Timing of gazes in child dialogues: a time-course analysis of requests and back channelling in referential communication.
BACKGROUND
This study investigates gaze behaviour in child dialogues. In earlier studies the authors have investigated the use of requests for clarification and responses in order to study the co-creation of understanding in a referential communication task. By adding eye tracking, this line of research is now expanded to include non-verbal contributions in conversation.


OBJECTIVE
To investigate the timing of gazes in face-to-face interaction and to relate the gaze behaviour to the use of requests for clarification.


METHODS
Eight conversational pairs of typically developing 10-15 year olds participated. The pairs (director and executor) performed a referential communication task requiring the description of faces. During the dialogues both participants wore head-mounted eye trackers. All gazes were recorded and categorized according to the area fixated (Task, Face, Off). The verbal context for all instances of gaze at the partner's face was identified and categorized using time-course analysis.


RESULTS
The results showed that the executor spends almost 90% of the time fixating the gaze on the task, 10% on the director's face and less than 0.5% elsewhere. Turn shift, primarily requests for clarification, and back channelling significantly predicted the executors' gaze to the face of the task director. The distribution of types of requests showed that requests for previously unmentioned information were significantly more likely to be associated with gaze at the director.


CONCLUSIONS
The study shows that the executors' gaze at the director accompanies important dynamic shifts in the dialogue. The association with requests for clarification indicates that gaze at the director can be used to monitor the response with two modalities. Furthermore, the significantly higher association with requests for previously unmentioned information indicates that gaze may be used to emphasize the verbal content. The results will be used as a reference for studies of gaze behaviour in clinical populations with hearing and language impairments.
Department of Logopedics, Phoniatrics and Audiology, Clinical Sciences, Lund University, Lund, Sweden. olof.sandgren@med.lu.se
Olof
O
Sandgren
Richard
R
Andersson
Joost
J
van de Weijer
Kristina
K
Hansson
Birgitta
B
Sahlén
D000293:Adolescent; D002648:Child; D002663:Child Language; D003142:Communication; D003147:Communication Disorders / Q000534:rehabilitation / Q000628:therapy*; D012048:Correction of Hearing Impairment; D005133:Eye Movements; D005145:Face; D005260:Female; D005403:Fixation, Ocular; D006311:Hearing Disorders / Q000628:therapy*; D006801:Humans; D007808:Language Therapy; D008297:Male; D009633:Nonverbal Communication; D011930:Reaction Time; D012919:Social Behavior; D014796:Visual Perception