Observing gestures facilitate listeners’ comprehension, especially for visual-spatial information. However, people differ in how and to what extent they benefit from gestures depending on their visual-spatial abilities. This study examined whether and how spatial skills (i.e., mental rotation) relate to how much listeners benefit from observing gestures. We tested 51 Turkish-speaking adults’ comprehension of spatial relations when the critical spatial information was provided in three different conditions: (1) only in speech (e.g., saying “right” without making any gesture), (2) both in speech and in gesture (saying “right” and gesturing to the right), and (3) only in gesture (saying “here” and gesturing to the right). We found that mental rotation scores were associated with increased accuracy only for speech + gesture (z = 2.37, p = .02) and the gesture-only conditions (z = 2.13, p = .03). These results suggest that visual-spatial cognitive resources might be important for gesture processing.

We investigated (1) how focal brain-injured patients describe causal events (causal verb like “push” and the instrument of the action like “the stick”) in speech and co-speech gestures and (2) whether gestures compensate for their impaired verbalization. 16 left hemisphere damaged (LHD), 16 right hemisphere damaged (RHD) and 14 controls were asked to describe causal events (22 video clips). The correct use of causal action components in speech and iconic gestures referring to these actions were coded. Results indicated that LHD patients were less accurate in using both components in speech compared to RHD and controls. There was no difference in the number of iconic gestures among groups. Yet, LHD patients were more likely to omit or misuse both components in speech and in gesture than RHD and controls. Particularly, damage to the left inferior and middle frontal gyrus resulted in problems in both modalities, suggesting conceptual deficits of causality.

Subjective duration estimates are positively related to the magnitude of various non-temporal stimuli (e.g. Xuan et al., 2007). Our study investigated whether temporal and spatial magnitude information conveyed by linguistic stimuli would affect perceived duration in a temporal reproduction task. We used time-related words referring to different exact durations (e.g. second; Experiment 1), and spatial-temporal metaphors (e.g. long), referring to indistinct temporal as well as spatial magnitudes (Experiment 2). In both experiments, participants over-reproduced the shorter target duration (2.4 s) and under- reproduced the longer target duration (4.8 s). In Experiment 1, participants under-reproduced the longer target duration more when they saw “week” in the training and “year” in the reproduction. Yet, we did not observe the same semantic magnitude effect in other word pairs either in Experiment 1 or 2. Overall, we did not find supporting evidence for magnitude information conveyed by language affecting subjective time estimates.

Language guides how we conceptualize the level of detail in categorical spatial relations (Bowerman, 1996; Choi, 2006). This study examined whether details in different dimensions (i.e., distance and direction) given in spatial descriptions vary as a function of spatial categories. We asked Turkish speaking participants (N=40) to describe the spatial relation between two geometric objects aligned either on the horizontal or the vertical axis. There were three relations (on/above, under/below, next to/near) of which the direction (left, right) and the distance (adjacent, 5 mm, 10 mm, 15 mm) varied equally. More detailed descriptions in terms of direction and distance were provided for ‘next to/near’ compared to ‘on/above’ and ‘under/below’ relations. These results suggest an asymmetry between vertical and horizontal axes. Sensitivity for detailed descriptions along the horizontal axis may relate to language-specific spatial categorization.

There is contradictory evidence on whether speech production gets impaired or enhanced when people are restrained from gesturing. There is also very little research on how this effect can change with aging. The present study sought evidence for these by asking young and elderly adults to describe two different routes on a map in spontaneous speech and when gestures were prohibited. We found that elderly adults produced more spatial language when they were restricted to use gestures compared to their spontaneous speech, whereas young adults produced comparable levels of spatial language in both conditions. Young and elderly adults used comparable levels of gestures in their spontaneous route descriptions. Yet, only young adults’ gesture use correlated positively with their spatial language production. Thus, the results of gesture prohibition on speech production are different for young and elderly adults.