Anterior Cingulate
Older news items (pre-2010) brought over from the old website
August 2009
Overweight and obese elderly have smaller brains
Analysis of brain scans from 94 people in their 70s who were still "cognitively normal" five years after the scan has revealed that people with higher body mass indexes had smaller brains on average, with the frontal and temporal lobes particularly affected (specifically, in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus, in obese people, and in the basal ganglia and corona radiate of the overweight). The brains of the 51 overweight people were, on average, 6% smaller than those of the normal-weight participants, and those of the 14 obese people were 8% smaller. To put it in more comprehensible, and dramatic terms: "The brains of overweight people looked eight years older than the brains of those who were lean, and 16 years older in obese people." However, overall brain volume did not differ between overweight and obese persons. As yet unpublished research by the same researchers indicates that exercise protects these same brain regions: "The most strenuous kind of exercise can save about the same amount of brain tissue that is lost in the obese."
Raji, C.A. et al. 2009. Brain structure and obesity. Human Brain Mapping, Published Online: Aug 6 2009
http://www.newscientist.com/article/mg20327222.400-expanding-waistlines-may-cause-shrinking-brains
May 2009
Brain's problem-solving function at work when we daydream
An imaging study has revealed that daydreaming is associated with an increase in activity in numerous brain regions, especially those regions associated with complex problem-solving. Until now it was thought that the brain's "default network" (which includes the medial prefrontal cortex, the posterior cingulate cortex and the temporoparietal junction) was the only part of the brain active when our minds wander. The new study has found that the "executive network" (including the lateral prefrontal cortex and the dorsal anterior cingulate cortex) is also active. Before this, it was thought that these networks weren’t active at the same time. It may be that mind wandering evokes a unique mental state that allows otherwise opposing networks to work in cooperation. It was also found that greater activation was associated with less awareness on the part of the subject that there mind was wandering.
Christoff, K. et al. 2009. Experience sampling during fMRI reveals default network and executive system contributions to mind wandering. Proceedings of the National Academy of Sciences, 106 (21), 8719-8724.
http://www.eurekalert.org/pub_releases/2009-05/uobc-bpf051109.php
September 2008
From 12 years onward you learn differently
Behavioral studies have found eight-year-olds learn primarily from positive feedback, with negative feedback having little effect. Twelve-year-olds, however, are better able to process negative feedback, and use it to learn from their mistakes. Now brain imaging reveals that the brain regions responsible for cognitive control (specifically, the dorsolateral prefrontal cortex and superior parietal cortex, and the pre-supplementary motor area/anterior cingulate cortex) react strongly to positive feedback and scarcely respond at all to negative feedback in children of eight and nine, but the opposite is the case in children of 11 to 13 years, and also in adults.
van Duijvenvoorde, A.C.K. et al. 2008. Evaluating the Negative or Valuing the Positive? Neural Mechanisms Supporting Feedback-Based Learning across Development. The Journal of Neuroscience, 28, 9495-9503.
http://www.eurekalert.org/pub_releases/2008-09/lu-f1y092508.php
http://www.physorg.com/news141554842.html
December 2006
Neurons targeted by dementing illness may have evolved for complex social cognition
Special elongated nerve cells called spindle neurons, also known as Von Economo neurons (VENs), are found in two parts of the cerebral cortex known to be associated with social behavior, consciousness, and emotion (the anterior cingulate and fronto-insular cortex). They have only been found in humans and great apes, and, recently, whales. Because of this link with social behaviour, and because these brain regions are targeted by frontotemporal dementia, a recent study investigated whether VENs play a role in this type of dementia that causes people to lose inhibition in social situations. Autopsies revealed that among FTD sufferers, the anterior cingulate cortex had a dramatic reduction in the number of VENs compared to controls. In contrast, Alzheimer's patients had only a small and statistically insignificant reduction.
