| Summary: | Background
People with mild aphasia and healthy elderly often exhibit similar impairments on language tests of word retrieval. However, variable practice effects in object naming by three individuals with aphasia compared to young and elderly adults have been reported (Wingfield et al. 2006). Wingfield et al. (2006) found that naming of the same pictures of objects over five trials demonstrated decreasing response latencies over repeated trials for both older and younger adults, but not for individuals with aphasia. In fact, among their three participants with aphasia, response latencies in the consecutive trials differed considerably. The authors suggested that different underlying processes may be involved in word retrieval for people with aphasia compared to adults without brain injuries. In our study we aimed to further consider the effect of practice on both object and action naming in individuals with mild aphasia.
Method
One woman with anomic aphasia (age 38 years; WAB Aphasia Quotient = 88) and one healthy woman (age 25 years) participated. Both were native English speakers and reported 18 years of formal education. Participants were tested individually, with a set of 27 object pictures and a set of 27 action pictures presented one at a time on a computer screen. The participants were instructed to name each picture as quickly as possible as soon as each picture appeared on the screen. There were 10 trials of each set of pictures, with different random orders for each trial. The order of presentation of the object and action picture sets alternated across participants.
Naming responses were recorded to computer sound files for later measurements of response latencies. A brief tone was presented simultaneous with the picture onset, allowing later measurement of response latencies from the onset of picture presentation to the onset of the participant’s correct response.
Results
Our findings resembled those reported in Wingfield et al. (2006) in that the healthy participant demonstrated reduced latencies after the initial trial followed by a plateau, whereas the participant with aphasia had variable latencies across trials. Both participants had longer latencies for action naming than for object naming (mean .61 and .97 seconds for objects and 1.35 and 2.09 for actions for the healthy person and the participant with aphasia, respectively). The healthy participant demonstrated a pattern in which after the initial trial, response latencies decreased in both object and action naming; the person with aphasia demonstrated an initial decrease in the action naming only (see Figure). ANOVAs confirmed a main effect of Trial for the healthy participant for both object and action naming and for the action only for the person with aphasia.
Conclusion
Our data support that different underlying processes may be involved in word retrieval for people with aphasia compared to adults without brain injuries, even when additional trials are examined. The effect of repetition on verbs and nouns may differ. Data collection and analysis from additional participants is in progress.
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