Older news items (pre-2010) brought over from the old website
Attention is more about reducing the noticeability of the unattended
No visual scene can be processed in one fell swoop — we piece it together from the bits we pay attention to (which explains why we sometimes miss objects completely, and can’t understood how we could have missed them when we finally notice them). We know that paying attention to something increases the firing rate of neurons tuned for that type of stimulus, and until a recent study we thought that was the main process underlying our improved perception when we focus on something. However a macaque study has found that the main cause — perhaps four times as important — is a reduction in the background noise, allowing the information coming in to be much more noticeable.
[1093] Mitchell, J. F., Sundberg K. A., & Reynolds J. H.
(2009). Spatial Attention Decorrelates Intrinsic Activity Fluctuations in Macaque Area V4.
Neuron. 63(6), 879 - 888.
http://esciencenews.com/articles/2009/09/23/rising.above.din
Brainwaves regulate our searching
A long-standing question concerns how we search complex visual scenes. For example, when you enter a crowded room, how do you go about searching for your friends? Now a monkey study reveals that visual attention jumps sequentially from point to point, shifting focus around 25 times in a second. Intriguingly, and unexpectedly, it seems this timing is determined by brainwaves. The finding connects speed of thinking with the oscillation frequency of brainwaves, giving a new significance to brainwaves (whose function is rather mysterious, but of increasing interest to researchers), and also suggesting an innovative approach to improving attention.
[1118] Buschman, T. J., & Miller E. K.
(2009). Serial, Covert Shifts of Attention during Visual Search Are Reflected by the Frontal Eye Fields and Correlated with Population Oscillations.
Neuron. 63(3), 386 - 396.
http://www.eurekalert.org/pub_releases/2009-08/miot-tme080609.php
Ability to ignore distraction most important for attention
Confirming an earlier study, a series of four experiments involving 84 students has found that students with high working memory capacity were noticeably better able to ignore distractions and stay focused on their tasks. The findings provide more evidence that the poor attentional capacity of individuals with low working memory capacity result from a reduced ability to ignore attentional capture (stimuli that involuntarily “capture” your attention, like a loud noise or a suddenly appearing object), rather than an inability to focus.
[828] Fukuda, K., & Vogel E. K.
(2009). Human Variation in Overriding Attentional Capture.
J. Neurosci.. 29(27), 8726 - 8733.
http://www.eurekalert.org/pub_releases/2009-08/uoo-bbo080609.php
Stress disrupts task-switching, but the brain can bounce back
A new neuroimaging study involving 20 male M.D. candidates in the middle of preparing for their board exams has found that they had a harder time shifting their attention from one task to another after a month of stress than other healthy young men who were not under stress. The finding replicates what has been found in rat studies, and similarly correlates with impaired function in an area of the prefrontal cortex that is involved in attention. However, the brains recovered their function within a month of the end of the stressful period.
[829] Liston, C., McEwen B. S., & Casey B. J.
(2009). Psychosocial stress reversibly disrupts prefrontal processing and attentional control.
Proceedings of the National Academy of Sciences. 106(3), 912 - 917.
Full text available at http://www.pnas.org/content/106/3/912.abstract
http://www.eurekalert.org/pub_releases/2009-01/ru-sdh012709.php
Attention, it’s all about connecting
An imaging study in which volunteers spent an hour identifying letters that flashed on a screen has shed light on what happens when our attention wanders. Reduced communication in the ventral fronto-parietal network, critical for attention, was found to predict slower response times 5-8 seconds before the letters were presented.
Daniel Weissman presented the results at the 38th annual meeting of the Society for Neuroscience, held Nov. 15 to 19 in Washington, DC.
http://www.newscientist.com/article/mg20026865.600-bored-your-brain-is-disconnecting.html
A rat study suggests that acetylcholine, a neurotransmitter known to be important for attention, is critical for "feature binding"— the process by which our brain combines all of the specific features of an object and gives us a complete and unified picture of it. The findings may lead to improved therapies and treatments for a variety of attention and memory disorders.
[1265] Botly, L. C. P. [1], & De Rosa E.
(2008). A Cross-Species Investigation of Acetylcholine, Attention, and Feature Binding.
