PSYCH 240 Exam 1 Study Guide PDF

Lecture 1: History & methodology (and study tips) Introspectionism ​ Structuralists (Wundt & Titchener): Believed in looking inward to examine mental processes. ​ Problems: ○​ Difficult to verify; private/internal thoughts aren’t observable. ○​ Different perspectives/...

Lecture 1: History & methodology (and study tips) Introspectionism ​ Structuralists (Wundt & Titchener): Believed in looking inward to examine mental processes. ​ Problems: ○​ Difficult to verify; private/internal thoughts aren’t observable. ○​ Different perspectives/opinions lead to inconsistent results. ○​ Focuses on the end product, not the process itself. Behaviorism ​ Key Figures: Pavlov, Watson (denied consciousness), Skinner (no difference between animals & humans). ​ Core Idea: Psychology should focus only on observable behavior (stimulus → response). ​ Methods: ○​ Stimuli, responses, reinforcements/rewards (e.g., rats in mazes). ○​ Ignored the mind as a "black box." ​ Problems: ○​ Can’t explain complex behaviors (e.g., language—Chomsky's critique). ○​ Science should not be limited to the directly observable. Cognitivism ​ Key Idea: Infer what’s happening inside the mind. ​ Computational View of Mind: The mind operates like a computer—input, processing, output. Variables & Graphs ​ Dependent Variable (DV): What is measured (e.g., reaction time, accuracy, brain activity). ​ Independent Variable (IV): What is manipulated (e.g., number of items memorized, alcohol intake). ​ Graph Interpretation: ○​ Main Effects: IV affects DV (parallel lines). ○​ Interactions: Effect of one IV depends on another (non-parallel lines). Mental Chronometry & Donders' Subtraction Method ​ Donders (1868): Studied mental process timing. ​ Information Processing Stages: ○​ Detection Task: Press a button when light appears (S → Detection → R). ○​ Choice Task: Press left for red, right for green (S → Detection → Decision → R).  ​ Subtraction Method: ○​ (S → Detection → Decision → R) − ( S → Detection → R ) = Decision Time. ​ Problems: ○​ Pure Insertion: New stages may alter existing ones. ○​ Additivity: Assumes stages are separate (they may operate in parallel). ○​ Knowing the Stages: Assumes correct identification of mental stages. Scientific Reasoning in Cognitive Psychology ​ Problem with Confirming Evidence: Weak as a scientific method. ​ Key Approach: Eliminate alternative explanations. Huppert & Piercy Amnesia Experiments ​ Tested Memory Impairments: ○​ Encoding: Trouble learning new info. ○​ Storage: Trouble retaining info. ○​ Retrieval: Trouble accessing stored info. ​ Findings: Ruled out storage issues. Effective Studying Techniques ​ Rehearsal Types: ○​ Elaborative Rehearsal: Deep processing (meaning-based). ○​ Maintenance Rehearsal: Repetition (shallow processing). ​ Spacing Effect: ○​ Massed Practice: Cramming (ineffective). ○​ Distributed Practice: Spreading study sessions over time (better retention). ​ Testing Effect: Self-testing improves retention. ​ Sleep & Consolidation: Sleep enhances memory consolidation. Sternberg 1 Reading Dialectic ​ Definition: Advancing knowledge by resolving opposing ideas (thesis vs. antithesis → synthesis). ​ Importance in Psychology: Helps reconcile differing theories to refine understanding of mental processes. 1.​ Structuralism (Wundt, Titchener) ○​ What? Breaks down mental processes into basic elements (sensations, images, feelings). ○​ Method: Introspection.  ○​ Criticism: Too subjective, lacks practical application. 2.​ Functionalism (James, Dewey) ○​ What? Focuses on the purpose of mental processes in adaptation. ○​ Criticism: Accused of lacking rigorous structure. 3.​ Behaviorism (Watson, Skinner) ○​ What? Focuses on observable behavior (stimulus → response) ○​ Method: Conditioning (classical & operant). ○​ Criticism: Ignores internal mental states. 4.