‘Working memory’ is thought to consist of three components: one concerned with auditory-verbal processing, one with visual-spatial processing, and a central executive that controls both. It has been hypothesized that the relationships between the components changes as children develop. Very young children are more reliant on visuospatial processing, but later the auditory-verbal module becomes more dominant. It has also been found that the two sensory modules are not strongly associated in younger (5-8) American children, but are strongly associated in older children (9-12). The same study found that this pattern was also found in Laotian children, but not in children from the Congo, none of whom showed a strong association between visual and auditory working memory. Now a new study has found that Ugandan children showed greater dominance of the auditory-verbal module, particularly among the older children (8 ½ +); however, the visuospatial module was dominant among Senegalese children, both younger and older. It is hypothesized that the cultural differences are a product of literacy training — school enrolment was much less consistent among the Senegalese. But there may also be a link to nutritional status.

A rat study reveals that, for rats at least, an understanding of place and a sense of direction appears within two weeks of being born, seemingly independently of any experience of the world. The directional signal, which allows the animal to know which way it is facing, is already at adult levels as soon as it can be measured in newborn rats. Sense of place is also present early, but improves with age. Representations of distance appear a few days later. These processes depend on specialized cells in the hippocampus, which in humans plays a crucial role in long-term memory for events as well as spatial navigation. The findings fit in with the theory that a pre-wired spatial framework may provide a conceptual framework for experience.

The first comparison of the brain sizes of social and non-social individuals of the same species provides more support for the social brain hypothesis (we evolved our big brains to deal with social groups). The tropical sweat bee species, Megalopta genalis, have two sorts of queen: solitary ones, who themselves go out from the nest to forage for food, or social ones — who stay at home and sends out her daughters. Although even the social queens don't have bigger brains overall, the area associated with learning and memory (the mushroom body) was more developed in the social queens than in the solitary bees (and also the social daughters — suggesting dominance is also a factor).

Like human faces, infants are predisposed to pay attention to words. Now a new study shows that they learn concepts from them from a very early age. In the study, in which 46 three-month-old infants were shown a series of pictures of fish that were paired either with words (e.g., "Look at the toma!") or beeps (carefully matched to the words for tone and duration), those who heard the words subsequently showed signs of having formed the category “fish”, while those who heard the tones did not. Categorization was assumed when infants shown a picture of a new fish and a dinosaur side-by-side, looked longer at one picture than the other.

A five-year study involving 214 children born to healthy, non-smoking Caucasian women in Krakow, Poland, has found that those prenatally exposed to high levels of polycyclic aromatic hydrocarbons (PAHs) had a significant reduction in scores on a standardized test of reasoning ability and intelligence at age 5 (an estimated average decrease of 3.8 IQ points). The mothers wore small backpack personal air monitors for 48 hours during pregnancy to estimate their babies' PAH exposure. The finding persisted after mother’s intelligence, secondhand smoke exposure, lead and dietary PAH were taken into account. Previously, prenatal exposure to PAHs was found to adversely affect children's IQ at age 5 in children of nonsmoking African American and Dominican American women in New York City. PAHs are released into the air from the burning of fossil fuels.