Iron deficiency is the world's single most common nutrient deficiency, and a well-known cause of impaired cognitive, language, and motor development. Many countries therefore routinely supplement infant foods with iron. However, a new study suggests that, while there is no doubt that such fortification has helped reduce iron deficiency, it may be that there is an optimal level of iron for infant development.
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Is there, or is there not, a gender gap in mathematics performance? And if there is, is it biological or cultural?
Why is diabetes associated with cognitive impairment and even dementia in older adults? New research pinpoints two molecules that trigger a cascade of events that end in poor blood flow and brain atrophy.
The olfactory bulb is in the oldest part of our brain. It connects directly to the amygdala (our ‘emotion center’) and our prefrontal cortex, giving smells a more direct pathway to memory than our other senses. But the olfactory bulb is only part of the system processing smells. It projects to several other regions, all of which are together called the primary olfactory cortex, and of which the most prominent member is the piriform cortex.
I recently discussed some of the implications of head injuries and how even mild concussions can have serious and long-term consequences. A follow-up study looking at the effects of childhood traumatic brain injury ten years after the event has found that even those with mild TBI showed some measurable effects, while those with severe TBI had markedly poorer performance on a number of cognitive measures.
American football has been in the news a lot in recent years, as evidence has accumulated as to the brain damage incurred by professional footballers. But American football is a high-impact sport. Soccer is quite different. And yet the latest research reveals that even something as apparently unexceptional as bouncing a ball off your forehead can cause damage to your brain, if done often enough.
So-called ‘Gulf War syndrome’ is a poorly understood chronic condition associated with exposure to neurotoxic chemicals and nerve gas, and despite its name is associated with three main syndromes: impaired cognition (syndrome 1); confusion-ataxia (syndrome 2); central neuropathic pain (syndrome 3). Those with syndrome 2 are the most severely affected. Note that the use of the term ‘impaired cognition’ for syndrome 1 is not meant to indicate that the other syndromes show no impaired cognition; rather, it signals the absence of other primary symptoms such as ataxia and pain.
Certainly experiences that arouse emotions are remembered better than ones that have no emotional connection, but whether negative or positive memories are remembered best is a question that has produced equivocal results. While initial experiments suggested positive events were remembered better than negative, more recent studies have concluded the opposite.
The idea that negative events are remembered best is consistent with a theory that negative emotion signals a problem, leading to more detailed processing, while positive emotion relies more heavily on general scripts.
A certain level of mental decline in the senior years is regarded as normal, but some fortunate few don’t suffer from any decline at all. The Northwestern University Super Aging Project has found seniors aged 80+ who match or better the average episodic memory performance of people in their fifties. Comparison of the brains of 12 super-agers, 10 cognitively-normal seniors of similar age, and 14 middle-aged adults (average age 58) now reveals that the brains of super-agers also look like those of the middle-aged.
In yet another study of the effects of pollution on growing brains, it has been found that children who grew up in Mexico City (known for its very high pollution levels) performed significantly worse on cognitive tests than those from Polotitlán, a city with a strong air quality rating.