Older news items (pre-2010) brought over from the old website

October 2009

First-time Internet users find boost in brain function after just 1 week

A study involving 24 older adults (55-78) who had minimal experience searching the internet, found that after conducting Internet searches for one hour a day for seven days (over a two-week period), they showed changes in brain activity — recruiting parts of the middle frontal gyrus and inferior frontal gyrus (areas important in working memory and decision-making). "The results suggest that searching online may be a simple form of brain exercise that might be employed to enhance cognition in older adults."

Moody, T.D., Gaddipati, H., Small, G.W. & Bookheimer, S.Y. 2009. Neural activation patterns in older adults following Internet training. Presented October 19 at the 2009 meeting of the Society for Neuroscience.

http://www.eurekalert.org/pub_releases/2009-10/uoc--fiu101509.php

June 2008

Older adults less affected by sleep deprivation than younger adults

A study involving 33 older adults (59-82) and 27 younger adults (19-38) has found that while the younger adults all showed significance deterioration on three different cognitive tasks after 36 hours of sleep deprivation, the older adults did not. The finding may be due to only the healthiest older adults being chosen, suggesting that older adults who remain the healthiest late in life may be less vulnerable to a variety of stressors, not just sleep loss.
It’s worth noting that sleep deprivation affects some people more than others. A recent study has found that those with the short variant of the PERIOD3 (PER3) gene compensate for sleep loss by "recruiting" extra brain structures to help with cognitive tasks. Those with the long variant however, showed reduced activity in brain structures normally activated by the task. These participants also showed reduced brain activity in the right posterior inferior frontal gyrus after a normal waking day, a finding consistent with previous research suggesting that people with the long gene variant perform better on executive tasks earlier, but not later, in the day (see http://www.eurekalert.org/pub_releases/2009-06/sfn-gph062409.php).

Wang, R.L. et al. 2009. Older Adults are Less Vulnerable to Sleep Deprivation than Younger Adults during Cognitive Performance. Presented on June 10 at SLEEP 2009, the 23rd Annual Meeting of the Associated Professional Sleep Societies; Abstract ID: 0420.

http://www.eurekalert.org/pub_releases/2009-06/aaos-oal060209.php

December 2007

Neural substrate of congenital amusia

Research has shown that musicians have more gray matter in certain regions of the brain involved in language and auditory processing. Now a study of tone-deaf people reveals that congenital amusia, thought to be due to a severe deficit in the processing of pitch information, is also associated with differences in gray matter distribution. Tone-deaf individuals had a thicker cortex in the right inferior frontal gyrus and right auditory cortex. This may be due to abnormal neuronal migration or atypical cell pruning during development.

Hyde, K.L. et al. 2007. Cortical Thickness in Congenital Amusia: When Less Is Better Than More. The Journal of Neuroscience, 27(47), 13028-13032.

http://www.physorg.com/news117303842.html

September 2007

Having right timing 'connections' in brain is key to overcoming dyslexia

New research has found that key areas for language and working memory involved in reading are connected differently in dyslexics than in children who are good readers and spellers. But, after the children with dyslexia went through a three-week instructional program, their patterns of functional brain connectivity normalized and were similar to those of good readers. The study looked specifically at activity in the left and right inferior frontal gyrus. The left inferior frontal gyrus may control the communication between the different areas involved in language, especially spoken language, while the right is thought to be involved in controlling the processing of letters in written words. Prior to the treatment these two areas were overconnected in the dyslexics, and the left inferior frontal gyrus also was overconnected to the middle frontal gyrus, which is involved in working memory that requires temporal coordination. It is not yet known how long the improvement in connectivity is maintained.

Richards, T.L. & Berninger, V.W. 2007. Abnormal fMRI connectivity in children with dyslexia during a phoneme task: Before but not after treatment. Journal of Neurolinguistics, Available online 17 August 2007.

http://www.eurekalert.org/pub_releases/2007-09/uow-hrt090407.php
http://www.sciencedirect.com/science/journal/09116044

May 2005

Brain networks change according to cognitive task

Using a newly released method to analyze functional magnetic resonance imaging, researchers have demonstrated that the interconnections between different parts of the brain are dynamic and not static. Moreover, the brain region that performs the integration of information shifts depending on the task being performed. The study involved two language tasks, in which subjects were asked to read individual words and then make a spelling or rhyming judgment. Imaging showed that the lateral temporal cortex (LTC) was active for the rhyming task, while the intraparietal sulcus (IPS) was active for the spelling task. The inferior frontal gyrus (IFG) and the fusiform gyrus (FG) were engaged by both tasks. However, Dynamic Causal Modeling (the new method for analyzing imaging data) revealed that the network took different configurations depending on the goal of the task, with each task preferentially strengthening the influences converging on the task-specific regions (LTC for rhyming, IPS for spelling). This suggests that task specific regions serve as convergence zones that integrate information from other parts of the brain. Additionally, switching between tasks led to changes in the influence of the IFG on the task-specific regions, suggesting the IFG plays a pivotal role in making task-specific regions more or less sensitive. This is consistent with previous studies showing that the IFG is active in many different language tasks and plays a role in integrating brain regions.

Bitan, T., Booth, J.R., Choy, J., Burman, D.D., Gitelman, D.R. & Mesulam, M-M. 2005. Shifts of Effective Connectivity within a Language Network during Rhyming and Spelling. Journal of Neuroscience, 25, 5397-5403.

http://www.eurekalert.org/pub_releases/2005-06/nu-bnc060105.php

Older news items (pre-2010) brought over from the old website

September 2009

Healthy older brains not significantly smaller than younger brains

A study using healthy older adults from Holland's long-term Maastricht Aging Study found that the 35 cognitively healthy people who stayed free of dementia showed no significant decline in gray matter, but the 30 people who showed substantial cognitive decline although still dementia-free showed a significant reduction in brain tissue in the hippocampus and parahippocampal areas, and in the frontal and cingulate cortices. The findings suggest that atrophy in the normal older brain may have been over-estimated in earlier studies, by not screening out people whose undetected, slowly developing brain disease was killing off cells in key areas.

Burgmans, S. et al. 2009. The Prevalence of Cortical Gray Matter Atrophy May Be Overestimated In the Healthy Aging Brain. Neuropsychology, 23 (5), 541-550.

http://www.eurekalert.org/pub_releases/2009-09/apa-hob090309.php

Tetris increases gray matter and improves brain efficiency

In a study in which 26 adolescent girls played the computer game Tetris for half an hour every day for three months, their brains compared to controls increased grey matter in Brodmann Area 6 in the left frontal lobe and BAs 22 and 38 in the left temporal lobe — areas involved in planning complex coordinated movements, and coordinating sensory information. Their brains also showed greater efficiency, but in different areas — ones associated with critical thinking, reasoning, and language, mostly in the right frontal and parietal lobes. The finding points to improved efficiency being unrelated to grey matter increases.