​ Cognitivism (Neisser, Piaget) ○​ What? Studies internal mental processes like perception, memory, and problem-solving. ○​ View of Mind: An information processor (like a computer). ○​ Criticism: Behaviorists argued it lacks empirical grounding due to focus on “invisible” processes. Critiques & Dialectic’s Role ​ Structuralism vs. Functionalism: Structuralists criticized functionalists for lacking structure; functionalists found structuralism impractical. ​ Behaviorism vs. Cognitivism: Behaviorists rejected cognitivism as unscientific; cognitivists argued behaviorism ignored crucial mental functions. ​ Dialectic’s Challenge: Attempts to integrate perspectives but struggles to merge fundamentally different paradigms. Bjork & Bjork Reading Learning vs. Performance ​ Learning = Long-term retention & transfer. ​ Performance = Immediate recall, but may not reflect actual learning. ​ Key Insight: Good performance in practice doesn’t guarantee effective learning. Desirable Difficulties ​ What? Strategies that make learning harder but improve long-term retention. ​ Examples: ○​ Spaced practice (instead of cramming). ○​ Interleaving (instead of blocking). ○​ Retrieval practice (testing instead of passive review). Effective Study Strategies 1.​ Varying Practice Conditions ○​ What? Changing study environments and contexts improves knowledge transfer. ○​ Why? Prevents dependence on specific conditions (avoiding context-dependent learning).  2.​ Spaced vs. Massed Practice ○​ Spaced: Studying over time enhances retention. ○​ Massed: Cramming feels productive but leads to fast forgetting. 3.​ Interleaving vs. Blocking ○​ Blocking: Practicing one topic repeatedly → Feels easier but leads to shallow learning. ○​ Interleaving: Mixing topics/skills → Forces comparisons, strengthens learning. ○​ Study on Artistic Styles: Participants who interleaved art styles learned to recognize new works better than those who studied one at a time. Memory & Testing Effects 1.​ Generation Effect ○​ What? Actively generating answers improves retention. ○​ Example: Solving a problem before seeing the solution. 2.​ Repeated Testing vs. Repeated Study ○​ Testing: Strengthens memory via retrieval. ○​ Studying: Repeated review builds familiarity but less retention. 3.​ Metacognitive Benefits of Testing ○​ Helps learners assess what they know and where they need improvement. ○​ Promotes active retrieval, reinforcing learning. 4.​ Familiarity Can Be Misleading ○​ Rereading and passive review create illusion of understanding. ○​ Overconfidence in learning without deep comprehension.  Lecture 2: Perception Perception – the process by which sensory information from the environment is transformed into experiences of objects, events, and sensations. Stages of Perception 1.​ Distal Stimulus – The actual object in the environment. 2.​ Proximal Stimulus – The pattern of stimulation on sensory receptors. 3.​ Perception/Percept – The brain's interpretation of sensory input (what you "see"). Perceptual Correspondence ​ Lack of Correspondence: Perception does not match reality (e.g., visual illusions). ​ Paradoxical Correspondence: The proximal stimulus does not match the distal stimulus, but perception does (e.g., size constancy, moving objects). Perceptual Constancies (Maintaining a stable perception despite changes in stimulus) ​ Size Constancy – Objects appear the same size despite distance changes. ​ Color Constancy – Perceived color remains stable despite lighting changes. ​ Shape Constancy – Objects are perceived as having a constant shape despite viewing angle changes. Theoretical Approaches to Perception: 1. Direct Perception (Gibsonian View) ​ The environment provides sufficient cues for perception. ​ The brain is hardwired to process these cues without additional knowledge. ​ Perception is largely bottom-up (stimulus-driven). 