Psychological Science. 19, 1185 - 1193.
http://www.eurekalert.org/pub_releases/2008-11/afps-bba111808.php
Attention grabbers snatch lion's share of visual memory
It’s long been thought that when we look at a visually "busy" scene, we are only able to store a very limited number of objects in our visual short-term or working memory. For some time, this figure was believed to be four or five objects, but a recent report suggested it could be as low as two. However, a new study reveals that although it might not be large, it’s more flexible than we thought. Rather than being restricted to a limited number of objects, it can be shared out across the whole image, with more memory allocated for objects of interest and less for background detail. What’s of interest might be something we’ve previously decided on (i.e., we’re searching for), or something that grabs our attention. Eye movements also reveal how brief our visual memory is, and that what our eyes are looking at isn’t necessarily what we’re ‘seeing’ — when people were asked to look at objects in a particular sequence, but the final object disappeared before their eyes moved on to it, it was found that the observers could more accurately recall the location of the object that they were about to look at than the one that they had just been looking at.
[1398] Bays, P. M., & Husain M.
(2008). Dynamic shifts of limited working memory resources in human vision.
Science (New York, N.Y.). 321(5890), 851 - 854.
http://www.physorg.com/news137337380.html
How Ritalin works to focus attention
Ritalin has been widely used for decades to treat attention deficit hyperactivity disorder (ADHD), but until now the mechanism of how it works hasn’t been well understood. Now a rat study has found that Ritalin, in low doses, fine-tunes the functioning of neurons in the prefrontal cortex, and has little effect elsewhere in the brain. It appears that Ritalin dramatically increases the sensitivity of neurons in the prefrontal cortex to signals coming from the hippocampus. However, in higher doses, PFC neurons stopped responding to incoming information, impairing cognition. Low doses also reinforced coordinated activity of neurons, and weakened activity that wasn't well coordinated. All of this suggests that Ritalin strengthens dominant and important signals within the PFC, while lessening weaker signals that may act as distractors.
[663] Devilbiss, D. M., & Berridge C. W.
(2008). Cognition-Enhancing Doses of Methylphenidate Preferentially Increase Prefrontal Cortex Neuronal Responsiveness.
Biological Psychiatry. 64(7), 626 - 635.
http://www.eurekalert.org/pub_releases/2008-06/uow-suh062408.php
Disentangling attention
A new study provides more evidence that the ability to deliberately focus your attention is physically separate in the brain from the part that helps you filter out distraction. The study trained monkeys to take attention tests on a video screen in return for a treat of apple juice. When the monkeys voluntarily concentrated (‘top-down’ attention), the prefrontal cortex was active, but when something distracting grabbed their attention (‘bottom-up’ attention), the parietal cortex became active. The electrical activity in these two areas vibrated in synchrony as they signaled each other, but top-down attention involved synchrony that was stronger in the lower-frequencies and bottom-up attention involved higher frequencies. These findings may help us develop treatments for attention disorders.
[1071] Buschman, T. J., & Miller E. K.
(2007). Top-Down Versus Bottom-Up Control of Attention in the Prefrontal and Posterior Parietal Cortices.
Science. 315(5820), 1860 - 1862.
http://dsc.discovery.com/news/2007/03/29/attention_hea.html?category=health
Asymmetrical brains let fish multitask
A fish study provides support for a theory that lateralized brains allow animals to better handle multiple activities, explaining why vertebrate brains evolved to function asymmetrically. The minnow study found that nonlateralized minnows were as good as those bred to be lateralized (enabling it to favor one or other eye) at catching shrimp. However, when the minnows also had to look out for a sunfish (a minnow predator), the nonlateralized minnows took nearly twice as long to catch 10 shrimp as the lateralized fish.
[737] Dadda, M., & Bisazza A.
(2006). Does brain asymmetry allow efficient performance of simultaneous tasks?.
Animal Behaviour. 72(3), 523 - 529.
http://sciencenow.sciencemag.org/cgi/content/full/2006/623/2?etoc
Why are uniforms uniform? Because color helps us track objects
Laboratory tests have revealed that humans can pay attention to only 3 objects at a time. Yet there are instances in the real world — for example, in watching a soccer match — when we certainly think we are paying attention to more than 3 objects. Are we wrong? No. Anew study shows how we do it — it’s all in the color coding. People can focus on more than three items at a time if those items share a common color. But, logically enough, no more than 3 color sets.
[927] Halberda, J., Sires S. F., & Feigenson L.
(2006). Multiple spatially overlapping sets can be enumerated in parallel.
