Psych Exam 2

Sensation vs. Perception

• Sensation: The process by which our sensory receptors (like the eyes or ears) receive stimuli from the environment.

• Perception: The process of organizing and interpreting sensory information to recognize meaningful objects and events.

Transduction

• Transduction: The process of converting sensory stimuli into electrical signals that the brain can understand.

Thresholds of Awareness

• Absolute threshold: The minimum amount of stimulus needed for detection 50% of the time.

• Difference threshold (Just-noticeable difference): The smallest change in stimulus that can be detected.

• Signal detection theory: A theory that predicts how and when we detect the presence of a faint stimulus amid background noise, factoring in both sensitivity and decision-making criteria.

• Weber’s law: The principle that the just-noticeable difference is a constant proportion of the original stimulus.

• How do we notice stimulus change?: We detect changes by comparing the current stimulus to a baseline and noticing when differences cross a threshold.

Adaptation

• Functions of adaptation: The decrease in response to a constant stimulus over time, helping organisms focus on changes in the environment.

• Aftereffect (afterimage): The visual illusion that occurs after staring at a stimulus for a prolonged time (e.g., seeing colors after looking at bright lights). It demonstrates adaptation because it shows how sensory systems "calibrate" to stimuli.

Vision

• Properties of light:

  • Wavelength: Determines color.

  • Amplitude: Determines brightness.

  • Purity: Determines saturation or richness of color.

• Cones vs. Rods:

  • Cones: Detect color and are concentrated in the fovea (central vision).

  • Rods: Detect light and dark, responsible for peripheral and night vision.

• Structure of the human eye:

  • Cornea: Protects the eye and focuses light.

  • Lens: Focuses light onto the retina.

  • Retina: Converts light into neural signals.

  • Fovea: The central focus point on the retina.

  • Optic nerve: Carries visual information to the brain.

  • Blind spot: Area of the retina with no photoreceptors.

• Myopia vs. Hyperopia:

  • Myopia: Nearsightedness (difficulty seeing distant objects).

  • Hyperopia: Farsightedness (difficulty seeing nearby objects).

• Color perception:

  • Trichromatic theory: Suggests that we have three types of photoreceptors (red, green, blue), explaining color vision and color blindness.

  • Opponent-process theory: Explains color vision by proposing three opposing color systems (red-green, blue-yellow, black-white) and how they account for afterimages.

Object Identification

• Parallel processing: The brain processes multiple aspects of an object (color, shape, motion) simultaneously.

• Feature detectors: Neurons that respond to specific features like lines or angles. Located in the visual cortex.

• Ventral vs. Dorsal stream:

  • Ventral: "What" pathway; responsible for object recognition.

  • Dorsal: "Where" pathway; responsible for spatial processing and movement.

• Recognition of faces: Specialized areas in the brain, like the fusiform face area (FFA), help process faces.

Sound

• Properties of sound:

  • Frequency: Determines pitch.

  • Amplitude: Determines loudness.

  • Complexity: Determines timbre (quality of sound).

• Structure of the ear:

  • Outer ear: Funnels sound to the eardrum.

  • Middle ear: Contains ossicles (small bones) that transmit vibrations.

  • Inner ear: Contains cochlea and auditory cilia that convert sound into neural signals.

• Hearing damage: Damage to the cochlea or auditory nerve can lead to hearing loss.

• Perception of pitch:

  • Frequency theory: Explains low-pitched sounds by suggesting that hair cells in the cochlea fire at the same frequency as the sound.

  • Place theory: Explains high-pitched sounds by suggesting that different parts of the cochlea respond to different frequencies.

• Perception of loudness: Based on the amplitude of sound waves.

• Primary auditory cortex: Located in the temporal lobe, processes sound information.

• Tonotopic organization: Mapping of sound frequencies along the cochlea and auditory cortex.

• Localization of sound: The brain uses differences in timing and intensity of sounds between ears to localize sound.

Body States

• Proprioception: The sense of body position and movement.

• Balance detection: The vestibular system in the inner ear and certain areas of the brain (like the cerebellum) detect balance.

Touch

• Primary somatosensory cortex: Located in the parietal lobe, processes sensory information related to touch.

