103_12_full

103_12_full - PSYC 103 Winter 2011 Lecture 12 Review...

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Unformatted text preview: PSYC 103 Winter 2011 Lecture 12 Review session: Pepper Canyon Hall, room 106 Feb 3rd @ 7:00 pm Memory Learning and memory are integrally related; you cannot have one without the other Studies of “Learning” and “memory” focus on different stages of the information processing pathway Memory experiments vary these Acquisition ➔ Retention ➔ Retrieval Learning experiments vary this Interference Proactive interference: disruption of recall at ‘time 2’ by information learned before the to-be-remembered item at ‘time 1’ confusing information acts here (Time 0) ….. Acquisition ➔ Retention ➔ Retrieval (Time 1) (Time 2) ‘distractor’ acts here Retroactive interference: Decrease in performance at time 2 (retrieval) due to the occurrence, during the retention interval, of items that are similar to the to-be-remembered target RETROACTIVE New learning interferes with old study for psy103 test study for bio test take psy test time PROACTIVE Old learning interferes with new study for psy103 test study for bio test take bio test Conditions at T1 Distribution of experience Radial arm maze performance (choices 2-8) The corrected mean probability of a correct response for choices on an eight-arm radial maze when 8 test trials were given in succession (adapted from Olton, 1978). Error rates increase during successive tests on the same day due to proactive interference Events during the retention interval Retroactive interference: Decrease in performance at T2 (retrieval) due to the occurrence, during the retention interval, of items that are similar to the to-be-remembered target Habituation response to tones, in rabbits Habituation effect Habituation is abolished when a “distractor” is presented - first tone is forgotten List learning: serial position effects List learning: serial position effects Percentage of correct recognitions by dolphins of a sound that had previously been presented in a list of six items, according to its serial position (adapted from Thompson & Herman, 1977). List learning: serial position effects in Radial Arm Maze Mean percentages of correct choices of a previously visited arm in a radial maze, from one that had not been visited, as a function of the position of the correct arm in a sequence of seven previously visited arms. In one experiment (lefthand panel) the choice trial for one group was given 5 seconds after the seven arms had been visited, but for another group this interval was 30 seconds. In a second experiment (right-hand panel) the choice trial was delayed for 10 seconds during which an experimental, but not a control group was allowed to eat chocolate (adapted from Harper et al., 1993). List learning: serial position effects Serial probe recognition Primacy: better performance with items at the beginning of a list recall Recency: better performance with items at the end of a list first Position in list last Coding Stimulus → retention interval → response Time 1 Time Retrospective coding: A stimulus “trace”. Performance derives from a memory of the sample stimulus at time 1 Prospective coding: Input at time 1 is transformed into a representation of the appropriate comparison stimulus. Under what conditions is one or the other more likely? As retention interval increases, comparison stimuli become more confusable Time 2 Symbolic matching Many-to-one symbolic matching: Many sample stimuli are associated with one comparison stimulus -- favors a prospective code. One-to-many symbolic matching: One sample stimulus is associated with many comparison stimuli -- favors a retrospective code. Matching task M-to-O 1 trial 2 Best Memory code O-to-M Prospective * * * * 3 * 4 * * * Retrospective Memory is context specific 1. Contextual stimuli guide retrieval 2. Time is a context Theory: memory decays with time, b/c context changes 3. Different memories depend differently on context Events of great significance for survival seem to be remembered better than less important ones 4. Interference occurs at the output Failure to show evidence of retention (memory) reflects the lack of appropriate context ….think of extinction. Memory duration and capacity •  Pigeons can learn very large sets of exemplars in category discrimination tasks (≥ 320 exemplars) •  Can retain memories for very long periods (at least 2 years) Clark’s Nutcracker In the wild: bury several thousand caches of pine seeds in the late summer and retrieve them up to 6 or more months later -  Caches 33,000 pine seeds in the autumn, 4 seeds per cache, spread out over 150 sq mi -  Nutcracker revisits 2500-3750 caches -  Needs to identify ≈ 3000 locations! In the lab: perform above chance when retrieving 18-25 caches 285 days after making them. Capacity Vaughan & Greene (1984) -  Instrumental conditioning with pigeons -  80 S+ 80 S- trials with random squiggle stimuli but took 1000 sessions to learn! - When photographs used as S+ and S-, pigeons performed well with 320 pictures Cook, Levison, Gillett & Blaisdell (2005) - Trained pigeons to approach LEFT magazine for half photographs, RIGHT magazine for the rest Added more photographs as discrimination was solved After 3 years of training – birds exposed to 1600 photographs – correct 75% of time - Estimated the limit of capacity ≈ 800 Durability -  Reichmuth-Kastah & Schusterman Sea lion trained on a matching task -  Schusterman (2002) Sea lion successfully returned to the task 10 yrs later -  Vaughan & Green (1984) Pigeons trained on a discrimination. Successfully returned to the task 2 yrs later -  Hendersen (1985) Rats given CS-shock pairings Trained with different shock intensities Retained after 60 days – shock magnitude remembered -  Miller & Berk (1977) Tadpoles trained to avoid a black compartment Tested 35 days later. Learning still retained, even though they had metamorphosed into frogs! 16 Species differences The “synthetic approach” Synthetic approach: species differences are predicted from ecological considerations and tested in more than one way. ‘Radial-maze’ Species differences The “synthetic approach” Retention interval (s) DMTS Species differences hold up in operant “spatial memory” tasks Nutcrackers are no better on color DMTS, suggest specific advantage for spatial memory Ecological view of animal intelligence: different species have evolved different cognitive abilities to cope with the demands of different environments Episodic memory Tulving (1983) Episodic memory: conscious awareness of an experience in a place at a certain time, e.g. where and when you first learned to ride a bike Clayton & Dickinson (1998) -  Episodic-like memory: information about what, where and when – consciousness not necessary -  Scrub jays allowed to cache nuts in location A (which contains landmark X) cache wax worms in location B (which contains landmark Y) Following an interval of either 4 or 124 hours, birds given a preference test of: Location A with landmark X vs Location B with landmark Y Location A preferred after 124 hours (wax worms were off), Location B preferred after 4 hours What, where and when? Difficult to replicate in other species but now confirmed in rats by Babb & Crystal (2005, 2006) 19 ...
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