Biological Psychology

Quasi-Experimentation and Validity

  • Quasi-Randomization: Not always possible, which affects internal and external validity

  • CNS: Central Nervous System

Biological Psychology

  • Ex.Meth Review:

    • Effect Size: Essential for measuring the significance of data

    • Experimenter Bias: Unintentional bias towards a specific outcome

      • Solution: Use double-blind experiments

    • Volunteer Bias: Participants who join without expected benefits

    • Demand Characteristics: Participants may change their behavior based on assumptions about the study's goals

    • Inter-Rater Reliability: High agreement (e.g., .8) between multiple observers in naturalistic observations

Reductionist Models

Epigenetic Model

  • Genotype: The body's genetic blueprint, which may be affected by environmental factors

  • Phenotype: The observable characteristics resulting from genotype

  • Humans possess approximately 25,000 genes

  • Gene Regulation: Amino acid switches can activate or deactivate genes

Evolutionary Model

  • Focuses on species adaptation (e.g., goosebumps as a survival mechanism)

Holistic Approach

  • Views systems like the nervous and endocrine system as interconnected rather than isolated

Neuron Structure

  • Dendrite: Receives information

  • Soma: Cell body containing the nucleus

  • Axon: Transmits information to other neurons

  • Myelin: Protective fatty substance that speeds up signal transmission

  • Glial Cells: Produce myelin and continue to be generated throughout life

Neuronal Activity

  • Resting Potential: State when the neuron is not transmitting

  • Action Potential: Occurs when the neuron is transmitting signals

  • Refractory Period: Short recovery time after an action potential

  • Synapse: The gap between neurons

Peripheral Nervous System (PNS)

  • Divided into:

    • Somatic: Controls voluntary movements

    • Autonomic: Regulates involuntary functions

      • Sympathetic: Activates fight or flight response (e.g., suppressing non-essential functions)

      • Parasympathetic: Calms the body after the fight or flight response

Neuroanatomy and Functions

Brain Imaging Techniques

  • Case Studies: In-depth investigations of a single subject or group

  • Neuroimaging: MRI, PET, CAT Scan

    • PET Scan: Uses radioactive glucose for imaging

    • fMRI: Observes both structure and activity

Major Brain Regions

  • Hindbrain:

    • Medulla: Controls autonomic functions (breathing, vomiting)

    • Pons: Relays information across hemispheres

    • Cerebellum: Coordinates motor control and cognitive functions

Midbrain and Forebrain

  • Cortex: Includes two hemispheres that operate contralaterally, connected by the corpus callosum

  • Reticular Activating System: Regulates alertness and wakefulness

  • Substantia Nigra: Contains dopamine receptors, critical for movement (disrupted in Parkinson’s disease)

Limbic System (Forebrain)

  • Thalamus: Relay for sensory information

  • Hypothalamus: Regulates hunger, thirst, temperature, and emotional responses

  • Hippocampus: Key role in memory and learning

  • Amygdala: Processes emotions such as fear

Vascular Supply to Brain

  • Vertebral Artery: Supplies blood to the back of the brain

  • Internal Artery: Supplies blood to the front

  • Cerebral Inflation: 80% of the brain consists of gyri (bumps) and sulci (grooves)

Brain Lobes Functions

  • Occipital Lobe: Visual processing

  • Parietal Lobe: Integrates sensory information, spatial awareness

    • Somatosensory Cortex: Processes touch and pain

  • Temporal Lobe: Responsible for auditory processing and language comprehension

  • Frontal Lobe: Involves reasoning, decision-making, and motor function

    • Prefrontal Cortex: Develops throughout the 20s, involved in complex cognitive behavior

Neuroplasticity

  • Corpus Callosum: Connects hemispheres allowing communication

  • Lateralization:

    • Right Hemisphere: Engaged in spatial tasks and emotional understanding

    • Left Hemisphere: Deals with language and analytical skills

  • Adaptability: Brain reshapes in response to experiences

  • Neural Growth:

    • Neurogenesis: Occurs predominantly in the hippocampus

    • Dendritic Growth: Encouraged through problem-solving and education

  • Adaptation to Sensory Loss: Blind individuals repurpose visual neurons for auditory processing

  • Phantom Limb Pain: Occurs due to sensory cortex reorganizing after amputation, leading to perceived sensations in missing limbs.