Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • Article talks about age differences in how long infants are able to retain the actions they observe. Mobile: learn to kick feet to produce movement in an overhead mobile and retention assessed after a delay. Showed retention increases between 2 and 6 months. Train task: infants learn to press a lever to make a miniature train move around the track with rate with which they press the lever is measured Preverbal infants represent events in long term memory and can access those memories months later.
  • Deferred imitation provides non-verbal index of recall So in this study they use deferred imitation procedures to trace age-related changes in retention between 18 and 24 months In ch 9, they mention how infants do not display deferred imitation until they are about 18 months old.
  • Infants tested in a deferred imitation paradigm 69 18 month old 63 24 month old
  • Scored by two independent observers, one of whom was blind to the infant’s group assignment
  • Each observer scored the presence or absence of each target action during the 60s test period If they show target action more frequently than do children who are given the toy for the first time (control group), this is good evidence for deferred imitation A child who has never seen that apparatus before would not know to put ball inside. So if child sees that the ball was pushed through diaphragm into cup, that fact that children who have seen the ball placed through the diaphragm implies that they learned the behavior from watching a model.
  • Imitation increased for 24month olds with older infants demonstrating higher levels of imitation during each delay interval than younger infants did. Number of target actions imitated during test decreased as function of delay Performance=retention 18month olds exhibited forgetting when tested after delays longer than 2weeks. 24month remembered for at least 8weeks
  • In Exp 2, we attempted to assess the maximum duration of retention by 24month infants Bought in an additional group of 24month olds Control was 30months at time of test which was 6mths
  • The demonstration and test procedures were identical to those in exp 1. Infants in the control condition did not observe the target actions prior to the test
  • Age-related changes in retention after longer delays
  • …as a function of maturation and experience, the slope of the forgetting function Flattens and the maximum period over which a given memory can be retained increases. Slope of the forgetting function may approach zero, allowing a memory to be retained over significant periods of development. Many factors that influence memory processing by adults also influence memory processing by infants and young children.

    1. 1. THE ONTOGENY OF LONG-TERM RETENTION DURING THE SECOND YEAR OF LIFE Jane Herbert and Harlene Hayne Chinyelu Mozie
    2. 2. Introduction <ul><li>Most complete picture of age-related changes in infant long-term memory obtained by Rovee-Collier </li></ul><ul><ul><li>mobile conjugate reinforcement paradigm, effective with infants between 2 and 6 months </li></ul></ul><ul><li>Rovee-Collier developed another operant procedure highly effective with infants between 6 and 18 months </li></ul><ul><ul><li>train paradigm </li></ul></ul><ul><li>Increase in retention between 2 and 18 months of age based on studies </li></ul><ul><li>Long term retention increases as a function of age </li></ul>
    3. 3. Introduction (cont.) <ul><li>What happens during the final quarter of infancy? </li></ul><ul><li>Important transition in cognitive development in period between 18 and 24 months </li></ul><ul><ul><li>Piaget-final stage of sensorimotor period </li></ul></ul><ul><ul><li>rapid language acquisition </li></ul></ul><ul><li>Use of deferred imitation </li></ul><ul><ul><li>child observes model then later tested after delay </li></ul></ul><ul><li>Study used to trace age-related changes in retention between 18 and 24 months </li></ul>
    4. 4. Experiment 1 Participants <ul><li>72 18-month old infants/three removed </li></ul><ul><li>72 24-month old infants/nine removed </li></ul><ul><li>Recruited from public birth records/word of mouth </li></ul><ul><li>Half were female and half were male at each age </li></ul><ul><li>European descent </li></ul>
    5. 5. Procedure <ul><li>Infants tested at their own homes during time of day identified by caregiver as alert/play period. </li></ul><ul><li>Experimenter interacted with infant for 5 minuets or until smile was elicited </li></ul><ul><li>Demonstration condition </li></ul><ul><li>Control condition </li></ul>
    6. 6. Demonstration condition <ul><li>Each infant exposed to two sets of stimuli </li></ul><ul><ul><li>modeled three-step sequence for rattle and rabbit stimuli three times in succession </li></ul></ul><ul><li>Stimuli was not verbally described or labeled </li></ul><ul><li>Groups of 12 infants tested immediately after delay of 24 hours, 2weeks, 4 weeks or 8 weeks </li></ul><ul><ul><li>behaviors videotaped for 60s period for both stimuli and scored based on imitation of target actions </li></ul></ul>
    7. 7. Control condition <ul><ul><li>Assess spontaneous production of target actions </li></ul></ul><ul><ul><li>12 infants exposed to stimuli for first time during test in absence of adult demonstration </li></ul></ul>
    8. 8. Stimuli
    9. 9. Results <ul><li>Demonstrated condition </li></ul><ul><ul><li>age-related and delay-related changes in infants’ performance after longer delays </li></ul></ul><ul><ul><li>24-month olds reproduced more target actions then 18-month olds during the test across delays </li></ul></ul><ul><li>Controls </li></ul><ul><ul><li>no age related change in the performance of control groups </li></ul></ul>
    10. 10. Results (cont.) <ul><li>Imitation was calculated for each infant by summing the number of target behaviors produced during the test with each stimuli (range 0-3) </li></ul>
    11. 11. Experiment 2 Participant <ul><li>24 24-month old infants </li></ul><ul><li>12 30-month old infants </li></ul><ul><li>Recruited through public birth records/word of mouth </li></ul><ul><li>Half of infants at each age were females </li></ul>
    12. 12. Procedure <ul><li>Same procedure followed in experiment 1 </li></ul><ul><li>Maximum duration of retention by 24 month olds was assessed </li></ul><ul><li>Delay between demonstration and test was either 3 or 6 months </li></ul>
    13. 13. Result <ul><li>24-month old infants exhibited some evidence of retention </li></ul><ul><ul><li>imitation scores higher than controls after 3 months </li></ul></ul><ul><li>Imitation scores after 6 months were the same in both ages </li></ul><ul><ul><li>forgetting appeared to be complete </li></ul></ul>
    14. 14. Results (cont.)
    15. 15. Discussion/Conclusion <ul><li>Memory development during second year of life is characterized by age-related change in the duration of retention </li></ul><ul><li>Childhood amnesia raising questions about memory processing across lifespan </li></ul><ul><ul><li>Found that it does not involve stage-like shift in memory processing but reflect an increase in basic retention across ontogeny </li></ul></ul><ul><ul><li>Maximum period over which a given memory can be retained increases and forgetting function flattens </li></ul></ul>
    16. 16. References <ul><li>Hayne, H., Herbert, J. (2000). The ontogeny of long-term retention during the second year of life. Developmental Science, 3(1), 50-56. </li></ul>