This is about research on macaque monkeys at Oxford uni, some of which are the brain damaged before further testing.
However, there is doubt about the need for this research, particularly the need to cause such brain damage to the monkeys.

This information was already known from studies in humans. The researchers here could clearly have obtained these results from scanning human
brains engaged in visual tasks. It is difficult to imagine benefits from this experiment significant enough to justify the enormous suffering of the
animals involved.

It seems some of the testing went on for 9 years, but could hardly have been valid, as at least 3 of the monkeys died in this time.
Another quote that questions the need for this research on the monkeys

Human head injury victims are, sadly, all too numerous, and would
clearly be the ideal research subjects ...........countless primates could be spared years of suffering and misery.

The article is here
www.speakcampaigns.org.uk...