Developmental Paths of Pointing for Various Motives in Infants with and without Language Delay

Pointing is one of the first conventional means of communication and infants have various motives for engaging in it such as imperative, declarative, or informative. Little is known about the developmental paths of producing and understanding these different motives. In our longitudinal study (N = 58) during the second year of life, we experimentally elicited infants' pointing production and comprehension in various settings and under pragmatically valid conditions. We followed two steps in our analyses and assessed the occurrence of canonical index-finger pointing for different motives and the engagement in an ongoing interaction in pursuit of a joint goal revealed by frequency and multimodal utterances. For understanding the developmental paths, we compared two groups: typically developing infants (TD) and infants who have been assessed as having delayed language development (LD). Results showed that the developmental paths differed according to the various motives. When comparing the two groups, for all motives, LD infants produced index-finger pointing 2 months later than TD infants. For the engagement, although the pattern was less consistent across settings, the frequency of pointing was comparable in both groups, but infants with LD used less canonical forms of pointing and made fewer multimodal contributions than TD children.

Effects of pointing compared with naming and observing during encoding on item and source memory in young and older adults

Research showed that source memory functioning declines with ageing. Evidence suggests that encoding visual stimuli with manual pointing in addition to visual observation can have a positive effect on spatial memory compared with visual observation only. The present study investigated whether pointing at picture locations during encoding would lead to better spatial source memory than naming (Experiment 1) and visual observation only (Experiment 2) in young and older adults. Experiment 3 investigated whether response modality during the test phase would influence spatial source memory performance. Experiments 1 and 2 supported the hypothesis that pointing during encoding led to better source memory for picture locations than naming or observation only. Young adults outperformed older adults on the source memory but not the item memory task in both Experiments 1 and 2. In Experiments 1 and 2, participants manually responded in the test phase. Experiment 3 showed that if participants had to verbally respond in the test phase, the positive effect of pointing compared with naming during encoding disappeared. The results suggest that pointing at picture locations during encoding can enhance spatial source memory in both young and older adults, but only if the response modality is congruent in the test phase.