Psychology: History and Critical Thinking

• Psychology is the scientific study of behavior and mental processes.
• Critical thinking involves clear, rational, and independent thought, with objective evaluation of evidence and arguments.

Historical Figures

• Wilhelm Wundt, the "father of psychology," founded the first psychology lab in 1879 and used introspection to study conscious experience.
• Introspection is a self-observation method where individuals report their thoughts and feelings, but it is subjective and unreliable.
• Structuralists studied the mind's structure by analyzing basic elements of consciousness through introspection.
• William James, known as the "father of American psychology," developed functionalism, which focuses on how mental processes aid adaptation.
• Functionalists studied the purpose and function of behavior and mental processes, differing from structuralists' focus on structure.
• Sigmund Freud founded psychoanalysis that emphasized the unconscious mind, childhood experiences, and repressed thoughts as influences on behavior.
• Behaviorists examined how interactions with the environment learn observable behaviors.
• Early psychology lacked diversity, leading to biased theories and underrepresentation of minority viewpoints.
• Kenneth and Mamie Phipps Clark's "doll study" influenced Brown v. Board of Education by showing the effects of segregation on Black children.

Psychology Professions

• Clinical psychologists diagnose and treat mental disorders through therapy and counseling.
• Psychiatrists are medical doctors who prescribe medicine, while clinical psychologists use therapy and psychological assessments.

Research Methods

• Basic research expands knowledge, while applied research solves practical problems.
• Naturalistic observation involves observing behavior in natural settings without interference.
• Case studies offer in-depth analysis of a single person or group to study conditions
• Correlation identifies relationships between variables for patterns and predictions. Correlation DOES NOT prove causation
• Positive correlation: variables increase or decrease together. Negative correlation: as one increases, the other decreases.
• Experimental studies manipulate variables to determine cause-and-effect relationships.
• The independent variable is manipulated; the dependent variable is the measured outcome.
• A representative sample accurately mirrors the population, while a convenience sample is chosen for ease but may be unrepresentative.
• Informed consent means participants are told about a study’s risks and agree voluntarily.

Brain and Neurons

• Parts of the Central Nervous System (CNS): brain and spinal cord, which process and transmits information.
• Sympathetic autonomic nervous system activates "fight or flight".
• Parasympathetic calms the autonominc nervous system for "rest and digest".
• Four Lobes of the Cerebral Cortex & Functions:
  • Frontal Lobe: Decision-making, problem-solving, movement.
  • Parietal Lobe: Sensory processing, spatial awareness.
  • Temporal Lobe: Hearing, memory, and language.
  • Occipital Lobe: Vision.
• Cerebellum controls coordination, balance, and motor control.
• Amygdala regulates emotion, especially fear and aggression.
• Hippocampus forms memories and enables learning.
• A neuron, or nerve cell, transmits information through:
  • Dendrites: Receive signals.
  • Cell Body (Soma): Processes information.
  • Axon: Transmits signals.
  • Myelin Sheath: Speeds signal transmission.
  • Axon Terminals: Release neurotransmitters.
• A synapse is a gap between neurons for communication.
• Neurotransmitters: Chemicals that transmit signals between neurons
• Serotonin modulates mood, sleep, and appetite.
• Dopamine involves pleasure, motivation, and movement
• Neural plasticity is the brain's ability to change and adapt through learning.
• Brain lateralization divides functions between the left and right hemispheres.

Sensation and Perception

• Sensation detects stimuli, while perception interprets stimuli.
• Bottom-up processing begins with sensory input, while top-down processing uses prior knowledge.
• Absolute threshold: the smallest detectable stimulus
• Difference threshold (just noticeable difference): smallest detectable change in a stimulus.
• Three Psychological Dimensions of Vision:
  • Hue: Determined by wavelength.
  • Brightness: Determined by amplitude.
  • Saturation: Determined by purity of wavelengths.
• Light Waves Through the Eye:
  • Cornea: Protects and focuses light.
  • Pupil: Controls light entry.
  • Lens: Focuses light onto the retina.
  • Retina: Contains photoreceptors (rods/cones).
  • Optic Nerve: Sends visual info to the brain.
• Rods detect light/dark in low light, while cones detect color in bright light.
• Three Psychological Dimensions of Hearing:
  • Pitch: Determined by frequency.
  • Loudness: Determined by amplitude.
  • Timbre: Determined by complexity of sound waves.
• Sound Waves Through the Ear:
  • Eardrum: Vibrates with sound.
  • Hammer, Anvil, Stirrup: Transmit vibrations to cochlea.
  • Cochlea: Converts vibrations to neural signals.
  • Auditory Nerve: Sends sound info to the brain.
• Five Basic Tastes: Sweet, sour, salty, bitter, umami.
• Synesthesia: when one sense triggers another.