ADD/ADHD News

February 28th 2005

Left blind-spot 'gives ADHD clue'

Press release 28th February 2005 from the Medical Research Council


New clues to understanding attention deficit hyperactivity disorder in children

Children suffering from Attention Deficit Hyperactivity Disorder (ADHD) may be ignoring visual information to their left and being diagnosed mistakenly as having dyslexia, according to new research by Dr Tom Manly and colleagues at the Medical Research Council (MRC) Cognition and Brain Sciences Unit in Cambridge and published in Journal of Child Psychology and Psychiatry and Brain and Cognition. The latest of three recent papers on the subject, published today, shows that this 'left neglect' phenomenon is more widespread in children than previously thought.

The research, conducted by Dr Manly and colleagues Dr Veronika Dobler and Melanie George, showed that children with ADHD might simply stop noticing things to their left, particularly when they are doing boring or unstimulating tasks. The phenomenon of 'left neglect' is well-known in adults who have suffered right-sided brain injury, who can act as if half the world has simply disappeared. Some children with ADHD, who had no brain damage and perfectly normal intelligence, showed 'left neglect' quite as severe as that seen in some adults with substantial damage to the right side of the brain. Remarkably, the studies show that most children's awareness of things to their left - but not their right - significantly declines if they are asked to perform a boring task for about 40 minutes.

The research published today shows that even perfectly healthy children can begin to lose some awareness of information on the left with boredom. Dr Manly said, "The right side of our brain seems to be heavily involved in keeping us awake and alert, particularly when we are bored. Because the right side of the brain is interested in what is going on to our left and vice versa, as this alertness declines over time or with boredom, it takes some of our awareness of the left with it. All children lose information disproportionately from the left, but children with ADHD appear to reach this point more quickly and to a greater extent than other children unless they are given stimulant medication.

Dr Manly highlighted the phenomenon in his earlier studies, "One boy with ADHD we worked with tended to ignore the first letters in words, reading 'TRAIN' as 'RAIN' and 'FLOAT' as 'OAT'. Another boy would miss details from the left in his drawing and compress his writing or drawing only into the right hand side of the page."

Dr Manly claims that this difficulty with noticing things on the left has often gone undiscovered because it is not routinely assessed. The problems may be attributed incorrectly to dyslexia or clumsiness.

He concludes, "We have no idea how many children are affected, or if they grow out of it or if it is permanent. However, there are some effective treatments for this problem in adults and our early studies suggest they may work for children, but more research is needed. Nevertheless, improving early assessment in children should be a priority."

For further information, or to arrange an interview, contact Adrian Penrose, MRC Regional Communications Manager, Cambridge, on (01223) 748179 or mobile 07990 541520.

Notes to Editors

The Medical Research Council (MRC) is a national organisation funded by the UK tax-payer. Its business is medical research aimed at improving human health; everyone stands to benefit from the outputs. The research it supports and the scientists it trains meet the needs of the health services, the pharmaceutical and other health-related industries and the academic world. MRC has funded work which has led to some of the most significant discoveries and achievements in medicine in the UK. About half of the MRC's expenditure of £450 million is invested in its 40 Institutes, Units and Centres. The remaining half goes in the form of grant support and training awards to individuals and teams in universities and medical schools. The MRC Cognition and Brain Sciences Unit in Cambridge investigates fundamental human mental processes such as attention, memory, communication and emotion. It conducts behavioural experiments to see how these processes work, builds computer models of their operation, studies how they could arise from the neural mechanisms of the brain, and explores the clinical implications for patient therapy and rehabilitation.

'Left spatial neglect' is the term used to describe a phenomenon whereby the eyes can still move to the left but the brain ceases to be alert to the visual signals. Visual awareness is controlled by opposite sides of the brain - the right hand side of the brain controls what we see to our left and vice-versa. For example, in the case of adults who have suffered brain injury, such as a stroke to the right hand side of the brain, they may ignore people approaching from the left, leave untouched food on the left side of the plate or even ignore their own left arm.

The other recent papers on this subject published by Dr Manly and colleagues are currently cited electronically (without page numbers) as:

" Dobler, V. B., Manly, T., Anker, S., Gilmore, J., Dezeryu, A. M., & Atkinson, J. (in press). Asymmetric deterioration of spatial awareness with diminishing levels of alertness in normal children and children with ADHD. Journal of Child Psychology and Psychiatry.
" George, M., Dobler, V. B., Nicholls, E., & Manly, T. (in press). Spatial awareness, alertness and ADHD: The re-emergence of unilateral neglect with time-on-task. Brain and Cognition.

From the BBC 28th February 2005

Left blind-spot 'gives ADHD clue'

Children who "miss" things on their left field of vision may have attention deficit hyperactivity disorder, Medical Research Council scientists say.

The phenomenon means children may miss the first letters of a written word, leading doctors to diagnose dyslexia.

However, it can also mean children only write or draw on the right-hand side of a page, or that they knock things on their left-hand side over more often.

The condition is seen in adults who have had stroke.

"Left neglect" is seen where the right side of the brain is affected.

It means things on someone's left-hand side are simply not noticed, especially if they are doing something they find boring or unstimulating.

Children who do not have ADHD may also show symptoms of the condition, the researchers say.

The research is published in the Journal of Child Psychology and Psychiatry, and in Brain and Cognition.

Fidgeting

Left neglect is a well-known condition in adults who have suffered right-sided brain injury. It means they may act as if half the world has simply disappeared.

Researchers from the MRC's Cognition and Brain Sciences Unit, in Cambridge, found some children with ADHD, who had no brain damage and perfectly normal intelligence, showed left neglect as severe as that seen in some adults with substantial damage to the right side of the brain.

This latest study asked parents and teachers of healthy Nottingham children to assess how much they ran around or fidgeted - potential indications of ADHD.

They then compared the 10% who displayed such habits the least with the 10% who displayed them the most.

It was found that those who fidgeted or ran around the most were more likely to have problems perceiving things on their left, even though their symptoms were not severe enough to merit a diagnosis of ADHD.

Dr Tom Manley, who led the research, said: "The right side of our brain seems to be heavily involved in keeping us awake and alert, particularly when we are bored.

"Because the right side of the brain is interested in what is going on to our left and vice versa, as this alertness declines over time or with boredom, it takes some of our awareness of the left with it.

"All children lose information disproportionately from the left, but children with ADHD appear to reach this point more quickly and to a greater extent than other children unless they are given stimulant medication."

He told the BBC News website: "This condition isn't expected in children, although people who work with adults who have had strokes know it well.

"There are three or four rehabilitative techniques used with adults which work well.

"Our early studies suggest they may work for children, but more research is needed. Nevertheless, improving early assessment in children should be a priority."

Eric Taylor, professor of child and adolescent psychiatry at the Institute of Psychiatry in London, said: "This is the first actual evidence of this link.

"But it's in keeping with research from our unit that there are right-sided brain problems in children with ADHD.

"Clearly, it is only part of the problem. It's not to be expected that treating this would be the answer to the whole problem of ADHD.

"But it may be one particular way of helping children with the condition."

for adders.org


News