Working on your Reference Memory from Space

Memory: Basic Concepts Memory – ability to respond to information that was experienced at an earlier time – Usually study Memory using verbal behavior in humans – Use behavior change from earlier experiences in non-human animals Be aware of the learning performance distinction Learning and memory are interconnected – the learning process resulting in storage of memory – retrieval of information from memory to demonstrate learning

Stages of information processing Three Stages of information processes: – Acquisition: the process of acquiring or gaining information through some experience – Retention: holding on to information after the experience has ended either in short-term or long-term memory – Retrieval: recalling information from long-term memory – See Table 11.1 – See Information Processing Model

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Hypothesized Memory Processes: Encoding, Consolidation, and Retrieval

Types of memory Categorized by type of information – Declarative: “what” facts that can be stated or described Semantic: general knowledge Episodic: autobiographical memory – Nondeclarative (procedural) “how” information shown by behavior Skill learning–learning to perform a task requiring motor coordination. Priming–repetition priming–a change in stimulus processing due to prior exposure to the stimulus. Conditioning–the association of two stimuli, or of a stimulus and a response – Classical conditioning – Instrumental conditioning Perceptual: interpret incoming stimuli by recognizing things

Subtypes of Declarative and Nondeclarative Memory

Types of memory Categorization by stages of information processing –Iconic memories are the briefest memories and store sensory impressions that only last a few seconds. –Short-term memories (STMs) usually last only for up to 30 seconds or throughout rehearsal. also known as working memory. –Long-term memories (LTMs) last for days to years. Long-term memory has a large capacity. Also known as reference memory

Hypothesized Memory Processes: Encoding, Consolidation, and Retrieval

Working and Reference Memory Working memory – short-term retention of info needed for successful completion of current task – In experiments memory for information which is required in order to respond on a particular trial – Should be ‘discarded’ when the task is done because information is no longer useful (and may even interfere with subsequent trials) – Examples: mechanic fixing a car Shopping list Phone number – Although Long-Term memory “reference” is required at the beginning of each task Retrieve information from long-term memory to use in working memory Experience doing a task will store information in the long-term reference memory

Working and Reference Memory Reference memory – memory for stable (trial invariant) features of a task - – long-term memory for information necessary for successful use of incoming and recently acquired information – Not transient like working memory However it can be easily modified Working memory requires proper reference memories

Working Memory in Non-Human Animals Walter S. Hunter (1913) – devised the delayed-response paradigm – a way of studying "symbolic thought" – the capacity for behavior to be guided by the mental representation of an event which was no longer physically present in the environment The delay duration was used to assess mental representation of symbolic processing in several species – Which demonstrated different capacities in dealing with delay – Rats (10-s), raccoons (25-s), dogs (>5-min) – Change in positional orientation during the delay had no effect on memory of the symbols

Delayed Matching to Sample Used by Blough 1959 to study short-term memory of visual cues and pigeons currently the most common procedure for studying short-term memory and nonhuman animals Procedure to study working memory with pigeons – 1. Start cue, illuminate center key, must respond to center key – 2. Display sample on center key, must respond to center key – 3. Display sample on one side and non-sample on the other side – Food reinforcement for responding to the sample Delayed matching to sample – delay between sample exposure and choice response – the center key is blank during step three – there is a delay between step 2 and step 3 which requires working memory

Delayed Matching to Sample Simultaneous matching to sample – cue for correct response (sample) visible when choice made – sample remains on the center key during set three – Does NOT require working memory Matching to Sample Examples – Simultaneous Matching-To-Sample Simultaneous Matching-To-Sample – Delayed Matching-To-Sample Delayed Matching-To-Sample Study with Schizophrenic individuals using complex patterns as stimuli – Figure 11.1 – Test stimulus for 500 msec followed by choice alternatives – Training with no delay between sample and choice then introduce four or eight second delay – As compared to controls individuals with schizophrenia showed a deficit with delay

Procedural Determinants of Delayed Matching to Sample Nature of the stimulus – Sample characteristics: colors, shapes, line tilt, sounds, Sample duration – Usually very short sometimes only half a second Delay interval “retention interval” – From a few seconds up to minutes or hours depending on the particular type of species being tested or type of stimulating be presented – Memory performance is worse with longer delay intervals – Originally explained by Trace Decay Hypothesis More recent research demonstrates that memory does not just fade automatically there are number of things that reduce memory such as interference which will be covered later – Length of the retention interval on the first training trials has a strong effect on performance at that retention interval