Haier, R.J. et al. 2009. MRI assessment of cortical thickness and functional activity changes in adolescent girls following three months of practice on a visual-spatial task. BMC Research Notes, 2, 174. 

http://www.eurekalert.org/pub_releases/2009-09/bc-itg090109.php

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

September 2008

Musicians use both sides of their brains more frequently than average people

A study of 20 classical music students with at least eight years of training and 20 matched controls (non-musician, psychology students) looked at performance and brain activity on a creative thinking task, in which they were shown a variety of household objects and asked to make up new functions for them.  The musicians suggested more novel uses for the household objects, and had greater activity in both sides of their frontal lobes. Because musicians and non-musicians were equated in terms of their performance, this finding was not simply due to the musicians inventing more uses; there seems to be a qualitative difference in how they thought. One reason for the musicians' elevated use of both brain hemispheres may be that many musicians must be able to use both hands independently to play their instruments. The musicians also had higher IQ scores and performed better on a word association test, supporting previous research indicating the benefits of musical training.

Gibson, C., Folley, B.S. & Park, S. In press. Enhanced divergent thinking and creativity in musicians: A behavioral and near-infrared spectroscopy study. Brain and Cognition

http://www.physorg.com/news142185056.html

March 2008

Different use of brain areas may explain memory problems in schizophrenics

New research indicates that schizophrenics’ memory problems may be related to differences in how their brains process information. While both schizophrenic patients and healthy individuals used their frontal cortex while remembering and forgetting, healthy subjects used the right side when asked to remember spatial locations and schizophrenics used a wider network in both hemispheres. When healthy people were correct in their remembering, there was an increased activation of the right frontal cortex, an increase that didn’t occur when they couldn’t remember, and this was associated with a lack of confidence in their memory. However, schizophrenic patients showed an activation pattern on error trials indicating that they were remembering something, albeit incorrect. This was associated with a feeling of confidence about their memory.

Lee, J. et al. 2008. Origins of Spatial Working Memory Deficits in Schizophrenia: An Event-Related fMRI and Near-Infrared Spectroscopy Study. PLoS ONE, 3(3), e1760.

http://www.eurekalert.org/pub_releases/2008-03/vu-duo031008.php

September 2007

Why music training helps language

Several studies have come out in recent years suggesting that giving children music training can improve their language skills. A new study supports these findings by showing how. The latest study shows that music triggers changes in the brain stem, a very early stage in the processing pathway for both music and language. It has previously been thought that the automatic processing occurring at this level was not particularly malleable, and the strength of neuron connections there was fixed.

And in another study, researchers have found evidence for more commonality in the brain networks involved in music and language. One network, based in the temporal lobes, helps us memorize information in both language and music— for example, words and meanings in language and familiar melodies in music. The other network, based in the frontal lobes, helps us unconsciously learn and use the rules that underlie both language and music, such as the rules of syntax in sentences, and the rules of harmony in music.

Musacchia, G., Sams, M., Skoe, E. & Kraus, N. 2007. Musicians have enhanced subcortical auditory and audiovisual processing of speech and music. Proceedings of the National Academy of Sciences USA, 104, 15894-15898.
Miranda, R.A. & Ullman, M.T. 2007. Double dissociation between rules and memory in music: An event-related potential study. NeuroImage, 38 (2), 331-345.

http://www.sciam.com/article.cfm?chanID=sa003&articleID=39568C58-E7F2-99DF-32A49429C2B356CD&sc=WR_20071002 (1^st)
http://www.sciencedaily.com/releases/2007/09/070926123908.htm (1^st)
http://www.eurekalert.org/pub_releases/2007-09/gumc-tat092707.php (2^nd)

August 2007

Brain network associated with cognitive reserve identified

An imaging study involving young (18-30) and older (65-80) adults has identified a brain network within the frontal lobe that is associated with cognitive reserve, the process that allows individuals to resist cognitive decline due to aging or Alzheimer’s disease. Those with higher levels of cognitive reserve were able to activate this network in the brain while working on more difficult tasks, while participants with lower levels of reserve were not able to tap into this particular network. The network was found more often in younger participants, suggesting the network may degrade during aging.

Stern, Y. et al. 2007. A Common Neural Network for Cognitive Reserve in Verbal and Object Working Memory in Young but not Old. Cerebral Cortex, Advance Access published on August 3, 2007

http://www.eurekalert.org/pub_releases/2007-08/cumc-cri082007.php

January 2007

Neural bottleneck found that thwarts multi-tasking

An imaging study has revealed just why we can’t do two things at once. The bottleneck appears to occur at the lateral frontal and prefrontal cortex and the superior frontal cortex. Both areas are known to play a critical role in cognitive control. These brain regions responded to tasks irrespective of the senses involved, and could be seen to 'queue' neural activity — that is, a response to the second task was postponed until the response to the first was completed. Such queuing occurred when two tasks were presented within 300 milliseconds of each other, but not when the time gap was longer.

Dux, P.E. et al. 2006. Isolation of a Central Bottleneck of Information Processing with Time-Resolved fMRI. Neuron, 52, 1109-1120.

http://www.eurekalert.org/pub_releases/2007-01/vu-nbf011807.php

October 2006

Brain scans reveal 'chemobrain' no figment of the imagination

A PET study of 21 women who had undergone surgery to remove breast tumors five to 10 years earlier found that the 16 who had been treated with chemotherapy regimens near the time of their surgeries to reduce the risk of cancer recurrence had specific alterations in activity of frontal cortex, cerebellum, and basal ganglia compared to 5 breast cancer patients who underwent surgery only, and 13 control subjects who did not have breast cancer or chemotherapy. The alterations suggested the chemotherapy patients’ brains were working harder to recall the same information.

Silverman, D.H.S. et al. 2006. Altered frontocortical, cerebellar, and basal ganglia activity in adjuvant-treated breast cancer survivors 5–10years after chemotherapy. Breast Cancer Research and Treatment, Published online ahead of print 29 September

http://www.eurekalert.org/pub_releases/2006-10/uoc--bn092906.php

Chemo drugs for treating breast cancer may cause changes in cognitive function

A study involving female mice confirms the existence of "chemobrain", finding mild to moderate learning and memory deficits in mice receiving methotrexate and 5-fluorouracil (5FU), two drugs widely used in women to prevent recurrence of breast cancer. The deficits extended only to those types of memory that involve the hippocampus or the frontal lobes (spatial memory and working memory, in this instance). The study only looked at short-term effects (2—4 weeks).

