1
Better maze learning, more complex dendrites, Etc.
Enriched
Impoverished Deprived
2
Hubel Weisel Nobel Prize 1981
Inject one eyegt examine projection to visual
cortex
See alternating stripes
Raise subjects with one eye closed?
Expanded innervation by open eye.
3
Tactile (whiskers) of the rodent
Remove whiskers gt ? barrel fields
(cortical areas innervated by whiskers)
Sensitive period
4
Auditory system of the chick.
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Summary

• Early experience influences the structure,
  function and even life and death of neurons.
• These effects are seen in all sensory systems.
• Many of these effects of are age-dependent.
  (sensitive period).

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Infantile amnesia More rapid forgetting in
young animals.
e.g., Hyson Rudy
8kHz Tone  Shock
Later that day
15 days old
or
or
3 days later
18 days old
15 day olds forget in 3 days
1 8 day olds dont forget in 3 days
(no learning)
Infantile Amnesia
1818
1821
1515
1518
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Why?
Development of the auditory system
Auditory system function Key words Cochlea Ba
se Apex Tonotopic Place code
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Developmental shift in the Place Code
Low Frequency
High Frequency
Base
Apex
Different Frequencies (Generalization Gradient)
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Low Frequency
High Frequency
Base
Apex
12 kHz (at 18)
8 kHz (at 18)
8 kHz (at 15)
Not forgetting, Things just sound different
1518
Developmental ? in perception accounts for what
looks like infantile amnesia (in this case).
1515