WEEK 6: LEARNING

→6.1 Basic Forms of Learning

-many important behaviors are biologically programmed into an organism, but organisms need to learn.

→ Learning: process by which an organism’s experience produces changes in both the brain and behavior- improved skill or understanding

    -involves adapting to environment to our desires and needs.

→Associative learning: making connections between diff events and our behavioral responses to them. (dark clouds lead to rain and umbrellas keep us dry)

    -involves many forms of learning

→Nonassociative learning: changes in how much or little we respond to a single event or stimulus with experience.

    -observed in the simplest of organisms- invertebrates (sea slugs)

-habituation and sensitization represent the two opposing poles of nonassociative learning.

→habituation: organism’s reflexive response to repeated stimulus becomes weaker

    -the brains “cry wolf” effect. it decreases attention to stimuli/environment that it learns are harmless or unimportant.

    -similar to decreased ability to detect stimulus due to adaptation of sensory receptors. but rather than altering sensory inputs, habituation reflects change in how we respond to those inputs. less abt sense and more abt what we bother to pay attention to.

    -researchers use patterns of habituation and dishabituation to infer what an animal or infant knows abt the environment without having to ask any questions.

    -a COMMON METHOD for studying learning and habituation is monitoring eye movements & measuring how long subjects look at something and where they look.

        -when first encountering something perceivers look longer and in more complex ways to learn abt it, but looking time decreases when events are repeated- or already seen. however if something changes about the event the looking time will increase again to the part of event that changed.

    -habituation is adaptive.

→dishabituation: recovery of a response that undergone habituation, typically result of the presentation of a novel stimulus.

→sensitization: organism’s reflexive response to repeated stimulus becomes stronger.

    -leads to an INCREASED response with repetition of stimulus- makes us more sensitive to it.

        -EXAMPLE: your new roommate has a habit of slamming the door. instead of habituating to the noise- it continues to startle you and your annoyance grows every time. this is sensitization.

-WHAT determines if repetition will result in habituation or sensitization?

    -the DUAL PROCESS THEORY of nonassociative learning suggest they are BOTH always at work. which of the two wins depends on your state of physiological arousal.

        -ex: when you are more aroused (feeling very alert and nervous/excited (taking a final exam)) sensitization is more likely than habituation. When you are more RELAXED with little to worry/fear (after yoga) habituation dominates.

→6.2 Nuts and Bolts of Classical Conditioning

-conditioning is a process that enables us to learn associations.

    -conditioning is called conditioning bc it refers to changes in behavior that are conditional on (dependent on) specific associations that have been made.

        -conditioning takes TWO forms: CLASSICAL AND OPERANT.

→classical conditioning: passive form of learning- an involuntary response- such as a reflex- becomes associated with a new stimulus. here, the brain learns to change behavior as a response to something in the environment.

→unconditioned stimulus: (US) a stimulus that produces a reflexive response without prior learning.

→unconditioned response: (UR) response that is automatically generated by the unconditioned stimulus

→conditioned stimulus (CS) stimulus that has no prior positive or negative association but comes to elicit a response after being associated with the unconditioned stimulus.

→conditioned response (CR) response that occurs in the presence of the conditioned stimulus after an association between the conditioned and unconditioned stimulus is learned.

→6.3 what classical conditioning teaches us about learning

→acquisition: the initial learning of an association between the US-CS link in classical conditioning.

-phase where the pairing of the US and the neutral stimulus is introduced.

    -such as the pairing of the food and the bell

—BEGINNING of phase there is no response to NS

—AFTER many pairings learning INCREASES rapidly as the now CS (bell) evokes the CR (salivating to the bell) more reliably- until it reaches max level when the association is fully learned.

→Generalization: tendency to respond to stimuli similar to CS, so learning is not tied too narrowly to specific stimuli.

-the greater similarity of two stimuli the more likely they are to be generalized.

—generalization can be adaptive to everyday life.

(ex.) Pavlovs dogs might salivate to a sound that was diff from original CS but just little louder,longer, or a diff pitch.

→DISCRIMINATION: learns to respond to particular stimulus -but not similar- preventing overgeneralizations.

—allows you to stop and look when hearing car horn but not trombone.

—ADAPTIOVE LEARNING is a balancing act between the opposing forces of generalization and discrimination.

→EXTINCTION: learning process where the CR-weakened in response the the CS if it is frequently presented in absence of US.

—when pavlov continues to ring bell (CS) but did not bring food (US) after rings-dogs would eventually stop salivating.

—extinction does not imply complete unlearning or forgetting the importance of the bell-CS.

—not forgetting- brain learning not to respond- the CS is no longer associated with US.

→SPONTANEOUS RECOVERY: observed when extinct behaviors reappear after a delay.

—after delay periods no US was ever presented - extinction would prevail and SR would not occur- the association may not be fully forgotten-just suppressed.

→6.4 classical conditioning provides the power of prediction

-contiguity- closeness in time of CS and US

-contingency- predictiveness

    -learning is essentially predicting the future based on the past

→BLOCKING: conditioning phenomenon where a prior association with conditioned stimulus prevents learning of an association with another stimulus because the second adds no further predictive value.

-brain selectively learns event associations- that are more valuable and informative for predicting the future