Winocur, G., Vardy, J., Binns, M.A., Kerr, L. & Tannock, I. 2006. The effects of the anti-cancer drugs, methotrexate and 5-fluorouracil, on cognitive function in mice. Pharmacology, Biochemistry and Behavior, 85 (1), 66-75.

http://www.eurekalert.org/pub_releases/2006-10/b-cdf102706.php

August 2006

Childhood sleep apnea linked to brain damage, lower IQ

It’s long been known that sleep apnea, characterized by fragmented sleep, interrupted breathing and oxygen deprivation, harms children's learning ability and school performance. Now a new study involving 19 children with severe obstructive sleep apnea has identified damage in the hippocampus and the right frontal cortex, and linked that to observable deficits in performance on cognitive tests. Children with OSA had an average IQ of 85 compared to 101 in matched controls. They also performed worse on standardized tests measuring executive functions, such as verbal working memory (8 versus 15) and word fluency (9.7 versus 12). Obstructive sleep apnea affects 2% of children in the United States, but it is unclear how many of these suffer from severe apnea.

Springer, M.V., McIntosh, A.R., Winocur, G. & Grady, C.L. 2005. The Relation Between Brain Activity During Memory Tasks and Years of Education in Young and Older adults. Neuropsychology and Aging, 19 (2)

http://www.eurekalert.org/pub_releases/2006-08/jhmi-csa081506.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

October 2005

Changes in brain, not age, determine one's ability to focus on task

It’s been established that one of the reasons why older adults may do less well on cognitive tasks is because they have greater difficulty in ignoring distractions, which impairs their concentration. But not all older people are afflicted by this. Some are as focused as young adults. An imaging study has now revealed a difference between the brains of those people who are good at focusing, and those who are poor. Those who have difficulty screening out distractions have less white matter in the frontal lobes. They activated neurons in the left frontal lobe as well as the right. Young people and high-functioning older adults tended to use only the right frontal lobe.

Colcombe, S.J., Kramer, A.F. , Erickson, K.I. & Scalf, P. 2005. The Implications of Cortical Recruitment and Brain Morphology for Individual Differences in Inhibitory Function in Aging Humans. Psychology and Aging, 20(3), 363-375.

http://www.eurekalert.org/pub_releases/2005-10/uoia-cib102605.php

March 2005

How higher education protects older adults from cognitive decline

Research has indicated that higher education helps protect older adults from cognitive decline. Now an imaging study helps us understand how. The study compared adults from two age groups: 18-30, and over 65. Years of education ranged from 11 to 20 years for the younger group, and 8 to 21 for the older. Participants carried out several memory tasks while their brain was scanned. In young adults performing the memory tasks, more education was associated with less use of the frontal lobes and more use of the temporal lobes. For the older adults doing the same tasks, more education was associated with less use of the temporal lobes and more use of the frontal lobes. Previous research has indicated frontal activity is greater in old adults, compared to young; the new study suggests that this effect is related to the educational level in the older participants. The higher the education, the more likely the older adult is to recruit frontal regions, resulting in a better memory performance.

Springer, M.V., McIntosh, A.R., Winocur, G. & Grady, C.L. 2005. The Relation Between Brain Activity During Memory Tasks and Years of Education in Young and Older adults. Neuropsychology and Aging, 19 (2).

http://www.eurekalert.org/pub_releases/2005-03/apa-bi030705.php

January 2005

Imaging reveals brain abnormalities in ADHD children

A new type of brain imaging called diffusion tensor imaging (DTI) has provided some suggestive evidence about brain abnormalities in children diagnosed with ADHD. Abnormalities were found in the white-matter pathways in the frontal cortex, basal ganglia, brain stem and cerebellum—areas that are involved in regulating attention, impulsive behavior, motor activity, and inhibition, which are all related to ADHD symptoms.

This research was presented at the 2004 annual meeting of the Radiological Society of North America.

http://www.sciencentral.com/articles/view.htm3?article_id=218392460

December 2004

Cigarette smoking exacerbates alcohol-induced brain damage

Heavy alcohol consumption is known to cause brain damage. A new imaging study has compared 24, one-week-abstinent alcoholics (14 smokers, 10 nonsmokers) in treatment with 26 light-drinking "controls" (7 smokers, 19 nonsmokers), and found that cigarette smoking can both exacerbate alcohol-induced damage as well as independently cause brain damage. The damage is most prominent in the frontal lobes (important in planning, decision-making, and multi-tasking among other functions). Independent of alcohol consumption, cigarette smoking also had adverse effects on brain regions involved in fine and gross motor functions and balance and coordination. Roughly 80% of alcohol-dependent individuals report smoking regularly.

Durazzo, T.C., Gazdzinski, S., Banys, P. & Meyerhoff, D.J. 2004. Cigarette smoking exacerbates chronic alcohol-induced brain damage: A preliminary metabolite imaging study. Alcoholism: Clinical & Experimental Research, 28(12), 1849-1860.

http://www.eurekalert.org/pub_releases/2004-12/ace-cse120504.php

November 2004

What happens in the brain when we remember our own past?

A new imaging study has managed to distinguish between two types of autobiographical memory — the “facts” of our lives (e.g., knowing that you attended your cousin’s wedding last year), and the experiences of our lives (e.g., remembering traveling to the wedding, the events and people). As with much autobiographical memory research, the study used a diary-type procedure, whereby volunteers spent several months recording the events of their lives on a micro cassette recorder, as well as personal facts of their lives. These recordings were then played back to the volunteers while their brains were being scanned with fMRI. The results showed that the two types of autobiographical memory engaged different parts of the brain, even when the memories concerned the same contents. Recall of personal episodic memories more strongly engaged parts of the frontal lobes involved in self-awareness, as well as areas involved in visual memory.