2. Constructivist Theory (Helmholtzian View) ​ Perception combines sensory data with prior knowledge and expectations. ​ Sensory information is often ambiguous, requiring top-down processing (knowledge-driven). ​ Uses both bottom-up and top-down processes. Bottom-Up vs. Top-Down Processing: ​ Bottom-Up Processing – Driven by raw sensory input (e.g., direct perception). ​ Top-Down Processing – Influenced by prior knowledge, expectations, and context (e.g., constructivism). Depth Perception: The Paradox & Cues The Paradox -​ We perceive a 3D world from a 2D retinal image. The brain reconstructs depth using monocular and binocular cues. Monocular Cues (One Eye) ​ Linear Perspective – Parallel lines converge in the distance. ​ Shape Cues – Objects change shape with perspective. ​ Relative Size – Smaller objects appear farther away. ​ Interposition – Overlapping objects create depth cues. ​ Shadows & Lighting – Help determine depth and shape. ​ Accommodation – Lens changes shape for focus: ○​ Far objects → Lens stretches. ○​ Close objects → Lens narrows. Binocular Cues (Both Eyes) ​ Retinal Disparity – Difference between images in each eye; larger disparity = closer object. ​ Convergence – Eyes turn inward for close objects, outward for distant ones. Sacks Reading: Dr. P & Visual Agnosia Dr. P’s Deficits ​ Visual Agnosia – Unable to recognize objects and faces visually. ​ Face Recognition Failure – Mistook his wife for a hat (prosopagnosia). ​ Partial Processing – Could describe shapes/colors but not integrate them into meaningful objects. ​ Navigation Issues – Relied on touch and routine instead of visual cues. Dr. P’s Preserved Abilities ​ Musical Skills – Singing and playing music remained intact. ​ Cognitive Abilities – Language, reasoning, and problem-solving were unaffected. ​ Compensatory Strategies – Used other senses (touch, sound) to navigate his world. Agnosia – A neurological disorder where sensory information is intact but recognition is impaired. Types of Visual Agnosia 1.​ Apperceptive Agnosia – Difficulty perceiving shapes and integrating visual elements. 2.​ Associative Agnosia – Can perceive objects but cannot assign meaning. 3.​ Prosopagnosia – Inability to recognize faces. Neural Basis: Dorsal vs. Ventral Streams ​ Dorsal Stream (“Where” Pathway, Parietal Lobe) ○​ Processes spatial location & movement. ○​ Intact in Dr. P (could navigate his environment). ​ Ventral Stream (“What” Pathway, Temporal Lobe) ○​ Recognizes objects and assigns meaning. ○​ Impaired in Dr. P (leading to agnosia).  Lecture 3: Visual system Retina & Photoreceptors: ​ Light first hits photoreceptors (rods & cones). ​ Blind spot: No photoreceptors in the optic disc where the optic nerve exits. Rods & Cones: ​ Rods: Detect brightness, more sensitive in low light. ​ Cones: Concentrated in the fovea, responsible for color vision (blue, green, red). ○​ Colorblindness results from missing or defective cone types. Ganglion Cells: ​ Gather input from photoreceptors and send signals to the brain via the optic nerve. ​ Responses depend on center-surround receptive fields (excitation/inhibition). Neuron Structure ​ Dendrites: Receive signals. ​ Soma (Cell Body): Processes input. ​ Axon: Sends signals. Action Potential & Transmission ​ Resting Potential: Baseline charge difference across axon. ​ Threshold: Minimum potential needed for firing. ​ All-or-None Principle: Neuron either fires fully or not at all. ​ Propagation: Action potential travels down axon via ion exchange. ​ Refractory Period: Brief pause before neuron can fire again. Neurotransmitters & Synapses ​ Electrochemical Transmission: ○​ Electrical (within neuron): Action potential. ○​ Chemical (between neurons): Neurotransmitters cross synapses. ​ Summation: Combined excitatory & inhibitory signals determine firing. Receptive Field ​ The area of external space that activates a particular neuron. ​ Ganglion cells respond to light stimuli in their receptive fields. Center-Surround Organization  ​ Enhances contrast and edge detection. ​ Functions: ○​ Point detection ○​ Edge detection ○​ Light-on-dark or dark-on-light perception M-Cells (Magnocellular) vs. P-Cells (Parvocellular) ​ M-Cells (Large receptive field, transient response) → Motion & Location. ​ P-Cells (Small receptive field, sustained response) → Color, Form, Patterns. The Cerebral Cortex & Visual Pathways Primary Visual Cortex (V1) Processing 1.