Differences in the Interplay of Face and Speech Processing in 5-Year-Olds and Adults

The current study examined to what extent face and speech processing interact with each other and whether they enhance or impair the processing of the other in 5-year-olds (n = 51) and adults (n = 34). Using a computer-based speeded sorting task allowed to directly test the influence of auditory speech on face processing and the influence of face identity on auditory speech processing within one experiment. Participants were asked to either sort faces while ignoring auditory speech information (face task) or to sort auditory speech while ignoring face information (speech task). The tasks comprised three conditions: control (irrelevant dimension constant), correlational (congruent pairing of relevant and irrelevant dimension), and orthogonal (random pairing). For the 5-year-olds, reaction times did not differ in the face task, but differed in the speech task. They were the fastest in the control and the slowest in the orthogonal compared with the constant conditions. Adults' reaction times were similar across conditions and tasks indicating an independent processing of faces and speech. Hence, we found an asymmetrical processing pattern between face and auditory speech processing in children, in which face identity is processed independent of auditory speech; however, auditory speech processing is affected by face identity.