Levine, B., Turner, G.R., Tisserand, D., Hevenor, S.J., Graham, S.J. & McIntosh, A.R. 2004. The Functional Neuroanatomy of Episodic and Semantic Autobiographical Remembering: A Prospective Functional MRI Study. Journal of Cognitive Neuroscience, 16(9), 1633-1646.

http://www.eurekalert.org/pub_releases/2004-11/bcfg-whi111604.php

July 2004

Intelligence based on the volume of gray matter in certain brain regions

Confirming earlier suggestions, the most comprehensive structural brain-scan study of intelligence to date supports an association between general intelligence and the volume of gray matter tissue in certain regions of the brain. Because these regions are located throughout the brain, a single "intelligence center" is unlikely. It is likely that a person's mental strengths and weaknesses depend in large part on the individual pattern of gray matter across his or her brain. Although gray matter amounts are vital to intelligence levels, only about 6% of the brain’s gray matter appears related to IQ — intelligence seems related to an efficient use of relatively few structures. The structures that are important for intelligence are the same ones implicated in memory, attention and language. There are also age differences: in middle age, more of the frontal and parietal lobes are related to IQ; less frontal and more temporal areas are related to IQ in the younger adults. Previous research has shown the regional distribution of gray matter in humans is highly heritable. The findings also challenge the recent view that intelligence may be a reflection of more subtle characteristics of the brain, such as the speed at which nerve impulses travel in the brain, or the number of neuronal connections present. It may of course be that all of these are factors.

Haier, R.J., Jung, R.E., Yeo, R.A., Head, K. & Alkire, M.T. 2004. Structural brain variation and general intelligence. Neuroimage. In press. http://dx.doi.org/10.1016/j.neuroimage.2004.04.025

http://www.sciencedaily.com/releases/2004/07/040720090419.htm
http://www.eurekalert.org/pub_releases/2004-07/uoc--hid071904.php

November 2003

Maturation of the human brain mapped

The progressive maturation of the human brain in childhood and adolescence has now been mapped. The initial overproduction of synapses in the gray matter that occurs after birth, is followed, for the most part just before puberty, with their systematic pruning. The mapping has confirmed that this maturation process occurs in different regions at different times, and has found that the normal gray matter loss begins first in the motor and sensory parts of the brain, and then slowly spreads downwards and forwards, to areas involved in spatial orientation, speech and language development, and attention (upper and lower parietal lobes), then to the areas involved in executive functioning, attention or motor coordination (frontal lobes), and finally to the areas that integrate these functions (temporal lobe). "The surprising thing is that the sequence in which the cortex matures appears to agree with regionally relevant milestones in cognitive development, and also reflects the evolutionary sequence in which brain regions were formed."

http://www.eurekalert.org/pub_releases/2003-11/sfn-smm110803.php

November 2002

Imaging confirms role of frontal lobes in planning

New research provides the first neuro-imaging evidence that the brain's frontal lobes play a critical role in planning and choosing actions.

Connolly, J.D., Goodale, M.A., Menon R.S. & Munoz, D.P. 2002. Human fMRI evidence for the neural correlates of preparatory set. Nature Neuroscience, 5 (12),1345–1352.

http://qnc.queensu.ca/story_loader.htm?id=3dc6a29d000a9

August 2002

How emotions interfere with staying focused

In a new imaging study, Duke University researchers have shown how emotional stimuli and "attentional functions" like driving move in parallel streams through the brain before being integrated in a specific part of the brain's prefrontal cortex (the anterior cingulate, which is located between the right and left halves). Emotional stimuli are thus more likely than simple distractions to interfere with a person's efforts to focus on a task such as driving. These findings may help us understand the neural dynamics underlying emotional distractibility on attentional tasks in affective disorders.

Yamasaki, H., LaBar, K.S. & McCarthy, G. Dissociable prefrontal brain systems for attention and emotion. Proc. Natl. Acad. Sci. USA, 99(17), 11447-51.

www.pnas.org/cgi/doi/10.1073/pnas.182176499
http://www.pnas.org/cgi/content/abstract/99/17/11447

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

November 2001

Gender differences in frontal lobe neuron density

A recent study has found that women have up to 15% more brain cell density in the frontal lobe, which controls so-called higher mental processes, such as judgement, personality, planning and working memory. However, as they get older, women appear to shed cells more rapidly from this area than men. By old age, the density is similar for both sexes. It is not yet clear what impact, if any, this difference has on performance.

Witelson, S.F., Kigar, D.L. & Stoner-Beresh, H.J. 2001. Sex difference in the numerical density of neurons in the pyramidal layers of human prefrontal cortex: a stereologic study. Paper presented to the annual Society for Neuroscience meeting in San Diego, US.

http://news.bbc.co.uk/hi/english/health/newsid_1653000/1653687.stm

Older news items (pre-2010) brought over from the old website

October 2008

Why it’s so hard to disrupt your routine

New research has added to our understanding of why we find it so hard to break a routine or overcome bad habits. The problem lies in the competition between the striatum and the hippocampus. The striatum is involved with habits and routines, for example, it records cues or landmarks that lead to a familiar destination. It’s the striatum that enables you to drive familiar routes without much conscious awareness. If you’re travelling an unfamiliar route however, you need the hippocampus, which is much ‘smarter’. The mouse study found that when the striatum was disrupted, the mice had trouble navigating using landmarks, but they were actually better at spatial learning. When the hippocampus was disrupted, the converse was true. This may help us understand, and treat, certain mental illnesses in which patients have destructive, habit-like patterns of behavior or thought. Obsessive-compulsive disorder, Tourette syndrome, and drug addiction all involve abnormal function of the striatum. Cognitive-behavioral therapy may be thought of as trying to learn to use one of these systems to overcome and, ultimately, to re-train the other.

Lee, A.S. et al. 2008. A double dissociation revealing bidirectional competition between striatum and hippocampus during learning. Proceedings of the National Academy of Sciences, 105 (44), 17163-17168.

http://www.eurekalert.org/pub_releases/2008-10/yu-ce102008.php

August 2008

One sleepless night increases dopamine

A study has found that sleep deprivation increases the level of the hormone dopamine in two brain structures: the striatum, which is involved in motivation and reward, and the thalamus, which is involved in alertness. The rise in dopamine following sleep deprivation may promote wakefulness to compensate for sleep loss. However, since the amount of dopamine correlated with feelings of fatigue and impaired performance on cognitive tasks, it appears that the adaptation is not sufficient to overcome the cognitive deterioration induced by sleep deprivation and may even contribute to it. Amphetamines increase dopamine levels.

Volkow, N.D. et al. 2008. Sleep Deprivation Decreases Binding of [¹¹C]Raclopride to Dopamine D₂/D₃ Receptors in the Human Brain. Journal of Neuroscience, 28, 8454-8461.

http://www.eurekalert.org/pub_releases/2008-08/sfn-osn081808.php

April 2008

How chronic exposure to solvents can impair the brain

Chronic occupational exposure to organic solvents, found in materials such as paints, printing and dry cleaning agents, has been linked to long-term cognitive impairment, but chronic solvent-induced encephalopathy (CSE) is still a controversial diagnosis. An imaging study of 10 CSE patients who had been exposed to solvents and had mild to severe cognitive impairment, 10 participants who had been exposed to solvents but had no CSE symptoms, and 11 participants who were not exposed to solvents and had no symptoms, has now found impairment in the frontal-striatal-thalamic (FST) circuitry of CSE patients. The disturbances are predictive of the clinical findings — impaired psychomotor speed and attention — and were also linked to exposure severity.