Smell

• Primary olfactory cortex: Located in the temporal lobe, processes smells.

• Connection to amygdala/hippocampus: Smell is closely linked to emotions and memory because of these connections.

Meaningful Perception

• Top-down processing: Guided by prior knowledge, expectations, or experiences.

• Bottom-up processing: Builds perception from sensory data without prior knowledge.

• Perceptual set: A mental predisposition to perceive things in a certain way based on experience, context, or expectations.

• Gestalt psychology: Focuses on how we organize sensory information into meaningful wholes, not just parts.

  • Gestalt principles:

    • Figure-ground: Distinguishing objects (figures) from the background.

    • Grouping: Organizing stimuli based on proximity, similarity, continuity, and closure.

Depth Perception

• Visual cliff: A test to assess depth perception, showing infants that they can detect depth even when a surface appears to drop off.

• Binocular cues: Require two eyes (e.g., convergence and retinal disparity).

• Monocular cues: Can be perceived with one eye (e.g., size, texture, interposition).

Motion Perception

• Motion detection cues: Involves detecting changes in visual stimuli based on the movement of the object and its surrounding environment.

Perceptual Constancy

• Perceptual constancy: The ability to perceive an object as unchanging despite changes in the sensory input (e.g., size, shape, color constancy).

Learning

• Learning: The process of acquiring new knowledge or behaviors through experience.

• Associative learning: Learning that certain events occur together (e.g., classical and operant conditioning).

• Non-associative learning: Learning from repeated exposure to a single stimulus (e.g., habituation and sensitization).

Classical Conditioning

• How classical conditioning works: Associating a neutral stimulus (NS) with an unconditioned stimulus (US) to create a conditioned response (CR).

• Acquisition: The initial stage where the NS becomes associated with the US.

• Extinction: The disappearance of the conditioned response when the CS is presented without the US.

• Spontaneous recovery: The reappearance of the CR after a rest period.

• Blocking: When a new stimulus does not become associated with the CS if it's already paired with another stimulus.

• Little Albert: A study that demonstrated emotional responses could be conditioned in humans.

• Generalization: When a CR occurs to stimuli similar to the CS.

• Discrimination: The ability to distinguish between the CS and other stimuli.

Operant Conditioning

• How operant conditioning works: Learning through consequences (reinforcement or punishment).

• Thorndike’s Law of Effect: Behaviors followed by satisfying outcomes are likely to be repeated.

• Skinner box: A device used to study operant conditioning with animals.

• Reinforcement vs. Punishment:

  • Reinforcement: Increases behavior.

  • Punishment: Decreases behavior.

  • Primary reinforcer: Inherently rewarding (e.g., food).

  • Secondary reinforcer: Learned rewards (e.g., money).

  • Positive reinforcement: Adding a desirable stimulus.

  • Negative reinforcement: Removing an undesirable stimulus.

  • Positive punishment: Adding an undesirable stimulus.

  • Negative punishment: Removing a desirable stimulus.

• Premack principle: Using a preferred activity to reinforce a less preferred one.

• Shaping: Reinforcing successive approximations of a desired behavior.

• Schedules of reinforcement:

  • Continuous reinforcement: Reinforcement after every behavior.

  • Partial reinforcement: Reinforcement after some behaviors.

  • Ratio vs. interval:

    • Ratio: Based on the number of responses.

    • Interval: Based on the time passed.

  • Fixed vs. variable:

    • Fixed: Reinforcement occurs after a set number of responses or time.

    • Variable: Reinforcement occurs after a random number of responses or time.

  • Most effective schedule: Variable-ratio, because it is unpredictable and keeps behavior more consistent.

Latent Learning

• Latent learning: Learning that occurs but is not demonstrated until there is an incentive to show it.

Insight Learning

• Insight learning: A sudden realization of a solution to a problem.

Observational Learning

• Observational learning: Learning by observing others.

• Bobo doll experiment: Showed that children imitated aggressive behavior after seeing an adult act aggressively toward a doll.

• Vicarious reinforcement: Learning by seeing others being rewarded.

• Vicarious punishment: Learning by seeing others being punished.