Psychological Science: A Journal of the American Psychological Society / APS. 17(7), 572 - 576.
http://www.eurekalert.org/pub_releases/2006-06/jhu-wau062106.php
An advantage of age
A study comparing the ability of young and older adults to indicate which direction a set of bars moved across a computer screen has found that although younger participants were faster when the bars were small or low in contrast, when the bars were large and high in contrast, the older people were faster. The results suggest that the ability of one neuron to inhibit another is reduced as we age (inhibition helps us find objects within clutter, but makes it hard to see the clutter itself). The loss of inhibition as we age has previously been seen in connection with cognition and speech studies, and is reflected in our greater inability to tune out distraction as we age. Now we see the same process in vision.
[1356] Betts, L. R., Taylor C. P., Sekuler A. B., & Bennett P. J.
(2005). Aging Reduces Center-Surround Antagonism in Visual Motion Processing.
Neuron. 45(3), 361 - 366.
http://psychology.plebius.org/article.htm?article=739
http://www.eurekalert.org/pub_releases/2005-02/mu-opg020305.php
We weren't made to multitask
A new imaging study supports the view that we can’t perform two tasks at once, rather, the tasks must wait their turn — queuing up for their turn at processing.
[1070] Jiang, Y., Saxe R., & Kanwisher N.
(2004). Functional magnetic resonance imaging provides new constraints on theories of the psychological refractory period.
Psychological Science: A Journal of the American Psychological Society / APS. 15(6), 390 - 396.
http://www.eurekalert.org/pub_releases/2004-06/aps-wwm060704.php
More light shed on memory encoding
Anything we perceive contains a huge amount of sensory information. How do we decide what bits to process? New research has identified brain cells that streamline and simplify sensory information, markedly reducing the brain's workload. The study found that when monkeys were taught to remember clip art pictures, their brains reduced the level of detail by sorting the pictures into categories for recall, such as images that contained "people," "buildings," "flowers," and "animals." The categorizing cells were found in the hippocampus. As humans do, different monkeys categorized items in different ways, selecting different aspects of the same stimulus image, most likely reflecting different histories, strategies, and expectations residing within individual hippocampal networks.
[662] Hampson, R. E., Pons T. P., Stanford T. R., & Deadwyler S. A.
(2004). Categorization in the monkey hippocampus: A possible mechanism for encoding information into memory.
Proceedings of the National Academy of Sciences of the United States of America. 101(9), 3184 - 3189.
http://www.eurekalert.org/pub_releases/2004-02/wfub-nfo022604.php
Neural circuits that control eye movements play crucial role in visual attention
Everyone agrees that to improve your memory it is important to “pay attention”. Unfortunately, noone really knows how to improve our ability to “pay attention”. An important step in telling us how visual attention works was recently made in a study that looked at the brain circuits that control eye movements. It appears that those brain circuits that program eye movements also govern whether the myriad signals that pour in from the locations where the eyes could move should be amplified or suppressed. It appears that the very act of preparing to move the eye to a particular location can cause an amplification (or suppression) of signals from that area. This is possible because humans and primates can attend to something without moving their eyes to that object.
[741] Moore, T., & Armstrong K. M.
(2003). Selective gating of visual signals by microstimulation of frontal cortex.
Nature. 421(6921), 370 - 373.
http://www.eurekalert.org/pub_releases/2003-01/pu-ssh012303.php
Different aspects of attention located in different parts of the brain
We all know attention is important, but we’ve never been sure exactly what it is. Recent research suggests there’s good reason for this – attention appears to be multi-faceted, far less simple than originally conceived. Patients with specific lesions in the frontal lobes and other parts of the brain have provided evidence that different types of attentional problems are associated with injuries in different parts of the brain, suggesting that attention is not, as has been thought, a global process. The researchers have found evidence for at least three distinct processes, each located in different parts of the frontal lobes. These are: (1) a system that helps us maintain a general state of readiness to respond, in the superior medial frontal regions; (2) a system that sets our threshold for responding to an external stimulus, in the left dorsolateral region; and (3) a system that helps us selectively attend to appropriate stimuli, in the right dorsolateral region.
[260] Stuss, D. T., Binns M. A., Murphy K. J., & Alexander M. P.
(2002). Dissociations within the anterior attentional system: effects of task complexity and irrelevant information on reaction time speed and accuracy.
Neuropsychology. 16(4), 500 - 513.
http://www.eurekalert.org/pub_releases/2002-10/apa-pda100702.php