Our ability to perceive and integrate multiple stimuli from the environment and to think in an abstract manner is remarkable. Here, we publish three articles that investigate the physiological and neuroanatomical underpinnings of multisensory integration, number processing and how changes in brain anatomy during puberty might contribute to adolescent social behaviour.

In an authoritative Review on page 255, Stein and Stanford discuss our knowledge of how information from different senses is integrated by neurons on multiple levels of the neural axis. They also consider how integration of sensory information in multiple brain regions contributes to perception and behaviour.

Only humans use abstract symbols to represent numerical magnitude. In his Review on page 278, Ansari discusses whether such abstract representations of number are processed using the same neural mechanisms as those that underlie basic number processing, which are also found in monkeys. In addition, Ansari reviews recent findings that show the effects of human development, learning and culture on the neural correlates of number processing and calculation.

Our ability to interact and empathise with other people is a social trait that is mediated by specific areas of the brain, develops during childhood and is further refined during adolescence. On page 267, Blakemore discusses how structural and functional changes in the medial prefrontal cortex and the superior temporal sulcus might underlie the alterations in social behaviour that characterize adolescence.

Exploring neuronal integration and cognitive processing will deepen our understanding of what makes us individual and will also reveal how these processes are influenced by age and external factors.