Biological Psychology

Biological Psychology Outline

Mind/Body Problem

  • Definition: The relationship between the mind (internal life, thoughts, feelings) and the brain/body.

  • Questions Posed:

    • How is the mind connected to physical processes in the brain/body?

    • What happens in scenarios like:

    • Heart transplant

    • Switched brains (e.g., with a parent)

    • Effects of brain injury on personal identity ("they are not themselves")

Historical Perspectives

  • Descartes: Proposed that the mind and body are separate entities.

  • Location of Mind/Body Interaction: Suggested to be at the pineal gland.

Learning Objectives

  • By the end of this section, students should be able to:

    1. Identify structures of the brain and their major functions.

    2. Develop learning strategies for associating brain structures with functions.

Brain Regions

  • 3 Major Regions:

    • Forebrain

    • Midbrain

    • Hindbrain

Hindbrain Functions

  • Cerebellum: Responsible for motor coordination and control.

  • Medulla: Coordinates autonomic functions like heart rate, circulation, respiration.

  • Reticular Formation: Regulates sleep, wakefulness, and arousal.

  • Pons: Relays information between the cerebellum and other parts of the brain.

Midbrain Components

  • Tegmentum:

    • Involved in orienting responses to stimuli.

  • Tectum: Also participates in sensory processing.

Forebrain: Subcortical Structures

  • Hypothalamus: Regulates the four Fs (Feeding, Fighting, Fleeing, and Mating).

  • Thalamus: Filters and transmits sensory information to the cortex.

  • Amygdala: Plays a pivotal role in emotional processing.

  • Hippocampus: Critical for creating and integrating new memories.

Patient Studies

  • Patient H.M.: Had his hippocampus removed, leading to profound memory issues.

  • Types of Amnesia:

    • Retrograde Amnesia: Loss of past memories.

    • Anterograde Amnesia: Inability to create new memories.

  • Clive Wearing: Documented experiences of severe amnesia revealing insights into memory.

Basal Ganglia

  • Directs intentional movement and plays a role in reward processing.

Online Resource

  • Brainfacts.org: Offers an interactive 3D brain model for better understanding of structures.

Review of Brain Parts

  • Limbic System: A complex set of structures involved in emotions and memory.

  • Cerebral Cortex:

    • Critically important for higher brain functions; folded to fit in the skull.

  • Lobes of the Cerebral Cortex:

    • Frontal Lobe

    • Temporal Lobe

    • Parietal Lobe

    • Occipital Lobe

Somatosensory Cortex

  • Sensitive body areas correspond to larger areas of the somatosensory cortex.

Brain Development

  • Prefrontal Cortex: Develops last; fully maturing by ages 20-25.

Motor Cortex

  • Details cortical representations of movement abilities heavily weighted by importance (Motor Homunculus).

Transcranial Magnetic Stimulation (TMS)

  • A method using strong magnets to disrupt normal brain activity, applicable in research and treatments.

Language in the Brain

  • Broca's Area: Involved in language production; damage results in Broca's Aphasia.

  • Wernicke's Area: Involved in speech comprehension; if impaired, it results in Wernicke's Aphasia.

Case Study: Aphasia

  • Aphasia defined as the inability to use or understand language.

Brain Plasticity

  • The ability of the brain to change throughout life, particularly in response to learning and experience.

Cerebral Hemispheres

  • The two hemispheres connected by the corpus callosum:

    • Left Hemisphere: Typically better at language processing.

    • Right Hemisphere: Often excels in spatial relationships.

Split Brain Studies

  • Split Brain: A condition resulting from severing the corpus callosum; leads to unique results in sensory processing and motor control.

Split Brain Patients

  • Demonstration of lateralization:

    • Left visual field processed in right hemisphere (spatial).

    • Right visual field managed in left hemisphere (language).

Neurons

  • Definition: A neuron is a specialized cell for receiving and transmitting information.

  • Parts of a Neuron:

    • Dendrites: Receive incoming information.

    • Cell Body: Manages information processing and keeps the cell alive.

    • Axon: Conducts electrical impulses away from the cell body.

    • Synapse: The junction between axons and other neurons.

    • Myelin Sheath: Insulates axons, increasing signal speed and efficiency.

Myelin Sheath Damage

  • Conditions like Multiple Sclerosis result from damage to the myelin sheath, disrupting communication.

Action Potential

  • Definition: An electrical signal transmitted along the axon of a neuron.

    • Characterized by 'all-or-nothing' behavior.

  • Phases of Action Potential:

    1. Resting Potential: About -70 mV; inside of the neuron is negatively charged compared to outside.

    2. Depolarization: Sodium (Na+) channels open, allowing positive ions to flood in.

    3. Repolarization: After the peak, Na+ channels close, K+ channels open, restoring negative charge.

Summary of Neural Transmission

  • Two Main Parts:

    1. Action Potential: An all-or-none response.

    2. Transmission Across the Synapse: A graded response.

Neurotransmitters

  • Chemical messengers that can be:

    • Excitatory: Increase the likelihood of an action potential.

    • Inhibitory: Decrease likelihood of an action potential.

  • Examples:

    • Acetylcholine (ACh): Important for voluntary motor control.

    • Dopamine: Linked to movement and pleasure; involved in Parkinson’s Disease when degenerated.

    • Serotonin: Regulates sleep, wakefulness, and eating behavior.

Agonists and Antagonists

  • Agonist: A drug that enhances neurotransmitter action.

  • Antagonist: Diminishes neurotransmitter function (e.g., Botox blocks ACh).

Brain Imaging Techniques

  • MRI: Produces structural images using magnetic fields.

  • fMRI: Measures brain activity through changes in blood oxygen levels; spatial resolution is strong, but temporal is weak.

  • EEG (Electroencephalography): Records electrical activity from neurons at the scalp; offers millisecond resolution, excellent temporal but poor spatial resolution.