Alzheimer's sufferers may function better with less visual clutter

October 11, 2012, University of Toronto
Participants in a University of Toronto and Georgia Institute of Technology study indicated whether two rotated objects were the same or different. The objects were ambiguous, blob-like stimuli which shared many similar features, or everyday objects which shared few features. In the Low Interference condition, blob-like comparisons were interspersed with the photographs of everyday objects. In the High Interference condition, all trials contained the blob-like objects. Memory impaired participants were impaired at discriminating the objects in the High Interference condition, but performed like controls on the Low Interference condition. Perceptual interference was reduced by minimizing the number of visually similar features. This study provides evidence that perception may be closely tied to memory. Credit: Image: Rachel Newsome, University of Toronto

Psychologists at the University of Toronto and the Georgia Institute of Technology – commonly known as Georgia Tech – have shown that an individual's inability to recognize once-familiar faces and objects may have as much to do with difficulty perceiving their distinct features as it does with the capacity to recall from memory.

A study published in the October issue of suggests that for people diagnosed with early stage Alzheimer's disease may in part be due to problems with determining the differences between similar objects. The research contributes to growing evidence that a part of the brain once believed to support memory exclusively – the medial temporal lobe – also plays a role in object perception.

"Not only does memory seem to be very closely linked to perception, but it's also likely that one affects the other," said Morgan Barense of the University of Toronto's Department of Psychology. "Alzheimer's patients may have trouble recognizing a loved one's face not just because they can't remember it but also because they aren't able to correctly perceive its distinct combination of features to begin with."

The research team tested patients with (MCI) – a disorder commonly thought to be a to Alzheimer's disease – on their ability to determine whether two rotated side-by-side pictures were different or identical.

In one set of trials, many pairs of photos of blob-like objects were shown. These were classified as high- trials as the photos varied only slightly when they weren't a perfect match, either by shapes or fill pattern. As expected, MCI patients struggled greatly to identify identical pairings.

In low-interference trials, the blob-like objects were interspersed with photos in which non-matches were more extreme and varied widely. For example, a picture of a butterfly was shown next to a photo of a microwave. Interspersing the very similar blob-like objects with photos of dissimilar objects greatly reduced the amount of interference.

"Minimizing the degree of perceptual interference improved patients' object perception by reducing the number of visually similar features," said lead author of the study Rachel Newsome, a PhD candidate in U of T's Department of Psychology.

The findings suggest that, under certain circumstances, reducing "visual clutter" could help MCI patients with everyday tasks. For example, buttons on a telephone tend to be the same size and color. Only the numbers are different – a very slight visual difference for someone who struggles with object perception. One solution could be a phone with varying sized buttons and different colors.

The researchers, which also included Georgia Tech psychology professor Audrey Duarte, administered the same tests to people at risk for MCI who had previously shown no signs of cognitive impairment.

"They performed the same as those with MCI, suggesting that the perception test could be used as an early indicator of cognitive impairment," said Barense. "It provides further support for the idea that any damage to a small area of the medial temporal lobe – especially the perirhinal cortex – affects perception as much as it does memory."

Explore further: Eliminating visual clutter helps people with mild cognitive impairment

More information: The study is reported in the paper "Reducing perceptual interference improves visual discrimination in mild cognitive impairment: Implications for a model of perirhinal cortex function" in the October special edition of Hippocampus titled Perirhinal Cortex: At the Crossroads of Memory and Perception.

Related Stories

Eliminating visual clutter helps people with mild cognitive impairment

October 1, 2012
(Medical Xpress)—A new study from Georgia Tech and the University of Toronto suggests that memory impairments for people diagnosed with early stage Alzheimer's disease may be due, in part, to problems in determining the ...

Training can improve memory and increase brain activity in mild cognitive impairment

March 1, 2012
If someone has trouble remembering where the car keys or the cheese grater are, new research shows that a memory training strategy can help. Memory training can even re-engage the hippocampus, part of the brain critical for ...

Test could detect Alzheimer's disease earlier than previously possible

May 16, 2011
(Medical Xpress) -- A new study has revealed the possibility of using a simple test for the early detection of Alzheimer’s disease, enabling the condition to be identified before significant and irreversible decline ...

Widespread brain atrophy detected in Parkinson's disease with newly developed structural pattern

December 12, 2011
Atrophy in the hippocampus, the region of the brain known for memory formation and storage, is evident in Parkinson's disease (PD) patients with cognitive impairment, including early decline known as mild cognitive impairment ...

Retired NFL players at higher risk for mild cognitive impairment

July 18, 2011
Retired NFL football players are at higher risk for mild cognitive impairment, which can be a precursor to Alzheimer's disease, a Loyola University Health System study has found.

Recommended for you

A new way of thinking about tau kinetics, an essential component of Alzheimer's disease

March 21, 2018
Alzheimer's disease is most often characterized by two different pathologies in the brain: plaque deposits of a protein called beta-amyloid and tangles of another protein called tau. A paper appearing March 21 in the journal ...

Could drugs used after an organ transplant protect against Alzheimer's?

March 21, 2018
A UT Southwestern study in mice provides new clues about how a class of anti-rejection drugs used after organ transplants may also slow the progression of early-stage Alzheimer's disease.

Cell therapy could improve brain function for Alzheimer's disease

March 15, 2018
Like a great orchestra, your brain relies on the perfect coordination of many elements to function properly. And if one of those elements is out of sync, it affects the entire ensemble. In Alzheimer's disease, for instance, ...

Physically fit women nearly 90 percent less likely to develop dementia

March 14, 2018
Women with high physical fitness at middle age were nearly 90 percent less likely to develop dementia decades later, compared to women who were moderately fit, according to a study published the March 14, 2018, online issue ...

Poor sleep may heighten Alzheimer's risk

March 12, 2018
(HealthDay)—Older adults who are sleepy during the day might have harmful plaque building in their brain that is a sign of impending Alzheimer's disease, researchers report.

Dementia patients with distorted memories may actually retain key information – researchers say

March 7, 2018
Some memories containing inaccurate information can be beneficial to dementia sufferers because it enables them to retain key information researchers say.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.