​ Simple Cells → Detect bars of light at specific orientations. 2.​ Complex Cells → Detect movement & edges. 3.​ Hypercomplex Cells → Respond to specific shapes (corners, gaps). Two Visual Pathways ​ Dorsal Stream (Parietal Lobe – "Where" Pathway) → Processes spatial location & motion. ​ Ventral Stream (Temporal Lobe – "What" Pathway) → Processes object recognition & meaning. Brain Imaging & Activity Measurement Method Measures Trade-offs  Single/Multi-unit Recording Individual neuron activity High spatial & temporal precision, invasive Lesions Damage effects Causal inference, but limited to patients fMRI/PET Blood flow & metabolism Good spatial, poor temporal resolution EEG/ERP/MEG Electrical activity High temporal, poor spatial resolution Brain Stimulation (TMS, Disrupts/influences Non-invasive causal method tDCS) activity Kohler Experiment: Object vs. Spatial Processing (PET Study) ​ Spatial Task ("Where") → Parietal Lobe (Dorsal) Activation. ​ Object Task ("What") → Temporal Lobe (Ventral) Activation. Population Coding ​ Recognition doesn’t rely on a single "grandmother cell." ​ Instead, patterns of activity across many neurons encode objects. McCloskey Reading: Patient A.H. & Constructive Perception Modality-Specific Localization Impairment ​ A.H. had difficulty localizing objects visually but could do so by touch or sound. ​ Suggests visual spatial localization is separate from other sensory systems. Identification vs. Localization ​ A.H. could identify objects but mislocated them (e.g., mirror-image errors). ​ Highlights the separation of object recognition and spatial processing. Constructive Nature of Perception ​ Perception is indirect and constructed from sensory inputs. ​ Errors in localization show how the brain separately processes spatial and identity information. Overall Takeaway ​ Temporal/Ventral ("What") Pathway → Intact, allowing object recognition. ​ Parietal/Dorsal ("Where") Pathway → Impaired, leading to mislocalization.  Lecture 4: Pattern recognition: bottom-up Representation Process ​ Distal Stimulus → Real-world object. ​ Proximal Stimulus → Sensory input on receptors. ​ Percept → The brain’s interpretation of the object. Bottom-Up Pattern Recognition ​ Matching (Primal Access): First-time recognition when a percept aligns with stored memory. ​ Shape Constancy: Objects are recognized regardless of viewing angle, size, or lighting. Template Theory ​ Concept: Recognition occurs by matching input to stored templates. ​ Problems: ○​ Transformations: Can’t account for variations (e.g., different fonts of letter “E”). ○​ Obstructed Objects: Can’t recognize objects when parts are missing. Feature Theory ​ Concept: The visual system breaks objects into primitive features (matching; bottom-up pattern recognition) for recognition. ​ Evidence: ○​ Physiology: Neurons in the temporal lobe respond to visual features. ○​ Stabilized Retinal Images: Constant retinal stimulation leads to desensitization of certain features. ○​ Visual Search: Recognizing an object is harder when surrounded by similar features (e.g., finding "T" among "L"s). ○​ Pandemonium Model: A hierarchy of demons detecting features leads to recognition. ○​ Caricatures: Exaggerated features enhance recognition. ​ Problems: ○​ Same Features, Different Objects: (e.g., “P”, “d”, “b” all share the same features but are different letters). ○​ Feature Arrangement Matters: Feature theory doesn’t explain how different configurations produce different objects. Recognition-by-Components (RBC) Theory: ​ Concept: Objects are recognized by geons (geometric ions) — 36 elementary 3D shapes.  ​ Non-Accidental Properties: Features that remain identifiable from most viewpoints (e.g., edges of a brick). ​ Matching Process: 1.