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Cognitive Psychology 4500 Spring 2010 n Section 1: MW n Section 2: MF n Dr. Diego Fernandez Duque

Today’s take-home message n psychology seems intuitive (unlike chemistry) n but our intuitions are often wrong n rather than relying only on intuition, we should apply the scientific method (like we do in chemistry)

Which center circle seems larger?

Visual Illusions: Sometimes we misperceive reality

Visual Attention n Basketball task Basketball taskBasketball task n Change Blindness Change Blindness Change Blindness n Although we believe that we have a complete and detailed visual representation of the outside world, studies on visual attention tell us otherwise n

our perception is constrained by our knowledge … sometimes multiple meanings exist (ambiguous figure)

A memory test Listen carefully to the list of words but don’t write them down Listen carefully to the list of words but don’t write them down When the list ends, count backward ‘by threes’ starting at ‘42’ (39, 36, etc.) When the list ends, count backward ‘by threes’ starting at ‘42’ (39, 36, etc.) When you get to ‘0’, write down all the words you recall When you get to ‘0’, write down all the words you recall

zsour zcandy zsugar zbitter zgood ztaste ztooth znice zhoney zsoda zchocolate zheart zcake ztart zpie Sometimes we misremember reality

Based on your gut feelings, quickly write down: 1.Your six FAVORITE letters 2.Your six LEAST FAVORITE letters

Look over each list and circle all of the letters that occur in your own first name. Count the number of circled letters in each list. Which list included more of the letters from your own first name?? Sometimes our choices are influenced by things other than the ones we believe are causing them

The Wason Card Selection Task AF67 If a card has a vowel on one side, it has an even number on the other side. Which cards should be turned over to determined whether this rule is being followed?

AF67 The correct answer: Most people select A and 6 to test the ‘if and only if’ Confirmation bias: We fail to truly test our beliefs

14 n Sometimes intuition is right –When ‘silently’ rehearsing a phone number, we use the brain speech areas. n but other times, it is not

In sum, psychology seems intuitive (unlike chemistry) n but intuitions are often wrong –We mis-perceive (visual illusions) –We mis-remember (memory illusions) –We are mis-guided (unconscious influences) –We fail to check conclusions (poor reasoning) n we shouldn’t rely only on intuition. n we should apply the scientific method (like we do in chemistry): SYSTEMATIC

How to investigate Perception & Cognition n Ask your subjects (Introspectionism) n First-Person Privileged Access n - before you ask, train your subjects n Shortcomings of Introspectionism: –It provides access to products of thinking, rather than the processes that underlie it. –It relies on conscious report: Many interesting mental events are unconscious (e.g. memory retrieval, or visual processes that lead to perceptual illusions). Edward Titchener ( )

How to investigate Perception & Cognition n Ask your subjects (Introspectionism, 1900s) Look at S-R patterns (Behaviorism, ’40s) - Restricts psychology to truly objective, observable data - Reaction against Instrospectionism

Behaviorism Stimulus Response Study stimulus-response relations, but do NOT attempt to understand unobservable mental processes Ivan Pavlov ( )

Classical Conditioning n Neutral stimulus becomes associated with a stimulus that already produces a response 1.sight of food  salivation 3. bell and food seen together 4. bell  salivation

Behaviorism n Psychology is the “science of behavior.” n Emphasis on what can be directly observed. –Stimuli  Responses –Reinforcements / Rewards n Ignore the mind (unobservable). n Goal: predict behavior

Assets of Behaviorism n rigorous scientific observation n controlled laboratory settings. n Applicable to certain areas (e.g., learning: pairing of stimuli and responses)

Problems with Behaviorism n Limiting science to observable things is a bad idea. Theories are about unobservable n Can’t account for much of human behavior. –Language; Attention

Examples –Language (Chomsky, 1959) n Novel words, over-generalizations, no feedback –‘mano’ (hand) -> ‘nano’ (meaningless) – ‘no mas’ (no more) -> ‘ma no’ n Vs. Associative Learning (Baldwin, 1992) –Referential looking –Attention n Change blindness –Two different stimulus -> same perception –Same stimulus -> different perception –Spatial learning (Cognitive Maps, Tolman 1930)

What do Tolman’s Maps look like? Edward C. Tolman ( ) learning can occur without reinforcement: learning can occur without reinforcement: Such ‘latent learning’ goes against standard behavioristic principles, which claim that learning comes only from outcomes

X this ability cannot be explained only by links between stimuli and responses. A better explanation is to pose the existence of an internal spatial map later they can deduce the shorter path. Rats learn to follow this path … X

Cognitive Maps in Bees, von Frisch 1967 n behavior of bees returning to hive after locating nectar n Can use a symbolic form of communication n Different patterns of dances represent different meanings n Round dance: source less than 100 yards from hive n Figure 8 dance: greater distances

Behaviorism Stimulus Response Study stimulus-response relations, but do NOT attempt to understand unobservable mental processes Cognitive Psychology Stimulus Response Study stimulus-response relations to infer the underlying mental processes. The contents of the mind CAN be studied scientifically

How to investigate Perception & Cognition n Ask your subjects (Introspectionism) n Look at S-R patterns (Behaviorism) n Infer mental processes (Cognitive Psychology) –from S-R patterns (Reaction Time, Accuracy) –from neural patterns (cognitive neuroscience)

Next …. How cognitive psychologists make inferences about what’s inside the black box...

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It is hard to predict based on intuition Answer: True/False; how sure you are about it? n People usually fall in love with someone very different from themselves. In other words, opposites attract. T or F How sure? just guessingcertain just guessingcertain n It is an optical illusion when the moon appears larger on the horizon than it does overhead. T or F How sure? just guessingcertain just guessingcertain n Hypnosis can help people accurately recall a crime scene T or F How sure? just guessingcertain just guessingcertain

Instead of relying on intuition, we should measure behavior n For example, how long does it take to respond? n carefully measuring reaction time, we can discover the steps of mental processing: Cognitive Psychology ( psy4500) Cognitive Science ( minor ) n To do it well requires: – A detailed analysis of the mental steps, and –A comparison between two conditions that are identical other than in the step being investigated. –Preferably using stimulus and designs that are simple –A classic example: Stroop Task

GREEN BLUE YELLOW RED BLUE YELLOW RED BLUE GREEN RED

ORANGE BLUE GREEN YELLOW ORANGE GREEN PURPLE GREEN BLACK YELLOW

Class activity n List the ways in which: – the two trials were well matched –the trials differed from each other –the experiment could be improved Group activity