biopsychology

Chapter 1: Introduction to Brain and Behaviour

Fixed vs. Flexible Behaviours

• Fixed behaviours: Innate, instinctual responses (e.g., reflexes).

• Flexible behaviours: Learned, adaptable responses (e.g., problem-solving).

Philosophical Perspectives

• Materialism: Mental processes are physical brain processes.

• Dualism: Mind and body are separate (Descartes).

• Mentalism: Reality is a mental construct.

• Mind-body problem: How mental states relate to physical states.

Brain Evolution

• Encephalization quotient (EQ): Brain size relative to body size.

• Evolution of larger brains: Linked to complex behaviours.

• Brain size vs. intelligence: Not always correlated; structure and connectivity matter more.

Chapter 2: Neuroanatomy & Nervous System

Neuroplasticity

• Brain’s ability to reorganize in response to experience.

Nervous System Divisions

• Somatic Nervous System (SNS): Voluntary muscle control.

• Autonomic Nervous System (ANS): Involuntary functions.

  • Sympathetic: "Fight or flight" (↑ heart rate).

  • Parasympathetic: "Rest and digest" (↓ heart rate).

• Afferent (sensory) vs. Efferent (motor): Signals to/from CNS.

Brain Structures

• Four lobes:

  • Frontal: Decision-making, motor control.

  • Parietal: Sensory processing.

  • Temporal: Auditory, memory.

  • Occipital: Vision.

• Ventricles: CSF-filled cavities.

• Grey vs. white matter: Cell bodies vs. myelinated axons.

• Meninges: Protective layers (dura, arachnoid, pia mater).

Spinal Cord & Reflexes

• Spinal reflex: Rapid response (e.g., knee-jerk).

• Dorsal (sensory) vs. Ventral (motor) roots.

Brain Function Theories

• Localized vs. distributed function: Some areas specialize, but networks collaborate.

• Left vs. right brain:

  • Left: Language, logic.

  • Right: Spatial, emotional processing.

Chapter 3: Neurons & Neurophysiology

Neuron Hypothesis

• Neurons are the brain’s functional units.

Neuron Structure

• Dendrites: Receive signals.

• Axon: Transmits signals.

• Myelin: Speeds conduction (PNS: Schwann cells; CNS: oligodendrocytes).

• Repair: PNS can regenerate; CNS cannot.

Ion Channels & Pumps

• Leak channels: Always open.

• Gated channels: Open with stimuli.

• Pumps (e.g., Na+/K+): Maintain gradients.

Genetic & Epigenetic Influences

• Transgenic techniques: Modify genes in models.

• Phenotypic plasticity: Environment affects gene expression.

• Epigenetics: Chemical modifications altering gene activity.

Chapter 4: Neural Signaling

Resting Potential (~-70mV)

• High K+ inside, high Na+ outside.

Action Potential

• Depolarization: Na+ influx.

• Repolarization: K+ efflux.

• All-or-none law: APs are uniform in strength.

• Refractory periods:

  • Absolute: No new AP possible.

  • Relative: Higher threshold.

• Saltatory conduction: AP jumps between Nodes of Ranvier.

Synaptic Potentials

• EPSPs (excitatory): Depolarize.

• IPSPs (inhibitory): Hyperpolarize.

• Summation:

  • Spatial: Multiple inputs.

  • Temporal: Rapid successive inputs.

Chapter 5: Synapses & Neurotransmitters

Synapse Types

• Chemical: Neurotransmitter release (vesicles).

• Electrical: Gap junctions (fast).

Neurotransmitter Inactivation

• Reuptake, enzymatic breakdown, diffusion.

Receptor Types

• Ionotropic: Fast, direct (e.g., GABA-A).

• Metabotropic: Slow, indirect (e.g., dopamine).

Activating Systems

• Cholinergic: Memory (ACh).

• Dopaminergic: Reward (DA).

• Serotonergic: Mood (5-HT).

• Noradrenergic: Alertness (NE).

Stress Responses

• Fast: Sympathetic activation (adrenaline).

• Slow: HPA axis (cortisol).

Chapter 6: Drugs & Addiction

Pharmacology

• Agonists: Mimic NTs (e.g., morphine).

• Antagonists: Block NTs (e.g., naloxone).

Tolerance & Sensitization

• Tolerance types: Metabolic, functional, learned.

Addiction Theories

• Wanting (dopamine) vs. Liking (opioids).

• SSRIs: Block 5-HT reuptake.

• Cocaine: Blocks DA reuptake.

Chapters 8–16: Highlights

Development (Ch. 8)

• Neural tube defects (e.g., spina bifida).

• Synaptic pruning: Refines connections.

Sensation & Perception (Ch. 9–12)

• Vision: Dorsal (where) vs. ventral (what) streams.

• Hearing: Tonotopic organization.

• Pain: Gate theory (inhibition by touch).

Memory (Ch. 14)

• Explicit (hippocampus) vs. Implicit (cerebellum).

• LTP/LTD: Strengthening/weakening synapses.

Disorders (Ch. 16)

• Schizophrenia: DA hyperactivity.

• Depression: Low 5-HT/NE, high cortisol.

• Alzheimer’s: Amyloid plaques.

• Parkinson’s: DA neuron loss.

Therapies

• DBS: Parkinson’s.

• ECT: Severe depression.