shows two groups: MAOA-L (Low) and MAOA-H (High).
p-values indicate significance:
Genetic influence (G):
Environmental influence (E):
Interaction (GxE):
Risk Assessment Findings
Based on statistical data, individuals most at risk for high levels of aggressive responses include those who:
Experienced severe childhood maltreatment and have the MAOA gene for low activity.
Example: An individual with the low-activity MAOA gene who experienced severe abuse as a child is statistically more likely to exhibit aggressive behaviors than someone with the same genetic makeup but no maltreatment, or someone with high-activity MAOA gene who experienced maltreatment.
The assessment highlights the interaction of genetic disposition and environmental factors in shaping behavior.
Study Validity Considerations
Internal Validity Evaluation:
A critical look at which study design (descriptive, correlational, experimental) offers greater internal validity. This requires understanding of methodological rigor in evaluating cause-effect relationships in psychological research.
Epigenetics
Concept: Epigenetics illustrates that the relationship between nature (genetics) and nurture (environment) is complex.
Suggests that environmental factors can influence the expression of genes, subsequently affecting behavior and development, reinforcing the interplay between genetic predispositions and environmental experiences.
Example: Identical twins share the same DNA, but one might develop a chronic illness (like diabetes) while the other doesn't, due to differences in diet, stress levels, or exposure to toxins. These environmental factors can "turn on" or "turn off" certain genes without changing the underlying DNA sequence.
Sensory Perception and Reality
Controversial Examples:
“Yanny or Laurel” Debate: Demonstrates how auditory perception can differ based on subjective experience. Encourages students to reflect on perceptual biases.
“The Dress” Illusion: Engages students in discussions about visual perception and the subjectivity of color interpretation.
Philosophical Implications:
These controversies prompt inquiries regarding whether our sensory experiences convey an objective reality or are merely subjective interpretations.
Conclusion
The discussions engage students in the philosophical exploration of perception and reality, stressing the importance of understanding psychological concepts in real-world applications.