Visser, I. et al. 2008. Cerebral impairment in chronic solvent-induced encephalopathy (p NA). Annals of Neurology, Published online April 15 2008

http://www.eurekalert.org/pub_releases/2008-04/w-dib041508.php

February 2007

Common gene version optimizes thinking but carries a risk

On the same subject, another study has found that the most common version of DARPP-32, a gene that shapes and controls a circuit between the striatum and prefrontal cortex, optimizes information filtering by the prefrontal cortex, thus improving working memory capacity and executive control (and thus, intelligence). However, the same version was also more prevalent among people who developed schizophrenia, suggesting that a beneficial gene variant may translate into a disadvantage if the prefrontal cortex is impaired. In other words, one of the things that make humans more intelligent as a species may also make us more vulnerable to schizophrenia.

Meyer-Lindenberg,A. et al. 2007. Genetic evidence implicating DARPP-32 in human frontostriatal structure, function, and cognition. Journal of Clinical Investigation, 117 (3), 672-682.

http://www.sciencedaily.com/releases/2007/02/070208230059.htm
http://www.eurekalert.org/pub_releases/2007-02/niom-cgv020707.php

July 2006

How multitasking impedes learning

A number of studies have come out in recent years demonstrating that the human brain can’t really do two things at once, and that when we do attempt to do so, performance is impaired. A new imaging study provides evidence that we tend to use a less efficient means of learning when distracted by another task. In the study, 14 younger adults (in their twenties) learned a simple classification task by trial-and-error. For one set of the cards, they also had to keep a running mental count of high tones that they heard while learning the classification task. Imaging revealed that different brain regions were used for learning depending on whether the participants were distracted by the other task or not — the hippocampus was involved in the single-task learning, but not in the dual-task, when the striatum (a region implicated in procedural and habit learning) was active. Although the ability of the participants to learn didn’t appear to be affected at the time, the distraction did reduce the participants' subsequent knowledge about the task during a follow-up session. In particular, on the task learned with the distraction, participants could not extrapolate from what they had learned.

Foerde, K., Knowlton, B.J. & Poldrack, R.A. Modulation of competing memory systems by distraction. Proceedings of the National Academy of Sciences, 103, 11778-11783.

http://www.sciencedaily.com/releases/2006/07/060726083302.htm

Older news items (pre-2010) brought over from the old website

August 2009

Common variation in gene linked to structural changes in the brain

Variations in the regions of the gene MECP2, previously associated with Retts Syndrome, autism, and mental retardation, has been found to be associated with changes in brain structure in both healthy individuals and patients with neurological and psychiatric disorders. The study used data from 289 healthy and psychotic subjects (the TOP study), and 655 healthy and demented patients (mostly Alzheimer's; from the ADNI study). The most significant genetic variation resulted in reduced surface area in the cortex (in particular in the cuneus, fusiform gyrus, pars triangularis), and was specific to males.

Joyner, A.H. et al. 2009. A common MECP2 haplotype associates with reduced cortical surface area in humans in two independent populations. Proceedings of the National Academy of Sciences, 106, 15483-15488; published online before print August 26, 2009, doi:10.1073/pnas.0901866106

http://www.eurekalert.org/pub_releases/2009-08/uoc--cvi081709.php
http://www.eurekalert.org/pub_releases/2009-08/sri-sru081809.php

April 2009

Research suggests words are seen as units and processed quickly

What exactly is going on in our brain when we read? Two new studies suggest the process is quicker and more direct than we thought. One study revealed that a region of the brain in the fusiform gyrus called the visual word form area (VWFA) recognizes words as whole units rather than letter by letter – words that differed in only one letter (e.g., "farm" and "form") produced changes in brain activity that were as profound as between completely different words (e.g., "farm" and "coat"), while incremental changes occurred in response to single-letter changes in made-up words. In another study, it was revealed that, rather than processing words in a slow, hierarchical way, we seem to process words quickly, through direct connections between visual and speech-processing systems. The first area to respond to text was the text recognition area in the occipito-temporal cortex, but it was followed within 15msec by both the VWFA and Broca's area (involved in speech processing). The results provide support for the idea that the brain has two rapid reading pathways (simultaneous rather than sequential): a lexical route using the VWFA and a sublexical route through Broca's area to the motor areas that control sound production (allowing us to sound out unfamiliar words).

Glezer, L.S., Jiang, X. & Riesenhuber, M. 2009. Evidence for Highly Selective Neuronal Tuning to Whole Words in the Visual Word Form Area. Neuron, 62 (2), 199-204.
Cornelissen, P.L. et al. 2009. Activation of the Left Inferior Frontal Gyrus in the First 200 ms of Reading: Evidence from Magnetoencephalography (MEG). PLoS ONE, 4(4), e5359. doi:10.1371/journal.pone.0005359

http://www.physorg.com/news160048496.html
http://www.sciencenews.org/view/generic/id/43348/title/Brain_reads_word-by-word

August 2006

No specialized face area

Another study has come out casting doubt on the idea that there is an area of the brain specialized for faces. The fusiform gyrus has been dubbed the "fusiform face area", but a detailed imaging study has revealed that different patches of neurons respond to different images. However, twice as many of the patches are predisposed to faces versus inanimate objects (cars and abstract sculptures), and patches that respond to faces outnumber those that respond to four-legged animals by 50%. But patches that respond to the same images are not physically connected, implying a "face area" may not even exist.

Grill-Spector, K., Sayres, R. & Ress, D. 2006. High-resolution imaging reveals highly selective nonface clusters in the fusiform face area. Nature Neuroscience, 9, 1177-1185.

http://www.sciencedaily.com/releases/2006/08/060830005949.htm

May 2005

Brain networks change according to cognitive task

Using a newly released method to analyze functional magnetic resonance imaging, researchers have demonstrated that the interconnections between different parts of the brain are dynamic and not static. Moreover, the brain region that performs the integration of information shifts depending on the task being performed. The study involved two language tasks, in which subjects were asked to read individual words and then make a spelling or rhyming judgment. Imaging showed that the lateral temporal cortex (LTC) was active for the rhyming task, while the intraparietal sulcus (IPS) was active for the spelling task. The inferior frontal gyrus (IFG) and the fusiform gyrus (FG) were engaged by both tasks. However, Dynamic Causal Modeling (the new method for analyzing imaging data) revealed that the network took different configurations depending on the goal of the task, with each task preferentially strengthening the influences converging on the task-specific regions (LTC for rhyming, IPS for spelling). This suggests that task specific regions serve as convergence zones that integrate information from other parts of the brain. Additionally, switching between tasks led to changes in the influence of the IFG on the task-specific regions, suggesting the IFG plays a pivotal role in making task-specific regions more or less sensitive. This is consistent with previous studies showing that the IFG is active in many different language tasks and plays a role in integrating brain regions.

