Gesture Helps, Only If You Need It: Inhibiting Gesture Reduces Tip-of-the-Tongue Resolution for Those With Weak Short-Term Memory

Abstract

People frequently gesture when a word is on the tip of their tongue (TOT), yet research is mixed as to whether and why gesture aids lexical retrieval. We tested three accounts: the lexical retrieval hypothesis, which predicts that semantically related gestures facilitate successful lexical retrieval; the cognitive load account, which predicts that matching gestures facilitate lexical retrieval only when retrieval is hard, as in the case of a TOT; and the motor movement account, which predicts that any motor movements should support lexical retrieval. In Experiment 1 (a between-subjects study; N = 90), gesture inhibition, but not neck inhibition, affected TOT resolution but not overall lexical retrieval; participants in the gesture-inhibited condition resolved fewer TOTs than participants who were allowed to gesture. When participants could gesture, they produced more representational gestures during resolved than unresolved TOTs, a pattern not observed for meaningless motor movements (e.g., beats). However, the effect of gesture inhibition on TOT resolution was not uniform; some participants resolved many TOTs, while others struggled. In Experiment 2 (a within-subjects study; N = 34), the effect of gesture inhibition was traced to individual differences in verbal, not spatial short-term memory (STM) span; those with weaker verbal STM resolved fewer TOTs when unable to gesture. This relationship between verbal STM and TOT resolution was not observed when participants were allowed to gesture. Taken together, these results fit the cognitive load account; when lexical retrieval is hard, gesture effectively reduces the cognitive load of TOT resolution for those who find the task especially taxing.

Keywords: Gesture; Individual differences; Lexical retrieval; Spatial short-term memory; Tip-of-the-tongue states; Verbal short-term memory.

Figure 1.

Boxplots depicting the proportion of self-resolved TOTs in each condition. Individual participants are depicted with a dot. We observed significantly greater variability in TOT resolution in the gesture-inhibited group compared to the gesture-allowed group. Plot was created using ggplot 2 for the R programing environment (Wikham, 2016).

Figure 2.

Predicted probability of resolving a TOT while gesture was inhibited as a function of the z-scored predictors (A) digit span, (B) spatial span, (C) representational gesture use, (D) TOT resolution ability while allowed to gesture. Bands around the regression lines indicate 95% CIs computed from SEMs. Plots were created using the plot_model function in sjplot (Lüdecke, 2019).