Chapter 4

The Development of Memory

Basic laws of habituation and operant conditioning are sufficient

for understanding behavioral relations called “memory.”

Overview Study of memory is difficult

Many different behaviors are used as evidence of memory

“Memory” refers to cognitive operations Explanation of memory involves understanding

these cognitive processes Hypothetical structures, mechanisms and processes

are inferred More scientific (behavior analytic) approach would

be to study the behavioral relations related to “memory” (e.g., habituation, operant conditioning)

Concept of Memory in Developmental Psychology

Remember circular reasoning (reification) from chapter 2?

behavior is observed & given a name- “memory” Name is referred to as concrete object and becomes

the object of study- as in “a memory” or “mental record of an event”

The memory or mental record is never directly observed

The term “memory” is used to explain the behavior it represents

Concept of Memory in Developmental Psychology

e.g. poor memory of preschoolers has been attributed to “limited information-processing capacity,” “lack of meaningful organization,” and inadequate knowledge base”

None of these descriptions can be observed- they are inferred from the behaviors that are supposed to explain memory (circular logic)

Environmental contingencies responsible for behavior are overlooked

hypothetical constructs versus behavior and environment

Research on Infant Memory

Visual Recognition Memory Single-stimulus habituation Paired-comparison (novelty preference) Novelty discrimination

Operant Conditioning Procedures Demonstration of long-term memory Reactivation of forgotten memories Contextual control over memory

Visual Recognition Memory

Recognition memory- indicate if a stimulus has been encountered before

Recall memory- produce a verbal response to name the stimulus

Infants are not capable of verbal behavior thus recall memory is not tested

Visual recognition memory- inferred when infants respond differentially to familiar and novel stimuli

Single- Stimulus Habituation Procedures

Habituation= process of repeatedly presenting an unconditional stimulus that results in a decrease in unconditional responding evoked by that stimulus

Single- Stimulus Habituation Procedures

DV= fixation time between 2 types of stimuli A single patterned visual stimulus is presented

repeatedly until visual fixation time toward it decreases

Familiar stimulus and novel stimuli are successively presented

e.g., Bornstein (1976)

Single- Stimulus Habituation Procedures

Explanation of results

Cognitive

Memory is inferred if fixation timeis shorter to familiar stimulus than novel stimuli

Infant is initiator of his/her own actions

Behavior Analytic

Habituation has been demonstrated if fixation time is shorter to familiar stimulus than novel stimuli

Results can be understood in terms ofstimulus control as predicted byexperimental literature on habituation

Stimulus generalizationStimulus discrimination

“Visual fixation” may be functionally related to consequence of seeing the stimulus displayed

Paired-Comparison (Novelty Preference) Procedures

Variation of single- stimulus habituation procedures Two identical patterned stimuli are presented

simultaneously until fixation time to both decreases (habituation)

Novel stimuli are presented simultaneously with familiar stimuli

DV= proportion of visual fixation to novel versus familiar stimulus

Paired-Comparison (Novelty Preference) Procedures

e.g. Fantz (1964) Simplest explanation of results: after an initially

high level of fixation to the constant stimulus, habituation occurs and duration of fixation decreases (habituation explanation).

Obscure terms, like “visual experience,” are not necessary

Extends principle of habituation to infants

Paired-Comparison (Novelty Preference) Procedures

Operant principles explanation Responses to novel visual events may be seen as

special operants specific to visual system of infants Decrease in fixation time reflects satiation (EO) or

operant extinction (function-altering) The visual stimulus initially elicits looking and then

the consequence of that looking (seeing the visual stimulus) ensures continued looking

Novelty Discrimination Procedures

Visual stimuli are used as reinforcers for high-amplitude sucking

Nipple connected to power supply which illuminates slides of visual stimuli

Conjugate reinforcement schedule- intensity of consequence is directly proportional to intensity of the response

Novelty Discrimination Procedures

Werner & Siqueland (1978) Cognitive interpretation

“visual recognition memory, in some rudimentary form, is evidenced in the conditioned sucking of...infants within the first days of life”

Behavior analytic interpretation Operant conditioning with visual stimuli as

reinforcers has been extended to newborn infants

Operant Conditioning Procedures

Rovee-Collier and colleagues Behaviorally trained researchers with cognitive

orientation Designs typically consisted of between subject

comparisons with large groups of infants Various aspects of infant “memory” were studied

using operant foot kicks

Operant Conditioning Procedures Basic paradigm: Rovee & Fagen, 1976 Results indicate that certain behavioral relations

endure over time- this endurance is called “memory” This is the essence of operant behavior!

Behavior analytic interpretation of results Extend basic principles of reinforcement and stimulus

control to 3-month-old infants (e.g., operant behavior could be conditioned using a visual reinforcer)

Reinforcement is function-altering; visual reinforcer altered sight of mobile to evoke foot kicks

Operant Conditioning Procedures

Major experimental findings fall into three general categories

1)Demonstration of long-term memory in infants

2)The reactivation of forgotten memories

3)Contextual control over memory

Long-Term Memory in Infants

“Forgetting”- testing for recall at various intervals of time

Presumably refers to a decrement in responding solely as a function of the passage of time (where there is no opportunity to make the response).

Issue of stimulus control- weakening ability of discriminative stimuli to evoke responses

No behavioral process by which stimulus control declines solely as a result of passage of time

Long-Term Memory in Infants

Stimulus control account of “forgetting” Failure to reinstate all stimulus conditions relevant

to original response strength

(e.g. mobile on other side of crib, no ribbon attached to leg)

Competing responses to same stimuli

(e.g. visual attending) Competing responses conditioned to other stimuli

Different conditions resemble discrimination training

Long-Term Memory in Infants

Limitations Experiments conducted in infants' home cribs Observers recorded foot kicks Only three sessions Analysis of group results may have overlooked

individual differences

Long-Term Memory in Infants

Conclusions about general results Operant conditioning demonstrated in infants Discrepancy in responding between extinction and

conditioning sessions demonstrates a stimulus-change decrement, possibly discrimination

Competing responses to same stimuli may account for loos of control during retention sessions

Reactivation of Forgotten Memories

“Reactivation treatment”- when a moving mobile is re-presented, previously weakened responding rebounds and remains stronger than if no mobile is presented

Cognitive interpretation= “reactivates” the forgotten memory

Behavior analytic interpretation= stimulus control that was previously weakened is reinstated

Contextual Control Over Memory Foot kicks were lower in the presence of crib

bumpers, novel mobiles or novel components of mobiles

Cognitive interpretation= normal memory retrieval in infants is dependent on the context, even if context was never paired with reinforcement

Behavior analytic interpretation= stimulus control is demonstrated not only by training stimuli but also by contextual stimuli

When compound stimuli are paired with reinforcement for responding to them, components that actually acquire control differ from person to person

Cognitive & Behavior Analytic Views on Memory

Summary

Cognitive

Interprets demonstration of operant conditioning in infants as evidence for inferred events(e.g. memory, forgetting, reactivation)

Behavior Analytic

“Memory” is a name for behaviors observed in certain contexts but it is never actually observed Accounts for memory phenomena largely in terms of stimulus control

The more similar the stimuli presented, the stronger the resulting behavior

(stimulus generalization)Foot kicks came under stimulus control of particular settings by producing a reinforcing consequence of the moving mobile