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Verb learning profiles in aphasic frontotemporal dementia subtypes
Brain and Language 95 (2005) 153–154 www.elsevier.com/locate/b&l
Verb learning profiles in aphasic frontotemporal dementia subtypes R.C. Murray 1, P. Koenig, G.M. McCawley, S. Antani, M. Grossman
*
Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA Accepted 8 July 2005 Available online 12 September 2005
Introduction Frontotemporal dementia (FTD) has two aphasic subtypes. Progressive nonfluent aphasia (PNFA) is characterized by decreased speech output and impaired comprehension of grammar. Semantic dementia (SD) results in profound loss of semantic knowledge of single words. Previous studies of language function in FTD have focused largely on decreased comprehension of previously acquired knowledge. An alternative way to assess language impairment is to monitor acquisition of different aspects of an unfamiliar word (Grossman, Mickanin, Onishi, Robinson, & D’Esposito, 1997). Language processing can thus be examined independent of inter-subject differences in previously held knowledge. We exposed PNFA and SD subjects to a new word and assessed their ability to acquire it. We hypothesized that each FTD subtype would demonstrate a different pattern of impairment. PNFA patients were expected to have difficulty understanding the grammatical information associated with the verb, and SD patients were expected to have difficulty acquiring the verb’s semantic content.
Acquisition of the grammatical aspects of lour was assessed by asking patients to judge the acceptability of 48 sentences. These included sentences using lour, sentences using a known verb of facial expression, and sentences using a pseudoword. In some sentences, lour and other words of facial expression were used in the appropriate sentence slot, while in others they were used inappropriately in the sentence slot of another word class (i.e., noun, adjective, preposition). Comprehension of the meaning of lour was assessed by presenting pictures paired with three word choices, and instructing patients to choose the word that best went with the picture. Word choices included lour, known verbs of facial expression, and pseudowords. Individual patient profiles were constructed to describe patient performance on each task. Scores that did not differ from chance were considered impaired. For the sentence task, performance on sentences using lour was compared to performance on known word sentences and pseudoword sentences. For the picture task, accurate endorsement of lour was compared to endorsements of known words and pseudowords. A subset of each patient group, including elderly controls, were conservative in their performances. These subjects rejected all uses of unfamiliar phonological shapes, including pseudowords and lour.
Design and methods FTD subtype diagnoses were made by an experienced neurologist (MG) according to published criteria. Participants included 6 PNFA patients and 12 SD patients along with 18 elderly controls matched for age, education, and scores on mini mental status examination (MMSE). We identified the very-low frequency English verb lour and exposed patients to the verb withinin the context of a narrative. The sentence ‘‘Louise sees the man lour at her’’ was paired with a picture showing a man frowning in disapproval at a girl named Louise. The word thus appears to denote a facial expression, and its grammatical word class is shown to be a verb that can take an indirect object. Five forced-choice picture-sentence matching pairs using the verb were subsequently given to each subject. Feedback was given until the correct picture was selected. *
1
Corresponding author. Fax: +1 44 1638 751909. E-mail address: [email protected] (M. Grossman). Present address: Animal Health Trust, Lanwades Park, Centre for Equine Studies, Kentford, New Market, Suffolk CB8 7UU, UK.
0093-934X/$ - see front matter Ó 2005 Published by Elsevier Inc. doi:10.1016/j.bandl.2005.07.084
Results PNFA and SD subjects were impaired on the sentence judgment task relative to controls. Only 17% of PNFA (n = 1) patients exhibited ideal patient profiles, whereas 50% (n = 3) were impaired and 33% (n = 2) were conservative. PNFA patients with impaired profiles were only impaired on sentences with lour. An ideal performance profile was seen in 17% (n = 2) of SD patients, 8% (n = 1) were conservative and 75% (n = 9) were impaired. Impaired SD patients were divided between those that were impaired in their judgments of lour and pseudowords (25%, n = 3), and those with a selective impairment for judging sentences with lour (50%, n = 6). On the picture–word matching task, no SD patients exhibited an ideal performance profile while roughly half of both elderly control patients and PFNA patients were ideal. Half of PNFA patients (n = 3) were ideal in their picture judgments, 33% (n = 2) were conservative and one (16%) was impaired. This patient was impaired on judgments of both lour and pseudowords. No SD patients were ideal in their
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Abstract / Brain and Language 95 (2005) 153–154
performance profile, 25% (n = 3) were conservative and 75% (n = 9) were impaired. Of the impaired patients, 58% (n = 7) were impaired in their judgments of lour and pseudowords, and 17% (n = 2) were impaired only in their judgments of lour.
