Lecture 22: Animal Cognition I (Memory) Learning, Psychology 5310 Spring, 2015 Professor Delamater

Historical Issues of Comparative Cognition 1.Grew out of evolutionary theory and search for evolution of mind 2.However, strongly experimentally focused. It developed as a reaction against anthropomorphic approaches that emphasized consciousness and intentionality 3. Also, it has been influenced by general-process approaches to the study of learning where in addition to searching for general cognitive processes, there is recognition of the importance of species-specific processes.

Learning versus Memory 1.These are really intertwined processes. The focus of learning and memory researchers is usually on different aspects of a learning experiment. Whereas learning experiments focus on acquisition processes, memory experiments Focus on retention and retrieval processes.

Types of Memory 1.Procedural vs declarative (episodic) – learning to do something (S-R association?) vs learning that such and such will occur (S-S association?). Episodic memory is usually thought of as a memory that binds together what, when, and where information. 2. Working vs reference – Working memory is retention of information long enough for use in a particular task (keeping track of a phone number, etc). Reference has to do with long-term storage of acquired information. How do we study these different types of memory? 1. S-S vs S-R studies in Pavlovian and instrumental learning are instructive… 2. Lots of different paradigms employed to study working/reference memory…

Working & Reference Memory Paradigms 1.Delayed Matching to Sample task (DMTS) 2.Spatial Memory tasks Morris Water Maze, Radial Arm Maze Three popular paradigms that have been used with lots of different animal species.

Working & Reference Memory Paradigms 1.Delayed Matching to Sample task (DMTS) Working and Reference Memory Birds trained with a 0-s delay show decreased accuracy when tested with longer delays. But notice that birds trained with longer delays show less of an effect of delay in testing. This suggests that the normal delay gradient does not simply reflect a trace decay process Working memory appears to be more active than that. Reference memory in this task refers to animals learning to always choose the matching stimulus Sargisson & White (2001) study

Working & Reference Memory Paradigms 1.Delayed Matching to Sample task (DMTS) Do animals learn a General Rule or Specific S-R associations? This question can be studied by varying the number of stimulus sets one uses to train the animals. If only one set is used (Red, Green), then animals seem to learn specific rules. This is known because when the animals are transferred to a new stimulus set, they do not spontaneously match to sample. They have to learn to do that. Had they acquired a general “matching” rule then they should have spontaneously transferred this rule to new stimulus sets. However, if you train the animal with more stimulus sets then their transfer increases, suggesting that they may be using a general matching rule under those circumstances. The trials-unique procedure is another one that can be used to assess learning of general rules.

Working & Reference Memory Paradigms 2. Spatial Memory – Morris Water maze Animals learn to find the hidden platform. They generally do so by relying on external spatial cues (window, door, etc).

Working & Reference Memory Paradigms 2. Spatial Memory – Morris Water maze Animals learn to find the hidden platform. They generally do so by relying on external spatial cues (window, door, etc). However, if a beacon is placed above the platform, then they learn to approach those cues and some research suggests that this interferes with them learning about other spatial cues. They may also learn about the general geometry of the pool (e.g., circular, or rectangular, etc). Thus, they may “code” the stimuli in various ways: specific stimuli, spatial landmarks, geometry relations Some have suggested that the animals develop an internal representation of the spatial arrangement of the pool, a “cognitive map,” and base their swimming behavior on that.

Working & Reference Memory Paradigms 2. Spatial Memory – Radial Arm Maze Animals learn retrieve all food rewards at the ends of each arm without revisiting arms. This task obviously involves “working memory” since the animal must keep track of where its been or where it needs to go to find food within each trial.

Working & Reference Memory Paradigms 2. Spatial Memory – Radial Arm Maze Animals learn retrieve all food rewards at the ends of each arm without revisiting arms. This task obviously involves “working memory” since the animal must keep track of where its been or where it needs to go to find food within each trial. The effects of memory delays can be studied: 4 Arms – Delay – 4 Arms Procedure Delay = 1 or 25 hours Train with either 24 or 48 hour ITI Crystal and Babb (2008) study Memory declines with the delay (as expected), but also memory is slightly better with longer ITI in training.

Working & Reference Memory Paradigms 2. Spatial Memory – Radial Arm Maze Animals learn retrieve all food rewards at the ends of each arm without revisiting arms. This task obviously involves “working memory” since the animal must keep track of where its been or where it needs to go to find food within each trial. The effects of memory delays can be studied: 4 Arms – Delay – 4 Arms Procedure Delay = 1 or 25 hours Train with either 24 or 48 hour ITI Memory declines with the delay (as expected), but also memory is slightly better with longer ITI in training. In addition, Reference Memory can also be studied: 4/4 Baited-Unbaited task: In this case, the same 4 arms are always baited with food and the other 4 never baited. The rats learn which ones are baited (reference memory) and they also learn not to revisit arms they’ve previously visited (working memory).

Memory Processes: Stimulus Coding 1.Stimulus Coding a. spatial codes (beacons – landmark-goal relations, geometry) b. Prospective vs Retrospective codes Chickadee study: Gp Expt – Eat Sunflower Seeds, 30 min later mealworms Gp Control – Eat Sunflower Seeds (no mealworms) The birds consume fewer sunflower seeds, presumably because they expect to get the more preferred mealworms later (prospective code).