​ Detect elementary features, edges. 2.​ Identify non-accidental properties. 3.​ Determine geons and their arrangement. 4.​ Match to stored object memory. Evidence for RBC ​ Partial/Degraded Objects: Recognition fails if non-accidental properties are removed. ​ Occluded Objects: Objects remain identifiable even if partially blocked. ​ Object Complexity: More geons = faster recognition. ​ Unusual Orientations: Uncommon viewpoints make recognition harder. Problems with RBC ​ Similar Objects: Can’t distinguish subtle differences (e.g., green apple vs. green pear, Beyoncé vs. Rihanna). ​ Lack of Brain Evidence: No geon-specific brain regions identified. ​ Context Effects: Assumptions based on surrounding context affect recognition, which RBC doesn’t fully explain. Strengths of RBC ​ Handles transformations (e.g., different fonts of “E”). ​ Explains feature relationships (e.g., how “P”, “d”, and “b” are distinct). ​ Accounts for novel object recognition (making sense of nonsense objects).  Lecture 5: Pattern recognition: top-down Top-Down vs. Bottom-Up Processing ​ Bottom-Up Processing: Sensory input is processed from lower-level brain areas (vision, audition) to higher-level cognition. ​ Top-Down Processing: Higher cognition (expectations, memory, decision-making) influences perception. Three Types of Top-Down Processing 1.​ Expectation/Bias – Perception influenced by prior knowledge (e.g., seeing a tumor in an x-ray based on patient history). 2.​ Context Effects – Surrounding environment shapes perception (e.g., recognizing objects in appropriate settings). 3.​ Interactive Activation – Higher and lower levels of processing interact (e.g., words influencing letter recognition). Signal Detection Theory (SDT): ​ Signal: The stimulus you are trying to detect. ​ Noise: Background stimuli that may interfere with detection. ​ Sensitivity: Ability to distinguish signal from noise (improves with clearer signals and better sensory ability). ​ Bias: Tendency to favor one response over another based on expectations or payoffs. Signal Detection Matrix Actual Signal Response: Yes Response: No Signal Hit (Correct detection) Miss (Failed detection) Present Signal False Alarm (Incorrect Correct Rejection (Accurate "no" Absent detection) response) ​ Accuracy = % Hits + % Correct Rejections. ​ Bias & Payoffs: ○​ More pay for hits → Yes bias (more false alarms).  ○​ More pay for correct rejections → No bias (more misses). Context Effects ​ Perception is influenced by surrounding context. ​ Subjective Contours: We perceive shapes (e.g., triangles) that aren’t actually there. ​ Letter Recognition: Identical stimuli (e.g., “B” vs. “13”) are interpreted differently based on surrounding letters/numbers. ​ Objects Out of Context: Objects are harder to recognize when they appear in an unusual setting (e.g., a fire hydrant in a kitchen). Word & Pseudoword Superiority Effects ​ Word Superiority Effect (Reicher, 1969) ○​ Letters are easier to recognize when part of a word than when alone or in isolation. ○​ Context helps narrow down options, increasing accuracy. ​ Pseudoword Superiority Effect ○​ Recognizing letters is easier in pronounceable non-words (e.g., "zord") than in random letter strings. ○​ Shows top-down influence, where context aids perception. Interactive Activation Model (McClelland & Rumelhart, 1981) ​ Explains word superiority effect using top-down & bottom-up processing. ​ Levels of processing: ○​ Feature Level → Recognizes individual letter features. ○​ Letter Level → Activated by feature combinations. ○​ Word Level → Activated by recognized letters, providing top-down reinforcement. Connections in the Model ​ Excitatory (→): Reinforces recognition (e.g., "WORK" boosts activation of "O" as a valid letter). ​ Inhibitory ( –): Suppresses conflicting interpretations (e.g., discouraging "Q" in "WORK"). Parallel Processing in the Brain ​ Dorsal (“Where”) & Ventral (“What”) Streams ○​ Both use bottom-up (sensory input) and top-down (context, expectations) processing. ○​ Interactive activation allows higher-level understanding to shape lower-level perception.  