Bitan, T., Booth, J.R., Choy, J., Burman, D.D., Gitelman, D.R. & Mesulam, M-M. 2005. Shifts of Effective Connectivity within a Language Network during Rhyming and Spelling. Journal of Neuroscience, 25, 5397-5403.

http://www.eurekalert.org/pub_releases/2005-06/nu-bnc060105.php

December 2004

How the brain is wired for faces

The question of how special face recognition is — whether it is a process quite distinct from recognition of other objects, or whether we are simply highly practiced at this particular type of recognition — has been a subject of debate for some time. A new imaging study has concluded that the fusiform face area (FFA), a brain region crucially involved in face recognition, extracts configural information about faces rather than processing spatial information on the parts of faces. The study also indicated that the FFA is only involved in face recognition.

Yovel, G. & Kanwisher, N. 2004. Face Perception: Domain Specific, Not Process Specific. Neuron, 44 (5), 889–898.

http://www.eurekalert.org/pub_releases/2004-12/cp-htb112304.php

How the brain recognizes a face

Face recognition involves at least three stages. An imaging study has now localized these stages to particular regions of the brain. It was found that the inferior occipital gyrus was particularly sensitive to slight physical changes in faces. The right fusiform gyrus (RFG), appeared to be involved in making a more general appraisal of the face and compares it to the brain's database of stored memories to see if it is someone familiar. The third activated region, the anterior temporal cortex (ATC), is believed to store facts about people and is thought to be an essential part of the identifying process.

Rotshtein, P., Henson, R.N.A., Treves, A., Driver, J. & Dolan, R.J. 2005. Morphing Marilyn into Maggie dissociates physical and identity face representations in the brain. Nature Neuroscience, 8, 107-113.

http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/4086319.stm

February 2004

Special training may help people with autism recognize faces

People with autism tend to activate object-related brain regions when they are viewing unfamiliar faces, rather than a specific face-processing region. They also tend to focus on particular features, such as a mustache or a pair of glasses. However, a new study has found that when people with autism look at a picture of a very familiar face, such as their mother's, their brain activity is similar to that of control subjects – involving the fusiform gyrus, a region in the brain's temporal lobe that is associated with face processing, rather than the inferior temporal gyrus, an area associated with objects. Use of the fusiform gyrus in recognizing faces is a process that starts early with non-autistic people, but does take time to develop (usually complete by age 12). The study indicates that the fusiform gyrus in autistic people does have the potential to function normally, but may need special training to operate properly.

Aylward, E. 2004. Functional MRI studies of face processing in adolescents and adults with autism: Role of experience. Paper presented February 14 at the annual meeting of the American Association for the Advancement of Science in Seattle.
Dawson, G. & Webb, S. 2004. Event related potentials reveal early abnormalities in face processing autism. Paper presented February 14 at the annual meeting of the American Association for the Advancement of Science in Seattle.

http://www.eurekalert.org/pub_releases/2004-02/uow-stm020904.php

May 2002

Babies' experience with faces leads to narrowing of perception

A theory that infants' experience in viewing faces causes their brains (in particular an area of the cerebral cortex known as the fusiform gyrus) to "tune in" to the types of faces they see most often and tune out other types, has been given support from a study showing that 6-month-old babies were significantly better than both adults and 9-month-old babies in distinguishing the faces of monkeys. All groups were able to distinguish human faces from one another.

Pascalis, O., de Haan, M. & Nelson, C.A. 2002. Is Face Processing Species-Specific During the First Year of Life? Science, 296 (5571), 1321-1323.

http://www.eurekalert.org/pub_releases/2002-05/uom-ssi051302.php
http://news.bbc.co.uk/hi/english/health/newsid_1991000/1991705.stm
http://www.eurekalert.org/pub_releases/2002-05/aaft-bbl050902.php

November 2001

Differential effects of encoding strategy on brain activity patterns

Encoding and recognition of unfamiliar faces in young adults were examined using PET imaging to determine whether different encoding strategies would lead to differences in brain activity. It was found that encoding activated a primarily ventral system including bilateral temporal and fusiform regions and left prefrontal cortices, whereas recognition activated a primarily dorsal set of regions including right prefrontal and parietal areas. The type of encoding strategy produced different brain activity patterns. There was no effect of encoding strategy on brain activity during recognition. The left inferior prefrontal cortex was engaged during encoding regardless of strategy.

Bernstein, L.J., Beig, S., Siegenthaler, A.L. & Grady, C.L. 2002. The effect of encoding strategy on the neural correlates of memory for faces. Neuropsychologia, 40 (1), 86 - 98.

http://tinyurl.com/i87v

October 2001

Differences in face perception processing between autistic and normal adults

Imaging studies continue apace! Having established that that part of the brain known as the fusiform gyrus is important in picture naming, a new study further refines our understanding by studying the cerebral blood flow (CBF) changes in response to a picture naming task that varied on two dimensions: familiarity (or difficulty: hard vs easy) and category (tools vs animals). Results show that although familiarity effects are present in the frontal and left lateral posterior temporal cortex, they are absent from the fusiform gyrus. The authors conclude that the fusiform gyrus processes information relating to an object's structure, rather than its meaning. The blood flows suggest that it is the left posterior middle temporal gyrus that is involved in representing the object's meaning.

Whatmough, C., Chertkow, H., Murtha, S., & Hanratty, K. (2002). Dissociable brain regions process object meaning and object structure during picture naming. Neuropsychologia, 40, 174-186.

Different brain regions implicated in the representation of the structure and meaning of pictured objects

An imaging study compared activation patterns of adults with autism and normal control subjects during a face perception task. While autistic subjects could perform the face perception task, none of the regions supporting face processing in normals were found to be significantly active in the autistic subjects. Instead, in every autistic patient, faces maximally activated aberrant and individual-specific neural sites (e.g. frontal cortex, primary visual cortex, etc.), which was in contrast to the 100% consistency of maximal activation within the traditional fusiform face area (FFA) for every normal subject. It appears that, as compared with normal individuals, autistic individuals `see' faces utilizing different neural systems, with each patient doing so via a unique neural circuitry.