Seeley, W.W. et al. 2006. Early Frontotemporal Dementia Targets Neurons Unique to Apes and Humans. Annals of Neurology, published online ahead of print Decumber 22
http://sciencenow.sciencemag.org/cgi/content/full/2006/1222/1?etoc
http://www.sciencedaily.com/releases/2006/12/061222090935.htm
http://www.eurekalert.org/pub_releases/2006-12/uoc--wih122106.htm
May 2006
Master planners in brain may coordinate other areas' roles in cognitive tasks
Scans of 183 subjects have identified 3 brain areas most consistently active during a variety of cognitive tasks — the dorsal anterior cingulate and the left and right frontal operculum. It’s suggested that these regions coordinate the activities of specialized regions. In a rather lovely analogy, researchers suggested that if the brain in action can be compared to a symphony, with specialized sections required to pitch in at the right time to produce the desired melody, then the regions highlighted by the new study may be likened to conductors. Until now, the function of the opercula has been a mystery; the findings also suggest a rethinking of the role of the cingulate.
Dosenbach, N.U.F. et al. 2006. A core system for the implementation of task sets. Neuron, 50(5), 799-812.
http://www.sciencedaily.com/releases/2006/05/060531165250.htm
http://www.eurekalert.org/pub_releases/2006-05/wuso-mpi053006.php
April 2006
AIDS-related cognitive impairment exists in two separate forms
Cognitive impairment in people with AIDS is caused when the HIV virus attacks the brain and can be a complicated syndrome resulting in deficits in mood, behavior, motor coordination and thought processes. While the incidence of severe dementia in people with AIDS has decreased significantly, a greater number of people are living with a milder form of cognitive impairment. A study of 54 participants with AIDS and 23 HIV-negative control subjects has found that cognitive impairment in people with AIDS exists in two forms -- one mild, another severe -- each affecting different areas of the brain. Of the 54 participants with AIDS, 17 demonstrated some level of mental impairment. The mild impairment group only showed problems in the area of psychomotor speed, and demonstrated atrophy in the frontal and anterior cingulate cortices. Those in the severe impairment group showed impairments in memory and visual-spatial processing as well as psychomotor speed, and had more significant atrophy that was located in the caudate and putamen.
The findings were presented April 5 at the American Academy of Neurology 58th Annual Meeting in San Diego.
http://www.eurekalert.org/pub_releases/2006-04/uopm-aci040306.php
February 2006
A single memory is processed in three separate parts of the brain
A rat study has demonstrated that a single experience is indeed processed differently in separate parts of the brain. They found that when the rats were confined in a dark compartment of a familiar box and given a mild shock, the hippocampus was involved in processing memory for context, while the anterior cingulate cortex was responsible for retaining memories involving unpleasant stimuli, and the amygdala consolidated memories more broadly and influenced the storage of both contextual and unpleasant information.
Malin, E.L. & McGaugh, J.L. 2006. Differential involvement of the hippocampus, anterior cingulate cortex, and basolateral amygdala in memory for context and footshock. Proceedings of the National Academy of Sciences, 103 (6), 1959-1963.
http://www.eurekalert.org/pub_releases/2006-02/uoc--urp020106.php
November 2005
Coffee jump-starts short-term memory
An imaging study of 15 males aged 26-47 has found that after consuming caffeine, all showed improved reaction times, and increased activity in part of the frontal lobe and in the anterior cingulate cortex. The findings are consistent with earlier research showing caffeine improves attention.
Koppelstätter, F. et al. 2005. Presented at the annual meeting of the Radiological Society of North America in Chicago.
http://www.eurekalert.org/pub_releases/2005-11/rson-cjs112005.php
August 2005
Insight into the processes of 'positive' and 'negative' learners
An intriguing study of the electrical signals emanating from the brain has revealed two types of learners. A brainwave event called an "event-related potential" (ERP) is important in learning; a particular type of ERP called "error-related negativity" (ERN), is associated with activity in the anterior cingulate cortex. This region is activated during demanding cognitive tasks, and ERNs are typically more negative after participants make incorrect responses compared to correct choices. Unexpectedly, studies of this ERN found a difference between "positive" learners, who perform better at choosing the correct response than avoiding the wrong one, and "negative" learners, who learn better to avoid incorrect responses. The negative learners showed larger ERNs, suggesting that "these individuals are more affected by, and therefore learn more from, their errors.” Positive learners had larger ERNs when faced with high-conflict win/win decisions among two good options than during lose/lose decisions among two bad options, whereas negative learners showed the opposite pattern.