Lecture 6: Attention 1. Selective (Focused) Attention ​ Actively focusing on relevant information while ignoring distractions. ​ Example: Finding a friend in a crowd, detecting a tumor on an x-ray. 2. Divided Attention (Multitasking) ​ Splitting attention between multiple tasks. ​ Example: Talking while driving—attention is not fully on the road. Stroop Task ​ Assesses ability to override automatic processing (e.g., reading color words vs. naming ink color). Cocktail Party Problem ​ Filtering out background noise while focusing on one conversation. Dichotic Listening & Shadowing ​ Task: Listen to two different messages (one per ear) and repeat (shadow) one. ​ Findings: ○​ Selection is based on physical characteristics (e.g., location, pitch). ○​ Unattended messages are mostly ignored except for key info (e.g., one’s name). Early vs. Late Selection Models Model Process Key Assumption Broadbent’s Early Input → Detection → Filter → Unattended info is completely Filter Recognition blocked. Treisman’s Input → Detection → Unattended info is weakened, not Attenuation Weakening Filter → blocked. Recognition  Deutsch & Deutsch’s Input → Detection → All info is processed for meaning, Late Selection Recognition → Filter but only some reaches awareness. Evidence for Processing Unattended Info ​ Galvanic Skin Response (GSR): Even when unaware, physiological responses (e.g., sweating) indicate some processing. ​ Name Recognition: People detect their own name in the unattended message. ​ Bilingual Processing: If the unattended message translates the attended one, it is sometimes noticed. Overt vs. Covert Attention ​ Overt Attention: Direct eye movements to a stimulus. ​ Covert Attention: Mental focus shifts without moving the eyes. Posner’s Spatial Cueing Task ​ Valid cue: Faster response (benefit of shifting attention correctly). ​ Invalid cue: Slower response (cost of shifting attention incorrectly). ​ Conclusion: Attention acts like a spotlight that enhances processing at a selected location. Feature Integration Theory (Treisman) ​ Attention is needed to bind features (color, shape) into a whole object. ​ Stages of Processing: 1.​ Pre-Attentive Stage → Features (color, shape) processed in parallel. 2.​ Focused Attention Stage → Features are combined using attention ("glue"). Visual Search: Feature vs. Conjunction Search Search Type Example Speed Effect of Distractors Feature Search "Find the red object" Fast Independent of (pop-out) distractors  Conjunction "Find the red O" (among red Slow & Slower with more Search Xs, green Os) effortful distractors Attention & Neural Responses ​ Attention modulates neural activity: ○​ Vertical bar → Fires strongly. ○​ Horizontal bar → Weak response. ○​ Attention enhances or suppresses responses based on relevance. ​ Evidence from animals and fMRI/ERP studies in humans. Visuospatial Neglect ​ Damage to right parietal lobe → left visual field ignored. ​ Contralateral Organization: ○​ Right hemisphere processes left visual field. ○​ Left hemisphere processes right visual field. Neglect Phenomena ​ Extinction: Left-side stimuli are ignored only when competing right-side stimuli are present. ​ Unconscious Processing: Some neglected stimuli still influence behavior. Theories of Neglect 1.​ Disengage Deficit (Posner) → Difficulty shifting attention away from the right side. 2.