Pierce, K., Müller, R.-A., Ambrose, J., Allen, G. & Courchesne, E. (2001). Face processing occurs outside the fusiform `face area' in autism: evidence from functional MRI. Brain, 124 (10), 2059-2073.

http://brain.oupjournals.org/cgi/content/abstract/124/10/2059

July 2001

Why recognizing a face is easier when the race matches our own

We have known for a while that recognizing a face is easier when its owner's race matches our own. An imaging study now shows that greater activity in the brain's expert face-discrimination area occurs when the subject is viewing faces that belong to members of the same race as their own.

Golby, A. J., Gabrieli, J. D. E., Chiao, J. Y. & Eberhardt, J. L. 2001. Differential responses in the fusiform region to same-race and other-race faces. Nature Neuroscience, 4, 845 - 850.

http://www.nature.com/nsu/010802/010802-1.html

parietotemporal region

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

July 2008

Autism's social struggles due to disrupted communication networks in brain

And a timely imaging study has now provided the clearest evidence to date that synchronization in what might be termed the Theory of Mind network is impaired in autistic people. The Theory of Mind network (which includes the medial frontal gyrus, the anterior paracingulate, and the right temporoparietal junction) is responsible for processing the intentions and thoughts of others. In the study 12 high-functioning autistic adults and 12 controls viewed animated interacting geometric figures, and then asked to select the word from several choices that best described the interaction. The control subjects were consistently better at inferring the intention from the action than the participants with autism were. Brain scans revealed that synchronization between the frontal and posterior regions in the network was reliably lower in the group with autism. The autistic participants' brains also showed much lower activation levels in the frontal regions, and an independent assessment of their Theory of Mind abilities found these reliably correlated with activation in the right temporoparietal junction. The findings point to the need to develop interventions that could target this problem, and also indicate a way to measure an intervention’s effectiveness.

Kana, R.K. et al. 2008. Atypical frontal-posterior synchronization of Theory of Mind regions in autism during mental state attribution. Social Neuroscience, Published online ahead of print 3 July

http://www.eurekalert.org/pub_releases/2008-07/cmu-ass072308.php

June 2008

Remedial instruction can close gap between good, poor readers

A brain imaging study of poor readers has found that 100 hours of remedial instruction not only improved the skills of struggling readers, but also changed the way their brains activated when they comprehended written sentences. 25 fifth-graders who were poor readers worked in groups of three for an hour a day with a reading "personal trainer," a teacher specialized in administering a remedial reading program. The training included both word decoding exercises in which students were asked to recognize the word in its written form and tasks in using reading comprehension strategies. Brain scans while the children were reading revealed that the parietotemporal region — responsible for decoding the sounds of written language and assembling them into words and phrases that make up a sentence — was significantly less activated among the poor readers than in the control group. The increases in activation seen as a result of training were still evident, and even greater, a year later.
Although dyslexia is generally thought of as caused by difficulties in the visual perception of letters, leading to confusions between letters like "p" and "d", such difficulties occur in only about 10% of the cases. Most commonly, the problem lies in relating the visual form of a letter to its sound.

Meyler, A., Keller, T.A., Cherkassky, V.L., Gabrieli, J.D.E.  & Just, M.A.. 2008. Modifying the brain activation of poor readers during sentence comprehension with extended remedial instruction: A longitudinal study of neuroplasticity. Neuropsychologia, 46 (10), 2580-2592.

http://www.eurekalert.org/pub_releases/2008-06/cmu-cmb061108.php

Older news items (pre-2010) brought over from the old website

December 2008

MRI brain scans accurate in early diagnosis of Alzheimer's disease

Adding to the growing body of evidence indicating MRI brain scans provide valuable diagnostic information about Alzheimer's disease, a study in which a new visual rating system for evaluating the severity of shrinkage in the medial temporal lobe was used on brain scans of 260 people has found that scores accurately distinguished those with Alzheimer’s from those with mild cognitive impairment and those without memory problems. The test also accurately predicted those who would move from one group to another within a year or two.

Duara, R. et al. 2008. Medial temporal lobe atrophy on MRI scans and the diagnosis of Alzheimer disease. Neurology, 71, 1986-1992.

http://www.eurekalert.org/pub_releases/2008-12/uosf-mbs121808.php

August 2007

Maturity brings richer memories

New research suggests adults can remember more contextual details than children, and that this is related to the development of the prefrontal cortex. While in a MRI scanner, 49 volunteers aged eight to 24 were shown pictures of 250 common scenes and told they would be tested on their memory of these scenes. In both children and adults, correct recognition of a scene was associated with higher activation in several areas of the prefrontal cortex and the medial temporal lobe when they were studying the pictures. However, the older the volunteers, the more frequently their correct answers were enriched with contextual detail. These more detailed memories correlated with more intense activation in a specific region of the PFC. A number of studies have suggested that the PFC develops later than other brain regions.

The report appeared in the August 5 advance online edition of Nature Neuroscience.

http://www.physorg.com/news105549812.html
http://www.eurekalert.org/pub_releases/2007-08/miot-msm080107.php

August 2005

Rating familiarity: how we do it

Previous research has indicated that recognizing a familiar object is accompanied by a reduction in activity in the medial temporal lobe. A new imaging study has confirmed the reduced activity and demonstrated that the degree of reduction is correlated with the degree of familiarity of the object (a face in this instance). The reduction began very rapidly in the recognition process. The researchers suggested that the graded response of medial temporal structures are what allows us to assess how familiar an object is.

Gonsalves, B.D., Curran, T., Norman, K.A. & Wagner, A.D. 2005. Memory Strength and Repetition Suppression: Multimodal Imaging of Medial Temporal Cortical Contributions to Recognition. Neuron, 47, 751–761.

http://www.eurekalert.org/pub_releases/2005-08/cp-tt082505.php

June 2005

Single cell recognition research finds specific neurons for concepts

An intriguing study surprises cognitive researchers by showing that individual neurons in the medial temporal lobe are able to recognize specific people and objects. It’s long been thought that concepts such as these require a network of cells, and this doesn’t deny that many cells are involved. However, this new study points to the importance of a single brain cell. The study of 8 epileptic subjects found variable responses from subjects, but within subjects, individuals showed remarkably specific responses to concepts. For example, a single neuron in the left posterior hippocampus of one subject responded to all pictures of actress Jennifer Aniston, and also to Lisa Kudrow, her co-star on the TV hit "Friends", but not to pictures of Jennifer Aniston together with actor Brad Pitt, and not, or only very weakly, to other famous and non-famous faces, landmarks, animals or objects. In another patient, pictures of actress Halle Berry activated a neuron in the right anterior hippocampus, as did a caricature of the actress, images of her in the lead role of the film "Catwoman," and a letter sequence spelling her name. The results suggest an invariant, sparse and explicit code, which might be important in the transformation of complex visual percepts into long-term and more abstract memories.

