Laterality Effects for Higher Cognitive Processes
Robert Miller in Axonal Conduction Time and Human Cerebral Laterality, 2019
Curiously, the right hemisphere dominance for inferences drawn from a connected utterance also appears to apply to mental arithmetic. Many aspects of calculation are left hemisphere dominant, for instance acalculia related to alexia or agraphia for numbers. On the other hand acalculia related to disordered spatial ability is right hemisphere dominant (Levin and Spiers, 1985). Such lateralizations do not go beyond the perceptual lateralization discussed in Chapter 6. However, it appears that in mental arithmetic there is also a right hemisphere dominance not predictable from principles of perceptual lateralization: Dimond and Beaumont (1972) presented three double-digit numbers visually to normal subjects (640 msec per number), who had to say whether the third number was the sum (or the difference) of the first two, with reaction time as the response measure. There was a significant left field advantage, larger for the subtraction than the addition task. Qureshi and Dimond (1979) used a task similar to this in brain-damaged subjects, who were required to respond by nodding or shaking their head, with digit-pairs flashed to either left or right visual fields. Right brain-damaged subjects were much more impaired than left brain-damaged ones, regardless of the hemisphere to which stimuli were directed.
In the Shadow of Memory
Peggy Munson in Stricken, 2014
Numbers can be a terrible problem. I spent seventeen years (I checked; it was seventeen) working in the field of public finance and fiscal policy. At one point, I managed the budget of a $400 million state construction agency. Numbers were second nature to me until I got sick. Now I cannot get my daughter's street address right, no matter how many letters I write to her. I either transpose the numbers (131 1/2 instead of 311 1/2) or flip-flop them altogether (113 1/2 instead of 311 1/2). I can no longer add or subtract numbers in my head if they're larger than two digits, or at all if I have to “carry” numbers. We just canceled our long-distance telephone credit card and ordered a new one; if I use if often enough, I may have its fourteen numbers memorized by the time the new millennium begins. With my agent's telephone number on a card before me, I added it to my speed dialing system incorrectly and ended up calling a New York City garbage collection company, which was perhaps more of a symbolic error than I would care to admit. The proper term for my selective difficulty in dealing with numbers is “acalculia.” But I prefer to believe that I multiply and divide numbers the way a new Chinese immigrant speaks English, as if I'd never really seen the alphabet before, as if I couldn't quite form the sounds. So I think of my math as having an accent.
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
Impairment in the ability to perform simple arithmetic calculations; also used more broadly to refer to any deficit in the ability to use numbers, whether or not calculation is affected. The term DYSCALCULIA is synonymous in most usages (although in the strictest sense acalculia refers to an inability to calculate or use numbers, whereas dyscalculia implies impairment without complete abolition of the ability). Acalculia may result from brain injury or disease (for instance, STROKE, head trauma, ALZHEIMER'S DISEASE), in which case the deficit is referred to as an acquired acalculia. In developmental acalculias children with no obvious neurological abnormalities have difficulty learning to use numbers or calculate, despite normal educational opportunities.
Occurrence of speech-language disorders in the acute phase following pediatric acquired brain injury: results from the Ghent University Hospital
Published in Brain Injury, 2021
Cassandra Alighieri, Katrien De Maere, Gaby Poncelet, Lore Willekens, Catharine Vander Linden, Kristine Oostra, Kristiane Van Lierde, Evelien D’haeseleer
For the acquired learning disorders, analyses were based on the sample of children who followed primary or secondary education (n = 119/228, 52.2%). In other words, children younger than 6 years old were excluded because they had not yet acquired reading, writing or mathematical skills. In addition, 5 children with premorbid dyslexia were excluded so that the final analysis was based on a sample of 114 children. Descriptive statistics revealed that 38 of these 114 children (33.3%) presented with at least one acquired learning disorder. More specifically, 12 children (12/114, 10.5%) presented with mathematical difficulties (i.e. acalculia or dyscalculia). Concerning the children’s reading skills after the onset of the brain injury, 22 children (22/114, 19.3%) presented with technical reading problems whereas 13 children (13/114, 11.4%) had problems with reading comprehension. Spelling problems were observed in 21 of the 114 children with ABI (21/114, 18.4%).
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