Module 2: Key Theories
Biopsychology encompasses various theories that explain the interactions between biological processes and psychological phenomena. These theories integrate insights from neuroscience, psychology, genetics, and physiology to understand behavior and mental processes.
Neuroplasticity Theory
Concept: Neuroplasticity refers to the brain's ability to reorganize itself by forming new neural connections throughout life. This adaptability is crucial for learning, memory, and recovery from brain injuries.
Key Points
Experience-Dependent Plasticity: The brain changes in response to experiences, such as learning a new skill or adapting to environmental changes.
Synaptic Plasticity: The strength and number of synapses can increase or decrease, affecting how neurons communicate.
Structural Plasticity: Changes in the brain's structure, such as the growth of new neurons (neurogenesis) and changes in the size and shape of brain regions.
Hebbian Theory
Concept: Often summarized as "cells that fire together wire together," Hebbian theory suggests that synaptic connections are strengthened when the presynaptic and postsynaptic neurons are activated simultaneously.
Key Points
Synaptic Strengthening: Repeated and persistent stimulation of one neuron by another leads to increased synaptic strength.
Learning and Memory: Hebbian theory forms the basis for understanding how learning and memory processes occur at the synaptic level.
The Dopamine Hypothesis of Schizophrenia
Concept: This theory posits that schizophrenia is associated with dysregulated dopamine transmission in the brain.
Key Points
Hyperdopaminergia: Excess dopamine activity in certain brain areas, such as the mesolimbic pathway, is linked to positive symptoms like hallucinations and delusions.
Hypodopaminergia: Reduced dopamine activity in other areas, such as the prefrontal cortex, is associated with negative symptoms and cognitive deficits.
The Monoamine Hypothesis of Depression
Concept: This theory suggests that depression is related to deficiencies in monoamine neurotransmitters, such as serotonin, norepinephrine, and dopamine.
Key Points
Neurotransmitter Imbalance: Reduced levels of these neurotransmitters are thought to contribute to depressive symptoms.
Antidepressant Effectiveness: Many antidepressants, such as SSRIs (Selective Serotonin Reuptake Inhibitors), work by increasing the levels of these neurotransmitters in the brain.
The Stress-Diathesis Model
Concept: This model explains the interaction between genetic vulnerability (diathesis) and environmental stressors in the development of psychological disorders.
Key Points
Genetic Predisposition: Individuals may inherit a susceptibility to certain disorders.
Environmental Stress: Stressful life events or environmental factors can trigger the onset of these disorders in genetically predisposed individuals.
The Two-Process Theory of Sleep
Concept: This theory explains sleep regulation through two processes: the homeostatic process (Process S) and the circadian process (Process C).
Key Points
Process S (Homeostatic): The need for sleep increases with the duration of wakefulness and decreases after sleep.
Process C (Circadian): The internal biological clock regulates the timing of sleep and wakefulness, aligning with the 24-hour day-night cycle.
Evolutionary Psychology
Concept: This theoretical approach suggests that many psychological traits and behaviors have evolved through natural selection to solve adaptive problems faced by our ancestors.
Key Points:
Adaptive Functions: Behaviors and mental processes are understood in terms of their adaptive value and evolutionary history.
Survival and Reproduction: Traits that enhance survival and reproductive success are more likely to be passed on to future generations.
The Theory of Mind
Concept: This theory pertains to the ability to attribute mental states—beliefs, intents, desires, emotions—to oneself and others, and to understand that others have beliefs, desires, and intentions different from one's own.
Key Points
Social Cognition: It plays a crucial role in social interactions and understanding others' perspectives.
Neural Correlates: Brain regions such as the medial prefrontal cortex and temporoparietal junction are involved in Theory of Mind processes.