Acquisition of the verb lour would be demonstrated by treating it similarly to known words, but differently than pseudowords. Few PNFA patients met these criteria for judgments on sentences in which the grammatical form class was varied (Fig. 1). However, the majority of non-conservative response profiles for picture judgments in PNFA did meet these criteria. Thus PNFA patients had greater difficulty acquiring the grammatical information associated with a novel verb, but seemed able to understand its semantic content. No SD patient exhibited intact acquisition of the meaning of lour. This was shown in the picture–word matching task (Fig. 1), which depends on semantic memory. In addition, while SD patients were impaired on the grammatical sentence judgment task, their errors differed from those of PNFA patients. SD profiles were more frequently impaired for sentences involving pseudowords as well as the test verb, rather than only those involving the test verb. Comprehension of the grammatical aspects of a novel verb is in part dependent upon intact semantic knowledge. It is possible that poor semantic acquisition of the test verb resulted in an impaired ability to understand grammatical aspects of the verb as well. Many of the language demands necessary for processing previously held lexical knowledge are in turn necessary for the acquisition of novel words. Our results provide evidence for selective impairments of distinct aspects of language in aphasic subtypes of FTD.
90 Percent in profile group
Discussion
Non-conservative patient profiles 100
80 70 60 50 40 30 20 10 0 Sentence
Picture
Elderly Control
Sentence
Picture
SD
Sentence
Picture
PNFA
Patient type Impaired Ideal
Fig.1. Patient profile analysis on sentence-judgement and picture–word matching.
Reference Grossman, M., Mickanin, J., Onishi, K., Robinson, K. M., & D’Esposito, M. (1997). Lexical acquisition in probable Alzheimer’s disease. Brain and Language, 60, 443–463.
Verb learning profiles in aphasic frontotemporal dementia subtypes R.C. Murray 1, P. Koenig, G.M. McCawley, S. Antani, M. Grossman
*
Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA Accepted 8 July 2005 Available online 12 September 2005
Introduction Frontotemporal dementia (FTD) has two aphasic subtypes. Progressive nonfluent aphasia (PNFA) is characterized by decreased speech output and impaired comprehension of grammar. Semantic dementia (SD) results in profound loss of semantic knowledge of single words. Previous studies of language function in FTD have focused largely on decreased comprehension of previously acquired knowledge. An alternative way to assess language impairment is to monitor acquisition of different aspects of an unfamiliar word (Grossman, Mickanin, Onishi, Robinson, & D’Esposito, 1997). Language processing can thus be examined independent of inter-subject differences in previously held knowledge. We exposed PNFA and SD subjects to a new word and assessed their ability to acquire it. We hypothesized that each FTD subtype would demonstrate a different pattern of impairment. PNFA patients were expected to have difficulty understanding the grammatical information associated with the verb, and SD patients were expected to have difficulty acquiring the verb’s semantic content.
Acquisition of the grammatical aspects of lour was assessed by asking patients to judge the acceptability of 48 sentences. These included sentences using lour, sentences using a known verb of facial expression, and sentences using a pseudoword. In some sentences, lour and other words of facial expression were used in the appropriate sentence slot, while in others they were used inappropriately in the sentence slot of another word class (i.e., noun, adjective, preposition). Comprehension of the meaning of lour was assessed by presenting pictures paired with three word choices, and instructing patients to choose the word that best went with the picture. Word choices included lour, known verbs of facial expression, and pseudowords. Individual patient profiles were constructed to describe patient performance on each task. Scores that did not differ from chance were considered impaired. For the sentence task, performance on sentences using lour was compared to performance on known word sentences and pseudoword sentences. For the picture task, accurate endorsement of lour was compared to endorsements of known words and pseudowords. A subset of each patient group, including elderly controls, were conservative in their performances. These subjects rejected all uses of unfamiliar phonological shapes, including pseudowords and lour.
