Neuroplasticity

Question 1

Draganski et al (2004) & neural pruning (2)

Answer 1

• after learning motor skill, are there structural / functional changes in brain
• MRI, field experiment, juggling vs non-juggling
• scans after 0, 3, 6 months
• told to stop juggling after 3 months
• increase in g.m. in mid-temporal areas for jugglers compared to non-jugglers

Question 2

Conclusion of Draganski et al

Answer 2

• The conclusion was that the action of watching balls in the air and learning to move in response to them strengthened the neuronal connections in the parts of the brain responsible for this activity.
• However, the differences were temporary and relied on continuing the activity or else neural pruning took place when the connections were no longer used.

Question 3

Strengths of Draganski et al (2004)

Answer 3

• pre-test, post-test design allowed for effective comparison
• field experiment but took place in natural env
• control group allowed for even more comparison

Question 4

Weaknesses of Draganski et al (2004)

Answer 4

• internal validity may be low (participants at home)
• replication needed to establish reliability
• lacks population validity (21 females, 3 males) - small sample

Question 5

Kolb et al (2003) –> certain criteria must be met for neural pruning to occur

Answer 5

• when weanling or adult rats were placed in a complex env, all groups showed large synaptic changes but they were surprisingly different
• increase in spine density expected
• rats placed in environments as juveniles showed DECREASE in spine density
• similar drop in spine density found in later studies in which newborn rats were given tactile stimulation w/ a soft rush for 15 mins, 3 times daily over the first 10 days of life but NOT in adulthood

The age-dependent nature of synaptic change is clearly important for understanding how experiences change the brain.

Question 6

HM Case Study

Answer 6

• HM had major seizures, to fix this tissue from temporal lobe was removed including
  hippocampus.
• After surgery seizures fixed but HM had anterograde amnesia (could not form
  new memories).
• HM could only recall childhood memories 10 years before surgery.
• HM’s anterograde amnesia never fixed meaning no other part of the brain assumed the function
  of the removed tissue.
• This is a case study that does not show neuroplasticity however certain conditions may not have been met for neuroplasticity, such as the damage being too
  severe.