People with mild COVID-19 who do not suffer any other traditional “long COVID” symptoms can cause attention and memory problems for six to nine months after recovery, a study by Britain’s Oxford University have found.
Oxford University published the findings, which show that people who had a mild Covid infection but did not report long-Covid symptoms still suffered from worse attention for up to nine months.
It supports other studies that have shown that long-Covid sufferers can have difficulties maintaining attention, a symptom often called “brain fog”.
The study worked by asking participants to complete a number of cognitive tests, focusing on attention, memory, planning, and semantic reasoning.
The study found that the participants could still perform well using their short-term working memory but they scored much worse when tested on their memory of past events and in their ability to sustain attention over time.
However, most people’s memory and attention came back 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.
“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,” said Dr Sijia Zhao of the Department of Experimental Psychology, University of Oxford.
“Our findings reveal that people can experience some chronic cognitive consequences for months.”
The researchers said that individuals over time demonstrated episodic memory and attention span largely returned to normal after six and nine months, respectively.