Memory Processes: Stimulus Coding 1.Stimulus Coding a. spatial codes (beacons – landmark-goal relations, geometry) b. Prospective vs Retrospective codes 12-arm Radial maze study (Cook, Brown, & Riley, 1985) Prospective vs Retrospective Codes Prospective code (memory for where you have NOT been) Errors should be greater early, and less later in the task. Retrospective code (memory for where you HAVE been) Errors should be less early, and greater late in the task. Different groups were allowed to retrieve food from 2, 4, 6, 8, or 10 arms before being taken out of the maze for a 15-min delay interval. After this, they were placed back in the maze and allowed to retrieve the remaining food items. The number of errors (revisits) made was assessed in all the groups.

Memory Processes: Stimulus Coding 1.Stimulus Coding a. spatial codes (beacons – landmark-goal relations, geometry) b. Prospective vs Retrospective codes 12-arm Radial maze study (Cook, Brown, & Riley, 1985) Prospective vs Retrospective Codes Prospective code (memory for where you have NOT been) Errors should be greater early, and less later in the task. Retrospective code (memory for where you HAVE been) Errors should be less early, and greater late in the task. Errors increased with number of choices, but then decreased thereafter. This suggests that rats use a retrospective code early and then switch to a prospective code later in the task.

Memory Processes: Retention 1.Stimulus Coding 2.Retention (Rehearsal) Processes Directed Forgetting/Remembering Task On some trials a cue occurs which signals that there will be no comparison choice. These are called “forget cue” trials. At issue is whether on a probe choice that occurs on such a trial, performace will be low. If it is, this suggests that there are active memory processes occurring during the retention interval.

Memory Processes: Retention 1.Stimulus Coding 2.Retention (Rehearsal) Processes Directed Forgetting/Remembering Task (DMTS) Performance on Forget Cue probe trials is worse than on Remember Cue trials This suggests that memory is not merely a passive process, but is active

Memory Processes: Retrieval 1.Stimulus Coding 2.Retention (Rehearsal) Processes 3.Retrieval Processes Reminder (i.e., retrieval) cues are thought to reactivate items into working memory. This can make them more available for use in a task. Baby can move the mobile by kicking. They learn to increase their kicking responses This is an example of simple instrumental conditioning in the human baby. Rovee-Collier Mobile Task

Memory Processes: Retrieval 1.Stimulus Coding 2.Retention (Rehearsal) Processes 3.Retrieval Processes Reminder (i.e., retrieval) cues are thought to reactivate items into working memory. This can make them more available for use in a task. Baby can move the mobile by kicking. They learn to increase their kicking responses This is an example of simple instrumental conditioning in the human baby. This study shows that 6-month old babies remember better when they are tested in the crib with the Same liner as was used during training. This shows that retrieval cues were effective. Rovee-Collier Mobile Task

Memory Processes: Retrieval 1.Stimulus Coding 2.Retention (Rehearsal) Processes 3.Retrieval Processes Reminder (i.e., retrieval) cues are thought to reactivate items into working memory. This can make them more available for use in a task. Baby can move the mobile by kicking. They learn to increase their kicking responses This is an example of simple instrumental conditioning in the human baby. This study shows that 6-month old babies remember better when they are tested in the crib with the Same liner as was used during training. This shows that retrieval cues were effective. In this study, babies normally forget when tested one week after training. But if they are exposed to the retrieval cue one day before testing (Same odor condition) they remember better. Rovee-Collier Mobile Task

Memory Processes: Forgetting 1.Is the memory lost or is it non-retrievable? Rats learned a one-way shuttle avoidance task Placed in the white compartment and shocked once entering the black compartment. Latency to reenter the black compartment is the measure of learning. This latency is long in conditioned animals, but it is shorter in animals given extinction. However, a hypothermia treatment administered immediately or 30 min later, but not 60 min, disrupted memory of extinction. Hypothermia caused amnesia for extinction. Briggs and Riccio (2007) study

Memory Processes: Forgetting 1.Is the memory lost or is it non-retrievable? Rats learned a one-way shuttle avoidance task Placed in the white compartment and shocked once entering the black compartment. Latency to reenter the black compartment is the measure of learning. This latency is long in conditioned animals, but it is shorter in animals given extinction. However, a hypothermia treatment administered immediately or 30 min later, but not 60 min, disrupted memory of extinction. Hypothermia caused amnesia for extinction. But, reexposure to the hypothermia treatment before testing brought back the extinction memory, suggesting that the amnesia was a retrieval deficit and NOT a permanent disruption of the consolidated memory. Briggs and Riccio (2007) study

Memory Processes: Consolidation, Reconsolidation, Memory Updating 1.Traditional View: Rehearsal within STM leads to consolidation in LTM 2.Modern View: Memories are either active or inactive Active memories can be consolidated into an inactive state. Previously stored (inactive) memories can be made active again through a retrieval process. But this places the memory in a vulnerable active state where it can be altered.

Memory Processes: Consolidation, Reconsolidation, Memory Updating Rats underwent Pavlovian fear conditioning (Tone – Shock Pairings) Then, one group was exposed to Tone alone, but this was followed by an infusion of a protein synthesis inhibitor into the amygdala. A control group received infusion of a control solution. Both groups were then tested the next day for fear to the Tone CS. The protein synthesis inhibitor group showed very little fear CRs in this test. The result means that reactivating the Tone- shock memory induced reconsolidation of the memory, but this also placed it in a vulnerable state of rewriting. The protein synthesis manipulation may have updated the memory by wiping it out. Nader, Schafe, and LeDoux (2000) study