Neural pruning - Luby

Neural pruning

• occurs when we lose synaptic connections in a neural network because we do not use them

• happens a lot during our teenager years and could be accelerated due to stress

• when we learn something new, our brain adapts by developing new synaptic connections

• if we don’t use these connections then we lose the synaptic connections

• this is healthy because the pruning helps to strengthen the connections that are used more frequently

Luby et al aim

• to investigate whether poverty experienced in early childhood impacts brain development and to explore mediators of this effect

luby method

• 145 right handed children recruited from large sample of 10 year longitudinal preschool depression study

• cognitively and socially assessed yearly for 3 to 6 years

• support or hostility of primary caregiver was also noted

• presence of stressful life experiences was also noted

• MRI scans measured brain volumes of white and grey matter and volumes of hippocampus + amygdala

luby results

• poverty was associated with less white and grey matter in brain and with smaller hippocampus and amygdala volumes

• if caregiver was supportive or hostile mediated effects of poverty on both hippocampi

• stressful life events affected volume of left hippocampus only

luby conclusion

• in conclusion, poverty experienced in early childhood impacted brain development because the amygdala and hippocampus of children in poverty had smaller volumes

luby link back

• thus, the stress and parenting explains why poverty was linked to the hippocampus

• stressful events could accelerate the neural pruning process in children