Design and methods FTD subtype diagnoses were made by an experienced neurologist (MG) according to published criteria. Participants included 6 PNFA patients and 12 SD patients along with 18 elderly controls matched for age, education, and scores on mini mental status examination (MMSE). We identified the very-low frequency English verb lour and exposed patients to the verb withinin the context of a narrative. The sentence ‘‘Louise sees the man lour at her’’ was paired with a picture showing a man frowning in disapproval at a girl named Louise. The word thus appears to denote a facial expression, and its grammatical word class is shown to be a verb that can take an indirect object. Five forced-choice picture-sentence matching pairs using the verb were subsequently given to each subject. Feedback was given until the correct picture was selected. *
1
Corresponding author. Fax: +1 44 1638 751909. E-mail address: [email protected] (M. Grossman). Present address: Animal Health Trust, Lanwades Park, Centre for Equine Studies, Kentford, New Market, Suffolk CB8 7UU, UK.
0093-934X/$ - see front matter Ó 2005 Published by Elsevier Inc. doi:10.1016/j.bandl.2005.07.084
Results PNFA and SD subjects were impaired on the sentence judgment task relative to controls. Only 17% of PNFA (n = 1) patients exhibited ideal patient profiles, whereas 50% (n = 3) were impaired and 33% (n = 2) were conservative. PNFA patients with impaired profiles were only impaired on sentences with lour. An ideal performance profile was seen in 17% (n = 2) of SD patients, 8% (n = 1) were conservative and 75% (n = 9) were impaired. Impaired SD patients were divided between those that were impaired in their judgments of lour and pseudowords (25%, n = 3), and those with a selective impairment for judging sentences with lour (50%, n = 6). On the picture–word matching task, no SD patients exhibited an ideal performance profile while roughly half of both elderly control patients and PFNA patients were ideal. Half of PNFA patients (n = 3) were ideal in their picture judgments, 33% (n = 2) were conservative and one (16%) was impaired. This patient was impaired on judgments of both lour and pseudowords. No SD patients were ideal in their
154
Abstract / Brain and Language 95 (2005) 153–154
performance profile, 25% (n = 3) were conservative and 75% (n = 9) were impaired. Of the impaired patients, 58% (n = 7) were impaired in their judgments of lour and pseudowords, and 17% (n = 2) were impaired only in their judgments of lour.
Acquisition of the verb lour would be demonstrated by treating it similarly to known words, but differently than pseudowords. Few PNFA patients met these criteria for judgments on sentences in which the grammatical form class was varied (Fig. 1). However, the majority of non-conservative response profiles for picture judgments in PNFA did meet these criteria. Thus PNFA patients had greater difficulty acquiring the grammatical information associated with a novel verb, but seemed able to understand its semantic content. No SD patient exhibited intact acquisition of the meaning of lour. This was shown in the picture–word matching task (Fig. 1), which depends on semantic memory. In addition, while SD patients were impaired on the grammatical sentence judgment task, their errors differed from those of PNFA patients. SD profiles were more frequently impaired for sentences involving pseudowords as well as the test verb, rather than only those involving the test verb. Comprehension of the grammatical aspects of a novel verb is in part dependent upon intact semantic knowledge. It is possible that poor semantic acquisition of the test verb resulted in an impaired ability to understand grammatical aspects of the verb as well. Many of the language demands necessary for processing previously held lexical knowledge are in turn necessary for the acquisition of novel words. Our results provide evidence for selective impairments of distinct aspects of language in aphasic subtypes of FTD.
90 Percent in profile group
Discussion
Non-conservative patient profiles 100
80 70 60 50 40 30 20 10 0 Sentence
Picture
Elderly Control
Sentence
Picture
SD
Sentence
Picture
PNFA
Patient type Impaired Ideal
Fig.1. Patient profile analysis on sentence-judgement and picture–word matching.
Reference Grossman, M., Mickanin, J., Onishi, K., Robinson, K. M., & D’Esposito, M. (1997). Lexical acquisition in probable Alzheimer’s disease. Brain and Language, 60, 443–463.