WELLINGTON, March 29 (Xinhua) -- Long-term exposure to earthquakes has left residents of New Zealand's Canterbury region less able to do simple tasks, according to a study out Wednesday.
The South Island region has been battered by quakes since September 2010, including a 6.3-magnitude tremor that killed 185 people in the country's second largest city of Christchurch in February 2011.
A group of people affected by the traumatic events of the February 2011 quake made 13 percent more errors on tasks involving learning the way through a maze compared to those who had not experienced the disruptive and ongoing natural phenomenon, according to the study by the University of Otago.
The "quake-affected group" included emergency responders, those who were injured or had a family member injured during the quake or whose property or neighborhood had been badly damaged, said the university's head of psychological medicine, Professor Richard Porter.
Despite having experienced trauma, they all identified themselves as being "resilient," Porter said in a statement.
They were tested two years after the February 2011 quake, and their results were compared to a group of people who had done the same test but had no experience of quakes.
The research showed the ongoing impact of quakes and that there was likely to have been a significant effect on memory for a large percentage of the population.
The problem was even greater for people who developed post-traumatic stress disorder after the earthquakes.
The research emphasized that the problems were common and others should make allowances for these sorts of difficulties, said Porter.
"We do not know how long this effect is likely to have lasted. We are currently seeking funding to re-test the group of people to see if their memory has now returned to normal," he said.