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Wednesday, November 22, 2017

Early Stages of Dementia Reduce Human Face Memorization Ability

NEUROSCIENCE NEWS   NOVEMBER 22, 2017
Source: Kumamoto University.

Summary: Kumamoto University researchers reveal people with MCI have a harder time memorizing human faces that their aging peers without the disorder. Additionally, researchers note, those with mild cognitive impairment express different gaze behavior while trying to memorize a face.

[LEFT] Patients with mild cognitive impairment (MCI) have a significantly reduced ability to memorize faces in comparison to healthy controls (HCs). [RIGHT] The gaze pattern of MCI patients (yellow) is focused over a greater area of the face, possibly as compensation for cognitive degradation, compared to the gaze pattern of HCs, which is more focused on the eyes. NeuroscienceNews.com image is credited to Toshikazu Kawagoe.


A Japanese research group has revealed that elderly people with mild cognitive impairment (MCI) have a particularly weakened ability to memorize human faces in the short term when compared to healthy elderly people. MCI patients also had a different gaze behavior when trying to memorize a face. This research may lead to the early detection of dementia.

Alzheimer’s disease is considered to be the most common type of dementia, and early detection of preliminary stages is important to halt its progression into a more serious form of the disease. MCI, which is thought to be a preliminary stage of Alzheimer’s, is a state in which cognitive functions, such as memory or thinking ability, decrease at a level that do not affect daily life.

Brain imaging studies show that areas of the brain for memory and visually processing human faces in people with MCI are structurally and functionally transformed. To investigate these specific and yet unstudied areas, a research group from Kumamoto University in Japan conducted comparative experiments with normal elderly subjects and MCI patients (18 each) using a delayed-matching task with face and house stimuli in independent blocks. In each block, they asked subjects to remember a single image and then, after a short delay, select a memorized image from a set new of images. The researchers also recorded subject gaze trends during the image memorization process.

Their experiments revealed that the memorization performance of MCI patients was lower for facial images than for house images, but found no performance difference in normal subjects. The research also showed that, during the memorization process, MCI patient gaze concentration on the eyes of an image decreased but the time spent looking at the mouth increased in comparison to normal subjects. In essence, MCI patients had reduced short-term memorization ability and a different gaze pattern for faces when compared to normal people.

“Looking at the eyes is important for remembering the entirety of the face,” said Emeritus Professor Kaoru Sekiyama. “MCI patients probably have an abnormality in the cognitive processing of faces due to the deterioration of brain function. It is possible that the distributed gaze pattern is compensation for this decreased function. We hope to shed some light on this possibility in future work.”
ABOUT THIS NEUROSCIENCE RESEARCH ARTICLE
Funding: Funding provided by Japan Society for the Promotion of Science.
Source: J. Sanderson, N. Fukuda – Kumamoto University
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is credited to Toshikazu Kawagoe.
Original Research: Full open access research for “Face-specific memory deficits and changes in eye scanning patterns among patients with amnestic mild cognitive impairment” by Toshikazu Kawagoe, Masateru Matsushita, Mamoru Hashimoto, Manabu Ikeda & Kaoru Sekiyama in Scientific Reports. Published online OCtober 31 2017 doi:10.1038/s41598-017-14585-5


Abstract

Face-specific memory deficits and changes in eye scanning patterns among patients with amnestic mild cognitive impairment

Amnestic mild cognitive impairment (aMCI) is a prodromal stage of Alzheimer’s disease (AD). Previous studies have shown functional and structural degradation of the fusiform face area, which is a core region for face processing, in addition to medial temporal lobe degradation. We predicted that patients with aMCI exhibit a loss of face processing and/or face memory, accompanied by abnormal eye scanning patterns, since patients who have deficits in face perception (i.e. prosopagnosia) exhibit such tendencies. Eighteen patients with aMCI and age-matched healthy controls were tested for perception and short-term memory of visually presented faces and houses while their gaze was recorded. Patients with aMCI showed a decline in memory, compared with control observers, for faces, but not for houses. Patients looked more at the mouth of faces, compared with control observers. We demonstrate here the loss of short-term face memory in aMCI with abnormal scanning patterns that might reflect the cerebral abnormality found in patients with aMCI.

“Face-specific memory deficits and changes in eye scanning patterns among patients with amnestic mild cognitive impairment” by Toshikazu Kawagoe, Masateru Matsushita, Mamoru Hashimoto, Manabu Ikeda & Kaoru Sekiyama in Scientific Reports. Published online OCtober 31 2017 doi:10.1038/s41598-017-14585-5


http://neurosciencenews.com/dementia-face-memorization-8006/

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