پردازش شناسایی صدا در پروسوپاگنوزیای تکاملی

Abstract Background Developmental prosopagnosia is a disorder of face recognition that is believed to reflect impairments of visual mechanisms. However, voice recognition has rarely been evaluated in developmental prosopagnosia to clarify if it is modality-specific or part of a multi-modal person recognition syndrome. Objective Our goal was to examine whether voice discrimination and/or recognition are impaired in subjects with developmental prosopagnosia. Design/methods 73 healthy controls and 12 subjects with developmental prosopagnosia performed a match-to-sample test of voice discrimination and a test of short-term voice familiarity, as well as a questionnaire about face and voice identification in daily life. Results Eleven subjects with developmental prosopagnosia scored within the normal range for voice discrimination and voice recognition. One was impaired on discrimination and borderline for recognition, with equivalent scores for face and voice recognition, despite being unaware of voice processing problems. Conclusions Most subjects with developmental prosopagnosia are not impaired in short-term voice familiarity, providing evidence that developmental prosopagnosia is usually a modality-specific disorder of face recognition. However, there may be heterogeneity, with a minority having additional voice processing deficits. Objective tests of voice recognition should be integrated into the diagnostic evaluation of this disorder to distinguish it from a multi-modal person recognition syndrome.

. Introduction Prosopagnosia is the inability to recognize faces. In line with cognitive models of face recognition as a hierarchy of operations (Bruce & Young, 1986), neuropsychological studies of acquired prosopagnosia suggest at least two functional variants, an apperceptive form in which subjects have difficulty perceiving facial structure, and an associative/amnestic form in which perception is relatively spared, but the ability to access memories of previously seen faces is disrupted (Barton, 2008 and Davies-Thompson et al., 2014). In acquired prosopagnosia, the apperceptive variant has been linked to right or bilateral occipitotemporal lesions, and the associative variant to right or bilateral anterior temporal lesions (Barton, 2008 and Damasio et al., 1990). The fact that voice recognition also activates the right anterior temporal lobes (Belin & Zatorre, 2003) has prompted questions as to whether some cases of associative prosopagnosia may instead have a multi-modal person recognition disorder, since voice recognition is seldom tested (Gainotti, 2013). This is not only a question with theoretical implications, but also potential clinical relevance: as there is some evidence that simultaneous voice processing can enhance face learning, (Bulthoff & Newell, 2015), impaired voice processing could accentuate prosopagnosic deficits while intact voice processing might offer rehabilitative avenues. To address this, a recent study of acquired prosopagnosia found that voice recognition was unaffected after right anterior temporal lesions but impaired by bilateral anterior temporal lesions (Liu, Pancaroglu, Hills, Duchaine, & Barton, 2014). These data tentatively suggest that impaired face recognition can be divided into an apperceptive form linked to occipitotemporal lesions, an associative form linked to right anterior temporal lesions, and a multi-modal person recognition syndrome, with parallel associative deficits in face and voice processing, typically after bilateral anterior temporal lesions. These preliminary function-structure correlations require replication. These observations are also relevant to the developmental form of prosopagnosia, whose functional and structural basis remains uncertain. Recent studies suggest the possibility of similar apperceptive, associative and other variants in developmental prosopagnosia (Dalrymple et al., 2014, Stollhoff et al., 2011 and Susilo and Duchaine, 2013). Less known is whether it is a modality-specific disorder or part of a multi-modal syndrome: currently there is only one report that studied voice recognition in one developmental prosopagnosic subject, which found some impairment (von Kriegstein, Kleinschmidt, & Giraud, 2006), and brief mention of inferior voice recognition in another who also had Asperger syndrome (Kracke, 1994). Addressing these functional questions in developmental prosopagnosia may help guide and refine studies of this condition. The goal of this study was to apply the same two tests of voice discrimination and recognition used in the study of acquired prosopagnosia (Liu et al., 2014) to a cohort with developmental prosopagnosia. We asked a) whether this condition is a modality-specific disorder of face recognition or part of a multi-modal person recognition syndrome, and b) whether the results were homogenous or heterogeneous in the cohort.

. Results 3.1. Voice discrimination 11 of 12 prosopagnosic subjects were normal, while one, DP035, had an abnormal score, at the 96.5th percentile (Fig. 1A). In the group analysis (Fig. 2), there was no difference compared to either the age-paired [t(11) = .15, p = .88] or age-range controls [t(30) = .26, p = .73]. Voice scores plotted as a function of age. A. voice discrimination, B. voice ... Fig. 1. Voice scores plotted as a function of age. A. voice discrimination, B. voice recognition. Control subjects (small dots) in both tests show a significant decline with age. Solid line shows the mean of the linear regression and the dotted line shows the age-adjusted lower 95% prediction limit. Subject DP035 is impaired on voice discrimination and has borderline performance on voice recognition. Subject DP021 performs normally, despite reporting voice recognition difficulties on the questionnaire. Figure options Age-matched group analyses. A. voice discrimination, B. voice recognition. The ... Fig. 2. Age-matched group analyses. A. voice discrimination, B. voice recognition. The prosopagnosia group is compared with the 12 control subjects closest in age (age-pair controls), and with all control subjects falling in the range of 27–67 years (age-range controls). Group means are shown, with error bars showing one standard deviation. Figure options 3.2. Voice recognition All 12 prosopagnosic subjects were normal, although DP035 was borderline, at the 94th percentile (Fig. 1B). The group analysis (Fig. 2) showed no difference between the prosopagnosic group and either age-paired [t(11) = .00, p = 1.00] or age-range controls [t(21) = .71, p = .48]. To compare the severity of short-term familiarity deficits for voices and faces, we correlated the z-scores on the voice recognition and Cambridge Face Memory tests (Fig. 3). Subject DP035 has equivalent deficits for both faces and voices, but as a group, developmental prosopagnosic subjects were worse on face than voice recognition [t(11) = 9.11, p < .0001]. Voice versus face recognition in developmental prosopagnosia. Z -scores for the ... Fig. 3. Voice versus face recognition in developmental prosopagnosia. Z -scores for the voice recognition test are plotted against z-scores for the Cambridge Face Memory Test (CFMT), with negative z-scores indicating impairment. Subject DP035 has equivalent deficits for face and voice recognition, but other subjects are more impaired for face recognition. Figure options 3.3. Questionnaire All but two subjects with developmental prosopagnosia reported impairment on the questionnaire's face recognition portion: DP029 and DP008 had borderline scores (Table 2). Only one subject (DP021) reported difficult voice recognition. However, this subject scored close to control age-adjusted mean score for both voice discrimination and recognition (Fig. 1). Of note, DP035 was unaware of problems with voice recognition. Table 2. Voice and face processing questionnaire, results. Questionnaire results (score 0–35). Faces Voices control mean 10.16 13.14 SD. 3.88 4.10 95% upper limit 19.39 22.89 DP003 20 9 DP008 18 12 DP014 27 7 DP016 22 13 DP021 31 27 DP024 24 8 DP029 18 8 DP032 28 12 DP033 26 18 DP035 32 14 DP038 22 21 DP044 23 17 Bold underline indicates abnormal scores.