Comparison of the recovery pattern in verb use in fluent and non-fluent aphasics in the first six months after stroke.

Background: Verbs in aphasia is a widely studied topic in the past decades. A distinction can be made between fluent and non-fluent aphasic patients. In the traditional view fluent aphasics primarily show lexical-semantic deficits, while non-fluent aphasics have mainly syntactic deficits. Yet, several studies disputed this traditional view. Syntactic deficits were found in fluent aphasics as well and non-fluent aphasics indeed show lexical-semantic deficits. The underlying deficit was denounced and a deficit on integration level was introduced (Bastiaanse and Bol, 2001). A reverse relation between the verb diversity and inflection in non-fluent aphasics was found, in which individuals show a high verb diversity, but poor verb inflection or vice versa. Most studies examined the use of verbs in the chronic phase of aphasia and used data collected at one time point post stroke. Aims: The current study was designed to investigate (a) whether the reverse relation described by Bastiaanse and colleagues (and Jonkers, 1998; and Bol, 2001) is also found in fluent aphasics, (b) whether this reverse relation is also found in the acute phase of aphasia, (c) whether this reverse relation changes during recovery, (d) whether the relation in recovery has a reverse character as well and (e) whether two different tasks yield different results on all variables examined. Methods and Procedures: Two groups of aphasics, fluent and non-fluent, were included. Speech samples on a story retelling task and the spontaneous speech were analyzed at 2 weeks and 6 months post stroke. Type token ratio of verbs (verb diversity) and finiteness index (inflection ability) were calculated and compared both within and between groups. Results: In the group comparisons no reverse relation was found for either one of the groups at one time point post stroke. By examining the individual results, this reverse relation was found in both groups of aphasics. In the recovery, both groups of aphasics showed a reverse relation as well. In the comparison of two examined tasks, the spontaneous speech task showed a significant discrepancy between both groups of aphasics in the TTR and the story retelling task did not; in the FI no difference between the both tasks relation between finiteness index and type token ratio? ; (c) Is this relation the same in fluent and non-fluent aphasia? ; (d) Does this relation change over time? ; (e) Is there a relation in recovery between finiteness index and type token ratio? ; and (f) Is there a discrepancy on the finiteness index and type token ratio between a story retelling task and spontaneous speech? The current study demonstrates the presence of a reverse relation between type token ratio and finiteness index for non-fluent aphasics at 2 weeks and 6 months post stroke and for fluent aphasics at 6 months post stroke. Like Bastiaanse and Bol (2001) point out, every patient is capable of producing and inflecting verbs; the competence is present, but does not always emerge. For that reason the underlying deficit of the verb retrieval and inflection problems of both fluent and non-fluent aphasics is equivocal. The traditional view of fluent aphasics being semantically affected and non-fluent aphasics being grammatically affected is no longer sufficient. The impairment at interface level implied by Bastiaanse and Bol appears to be plausible. The findings of the current study, particularly the presence of a reverse relation in both fluent and non-fluent aphasics, amplify the theory formulated by Bastiaanse and Bol.