Mentors: Professor Robert Wozniak and Kristin Kopple
Body-Part-as-Object (BPO) and Imagined-Object (IO) gestures are two forms of empty-handed gestures that signify an object through visual resemblance to an action normally associated with the specific referent. In BPO gestures, a body part takes the place of the object when an action related to that object is performed. For example, a fist moving up and down in a pounding motion may represent the action of hammering. In IO gestures, the observer must visualize or imagine the object. For example, to convey the action of a hammer using an IO gesture, the hand is slightly opened as if grasping an imaginary hammer, while the arm flexes to perform the pounding action of hammering. The goal of our research is to understand the age-of-onset for the comprehension of empty-handed gestures, determine whether one gesture form (BPO or IO) is more readily comprehended, and ask whether toddlers may profit from gesture comprehension training. Furthermore, we are interested in whether gestures for certain objects (e.g., a hammer gesture versus a crayon gesture) are more easily comprehended than others.
Participants included 60 typically-developing 30-month-old and 42-month-old males and females from the suburban Philadelphia area. Each session was divided into 5 experimental phases: Spontaneous Behavior, Baseline, Training/Filler, Posttest, and Verbal Comprehension. In each trial of the 5 phases, the participant retrieved objects from a box with four partitioned compartments, which held 4 randomized objects. The Spontaneous Behavior phase allowed the participant to freely select 2 objects of his/her choice. The Baseline phase assessed the participant’s level of gesture comprehension prior to gesture comprehension training, as the experimenter asked the participant to retrieve target objects using either BPO or IO gestures. The Training phase involved the experimenter asking the participant to retrieve target objects using BPO or IO gestures, but, contrary to the other phases, the child received verbal feedback about his/her performance. For a participant not in the Training condition, a Filler task involved the experimenter asking him/her to retrieve target objects using verbal request instead of gestures. The Posttest phase assessed the participant’s comprehension of gestures after receiving gesture comprehension training. Finally, a Verbal Comprehension phase measured the participant’s language skills, as the experimenter verbally requested target objects.
Data were coded by examining which objects each participant chose in order to assess the participant’s initial level of gesture comprehension and improvements in gesture comprehension after gesture comprehension training. We hypothesize that 42-month-old toddlers will comprehend gestures more successfully than the 30-month-old toddlers, that BPO gestures, which make less of a cognitive demand on the child, will be easier to comprehend than IO gestures, and that children will benefit from gesture comprehension training.