Quiroga, R.Q., Reddy, L., Kreiman, G., Koch, C & Fried, I. 2005. Invariant visual representation by single neurons in the human brain. Nature, 435, 1102-1107.

http://www.eurekalert.org/pub_releases/2005-06/uoc--scr062005.php

May 2005

Long-term storage of autobiographical memories

By studying in detail the ability of patients with selective brain damage to recall events in their past, researchers have helped settle a long-standing controversy about whether long-term memory of one's personal experiences continue to be stored in the medial temporal lobe, or whether they gradually become independent of this area. The evidence from this new study suggests that autobiographical memories gradually become distributed throughout the neocortex.

Bayley, P.J., Gold, J.J., Hopkins, R.O. & Squire, L.R. 2005. The Neuroanatomy of Remote Memory. Neuron, 46, 799–810.

http://www.eurekalert.org/pub_releases/2005-06/cp-wlm052605.php

October 2004

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 cortex 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

September 2004

New technique sheds light on autobiographical memory

A new technique for studying autobiographical memory has revealed new findings about autobiographical memory, and may prove useful in studying age-related cognitive impairment. Previous inconsistencies between controlled laboratory studies of memory (typically, subjects are asked to remember items they have previously seen in the laboratory, such as words presented on a computer screen) and studies of autobiographical memory have seemed to indicate that the brain may function differently in the two processes. However, such differences might instead reflect how the memories are measured. In an effort to provide greater control over the autobiographical memories, volunteer subjects were given cameras and instructed to take pictures of campus scenes. The subjects were also instructed to remember the taking of each picture as an individual event, noting the physical conditions and their psychological state, such as their mood and associations with the subject of the images. The subjects were then shown a selection of campus photos they had not taken. While their brains were scanned, they were then shown a mix of their own photos with those they had not taken, and asked to indicate whether each photo was new, seen earlier in the lab, or one they had taken themselves. The researchers found that recalling the autobiographical memories activated many of the same brain areas as laboratory memories (the medial temporal lobe and the prefrontal cortex); however, they also activated brain areas associated with "self-referential processing" (processing information about one's self), and regions associated with retrieval of visual and spatial information, as well as showing a higher level of activity in the recollection areas in the hippocampus.

The report will appear in the November issue of the Journal of Cognitive Neuroscience.

http://www.eurekalert.org/pub_releases/2004-09/du-blm092904.php

November 2003

Questioning the medial temporal lobe

The medial temporal lobe includes the hippocampus, the amygdala, and the entorhinal and perirhinal cortices. It is often talked about as a single unit, but recently a prominent neurobiologist has questioned this usage. For one thing, the region didn’t evolve as one unit — the different regions arose at different times during primate evolution. Therefore, can it really be an integrated system with a common function? Her work with rhesus monkeys suggests rather that these different parts may serve cooperative and even competitive functions.

Magnetic resonance imaging may help predict future memory decline

A six-year imaging study of 45 healthy seniors assessed changes in brain scans against cognitive decline. They found that progressive atrophy in the medial temporal lobe was the most significant predictor of cognitive decline, which occurred in 29% of the subjects.

Rusinek, H., De Santi, S., Frid, D., Tsui, W-H., Tarshish, C.Y., Convit, A., & de Leon, M.J. 2003. Regional Brain Atrophy Rate Predicts Future Cognitive Decline: 6-year Longitudinal MR Imaging Study of Normal Aging. Radiology, 229, 691-696.

http://www.eurekalert.org/pub_releases/2003-11/rson-mhr111703.php

March 2003

Activity in the mediotemporal lobe lower in elderly with poor memory

An imaging study has revealed that, although there is no difference on standard MRI scans,scans showing the amount of oxygen (and thus activity) find that elderly persons with a poor memory have less activity in the mediotemporal lobe when storing new information than elderly persons with a normally functioning memory.This more sensitive scan may help early diagnosis of Alzheimer's.

The research was done as part of a doctoral thesis by Dr Sander Daselaar.

http://www.eurekalert.org/pub_releases/2003-03/nofs-svp032103.php

November 2001

Imaging study confirms role of medial temporal lobe in memory consolidation

Lesions in the medial temporal lobe (MTL) typically produce amnesia characterized by the disproportionate loss of recently acquired memories. Such memory loss has been interpreted as evidence for a memory consolidation process guided by the MTL. A recent imaging study confirms this view by showing temporally graded changes in MTL activity in healthy older adults taking a famous faces remote memory test. Evidence for such temporally graded change in the hippocampal formation was mixed, suggesting it may participate only in consolidation processes lasting a few years. The entorhinal cortex (also part of the MTL) was associated with temporally graded changes extending up to 20 years, suggesting that it is the entorhinal cortex, rather than the hippocampal formation, that participates in memory consolidation over decades. The entorhinal cortex is damaged in the early stages of Alzheimer’s disease (AD).

Haist, F., Gore, J.B. & Mao, H. 2001. Consolidation of human memory over decades revealed by functional magnetic resonance imaging. Nature neuroscience, 4 (11), 1139-1145.

http://www.nature.com/neurolink/v4/n11/abs/nn739.html

Competition between memory systems

Learning and memory in humans rely upon several memory systems. For example, the medial temporal lobe (MTL) is associated with declarative learning (facts and events). The basal ganglia is associated with nondeclarative learning (learning you derive from experience, that may not be conscious). A recent imaging study looked at how these memory systems interact during classification learning. During the nondeclarative learning task, there was an increase in activity in the basal ganglia, and a decrease in activity in the MTL. During the memorization task (testing declarative learning), the reverse was true. Further examination found rapid modulation of activity in these regions at the beginning of learning, suggesting that subjects relied upon the medial temporal lobe early in learning. However, this dependence rapidly declined with training.

Poldrack, R.A., Clark, J., Paré-blagoev, E.J., Shohamy, D., Moyano, J.C., Myers, C. & Gluck, M.A. 2001. Interactive memory systems in the human brain. Nature, 414, 546 - 550.

http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v414/n6863/abs/414546a0_fs.html
http://www.eurekalert.org/pub_releases/2001-11/mgh-isi112601.php