Visual tests could indicate cognitive decline – study
Reaction times could help detect problems before conventional memory tests
Simple visual tests could be an early indicator of cognitive decline, a precursor to dementia, according to a new study published in the journal Brain Sciences.
Researchers from Anglia Ruskin University (ARU) found that people screening positive for mild cognitive impairment (MCI) performed significantly worse on visual tasks and consistently took longer to respond than cognitively healthy adults, suggesting reaction times could warn of cognitive decline before the type of memory tests that are typically used.
The study involved 115 participants, including healthy young adults, cognitively healthy older adults, and older adults who screened positive for MCI.
Researchers assessed participants using short-term memory tasks that each had a strong visual element. These were designed to test participants’ ability to remember and process information while ignoring distracting or conflicting cues.
One of the tasks incorporated a variation of the classic Stroop test, in which participants were shown colour words displayed in either matching or conflicting ink colours, such as the word “RED” printed in blue ink. Another task required participants to remember arrows whose direction and movement either matched or conflicted with one another.
Participants who screened positive for MCI recorded lower memory scores overall and took 27% longer to respond than healthy older adults. When they were presented with conflicting visual information, their reaction times also increased, becoming 42% longer than those of cognitively healthy older adults.
According to the study, this finding indicates that reaction-time measurements may reveal subtle changes in brain function that may not be picked up by traditional assessments which are solely focused on whether a given answer is correct or incorrect.
There are currently several different tests used in the UK whereby patients are tested on their mental abilities to assess their cognition. These include the General Practitioner Assessment of Cognition, which is commonly used by GPs.
“Our study shows that reaction times can provide valuable information about cognitive function that may be missed by conventional memory testing.
“People who screened positive for mild cognitive impairment not only performed less accurately overall but often needed significantly longer to process information and respond, particularly when faced with conflicting visual cues.
“These findings suggest that measuring reaction times alongside memory performance could help clinicians detect subtle cognitive changes at an earlier stage.
“As populations continue to age and dementia becomes an increasing public health challenge, there is a growing need for sensitive, accessible tools that can identify people at greater risk before symptoms become more severe.”
Professor Shahina Pardhan, Director of the Vision and Eye Research Institute (VERI) at ARUThe full, open-access study can be read here: https://www.mdpi.com/2076-3425/16/8/898