PassingPsych

Neural pruning occurs when unused synaptic connections in the neural pathway are lost. Every time you learn something new, neurons connect to create a new trace in the brain. This is referred to as dendritic branching because the dendrites of the neurons grow in numbers and connect with other neurons. Neural pruning is the process of losing these connections. In this essay, I will provide a detailed account of neural pruning, including the supporting study of Draganski et al.

Draganski et al aimed to investigate whether the structure of an adult human brain would alter in response to environmental demands as a result of learning a new motor skill. To investigate, Draganski conducted a field experiment involving a total of 24 participants (21 females and 3 males). The participants’ brains were scanned using structural MRI scans so that researchers could observe the effect of learning-induced plasticity in the brains of the volunteers. Participants had their brains scanned three times: once prior to learning to juggle, another scan after practising juggling over three months, and a final time after three months of not juggling. This is known as a repeated measures design as participants took part in both conditions. The results of the MRI scans showed no structural differences in the participants’ brains before juggling. However, there was an increase in the volume of the two regions (motor and visual areas) of the jugglers’ brains associated with the retention of visually detected movement information after learning. This difference decreased after three months of no practice. They found these individuals had a transient and selective structural change in areas associated with the processing and storage of complex visual motion. Practising watching the balls and learning to move in response strengthened the neural connections in the brain areas responsible for the activity. This discovery of a stimulus-dependent alteration in the brain’s structure contradicts the traditionally held view that cortical plasticity is associated with functional rather than anatomical changes.

Draganski et al demonstrate neural pruning in the brain. For example, the volumes of the two regions of the brain (visual and motor areas) decreased after three months of no practice. This is significant because the decrease in these two regions of the brain is due to their lack of use, resulting in the loss of synaptic connections within the neural pathway. Therefore, neural pruning impacts the brain.