Posts tagged attention
Articles and news from the latest research reports.
Though the seconds may tick by on the clock at a regular pace, our experience of the ‘fourth dimension’ is anything but uniform. When we’re waiting in line or sitting in a boring meeting, time seems to slow down to a trickle. And when we get caught up in something completely engrossing – a gripping thriller, for example – we may lose sense of time altogether.
But what about the idea that time flies when we’re having fun? New research from psychological science suggests that the familiar adage may really be true, with a caveat: time flies when we’re have goal-motivated fun.
A mysterious region deep in the human brain could be where we sort through the onslaught of stimuli from the outside world and focus on the information most important to our behavior and survival, Princeton University researchers have found.
The researchers report in the journal Science that an area of our brain called the pulvinar regulates communication between clusters of brain cells as our brain focuses on the people and objects that need our attention. Like a switchboard operator, the pulvinar makes sure that separate areas of the visual cortex — which processes visual information — are communicating about the same external information, explained lead author Yuri Saalmann, an associate research scholar in the Princeton Neuroscience Institute (PNI). Without guidance from the pulvinar, an important observation such as an oncoming bus as one is crossing the street could get lost in a jumble of other stimuli.
Saalmann said these findings on how the brain transmits information could lead to new ways of understanding and treating attention-related disorders, such as attention deficit hyperactivity disorder (ADHD) and schizophrenia.
'Inattention blindness' due to brain load
“Engaging attention on a high load task has a strong effect on the brain’s response to the rest of the world,” says Professor Nilli Lavie of the UCL Institute of Cognitive Neuroscience.
"It reduces both the level and precision, or ‘tuning’, of neural response to anything else around us that is not part of the task. "These effects of load on neural response explain inattentional blindness. Although our environment hasn’t changed, the change in our brain response under load leads to inability to perceive otherwise perfectly visible stimuli outside our focus of attention,” she explains.
Eyes and Attention of Men and Women Meander in Distinctly Different Ways
Dr. Itti’s lab studied 34 participants as they watched videos of people being interviewed. Behind the interview subjects, within the video frame, pedestrians, bicycles and cars passed by — distractions included to pull attention away from the filmed conversation.
While participants watched and listened to the interview, another camera was pointed at participants’ eyes, recording the movement of their pupils as they glanced across the screen.
Researchers discovered the following:
• Men, when focused on the person being interviewed, parked their eyes on the speaker’s mouth. They tended to be most distracted by distinctive movement behind the interview subjects.
• By contrast, women shift their focus between the interview subject’s eyes and body. When they were distracted, it was typically by other people entering the video frame.
Study offers new clue on how brain processes visual information, provides insight into neural mechanisms of attention
July 23, 2012
Ever wonder how the human brain, which is constantly bombarded with millions of pieces of visual information, can filter out what’s unimportant and focus on what’s most useful?
The process is known as selective attention and scientists have long debated how it works. But now, researchers at Wake Forest Baptist Medical Center have discovered an important clue. Evidence from an animal study, published in the July 22 online edition of the journal Nature Neuroscience, shows that the prefrontal cortex is involved in a previously unknown way.
Two types of attention are utilized in the selective attention process – bottom up and top down. Bottom-up attention is automatically guided to images that stand out from a background by virtue of color, shape or motion, such as a billboard on a highway. Top-down attention occurs when one’s focus is consciously shifted to look for a known target in a visual scene, as when searching for a relative in a crowd.
Traditionally, scientists have believed that separate areas of the brain controlled these two processes, with bottom-up attention occurring in the posterior parietal cortex and top-down attention occurring in the prefrontal cortex.
"Our findings provide insights on the neural mechanisms behind the guidance of attention," said Christos Constantinidis, Ph.D., associate professor of neurobiology and anatomy at Wake Forest Baptist and senior author of the study. "This has implications for conditions such as attention deficit hyperactivity disorder (ADHD), which affects millions of people worldwide. People with ADHD have difficulty filtering information and focusing attention. Our findings suggest that both the ability to focus attention intentionally and shifting attention to eye-catching but sometimes unimportant stimuli depend on the prefrontal cortex."
In the Wake Forest Baptist study, two monkeys were trained to detect images on a computer screen while activity in both areas of the brain was recorded. The visual display was designed to let one image “pop out” due to its color difference from the background, such as a red circle surrounded by green. To trigger bottom-up attention, neither the identity nor the location of the pop-out image could be predicted before it appeared. The monkeys indicated that they detected the pop-out image by pushing a lever.
The neural activity associated with identifying the pop-out images occurred in the prefrontal cortex at the same time as in the posterior parietal cortex. This unexpected finding indicates early involvement of the prefrontal cortex in bottom-up attention, in addition to its known role in top-down attention, and provides new insights into the neural mechanisms of attention.
"We hope that our findings will guide future work targeting attention deficits," Constantinidis said.
Provided by Wake Forest University Baptist Medical Center
Source: medicalxpress.com
Neuroscientists identify how the brain works to select what we (want to) see
If you are looking for a particular object — say a yellow pencil — on a cluttered desk, how does your brain work to visually locate it?
For the first time, a team led by Carnegie Mellon University neuroscientists has identified how different neural regions communicate to determine what to visually pay attention to and what to ignore. This finding is a major discovery for visual cognition and will guide future research into visual and attention deficit disorders.
The study, published in the Journal of Neuroscience, used various brain imaging techniques to show exactly how the visual cortex and parietal cortex send direct information to each other through white matter connections in order to specifically pick out the information that you want to see.
"We have demonstrated that attention is a process in which there is one-to-one mapping between the first place visual information comes from the eyes into the brain and beyond to other parts of the brain," said Adam S. Greenberg, postdoctoral fellow in the Dietrich College of Humanities and Social Sciences’ Department of Psychology and lead author of the study.
(Click on the title to read the full article)