Psych 120 General Psychology Christopher Gade Office: 1030A Office hours: MW 4:30-5:30 Email: gadecj@gmail.com Class MW 1:30-4:30 Room 2240 What’s on tap? Today we’re going to discuss behaviorism and how it relates to learning. We’ll do this by… Briefly reviewing the field of behaviorism and discussing one of its most influential characters. Going over one of the most popular behavioral discoveries of all time. Discussing classical conditioning and the basics of how this learning process works. Learning: A relatively permanent change in an organism’s behavior due to experience. Behaviorism: the approach to Psychology that involves observable cause-and-effect relationships between conditions and behavior. • Origins in ‘stimulus-response’ psychology. • Takes into account an organism’s history of experiences, i.e. knowledge. • Aims to decode the ‘basic laws of behavior’. • Assumes a deterministic perspective and emphasizes the influence of the environment. John B Watson Pioneer in the field of behaviorism Considered by many to be the founding father of behaviorism. This might not be the case, but he was definitely their poster boy. Famously known for his statement: “Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of specialist I might select…” Most famous experiment was with Baby Albert. Ivan Pavlov (1839-1946) • Originally interested in the digestive system of dogs. • From his research, he discovered ‘psychic salivations’ that dogs would show (for which he was awarded a Nobel prize) • Realized that this form of learning was interesting and dedicated his time to studying how dogs developed this behavior • 5:28 Classical Conditioning In this form of learning, the learned responses develop from an initial pairing of two pieces of information: • The unconditioned stimulus (US): a stimulus that elicits an unlearned, or reflexive response. • The unconditioned response (UR): a response to a stimulus that is automatic. Classical Conditioning After the initial pairing of information, a “neutral stimulus” (NS) is presented to the individual. A “training” or “pairing” procedure then begins until the neutral stimulus is recognized to be associated with the unconditioned stimulus: This pairing of stimuli eventually leads to a “conditioned response” (CR) to the newly “conditioned stimulus” (CS). Classical Conditioning Important concepts • A learning curve tells us whether conditioning is occurring, that is, whether, when and how strongly the CS is eliciting the CR over time. • Second-order conditioning is a process of adding new CSs to the conditioned CSs (sequentially). • If, after the conditioning, the CS is presented without the US repeatedly, the association will deteriorate and the CS will cease to elicit the CR – this is called extinction. – however, extinguished associations can be reconditioned (usually faster than the initial conditioning) AND, sometimes organisms show spontaneous recovery of extinguished behaviors. Extinction and Spontaneous Recovery Strength of CR Acquisition (CS+US) Extinction (CS alone) Spontaneous recovery of CR Extinction (CS alone) Pause What influences the strength of a learned response through classical conditioning? Conditioning occurs more rapidly when the neutral stimulus is relatively unfamiliar. The less time that elapses between the presentation of the CS and the UCS, the faster the CR is acquired. The CR will be acquired more quickly when the CS precedes the UCS (forward conditioning). Specific connections between CS’s and UCS’s are stronger in different species. Rat and Poison example What about stimuli that are similar to the neutral stimulus? • Sometimes, organisms respond to new, irrelevant stimuli that closely resemble the original Neutral stimulus with the same CR, this is called generalization. • Organisms can also learn through conditioning to discriminate between similar stimuli, if a CS– is introduced into the conditioning process. What does this tell us about learning? It tells us how we can learn about how our minds might pair stimuli with each other. However, it doesn’t inform us about how we know about what to do and not to do in our world. Next, we’ll revisit the world of behaviorism from a different perspective; from the world of operant conditioning. Edward Thorndike (1874-1949) • Originated the idea of instrumental learning. • Studied cats and other animals learning by trial and error to escape from puzzle boxes. The Thorndike Laws Law of Effect: Behaviors followed by favorable consequences become more likely; behaviors followed by unfavorable consequences become less likely. Law of Readiness: A series of responses can be chained together if they belong to the same action sequence and will result in annoyance if blocked. Law of Exercise: Connections become strengthened with practice and weakened when practice is discontinued. B. F. Skinner (1904-1990) Skinner attempted to expand on Thorndike’s original theories of instrumental learning. He proposed that the learning process has a very predictable response to rewards and punishments. His work set out to show how those responses to behavior influenced future behaviors (e.g. operant conditioning). The majority of Skinner’s work was done on rats and pigeons in elaborate boxes that he designed. These boxes were called “Skinner Boxes”. 15:30 Operant Conditioning • The process of learning to associate a behavior with a consequence, in order to behave in a manner that maximizes reinforcing and minimizes punishing events. – Reinforcement: any event that increases the future probability of the most recent behavior. – Punishment: any event that decreases the frequency of the preceding behavior – What makes something reinforcing or punishing? – Biologically useful – Intrinsically satisfying – Restores equilibrium * Disequilibrium principle: any behavior that leads to a return to equilibrium will be reinforcing. But there’s more… Not only are there reinforcements and punishments in operant conditioning, but these responses are either positive (adding something), or negative (taking something away). The 2x2 Matrix of Operant Conditioning: • • • • Positive reinforcement: an introduction of a pleasurable stimulus, which will increase the likelihood of the future occurrence of the behavior (e.g. chocolate cake). Negative reinforcement: a removal of an aversive stimulus, which will increase the likelihood of the future occurrence of the behavior (e.g. nagging). Positive punishment: an introduction of an aversive stimulus, which will decrease the likelihood of the future occurrence of the behavior (e.g. spanking). Negative punishment: a removal of a pleasurable stimulus, which will decrease the likelihood of the future occurrence of a behavior (e.g. taking away your