Reducing visual clutter may help Alzheimer’s patients

It’s a finding that could help Alzheimer’s patients better cope with their condition.

Psychologists at the University of Toronto and the Georgia Institute of Technology (Georgia Tech) have shown that the 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 Hippocampus suggests that memory impairments 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.

The Marshmallow Study Revisited

For the past four decades, the “marshmallow test” has served as a classic experimental measure of children’s self-control: will a preschooler eat one of the fluffy white confections now or hold out for two later?

Now a new study demonstrates that being able to delay gratification is influenced as much by the environment as by innate ability. Children who experienced reliable interactions immediately before the marshmallow task waited on average four times longer—12 versus three minutes—than youngsters in similar but unreliable situations [Video]

"Our results definitely temper the popular perception that marshmallow-like tasks are very powerful diagnostics for self-control capacity," says Celeste Kidd, a doctoral candidate in brain and cognitive sciences at the University of Rochester and lead author on the study to be published online October 11 in the journal Cognition.

How Do Blind People Picture Reality?

Paul Gabias has never seen a table. He was born prematurely and went blind shortly thereafter, most likely because of overexposure to oxygen in his incubator. And yet, Gabias, 60, has no trouble perceiving the table next to him. “My image of the table is exactly the same as a table,” he said. “It has height, depth, width, texture; I can picture the whole thing all at once. It just has no color.”

If you have trouble constructing a mental picture of a table that has no color — not even black or white — that’s probably because you’re blinded by your ability to see. Sighted people visualize the surrounding world by detecting borders between areas rich in different wavelengths of light, which we see as different colors. Gabias, like many blind people, builds pictures using his sense of touch, and by listening to the echoes of clicks of his tongue and taps of his cane as these sounds bounce off objects in his surroundings, a technique called echolocation.

Read more

Whether you like someone can affect how your brain processes their actions, according to new research from the Brain and Creativity Institute at the USC Dornsife College of Letters, Arts and Sciences.

Most of the time, watching someone else move causes a “mirroring” effect — that is, the parts of our brains responsible for motor skills are activated by watching someone else in action.

But a study by USC researchers appearing in PLOS ONE shows that whether you like the person you’re watching can actually have an effect on brain activity related to motor actions and lead to “differential processing” — for example, thinking the person you dislike is moving more slowly than they actually are.

“We address the basic question of whether social factors influence our perception of simple actions,” said Lisa Aziz-Zadeh, assistant professor with the Brain and Creativity Institute and the Division of Occupational Science. “These results indicate that an abstract sense of group membership, and not only differences in physical appearance, can affect basic sensory-motor processing.”

What is reality?

WHEN you woke up this morning, you found the world largely as you left it. You were still you; the room in which you awoke was the same one you went to sleep in. The outside world had not been rearranged. History was unchanged and the future remained unknowable. In other words, you woke up to reality. But what is reality? The more we probe it, the harder it becomes to comprehend. In the eight articles on this page we take a tour of our fundamental understanding of the world around us, starting with an attempt to define reality and ending with the idea that whatever reality is, it isn’t what it seems. Hold on to your hats.

When Your Eyes Tell Your Hands What to Think: You’re Far Less in Control of Your Brain Than You Think

You’ve probably never given much thought to the fact that picking up your cup of morning coffee presents your brain with a set of complex decisions. You need to decide how to aim your hand, grasp the handle and raise the cup to your mouth, all without spilling the contents on your lap.

A new Northwestern University study shows that, not only does your brain handle such complex decisions for you, it also hides information from you about how those decisions are made.

"Our study gives a salient example," said Yangqing ‘Lucie’ Xu, lead author of the study and a doctoral candidate in psychology at Northwestern. "When you pick up an object, your brain automatically decides how to control your muscles based on what your eyes provide about the object’s shape. When you pick up a mug by the handle with your right hand, you need to add a clockwise twist to your grip to compensate for the extra weight that you see on the left side of the mug.

"We showed that the use of this visual information is so powerful and automatic that we cannot turn it off. When people see an object weighted in one direction, they actually can’t help but ‘feel’ the weight in that direction, even when they know that we’re tricking them," Xu said.

Detection of Appearing and Disappearing Objects in Complex Acoustic Scenes

The ability to detect sudden changes in the environment is critical for survival. Hearing is hypothesized to play a major role in this process by serving as an “early warning device,” rapidly directing attention to new events. Here, we investigate listeners’ sensitivity to changes in complex acoustic scenes—what makes certain events “pop-out” and grab attention while others remain unnoticed? We use artificial “scenes” populated by multiple pure-tone components, each with a unique frequency and amplitude modulation rate. Importantly, these scenes lack semantic attributes, which may have confounded previous studies, thus allowing us to probe low-level processes involved in auditory change perception. Our results reveal a striking difference between “appear” and “disappear” events. Listeners are remarkably tuned to object appearance: change detection and identification performance are at ceiling; response times are short, with little effect of scene-size, suggesting a pop-out process. In contrast, listeners have difficulty detecting disappearing objects, even in small scenes: performance rapidly deteriorates with growing scene-size; response times are slow, and even when change is detected, the changed component is rarely successfully identified. We also measured change detection performance when a noise or silent gap was inserted at the time of change or when the scene was interrupted by a distractor that occurred at the time of change but did not mask any scene elements. Gaps adversely affected the processing of item appearance but not disappearance. However, distractors reduced both appearance and disappearance detection. Together, our results suggest a role for neural adaptation and sensitivity to transients in the process of auditory change detection, similar to what has been demonstrated for visual change detection. Importantly, listeners consistently performed better for item addition (relative to deletion) across all scene interruptions used, suggesting a robust perceptual representation of item appearance.