​ Unbalanced Competition → Right and left hemispheres inhibit each other. ○​ If right hemisphere is damaged, the left hemisphere dominates, leading to neglect of the left side. Driver Reading Selective Shadowing & Cocktail Party Effect ​ When repeating a shadowed message, most details of the unattended message are lost. ​ Some key features (e.g., pitch, name recognition) still break through. Broadbent’s Early Filtering Model ​ Attention acts as a hard filter—unattended info is fully blocked. ​ Problem: People can recognize their name in an unattended stream. Falsifications & Alternative Theories ​ Late Selection (Deutsch & Deutsch): Everything is processed for meaning, but only some info reaches conscious awareness. ​ Treisman’s Attenuation Model: Unattended info is weakened but still processed at a lower level. Perceptual Load Theory (Lavie) ​ Early vs. Late Selection depends on task load: ○​ High-load tasks → Early filtering (limited resources, distractions blocked). ○​ Low-load tasks → Late filtering (extra capacity allows more info in).  Lecture 7: Visual imagery Propositional (Language-Like) ​ Concept: Information is stored as abstract, language-like propositions (e.g., ON(GLOBE, DESK)). ​ Characteristics: ○​ Not image-based → No one-to-one mapping to a picture. ○​ Highly flexible → Can represent anything. Depictive (Analog, Image-Like) ​ Concept: Mental representations resemble pictures with spatial structure. ​ Characteristics: ○​ One-to-one mapping with objects. ○​ Allows scanning, zooming, rotation. Infinite Regress (Homunculus Problem) ​ Flawed Idea: A “little man” inside your brain sees the image, implying another “little man” in his brain, leading to an infinite loop. Evidence for Depictive Codes: Interference Effects ​ Performing two tasks that rely on the same mental system causes interference. ​ Example: Visual imagery tasks interfere with visual perception tasks. Kosslyn’s Image Scanning Experiment ​ Findings: ○​ Longer distances take more time to scan mentally. ○​ Suggests mental images preserve spatial relationships. ​ Counterargument (Demand Characteristics): ○​ Participants may behave as expected (biasing results). ○​ However, similar results occur even when subjects don’t know the expected outcome. Image Zooming ​ Larger mental images → Faster responses to questions about details. ​ Smaller mental images → Slower responses due to the need to “zoom in.” Mental Rotation  ​ More rotation → Longer response times (suggesting continuous transformation). ​ Intermediate Rotations: ○​ If shown a rotated letter mid-mental rotation, recognition is faster when it matches the expected orientation. Differences Between Imagery & Perception ​ Perception has precise metric properties (e.g., exact distances, size relationships). ​ Imagery lacks metric precision (harder to compare sizes mentally). Part-Whole Relationships ​ Example: ○​ A star contains a parallelogram. ○​ People fail to see the parallelogram when recalling the star from memory. Ambiguous Figures ​ When recalling an ambiguous figure (e.g., duck/rabbit), people cannot reinterpret it in their mental image. ​ Suggests mental images are fixed once formed, unlike perception. Compromise Theory (Kosslyn) 1.​ Long-term storage is propositional (abstract representation). 2.​ Mental imagery is generated from propositional codes into depictive images. 3.​ Depictive images allow operations like scanning, zooming, and rotating, but with errors due to the initial propositional encoding. Brain Evidence for Mental Imagery: Sequential Generation of Image Parts ​ Complex images take longer to construct, showing a step-by-step building process. ​ Example: People mentally draw letters in the same order they would write them. Shared Brain Areas for Imagery & Perception ​ fMRI Evidence: ○​ The visual cortex activates more during imagery than perception. ○​ Pattern classification (voxel analysis) can decode mental images from fMRI data. TMS (Transcranial Magnetic Stimulation) & Imagery ​ TMS applied to the visual cortex disrupts mental imagery, proving its involvement. Image Complexity & Mental Construction ​ Complex images take longer to visualize. ​ Mental images are built sequentially, similar to drawing. Imagery & Motor Cortex ​ Imagining an action activates the motor cortex, just like physically performing it. ​ Example: Thinking about drawing a shape activates the same brain regions as actual drawing.  