Download Long-term memories

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.
Types of memory
• Categorized by type of information
– Declarative: “what” facts that can be stated or described (human centric)
• Semantic: general knowledge such as what is a cat
• Episodic: autobiographical memory such as petting a cat
– Nondeclarative (procedural) “how” information shown by behavior
• Skill learning–learning to perform a task requiring motor coordination such tie
your shoe laces
• Priming–repetition priming–a change in stimulus processing due to prior
exposure to the stimulus such red stop lights
• Conditioning–the association of two stimuli, or of a stimulus and a response
– Classical conditioning (as you already know)
– Instrumental conditioning
• Perceptual: interpret incoming stimuli by recognizing things such as
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
–H E L L O
• 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
with pigeons
• currently the most common procedure for studying short-term
memory with nonhuman animals
• Procedure to study working memory with pigeons
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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
– Delayed Matching-To-Sample
• Test 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
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–
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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 non-human 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
Using Comparative Cognition to Study
Environmental Health Risks to Children
• Visual Habituation/Novelty Preference Tasks (see Figure 2.6)
– Habituation to repeated stimuli followed by a novel stimulus
– preference for novelty demonstrates processing of stimulus information
– See "Ape Genius" video,
• 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
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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