A study involving 130 HIV-positive people has found that memory impairment was associated with a significantly larger waistline.
Some 40% of participants (average age 46) had impaired cognition. This group had an average waist circumference of 39 inches, compared to 35 inches for those without such problems. Memory impairment was also linked to diabetes in those older than 55 (15% of those with memory problems had diabetes compared to only 3% of those without memory problems).
Women who received a once-standard type of chemotherapy regimen for breast cancer between 1976 and 1995 have been found to score worse on cognitive tests than women who never had cancer. Specifically, they tended to have lower scores on tests of immediate and delayed verbal memory, executive function, information processing speed, and psychomotor speed. The difference was comparable to some six years of age-related decline.
Data from 11,926 older twins (aged 65+) has found measurable cognitive impairment in 25% of them and subjective cognitive impairment in a further 39%, meaning that 64% of these older adults were experiencing some sort of cognitive impairment.
Data from the Nurses' Health Study Cognitive Cohort, involving 19,409 older women (70-81), has found that higher levels of long-term exposure to air pollution were associated with faster rates of cognitive decline over a four-year period.
For each 10 micrograms per cubic meter of air increase in pollutants, cognitive decline was comparable to two years of age-related decline.
Pollution exposure was estimated from geography. Cognition was tested by three telephone interviews, administered at roughly two-year intervals.
A review of 15 randomized controlled trials in which people with mild to moderate dementia were offered mental stimulation has concluded that such stimulation does indeed help slow down cognitive decline.
Previous research has pointed to a typical decline in our sense of control as we get older. Maintaining a sense of control, however, appears to be a key factor in successful aging. Unsurprisingly, in view of the evidence that self-belief and metacognitive understanding are important for cognitive performance, a stronger sense of control is associated with better cognitive performance. (By metacognitive understanding I mean the knowledge that cognitive performance is malleable, not fixed, and strategies and training are effective in improving cognition.)
A new study explains how marijuana impairs working memory. The component THC removes AMPA receptors for the neurotransmitter glutamate in the hippocampus. This means that there are fewer receivers for the information crossing between neurons.
The research is also significant because it adds to the growing evidence for the role of astrocytes in neural transmission of information.
A number of studies have found evidence that older adults can benefit from cognitive training. However, neural plasticity is thought to decline with age, and because of this, it’s thought that the younger-old, and/or the higher-functioning, may benefit more than the older-old, or the lower-functioning. On the other hand, because their performance may already be as good as it can be, higher-functioning seniors may be less likely to benefit. You can find evidence for both of these views.
The first study to look at the effects of the drug ecstasy on infant development has shown that infants exposed to ecstasy before they were born tend to be behind, especially in motor and coordination skills, at four months.
While smartphones and other digital assistants have been found to help people with mild memory impairment, their use by those with greater impairment has been less successful. However, a training program developed at the Baycrest Centre for Geriatric Care has been using the power of implicit memory to help impaired individuals master new skills.