Lecture 8: Visuospatial processing Extraordinary Visual Memory ​ Toscanini reportedly memorized 250+ symphonies. ​ Shepard (1967): Subjects viewed 612 pictures, recognition was ~98%. ​ Standing (1973): Estimated people could recognize ~731,400 out of 1,000,000 vivid images. When is Visual Memory Poor? ​ Unimportant/unattended details. ​ Lack of meaning in stimuli. ​ When lookalike foils are similar. What Improves Recognition? ​ Attention to details. ​ Meaningfulness & relevance. ​ Distinctive alternatives. Visual Memory Theories: 1. Richer Code Hypothesis (Incorrect) ​ Suggests visual memory is superior because images contain more detail. ​ Disproven: No difference in recall between detailed vs. simple images. 2. Dual-Code Hypothesis (Paivio) ​ Two types of mental codes: ○​ Verbal Code → Symbolic (e.g., "desk"). ○​ Nonverbal (Visual) Code → Analog image of a desk. ​ Support for Dual-Code Theory: ○​ Concrete words (apple, car) → Stored in both verbal & visual forms, better memory. ○​ Abstract words (virtue, peace) → Stored only in verbal form, harder to recall. ○​ Explains poor memory for unattended details & lookalike foils (no verbal encoding). Tolman’s Maze Experiment (1930) ​ Rats learned spatial layouts of mazes, not just sequences of turns. ​ Evidence for Cognitive Maps: Rats took shortcuts when available. Direction Judgments & Distance Estimates  ​ Humans accurately point to known cities & track location changes. ​ Jonides & Baum (1970s): Humans estimate distances well. Distortions in Cognitive Maps (Heuristics) Heuristic Description Example Right-Angle Bias Intersections remembered as Non-square roads recalled as 90-degree angles square Symmetry Shapes remembered as more Rivers appear straighter than Heuristic symmetrical than reality they are Rotation Tilted features remembered as more U.S. coastline straightened Heuristic vertical/horizontal Alignment Geographic locations remembered as Europe & U.S. assumed to be Heuristic more aligned than they are on the same latitude Relative-Position Conceptual knowledge overrides "Canada is above the USA" Heuristic actual spatial position (Vancouver is west of Seattle) Subjective Related locations remembered as Two restaurants seem closer Clusters closer together than a restaurant & a bank Observer Familiar places seem farther than Overestimate distance from Perspective unfamiliar ones home to unknown place Knowledge Representation 1. Declarative Knowledge ​ Facts & events (e.g., "Paris is the capital of France"). 2. Procedural Knowledge ​ How-to knowledge (e.g., riding a bike, solving a math problem). Dual-Code Theory (Paivio) ​ Uses both verbal & visual representations. Analog vs. Symbolic Codes ​ Analog (Depictive) → Mental images function like pictures. ​ Symbolic (Propositional) → Stored as abstract descriptions (not literal pictures). Propositional Theory ​ All mental images stored as abstract relationships (e.g., "The globe is on the desk" → ON(GLOBE, DESK)). Functional-Equivalence Hypothesis ​ Mental imagery & perception share similar neural processes. Mental Rotation (Shepard & Metzler, 1971) ​ Larger rotation → Slower reaction time. ​ Supports depictive (analog) mental imagery. Neuroimaging Evidence ​ fMRI shows visual cortex activation during mental rotation. Image Scaling (Kosslyn) ​ Smaller images take longer to analyze. ​ E.g., easier to answer questions about a large imagined rabbit than a small one. Image Scanning (Kosslyn) ​ Scanning time correlates with actual spatial distances in the image. ​ Supports depictive mental representation. Demand Characteristics ​ Subjects may unconsciously adjust behavior to fit the experimenter’s expectations. Brain Lateralization & Imagery  Hemisphere Function Left Hemisphere Language, verbal processing, symbolic representations Right Hemisphere Visuospatial tasks, analog representations Dissociation Between Visual & Spatial Imagery ​ Brain-damaged patients can lose visual imagery but retain spatial reasoning, indicating separate systems.