Procedural Determinants of Delayed Matching to Sample White 2001 – trained pigeons to peck at red or green sample stimulus – used several different delay intervals from the beginning of training Independent groups for 0, 2, 4, or 6 second delays – Do not get typical decline in performance with delay – Responding was best for the delay interval used in training – Can not be explained by the trace decay hypothesis and demonstrates a type of temporal processing of the training procedure – See Figure 11.2 Matching is similar to instrumental choice behavior – better performance with larger rewards

FIGURE 11.2 Accuracy of matching-to-sample performance as a function of delay between the sample and choice stimuli for independent groups of pigeons that were previously trained with delays of 0, 2, 4, or 6 seconds. (Based on “Forgetting Functions,” by R. J. Sargisson & K. G. White, 2001, Animal Learning & Behavior, 29, pp. 193–207.) The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Response Strategies during Matching to sample Matching to sample is a two-alternative choice task can be solved by – 1. Responding to the correct alternative – 2. Avoiding the incorrect alternative – 3. Both responding to the correct alternative and avoiding the incorrect alternative Pigeons appear to focus more on finding the correct alternative than on avoiding the incorrect alternative

General versus Specific Rule Learning In matching to sample task – Choosing the stimulus that is the same as the prior sample Can be solved in two different ways – General “Same-as” rule: “Choose the comparison stimulus that is the same as the sample stimulus” General matching rule predicts strong positive transfer of learning – Specific “If-Then” rule: “if red sample choose red comparison” “if green sample choose green comparison” Even when matching to sample procedure uses six or eight different sample stimuli “if-then” rule predicts very little positive or negative transfer of learning Transfer of learning experiments can determine if the general “same-as” rule is being used

General versus Specific Rule Learning Transfer of Learning Test – Train with one set of stimuli then switch to a new set of stimuli for testing trained with Red and green stimuli tested with blue and yellow stimuli – Use of a general rule depends on species and size of the stimulus set used Chimpanzees – (Oden, Thompson & Premack, 1988) – general rule learning when trained with only 2 stimuli Pigeons – (Wright et al., 1988). – “if-then” learning with small set sizes (6 - 8) – General rule with large set sizes (200) or trial-unique stimuli Trials-unique procedure – the stimuli change on every trial and never repeat – use a different stimulus as the sample on each trial – can only be solved using a general same-as rule – used to study concept learning covered in chapter 12

Using Comparative Cognition to Study Environmental Health Risks to Children Developmental delays in human infants – Exposure to neurotoxins can impair cognitive function lead, mercury, polychlorinated biphenyls (PCBs) – Genetic effects such as Down’s syndrome Study the effect of environmental neurotoxins in non-human animals and relate those findings to humans Need to use similar testing procedures to measure cognitive capacities in developing humans and animals Some cognitive testing with toddlers and young children – operant battery test, radial arm maze, Morris search apparatus – more difficult to use comparable tests for human infants – most of the procedures have been habituation or simple classical conditioning such as eyeblink conditioning – Examine age-related performance to track developmental changes Infant cognitive development compared to developmental changes in rats

Visual Habituation/Novelty Preference Tasks – Habituation to repeated stimuli followed by a novel stimulus – preference for novelty demonstrates processing of stimulus information Visual Recognition Memory Tasks – Paired-comparison task Familiarization with a target then the target is paired with a novel object Preference for the novel object indicates recognition memory A-not-B Task requires an aspect of working memory – Based on Piaget’s A-not-B task a treat (or toy) is hidden for a few seconds – rewarded for reaching correctly Tolerance to delay improves with age Mobile/Train Conjugate Reinforcement Tasks – Instrumental: behavior of moving a foot reinforced by movement of a mobile – A similar study examining retrieval cues will be covered in the next topic Using Comparative Cognition to Study Environmental Health Risks to Children

Delayed Nonmatching-to-Sample Tasks – Sample object is presented – After a delay the sample object is presented alongside a novel object – The correct choice is to select the novel object – Assessment of working memory and attention 21 months old children can handle delays of only 5–10 sec Similar to infant monkeys 4 months of age – This test may be difficult because of the relationship of the reinforcement on object When length of the delay is 5-sec When rewards are attached to the base of the stimuli Most 9-month-olds pick the novel object Using Comparative Cognition to Study Environmental Health Risks to Children