Irmgard Radermacher

Decreasing and increasing cues in naming therapy for aphasia

Background : Applying a hierarchy of cues is a well-established method in therapy for aphasic naming disorders (see overview in Nickels, 2002b; and Hillis & Caramazza, 1994; Wambaugh, 2003). Usually, cues are used in the increasing direction. Giving assistance as sparsely as possible, the naming of an individual item remains effortful which enhances the chance to recall it later on. But the high opportunity to make errors may be disadvantageous. As an alternative, the method of vanishing cues (see Glisky, 1992), which was designed for treatment of memory disorders, provides as much assistance as needed, thereby helping patients to avoid errors (see Riley & Heaton, 2000). Therefore, this method complies with “errorless learning” (see Baddeley & Wilson, 1994). It is favoured when amnesic patients have to learn new information. In aphasia therapy, the errorless learning procedure may be interesting for patients with severe naming disorders because it prevents them from producing frequent errors. Aims : The purpose of this study was to compare the effectiveness of increasing and vanishing cues for aphasic patients with naming disorders in a 4-week therapy programme. As patients may differ in the underlying mechanism of impairment, we expected a different therapy effect among and within patients. Furthermore, the importance of errorless learning should increase with severity of impairment because of error opportunity. Methods & Procedures : A total of 100 line drawings were selected and split into four sets of 25 items each. The sets were assigned to four conditions: control (no training), vanishing cue, increasing cue, and both-cue condition (training with both methods). Then 20 therapy sessions were ordered according to the alternating treatments design. During treatment, the patients attempts to name a picture were assisted by a hierarchy of oral cues given by the therapist. Treatment methods differed in order of application but not in the type of cues used. Outcomes & Results : Cueing therapy in general was effective for 8 of 10 patients. Those patients with moderate naming disorders profited less than those with severe naming disorders. Both methods differed among and within patients. However, in contrast to our prediction, we found no patient who improved only under vanishing cues but several who showed positive effects with increasing cues alone or with both, increasing and vanishing cues. Conclusions : Unlike patients with amnesia, patients with aphasia do not seem to be troubled by their errors and may not require the vanishing cue method.

Lexical decision of nonwords and pseudowords in humans: a positron emission tomography study

In this functional positron emission tomography study brain activations during an auditory lexical decision task with two experimental conditions were investigated. First, the subjects had to discriminate between real words and nonwords; second, real words varied with pseudowords. Comparing each of these tasks to an auditory control condition we found bilateral activation of the superior temporal and inferior frontal gyrus, lateralized to the left in the pseudoword condition. The comparison of the lexical decision tasks revealed higher rCBF during the pseudo-/real word decisions within BA 47, adjacent to Brocas area, and the anterior cingulate. The data support the notion that the lexical decision during a nonword task is mainly based on a phonological discrimination process, whereas a pseudoword task more strongly requires lexical access resulting in activation of BA 47.