Instrumental Conditioning Foundations Instrumental Conditioning is not the same as Instrumental learning Learning involves the mechanisms of behavior not behavior itself Instrumental behaviors previously produces some consequences are goal directed must be studied under experimental control Thorndike and Puzzle Boxes the consequence food of a response escaping the box strengthens the association As the association gets stronger the Law of Effect ensues Law of Effect satisfying events strengthen the association annoying effects weaken the association Stimulus Response is responsible for behavior in the context in which the subject has previously been reinforced No learning about RO association Habits typical responses whether or not reinforced addictions Modern Approaches Discrete trials the response terminates the trial Runaways and mazes running speed latency correct choices Free Operant Responses Skinner Operant a measurable unit of behavior more natural Operant response defined by its effect not by the behavior itself Magazine Training Sign tracking shaping Reinforcement of successive approximations non reinforcement of earlier reinforced response forms constructing a new operant from already known behaviors autoshaping deprive rat of food Discrete trial procedures Latency how long does the animal hang around for Running speed reinforced quickly correct choices Free operant responding response rate Appetitive and Reverse Stimuli reinforcement response and appetitive stimulus Punishment positive response positive aversive stimulus Negative reinforcement escape avoidance negative response eliminates avoids response of aversive stimulus Ommission Training Negative response eliminates occurrence of appetitive stimulus Skinners 3 part contingency Environment Event Effect Domjan s contingency response outcome contingency Responses in Positive Reinforcement Procedures Thorndike stamping in Skinner reinforcement Both increase the probability that the behavior will occur in the future in that environment Reinforced response variability Pigeons had 2 disks in their cage and had to peck 8 times ot get their food At first it doesn t matter any 8 pecks works Variability group in making sequence of 8 key pecks have to make a sequence that you haven t used in various trials Combo of 256 different sequences the animal can use If the sequence hasn t been used will be reinforced but if reuse will not be reinforced Animals gave more different response periods at the end of the conditioning response period then the ones in the control group Belongingness Cats Manipulating strings etc belongs to escaping Yawning and scratching don t Stickleback Fighting vs courting Breland Breland s instinctive drift Raccoons pigs and piggybanks Shettleworth replicated Thorndike s findings in cats with hamsters rearing up digging and scrabbling are all part of the food acquistion system but grooming and scratching aren t The Instumental Reinforcer Quality and Quantity Animals can learn to select water with more choloric density vs less c d quality This graph is based on quantity based on DRO Differential response behaviors The behavior he was required to make more and more responses when reinforced paid attention to 10 seconds after do it 105 seconds after 120 seconds after more and more responses before reinforcing The more you are made to do the more quickly you will stop doing it the rate at which you stop is related to how much you give to get the response The more you get the longer and more effort you will put in Thorndike Positive and negative contrast reinforcer gets better or worse over time Either given small or large reward of pellets Intially the large award groups has faster running speed then small reward groups Take the group that originally got the small reward and give them large reward and running speed increases drastically Large reward increases a little but not a lot If the reinforcer gets better then you get a more vigorous response if it becomes less good then the response decreases Strengthening or weakening the association Rats saccharin and cocaine Rats like cocaine can associate cocaine with the administer of saccharin Types of Reinforcers Primary food sex water Secondary money Teritary Marking and Blocking Reinforcer delayed either signal delayed blocking or marking reinforcers sequence completed animal figures out they will get something eventually Response Reinforcer Contingences Skinner s superstitous behavior accidental reinforcement Terminal vs interim responses Terminal responses have more belongingness and are analogous to focal search Interim responses less belongingness and analogous to general search Wanting to be able to control the choices is a reinforcer restaurants and snack machines examples Learned Helplessness may be a function of response type Shock cessation and safety signal feedback cues Escape shock by manipulating something Schedules of Reinforcement and Choice Behaviors reinforcement schedule a program or rule governing when reinforcement is delivered CRF continuous reinforcement each instance of the target behavior is reinforced Partial or intermittent schedules SOME instances of the target behavior are reinforced Partial schedules are more concerned with manitenance of the behavior rather then learning FR Fixed Ratio VR Variable Ratio FI Fixed Interval VI Variable Interval Free will working hard depends more on schedule of reinforcement then personality Domjan Simple Schedules which instances of the target behavior are reinforced are controlled by a single factor Ratio Schedules FR bursts of reinforcement Ratio Run and post reinforcement pause Post reinforcement pause duration is a function of the upcoming ratio Higher the ratio longer the longer the post reinforcement pauses Small increases little effect on ratio run prp Ratio Strain is caused by large increases pauses in the run or extinction More steady response pattern and higher response rate with VR then FR FI scallop learns doesn t have to respond for a while but will be reinforced about a little bit of responding Yoking 2 animals have the same response and one of them controls the ability of the other to be reinforced Faster responding on ratio then interval schedules Short IRT inter response times reinforced by ratio not by interval Long IRTs reinforced by interval not by ratio Ratio Schedules no fixed limit of reinforcements unit time and unlimited feedback Interval Schedules Fixed limit of
View Full Document