allowance). What type of reinforcement is this? What about this one? A final review of the 2x2 matrix… Different Schedules of Reinforcement/Punishment • Continuous reinforcement: reinforcement for every correct response. • Partial/intermittent reinforcement: occasional reinforcement for a correct response. a. Fixed ratio: Reward for a behavior after “X” responses. Causes faster responders to get more rewards. Produces high rates of responding, but quick extinction when the reinforcement is removed. b. Variable ratio: Reward for a behavior after a variable and unpredictable numbers of responses. Gambling is a great example of this reward system. It is very hard to extinguish after the connection is made. c. Fixed interval: Reward for a behavior after “X” amount of time has passed. The responses are rather sparse in down time, but get more vigorous right before time X. d. Variable interval: Reward for a behavior after a variable and unpredictable amount of time. This causes slow, steady responding. Responses x Time Diagram Number of responses 1000 Fixed Ratio Variable Ratio Fixed Interval 750 Rapid responding near time for reinforcement 500 Variable Interval 250 Steady responding 0 10 20 30 40 50 Time (minutes) 60 70 80 Effectiveness of Reinforcement All things being equal, most people learn fastest with immediate reinforcement or immediate punishment. Punishment tends to be ineffective except for temporarily suppressing undesirable behavior. Mild, logical and consistent punishment can be informative and helpful. Though vicarious reinforcement can be effective, vicarious punishment is often not. So What Did We Learn? We learned about operant conditioning. We learned about Edward Thorndike and BF Skinner. We learned about how different reward schedules can influence the rate, timing, and extinction of learned responses. We learned about learning. And now… After learning about how we take in information, we’re going to examine how we keep that information in our head. Namely, this next series of topics is going to discuss memory, and the way the mind stores information. What’s on tap? In today’s last section, we’re going to discuss the topic of memory. In this lecture we’ll be addressing… The pioneer in research done on memory. Different tests of memory. Different memory time frames. Hermann Ebbinghaus (1850-1909) Sought to examine the concept of memory from a purely scientific viewpoint. Had only one subject in almost all of his studies on memory… himself. In these studies, he used lists of nonsense syllables in his attempts to examine how our memories work. Ebbinghaus (cont.) His research was based on discovering how fast a “normal” individual can learn, and forget information. From this, he was able to generate both Learning curves Forgetting curves Ebbinghaus conducted experiments that varied in the # of syllables in the list length of time before checking his memory after “learning” the syllables length of time before checking his memory after reading the syllables This variation in timing and the fact that he measure memory after both introduction and memorization of information provided us with a great starting block when it came to examining memory One of Ebbinghaus’ Remembering Curves One of Ebbinghaus’ Forgetting Curves Another One of Ebbinghaus’ Forgetting Curve Let’s attempt a replication of one of Ebbinghaus’ experiment... Listen to the list of nonsense syllables that are about to be read to you. Do not write them down until you are instructed to do so. So what? What does that mean? Ebbinghaus’ work led us to conclusions about how the mind functions when storing meaningless information that we are asked to recall. It also led other researchers to begin exploring memory in a more systematic way. However, his work didn’t tell us about… our memories for meaningful information. the different types of memory that we have. our ability to remember information when we are asked to reproduce it in a different manner. how our reproduction of information might be altered. Different Types of Memory Tests Free Recall Ebbinghaus’ work Cued Recall Famous authors Recognition Name the dwarfs Savings Name the capitols Implicit Memory Performance Impaired memory example Cued Recall Example Cued Recall Example Recognition Task Grouchy Gabby Fearful Sleepy Smiley Jumpy Hopeful Shy Droopy Dopey Sniffy Wishful Puffy Dumpy Sneezy Lazy Pop Grumpy Bashful Cheerful Teach Shorty Nifty Happy Wheezy Doc Stubby Different types of memory categorized by length of storage (temporal) Sensory input Attention to important or novel information Encoding External events Sensory memory Short-term memory Encoding Long-term memory Retrieving Sensory Memory First temporal category of memory Capacity is thought to be infinite (or at least really large) Attention to this information lasts only a fraction of a second After this fraction of a second, your brain breaks down the information and attends to / remembers only the information deemed relevant Involves not only vision, but all of our senses Is unfiltered by any portion of our brain Lets test whether or not sensory memory exists… F A U B M V X E W Q H K A X Z D T B M F O Y R G P S Q E N H W L B C I U K H V W G R N U P X Z M S O W A D R P N M Q E I Sperling’s Sensory Memory Experiment Short-Term Memory (aka Working Memory) Said to have a capacity of 7 + or – 2 items. Nonsense syllables example Contains information from our sensory store that our brain has deemed relevant (at least for the time being). Information can be stored in this stage of memory from anywhere between 10 seconds to a few days (some scientists even argue that this can last up to 6 years). After that, the memories stored are either forgotten (information not regarded as important), or placed in our long-term memory store. Long-Term Memory A collection of information that we value, have time to remember, and feel like it will be of use in the future. Information in this part of our memory is often very complex, but also subject to distortions or complete fabrications. There is debate as to whether or not we actually ever forget information once it’s stored on long term memory. Permanent storage that sometimes needs cues to recall information. Mixture of memories that are sometimes forgotten or changed. This change/forgetting can be due to Decay of neural connections Rewriting of neural connections (computer example) The Differences Between Our Memory Systems The Long-Term Memory Hierarchy memories Explicit (declarative) With conscious recall Facts-general knowledge (“semantic memory”) Personally experienced events (“episodic memory”) Implicit (nondeclarative) Without conscious recall Skills-motor and cognitive Dispositionsclassical and operant conditioning effects