Semantic attributes of iconic gestures in fluent and non-fluent aphasic adults

Semantic attributes of iconic gestures in fluent and non-fluent aphasic adults

Brain and Language 99 (2006) 8–219 www.elsevier.com/locate/b&l Semantic attributes of iconic gestures in fluent and non-fluent aphasic adults Sergio Ca...

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Brain and Language 99 (2006) 8–219 www.elsevier.com/locate/b&l

Semantic attributes of iconic gestures in fluent and non-fluent aphasic adults Sergio Carlomagno b

a,*

, Carla Cristilli

b

a Dipartimento di Psicologia, Universita´ di Trieste, Italy Dipartimento di Studi Linguistici dell’Occidente, Universita´ Orientale di Napoli, Italy

Accepted 6 July 2006

Introduction It has been suggested that coverbal gestures by fluent and non-fluent aphasic adults (henceforth: Fs and NFs) closely parallel their speech as to the incidence, semantic content and clarity (Cicone, Wapner, Foldi, Zurif, & Gardner, 1979, see also McNeill, 1992). However, this claim has been challenged. For instance, in NFs, although gesture production rate is reduced, gesture to word ratio is increased (Feyereisen, 1983). Furthermore, according to Cicone et al. (1979), NFs mostly produce referential gestures (emblems and pantomimes), while Fs mostly rely on vague iconic gestures. In their study, however, 39% of Fs’ gestures were rated as pantomimes (37% in NF). Perhaps, in Fs semantic content of coverbal gestures is masked by paraphasic speech, whereas in NFs gestural clarity relies on the overproduction of Yes/No emblemes. The present study explored semantic content of gestures produced by Fs, NFs, and normal controls (Ns) by examining how specific attributes of objects and actions are communicated via iconic representation within individual gestures. Subjects and methods Ten adults with moderate aphasia (five NFs with diagnosis of Broca’s aphasia, and five Fs with Wernicke’s) and 10 normal controls participated in the study. Their performance in narrating two pieces of news (a shipwreck and a robbery) to an apparently unaware experimenter was video-recorded. The first analysis (Analysis A) concerned the alphabetic transcription of the speech samples in order to control for linguistic performance and presence, accuracy and completeness of main concepts (Nicholas & Brookshire, 1995). Analysis B, conducted by two independent judges, evaluated the production of iconic, deictic (pointing), and metalinguistic (related to the speech rhythm) gestures (Carlomagno, Pandolfi, Marini, Di Iasi, & Cristilli, 2005). Emblematic gestures (less than 2%) were not considered. Analysis C, conduced by two new judges, examined the semantic content of the iconic gestures produced by the participants according to Beattie and Shovelton’ s categorization scheme (1999). This has been proven an efficient tool in showing how nine semantic features of objects (e.g., size or shape) and actions (e.g., modality) are communicat*

Corresponding author. E-mail address: [email protected] (S. Carlomagno).

doi:10.1016/j.bandl.2006.06.061

ed via iconic gestures in story telling. An ‘‘other’’ category was added in oder to evaluate the proportion of gestures that did not correspond to the categories in the scheme. Results, expressed as mean values per story telling (Analysis A and B) and number of gestures in the corpus classified in semantic categories (Analysis C), were analysed with ANOVAs or contingency table. Results The three groups differed for word production (F = 14.7, df = 2, p < .0001) and speaking time (F = 52.5, p < .0001). Due to the presence of semantic paraphasias and circumlocutions, Fs produced more words per story than NFs or Ns (p < .001). Fs’ mention of main themes was Accurate/Complete less than 10% of times and Inaccurate 46.3% of times. The reverse pattern was observed in the NFs (Complete/Accurate = 37%, Inaccurate = 16%). Gesture production was analysed with 3 · 3 ANOVA that showed a significant effect of group (F = 23.9, df = 2, p < .0001), of type of gesture (F = 34.8, df = 2, p < .0001) and a significant interaction (F = 14.9, df = 4, p < .001). Ns produced fewer gestures per story-telling than Fs and NFs (p < .001), who did not differ from each other. Also, Fs produced more iconic gestures than NFs and Ns (p < .01), whereas NFs produced more deictic (p < .01) and metalinguistic gestures (p < .01) than the two other groups. Finally, NFs produced more gestures per word than Fs and Ns (F = 15.9, p < .0001), although their gesture per time rate was reduced. In Analysis C, the percentage of agreement between the two judges ranged from 84% (direction) to 94.5% (object identity). Fs, NFs, and Ns’ distribution of iconic gestures in the ten categories of the semantic categorization scheme is reported in the Table as number of gestures in each category. No differences was found (chi-square = 25.5, df = 18, NS) (Table 1). Discussion The differences between Fs and NFs in terms of gesture per time (Cicone et al., 1979) or gesture per word (Feyereisen, 1983) were confirmed in our study. Furthermore, differences were also evident when the type of gesture was taken into account. In contrast, there was no evidence that the way in which the two groups enacted semantic attributes of objects and actions in the story differed from each other and from Ns.

Abstracts / Brain and Language 99 (2006) 8–219 Table 1 Mean values of language (Analysis A) and gesture (Analysis B) parameters and number of iconic gestures in each category of the semantic categorization scheme (Analysis C) in the three groups Fluent

Non-fluent

Normal

169.1 128.8 .7

107.5 220.3 3.0

101.7 52.5 5.9

3.2

3.2

1.4

3.8

1.3

.9

Analysis B Iconic gestures Deictic gestures Metalinguistic gestures Gesture/minute Gesture/word

14.7 2.2 1.7 9.1 .12

9.4 5.7 6.8 6.0 .22

3.0 2.1 1.5 7.8 .07

Analysis C Identity of object Number Shape Size Relative position Modality of action Movement Direction Speed Other

16 6 26 10 7 28 4 25 2 10

Analysis A Number of words Speaking time Accurate/complete mention of main themes Accurate/incomplete mention of main themes Inaccurate mention of main themes

10 7 13 0 3 30 6 22 1 2

3 1 4 1 3 10 1 5 1 1

105

However, Fs conveyed main concepts of stories less clearly than NFs. Taken together, these results are at variance with the hypothesis of the parallel dissolution of speech and gestures in aphasia (Cicone et al., 1979; McNeill, 1992). Instead, they support the view that impaired processing of verbal semantics in Fs may create mis-matches between speech content and unimpaired gesture form (Butterworth & Hadar, 1989). References Beattie, G., & Shovelton, H. (1999). Mapping the range of information contained in iconic hand gestures that accompany spontaneous speech. Journal of Language and Social Psychology, 18, 438–462. Butterworth, B., & Hadar, U. (1989). Gesture, speech and computational stages. Psychological Review, 96, 168–174. Carlomagno, S., Pandolfi, M., Marini, A., Di Iasi, A., & Cristilli, C. (2005). Coverbal gestures in Alzheimer’s type dementia. Cortex, 41, 535–546. Cicone, M., Wapner, W., Foldi, N., Zurif, E., & Gardner, H. (1979). The relation between language and gesture in aphasic communication. Brain and Language, 8, 324–349. Feyereisen, P. (1983). Manual activity during speaking in aphasic subjects. International Journal of Psychology, 18, 545–556. McNeill, D. (1992). Hand and mind: what gestures reveal about thoughts. Chicago: University of Chicago Press. Nicholas, L., & Brookshire, R. H. (1995). Presence, completeness and accuracy of main concepts in the connected speech of non-brain damaged adults and adults with aphasia. Journal of Speech and Hearing Research, 38, 145–156.