New Delhi, Jan 19 : Mild Covid infection can cause attention and memory problems for months after recovery, new research suggests, the Daily Mail reported. The findings, reported by researchers from the Oxford University, showed that people who had mild Covid infection but did not report long Covid symptoms still had worse attention and memory for up to six to nine months, the report said. Previous studies have shown that long-Covid sufferers experience difficulties maintaining attention, which is known as "brain fog". However, it was not known if similar effects were felt by those who had experienced no other issues after recovery from Covid-19. Sijia Zhao from Oxford's Department of Experimental Psychology said: "What is surprising is that although our Covid-19 survivors did not feel any more symptomatic at the time of testing, they showed degraded attention and memory," the report added. "Our findings reveal that people can experience some chronic cognitive consequences for months," Zhao said. Participants in the study were asked to complete a number of cognitive tests, with a focus on sustaining attention, memory, planning, and semantic reasoning. While they performed well in short-term working memory and planning compared with the control group, the participants scored significantly worse in their memory of past events and in their ability to sustain attention over time. All the participants had previously suffered from Covid-19 and were similar to the control group in factors such as fatigue, forgetfulness, sleep patterns or anxiety at the time of testing, the report said. Luckily, most people's memory and attention returned to normal after six to nine months. The research was conducted by psychologists at Oxford's Department of Experimental Psychology and Nuffield Department of Clinical Neurosciences. /IANS