| The current study investigated the role of sub vocalization supported by phonological working memory in visual narrative comprehension, specifically, it's role in memory for explicit content and inferencing. The role of sub vocalization was investigated using a concurrent articulatory suppression paradigm while participants viewed four children's picture stories. Target event episodes were identified in each story, each consisting of three episodic components: an initiating event, an action and an outcome. Inferencing was tested by systematically removing episodic components from target episodes. Measures of memory for explicit story content (A') and inferencing (False alarms) were calculated based on responses during a recognition task that included both seen and unseen pictures from target event episodes. There was no reduction of false alarm rates under articulatory suppression as predicted. However, view times did increase for episodic images that occurred after an episodic component was removed, suggesting that participants did generate inferences for missing episodic components. Together these results suggest that sub vocalization does not play a role in generating inferences during visual narrative viewing. While articulatory suppression did reduce memory performance for explicit content (A') so did foot tapping. Based on the current results it cannot be determined whether the impairment in the two conditions was due to different mechanisms (e.g., suppression of phonological working memory and grounded working memory systems) or due to a common mechanism (e.g., attentional control). Possible avenues of investigation to isolate the source of this effect are considered. |
