The Effect of Word Familiarity and Treatment Approach on Word Retrieval Skills in Aphasia

The purpose of this investigation was to examine the influence of subjective word familiarity on word retrieval ability and responsiveness to short, intensive aphasia treatment. Four native English-speaking participants with chronic aphasia received Phonological Components Analysis (PCA) and Semantic Feature Analysis (SFA) treatments in a crossover design. Each treatment focused on retrieval of familiar and unfamiliar words based on participant self-rating. There has been limited research relative to the influence of subjective familiarity on word retrieval. Furthermore, no studies to date have examined the effect of familiarity on treatments targeting improved word retrieval of individuals with aphasia. Additional information is needed relative to the factors that influence word retrieval as well as how these factors affect an individual's response to treatment. As individuals with aphasia have been observed to respond differently to treatment, it is valuable to examine the variables that may motivate change, such as subjective familiarity.  Both accuracy and reaction time measurements were obtained for all stimuli at baseline and at the beginning of each day of treatment during SFA and PCA treatment protocols for each participant. Probe stimuli were presented throughout each treatment protocol to examine generalization. The Western-Aphasia Battery Revised and the Test of Adolescent/Adult Word Finding were administered pre-treatment and periodically throughout the experimental protocol.  Subjective familiarity of stimuli influenced word retrieval relative to accuracy and reaction time for two of the four participants. SFA and PCA treatments had varied effects on accuracy and reaction time across participants. Specifically, treatment effectiveness was significantly evident for three of four participants for SFA whereas one participant demonstrated significant changes after PCA treatment. Generalization to untreated stimuli was minimal; only one participant demonstrated significant changes relative to improvement from treatment. Relationship between accuracy and reaction time was observed for one participant relative to familiarity. Specifically, JD demonstrated a direct relationship between accuracy and RT for familiarity with increased accuracy and faster retrieval for familiar stimuli at baseline. However, JD showed an inverse relationship between speed and accuracy for familiar stimuli after both treatment approaches. Two participants (RR, RM) demonstrated a direct relationship between accuracy and RT relative to treatment with increased accuracy and faster retrieval after SFA treatment. IC exhibited a speed-accuracy of retrieval trade-off with increased accuracy accompanied by slower retrieval, specific to SFA treatment. Further understanding of these variables in treatment of word retrieval is needed to determine effectiveness of specific treatments.   Overall, the present findings suggest that subjective familiarity may influence word retrieval skills relative to accuracy and reaction time for some individuals with aphasia. Furthermore, intensive SFA or PCA treatment can yield improvement in word retrieval skills and may result in standardized aphasia test performance in participants with aphasia, regardless of severity, chronicity, or basis of retrieval impairment.  M.S