Dynamic aphasia and the generation of language Gail Robinson * and Lisa Cipolotti National Hospital for Neurology and Neurosurgery, London, WC1N 3BG, UK Available online 23 July 2004 Severely reduced propositional speech in the context of intact nominal language skills (i.e., repetition, naming, comprehension, and reading) is the hallmark of dynamic aphasia (Luria, 1970). Recent evidence suggests there may be different types of dynamic aphasia as some patients do not produce any response on verbal generation tasks, whilst others are able to perform normally on verbal genera- tion tasks. For example, Robinson and colleagues (Robinson, Blair, & Cipolotti, 1998; Robinson, Shallice, & Cipolotti, 2004) reported two dynamic aphasics who failed to produce a verbal response when many verbal response options were activated by a stimulus, but not when a dominant response was available. By contrast, a dynamic aphasic patient reported by Snowden, Griffiths, and Neary (1996) was able to produce sentences and words on specific verbal gener- ation tasks. We report a dynamic aphasic patient (KAS) who, sim- ilarly to the patient reported by Snowden et al. performed flawlessly on all verbal generation tasks, despite almost abolished propositional speech. Subjects KAS, a patient with progressive supranuclear palsy, presented with a severe verbal inertia. Spontaneous speech was virtually abolished in the context of well-preserved repetition, naming, reading, and com- prehension skills. This pattern can be classed as dynamic aphasia. MRI brain scan revealed generalized cerebral atrophy, severe midbrain at- rophy and white matter change in the frontal lobes bilaterally. Three matched healthy controls were used. Methods KAS and controls were administered five verbal generation and two narrative production tasks. The verbal generation tasks consisted of 30 sentence frames, 30 phrases, 30 word pairs, 30 words, and 30 simple pictorial scenes (based on Robinson et al., 1998, 2004). KAS was required to generate a word or phrase to complete sentence frames and phrases, respectively, and to generate a sentence from word pairs, single words, and pictorial scenes. Number correct was recorded. The narrative production tasks involved an interview and a topic-based discussion. The interview was either unstructured with minimal verbal prompting (duration = 16 min for KAS and a mean of 14.2 min for controls) or highly structured and much shorter with unlimited verbal prompting (duration = 8 min). For the topic-based discussion, three topics were discussed: films, actresses, and stage shows. There were two conditions for the source of the topic. The topic was either externally driven in that the examiner selected an example of the topic (familiarity with the topic was ensured) or internally generated in that KAS selected her favorite example of a topic. Subjects were given a maximum of 2 min for each topic for both conditions. For both narrative production tasks, speech rate (words per minute), and total number of words produced were calculated. Results KAS was unimpaired on all verbal generation tasks. Despite al- most abolished propositional speech, CK was able to generate 29/30 words to complete sentences, 30/30 phrases to complete phrases, 29/30 sentences from a single word, 30/30 sentences from word pairs, and 30/ 30 sentences that described pictorial scenes. In contrast, KAS was severely impaired on both narrative production tasks. Both in the interviews and in the topic-based discussions her speech rate and total number of words she was able to produce was severely reduced. However, her difficulties were far greater in the unstructured interview that contained minimal prompting and in the discussion task when the source of the topic was externally driven. In particular, in the unstructured interview her speech rate was less than half than in the shorter structured interview. Moreover, she produced much less words (speech rate, No. of words produced: unstructured = 9.4, 149; structured = 21.4, 171; Controls—unstructured = 180.6, 2602; structured = 155.9, 1247). Similarly in the topic-based discussion task her speech rate and total number of words produced were more reduced when a topic was exter- nally generated (speech rate, No. of words produced: externally gener- ated = 9.2, 18.3; internally generated = 25.2, 50.3; Controls—externally generated = 180.7, 361.3; internally generated = 183.7, 367.3). Discussion Despite almost abolished propositional speech, KAS performed well on verbal generation tasks. Thus, similar to the dynamic aphasic described by Snowden et al. (1996), KAS is able to produce a verbal response on specific verbal generation tasks. Nevertheless, KAS’s performance on narrative production tasks is severely im- paired, especially when the task is unstructured or when the source Brain and Language 91 (2004) 49–50 www.elsevier.com/locate/b&l * Corresponding author. Fax: +44-20-78132516. E-mail address: g.robinson@ion.ucl.ac.uk (G. Robinson). 0093-934X/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.bandl.2004.06.027