title: The neural basis of somatosensory remapping develops in human infancy.
abstract: When we sense a touch, our brains take account of our current limb position to determine the location of that touch in external space [1, 2]. Here we show that changes in the way the brain processes somatosensory information in the first year of life underlie the origins of this ability [3]. In three experiments we recorded somatosensory evoked potentials (SEPs) from 6.5-, 8-, and 10-month-old infants while presenting vibrotactile stimuli to their hands across uncrossed- and crossed-hands postures. At all ages we observed SEPs over central regions contralateral to the stimulated hand. Somatosensory processing was influenced by arm posture from 8 months onward. At 8 months, posture influenced mid-latency SEP components, but by 10 months effects were observed at early components associated with feed-forward stages of somatosensory processing. Furthermore, sight of the hands was a necessary pre-requisite for somatosensory remapping at 10 months. Thus, the cortical networks [4] underlying the ability to dynamically update the location of a perceived touch across limb movements become functional during the first year of life. Up until at least 6.5 months of age, it seems that human infants' perceptions of tactile stimuli in the external environment are heavily dependent upon limb position.
authors.affiliation: Department of Psychology, University of Essex, Colchester CO4 3SQ, UK; Sensorimotor Development Research Unit, Department of Psychology, Goldsmiths, University of London, New Cross, London SE14 6NW, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Rigato
authors.affiliation: Sensorimotor Development Research Unit, Department of Psychology, Goldsmiths, University of London, New Cross, London SE14 6NW, UK.
authors.forename: Jannath
authors.initials: J
authors.lastname: Begum Ali
authors.affiliation: Sensorimotor Development Research Unit, Department of Psychology, Goldsmiths, University of London, New Cross, London SE14 6NW, UK.
authors.forename: José
authors.initials: J
authors.lastname: van Velzen
authors.affiliation: Sensorimotor Development Research Unit, Department of Psychology, Goldsmiths, University of London, New Cross, London SE14 6NW, UK. Electronic address: a.bremner@gold.ac.uk.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bremner
mesh_terms: D005073:Evoked Potentials, Somatosensory; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D010812:Physical Stimulation; D011187:Posture; D011597:Psychomotor Performance; D013028:Space Perception; D055698:Touch Perception