The effect of redundant cues on comprehension of spoken messages by aphasic adults.

Aphasic adults with severe auditory comprehension impairment responded to redundant and nonredundant spoken and/or gestured messages by pointing to pictures. Messages of two types (pantomime and emblem) were presented under four conditions (spoken message alone, spoken message repeated, gestured message alone, and spoken message plus redundant gesture). Though spoken messages repeated and spoken messages with gestures were comprehended significantly more often than gestures alone, neither of these stimulus conditions was reliably superior to spoken messages alone. This finding casts doubt on the clinical strategy of supplementing spoken messages with redundant gestures when auditory comprehension is severely impaired, and raises questions about the ability of severely aphasic individuals to utilize semantically redundant message content. Pantomimes were consistently comprehended more frequently than emblems, regardless of stimulus condition. This finding was attributed to a depictability factor: the pictures associated with pantomimes were relatively direct representations of item content, while those associated with emblems were necessarily less direct representations. For this group of subjects, whose range of comprehension deficit was deliberately restricted, neither auditory nor reading comprehension at the single-word level was found to correlate with comprehension of symbolic gestures.