Module 1.4a – The Brain: Neuroplasticity and Tools of Discovery

Unit 1 - Part 2: The Brain

Module 1.4a – The Brain: Neuroplasticity and Tools of Discovery

• Learning Targets:

  • Explain why psychologists are concerned with human biology.

  • Understand how biology and experience enable neuroplasticity.

  • Compare and contrast techniques for studying the brain’s connections to behavior and mind.

Phrenology

• Franz Gall: Developed the idea of phrenology.

  • Phrenology: Study of the bumps on the skull.

  • Limitation: Provides no information about the brain's actual functions.

Biological Psychology

• Definition: Scientific study of links between biological (genetic, neural, hormonal) and psychological processes.

• Professionals: Behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, biopsychologists.

• Biopsychosocial Approach: Integrates biological, psychological, and sociocultural analysis levels.

• Levels of Analysis: Different complementary perspectives to analyze phenomena (biological, psychological, sociocultural).

The Power of Neuroplasticity

• Neuroplasticity: Brain's ability to reorganize itself after damage or build new pathways based on experience.

  • Critical during childhood.

  • The brain is dynamic and adaptable, allowing better adaptation compared to other species.

Tools of Discovery: Having Our Head Examined

• Case Studies: Help localize brain functions.

• Lesions: Reference to tissue destruction (natural, surgical, experimental).

• Brain Stimulation: Techniques include electrical, chemical, or magnetic stimulation.

• Optogenetics: Controls individual neuron activity using light.

Brain Scans

• Techniques:

  • EEG: Records electrical activity across the brain via scalp electrodes.

  • MEG: Measures brain's magnetic fields from electrical activity.

  • CT Scan: Combines X-ray images to represent brain structure slices.

  • PET Scan: Shows where radioactive glucose is used during tasks.

  • MRI: Uses magnetic fields for soft tissue imaging.

  • fMRI: Tracks blood flow to indicate brain activity.

Module 1.4b - The Brain: Brain Regions and Structures

• Learning Targets:

  • Explain functions of the hindbrain, midbrain, and forebrain in behavior and mental processes.

  • Describe brainstem structures and their functions (thalamus, reticular formation, cerebellum).

  • Explain limbic system structures and functions.

  • Describe the cerebral cortex's lobes and functions (motor and sensory cortices, association areas).

Hindbrain, Midbrain, Forebrain

• Hindbrain: Includes medulla, pons, cerebellum; regulates essential survival functions (breathing, sleeping, coordination).

• Midbrain: Connects hindbrain and forebrain; processes auditory and visual information, controls some movements.

• Forebrain: Consists of cerebral cortex, thalamus, hypothalamus; manages complex cognitive activities, sensory processing, and voluntary movements.

Brainstem, Thalamus, and Reticular Formation

• Brainstem: Manages automatic survival functions; sends/receives information.

• Medulla: Regulates heartbeat and breathing.

• Pons: Coordinates movement and controls sleep.

• Thalamus: Filters sensory information (excluding smell) to the cortex; shares messages with cerebellum and medulla.

• Reticular Formation: Filters information, important for arousal control.

Cerebellum

• Acts as the “little brain” with half of the brain's neurons.

  • Manages balance, coordination, fine motor movements.

  • Involved in procedural memory (nonverbal learning).

  • Affected by alcohol, impairing movement and balance.

Limbic System

• Hippocampus: Involved in explicit memory formation and learning.

• Amygdala: Regulates emotions, particularly fear and aggression.

• Hypothalamus: Governs autonomic functions, drives (hunger, thirst, sexual behavior), emotional responses, and endocrine functions (influences pituitary gland).

Cerebral Cortex

• Definition: Complex network of interconnected neurons covering cerebral hemispheres; responsible for higher-order functions.

• Lobes:

  • Frontal Lobe: Involved in decision-making, muscle movement, higher-order processing.

  • Parietal Lobe: Processes sensory input, touch, and body position.

  • Occipital Lobe: Responsible for vision.

  • Temporal Lobe: Manages audio perception and language processing.

Structure of the Cerebral Cortex

• Cerebrum: All brain areas excluding brainstem and cerebellum; handles advanced thought.

• Internal Layer: Axons (White Matter).

• Cerebral Cortex: Cell bodies of neurons (Gray Matter).

  • Surface Features: Gyri (ridges), sulci (valleys), and fissures (deep grooves dividing lobes).

Functionality of Lobes

1. Occipital Lobes: Visual input, perception, and word recognition.

2. Parietal Lobes: Visual attention, touch perception, and goal-oriented movements.

3. Temporal Lobes: Hearing, memory, and emotional processing; includes Wernicke's (receptive) and Broca’s (expressive) areas.

4. Frontal Lobes: Consciousness, goal-setting, attention, emotional regulation, and language.

Prefrontal Lobes - Uniqueness

• Continue developing into adulthood (mature around age 25).

• Critical for decision-making and evaluating complex situations; most vulnerable to injury.

Functions of the Cortex

• Motor Cortex: Controls voluntary movements; highly represented for areas requiring fine control (e.g., hands).

• Sensory Cortex: Processes body sensations; more sensitive regions correspond to larger cortical areas (Lips vs. Rats vs. Owls).

• Auditory Cortex: Processes sound information.

Association Areas

• Non-motor/sensory areas involved in higher functions (learning, memory, thinking, speaking).

• Cannot map or electrically probe; functions include planning, judgment, and integration of information from various regions.

Language

• Aphasia: Language impairment due to hemisphere damage (Broca’s for speaking, Wernicke’s for understanding).

  • Broca’s Area: Controls speech production.

  • Wernicke's Area: Manages language comprehension and expression.

Split Brain Research

• Vogel and Bogen’s Experiment: Split brain to treat seizures, allowed research into hemispheric function differences.

• Effects include inability to relay visual information between hemispheres; demonstrated functional independence.

Right-Left Differences

• Right Hemisphere: Nonverbal, creative tasks (art, music), emotional expression.

• Left Hemisphere: Verbal, analytical tasks (language, mathematics).

• Corpus Callosum: Essential for communication between hemispheres.

Cognitive Neuroscience

• Interdisciplinary study linking brain activity with cognitive processes (perception, thinking, memory, language).

Learning Targets – Are YOU Ready?

• Describe nervous system subdivisions and functions, major brain regions, lobes, and cortical areas; brain lateralization; the role of neuroplasticity in brain injury; historical and contemporary research strategies (case studies, split-brain research, imaging techniques).