PSY101 Topic 3 lecture

Introduction to Biological Psychology

• Instructor: Dr. Nicole Sugden, CSU Graduate

• Subjects Taught: Biopsychology, Psychological Assessment

• Research Areas: Biological psychology, prospective memory, neuropsychological assessment, sensation and perception, with a focus on brain injury, dementia, and neuropsychological conditions.

Learning Objectives

• Overview of neuron structure and function

• Electrical responses of neurons and action potentials

• Communication between neurons via neurotransmitters

• The brain's adaptability through development, learning, and injury

• Overview of the central nervous system, somatic and autonomic systems

• Impact of hormones on behavior

• Measurement techniques for brain activity

• Brain localization of function

• Influence of genes on psychological traits and misconceptions about behavior genetics

Importance of Biopsychology

• Essential understanding of cellular processes underlying behavior

• Knowledge of brain structure and terminology aids psychological assessments and research reading

• Useful for general comprehension of psychology in media (e.g., "Grey's Anatomy", "The Good Doctor")

Neurons: The Core of Nervous System

• Structure of Neurons:

  • Dendrites: Receive signals from other neurons

  • Cell Body (Soma): Contains nucleus and regulates cell activities

  • Axon: Transmits electrical signals known as action potentials; covered in myelin sheath for insulation and speed

  • Axon Terminals: Release neurotransmitters into the synapse

• Glial Cells: Support neurons, providing nutrients, structure, and cleaning debris

  • Astrocytes: Feed neurons and maintain environment

  • Oligodendrocytes: Form myelin sheath

  • Microglia: Clean up waste and involved in immune response

Synaptic Transmission

• Synapse: Gap between neurons where neurotransmitter release occurs

• Neurotransmitter Binding:

  • Neurotransmitters act like keys to fit into receptor locks on postsynaptic cells.

  • Determines whether the postsynaptic neuron will fire (action potential) based on excitatory or inhibitory inputs.

• Ion Channels: Sodium, potassium, calcium, and chloride channels that dictate neural signal firing based on neurotransmitter action.

Action Potentials

• Process:

  1. Resting Potential: Neuron at -70mV, primarily permeable to potassium.

  2. Depolarization: Sodium channels open, neuron becomes more positive.

  3. Repolarization: Sodium channels close, potassium channels open, returning to negative state.

  4. Hyperpolarization: Brief state where the neuron becomes more negative than resting potential.

• All or Nothing Rule: Once initiated, an action potential cannot be stopped and must propagate through the axon.

• Saltatory Conduction: Speeding up transmission through myelinated axons using nodes of Ranvier.

Types of Neurotransmitters

• Glutamate: Main excitatory neurotransmitter critical for learning; excessive glutamate can cause toxicity.

• GABA (Gamma-Aminobutyric Acid): Main inhibitory neurotransmitter, enhances relaxation effects from substances like alcohol.

• Acetylcholine (ACh): Involved in muscle contraction and cortical arousal.

• Noradrenaline (Norepinephrine): Involved in arousal and attention; drugs like amphetamines enhance activity.

• Dopamine: Linked to motor functions (Parkinson's) and reward systems; high levels relate to schizophrenia.

• Serotonin: Important in mood regulation, imbalances linked to depression, targeted by SSRIs for treatment.

• Endorphins and Anandamides: Related to pain reduction and euphoria; activated by exercise and drugs like opiates.

Roles of the Nervous System

• Central Nervous System (CNS): Comprising the brain and spinal cord, protected by bone.

• Peripheral Nervous System (PNS): Nerves outside CNS, divided into somatic (voluntary control) and autonomic systems (involuntary control).

• Autonomic Nervous System (ANS): Divided into sympathetic (fight or flight response) and parasympathetic (rest and digest).

Endocrine System

• Connected to the nervous system; produces hormones for widespread messaging in the body.

• Hypothalamus: Signals endocrine function; controls vital behaviors and hormone release.

• Key glands include pituitary (controls other glands), adrenal (stress-related hormones), thyroid (metabolism), etc.

Brain Structures and Their Functions

• Cerebral Cortex: Largest brain part for higher-order functions, divided into lobes (frontal, parietal, temporal, occipital).

  • Frontal Lobe: Executive functions, planning, movement.

  • Parietal Lobe: Sensory processing, spatial orientation.

  • Occipital Lobe: Visual processing.

  • Temporal Lobe: Auditory processing, language understanding.

• Limbic System: Includes the amygdala (emotion), hypothalamus, and hippocampus (memory).

• Basal Ganglia: Involved in movement control and reward.

Measuring Brain Activity

• Techniques: EEG (electrical activity), PET (radioactive substance), MRI (high-resolution imaging), fMRI (functional imaging).

  • Limitations: Spatial resolution challenges in EEG and PET; MRI provides snapshots not indicating activity.

Brain Function Myths

• Misconception of left-brain/right-brain functionality; both hemispheres collaborate for tasks requiring language and creativity.

• Split-brain cases exhibit fascinating consequences where each hemisphere exhibits separate consciousness under certain conditions.

Genetic Influences on Behavior

• Intelligence and behavior influenced by genetic heritage; heritability studies provide insights into environmental vs. genetic influence.

• Emotional and psychological characteristics are shaped by genetic predispositions and environmental interactions.

Conclusion

• Biological psychology explores the intricate relationship between brain function and behavior.

• Understanding brain structures, neurotransmitters, and their effects is crucial for effective psychological assessment and treatment.

• Continuous research and technological advancements hold promise for future discoveries in the cellular basis of behavior.