The development of pointing perception in infancy: Effects of communicative signals on covert shifts of attention

The present study aims to investigate the interplay of verbal and non-verbal communication with respect to infants’ perception of pointing gestures. Infants were presented with still images of pointing hands (cue) in combination with an acoustic stimulus. The communicative content of this acoustic stimulus was varied from being human and communicative to artificial. Saccadic reaction times (SRTs) from the cue to a peripheral target were measured as an indicator of the modulation of covert attention. The cueing effect (facilitated SRTs for congruent compared to incongruent trials) increased the more human and communicative the acoustic stimulus was, with a significant cueing effect being present only in the condition with referential language. This indicates a beneficial effect of verbal communication on the perception of non-verbal pointing gestures, emphasizing the important role verbal communication has in facilitating social understanding across domains. These findings additionally suggest that language and action are already closely interrelated at one year of age