Infants' haptic perception of texture in the presence and absence of visual cues

Seven-month-old infants' haptic perception of texture was examined using visually identical smooth and rough textures. Forty-eight infants participated in a familiarization-novelty-return-to-familiar procedure. Following familiarization, experimental infants received a novel texture (either rough or smooth) during the novelty phase and the original texture from the familiarization phase was presented in the return-to-familiar phase. Control infants received the same texture, either rough or smooth, throughout the three phases. For half of the infants in each of che groups the stimuli were occluded by an opaque cover. For the remaining infants, stimuli were visible through a transparent cover, infants were allowed to freely explore the textures in each phase. Manual contact (touching and grasping), bimanual contact, scrumbling, fingering, and total visual attention and fixation were measured. The findings suggest chat: (i) processing of texture may take longer than indicated in past literature; infants in both the experimental and control groups maintained high levels of manual contact throughout the three phases; (ii) 7-month-old infants may, nonetheless, be capable of making texture discriminations; experimental infants' responses during the return-to-familiar phase were indicative of recognition memory for the familiarization texture; (iii) infants use more efficient exploratory hand strategies when texture stimuli are nor visible; and (iv) while vision appears to increase coral visual attention, to direct visual fixation and to direct both hands towards the stimuli, it does not facilitate haptic perception of texture.