Frank, M.J., Woroch, B.S. & Curran, T. 2005. Error-Related Negativity Predicts Reinforcement Learning and Conflict Biases. Neuron, 47, 495-501.
http://www.eurekalert.org/pub_releases/2005-08/cp-iit081205.php
October 2004
How false memories are formed
An imaging study has attempted to pinpoint how people form a memory for something that didn't actually happen. The study measured brain activity in people who looked at pictures of objects or imagined other objects they were asked to visualize. Three brain areas (precuneus, right inferior parietal cortex and anterior cingulate) showed greater responses in the study phase to words that would later be falsely remembered as having been presented with photos, compared to words that were not later misremembered as having been presented with photos. Brain activity produced in response to viewed pictures also predicted which pictures would be subsequently remembered. Two brain regions in particular -- the left hippocampus and the left prefrontal cortex -- were activated more strongly for pictures that were later remembered than for pictures that were forgotten. The new findings directly showed that different brain areas are critical for accurate memories for visual objects than for false remembering -- for forming a memory for an imagined object that is later remembered as a perceived object.
Gonsalves, B., Reber, P.J., Gitelman, D.R., Parrish, T.B., Mesulam, M-M. & Paller, K.A. 2004. Neural Evidence That Vivid Imagining Can Lead to False Remembering. Psychological Science, 15 (10), 655-660.
http://www.eurekalert.org/pub_releases/2004-10/nu-nrp101404.php
http://www.northwestern.edu/newscenter/stories/2004/10/kenneth.html
Development of working memory with age
An imaging study of 20 healthy 8- to 30-year-olds has shed new light on the development of working memory. The study found that pre-adolescent children relied most heavily on the prefrontal and parietal regions of the brain during the working memory task; adolescents used those regions plus the anterior cingulate; and in adults, a third area of the brain, the medial temporal lobe, was brought in to support the functions of the other areas. Adults performed best. The results support the view that a person's ability to have voluntary control over behavior improves with age because with development, additional brain processes are used.
http://www.eurekalert.org/pub_releases/2004-10/uopm-dow102104.php
Can't place a name to the face you just saw?
We’re all familiar with that “I know I know it, I just can’t bring it to mind” feeling. Among researchers, this is known as FOK — “feeling of knowing”. It is a common phenomenon, that occurs more frequently as we age. A new imaging study involving a dozen people aged 22 to 32, has investigated the FOK state using pictures of 300 famous and not-so-famous faces. They found that the medial prefrontal cortex showed activity during the FOK state, but not when the subjects either knew or did not know a face. Possibly this reflects a state in which subjects were evaluating the correctness of retrieved information. Additionally, the anterior cingulate area became activated both in the FOK state and when subjects successfully retrieved a name but with some effort. The anterior cingulate area is associated with cognitive conflict processes which allow a person to detect errors in automatic behavior responses. The results suggest that, during a FOK state, the brain may be enlisting additional processes to aid in recalling accurate memories.
http://www.eurekalert.org/pub_releases/2004-10/uoa-cpa102604.php
April 2004
How we retrieve distant memories
We know that recent memories are stored in the hippocampus, but these memories do not remain there forever. It has been less clear how we retrieve much older memories. Now studies of mice genetically altered to be unable to recall old memories have demonstrated that a part of the cortex called the anterior cingulate is critical for this process. It is suggested that, rather than this structure being the storage site for old memories, the anterior cingulate assembles signals of an old memory from different sites in the brain. Dementia may result from a malfunction in this assembling process, leaving the memory too fragmented to make proper sense. Both ageing and certain aspects of Alzheimer's disease and other dementias are all accompanied by reduced activity in the anterior cingulate.
Frankland, P.W., Bontempi, B., Talton, L.E., Kaczmarek, L. & Silva, A.J. 2004. The Involvement of the Anterior Cingulate Cortex in Remote Contextual Fear Memory. Science, 304, 881-883.
http://news.bbc.co.uk/2/hi/health/3689335.stm
August 2002
Identity memory area localized
An imaging study investigating brain activation when people were asked to answer yes or no to statements about themselves (e.g. 'I forget important things', 'I'm a good friend', 'I have a quick temper'), found consistent activation in the anterior medial prefrontal and posterior cingulate. This is consistent with lesion studies, and suggests that these areas of the cortex are involved in self-reflective thought.
Johnson, S.C., Baxter, L.C., Wilder, L.S., Pipe, J.G., Heiserman, J.E. & Prigatano, G.P. 2002. Neural correlates of self-reflection. Brain, 125 (8), 1808-14.
http://brain.oupjournals.org/cgi/content/abstract/125/8/1808