Relational congruence facilitates neural mapping of spatial and temporal magnitudes in preverbal infants

- Infants show a relational congruence bias in learning spatial and temporal pairings.
- Relational congruence bias is not dependent on redundancy within or across the senses.
- Representations of space and time interact in infancy, before schooling or language.

Mental representations of space, time, and number are fundamental to our understanding of the world around us. It should come as no surprise that representations of each are functional early in human development, appear to share a common format, and may be maintained by overlapping cortical structures. The consequences of these similarities for early learning and behavior are poorly understood. We investigated this issue by assessing neurophysiological processing of audio-visual temporal and spatial magnitude pairs using event-related potentials (ERPs) with young infants. We observed differential early processing and later enhanced attentional processing for pairings of spatial and temporal magnitudes that were relationally congruent (short visual character paired with a short auditory tone or long visual character paired with a long auditory tone) compared to the same stimuli paired in a relationally incongruent manner (short visual character with the long auditory tone or long visual character with a short tone). Unlike previous studies, these results were not dependent on a redundancy of information between the senses or an alignment of congruent magnitude properties within a single sense modality. Rather, these results demonstrate that mental representations of space and time interact to bias learning before formal instruction or the acquisition of spatial language.