International audienceThe present study investigated language outcomes in children with Landau-Kleffner syndrome compared with 7 to 8 year-old healthy children and healthy adults. We examined their capacity of understanding simple sentences using linguistic and affective prosodic cues and perceiving them. A battery of prosodic tests was elaborated and used for this study. Results revealed certain delayed language development or a different pattern of performance in participants with Landau-Kleffner syndrome. With more subjects tested in the future results from our battery of prosodic tests would allow us to better understand language development in child and it would be helpful for speech-language therapies

Astesano, Corine

Dufor, Olivier

Ferragne, Emmanuel

Kim-Dufor, Deok-Hee

Nespoulous, Jean-Luc

Hal-Diderot

Perception and comprehension of linguistic & affective prosody in children with Landau-
Kleffner syndrome 
 
Deok-Hee Kim-Dufor1*, Emmanuel Ferragne2, Olivier Dufor3, Corine Astésano1 and Jean-Luc Nespoulous1 
1 Laboratoire Jacques Lordat-OCTOGONE, Université de Toulouse II Le Mirail, France 
2
 Laboratoire Dynamique du langage-UMR 5596 CNRS, Université Lyon Lumière, France 
3 CogNeuro Research Lab, Johns Hopkins University, Baltimore, MD, USA 
*Corresponding author: deok-hee.kim@univ-tlse2.fr 
 
Keywords: linguistic prosody, affective prosody, auditory tests, Landau-Kleffner syndrome, language 
development/outcome 
 
Introduction 
Landau-Kleffner syndrome, aka acquired epileptic 
aphasia in children, is a type of epilepsy in which the 
most characteristic symptom is word deafness (aphasia) 
evolving into auditory agnosia and/or mutism. Since 
Landau-Kleffner syndrome was discovered by Dr. 
Landau and Dr. Kleffner in 1957 [1], there have been 
some case studies examining language outcomes in 
children suffering from this disease [2], [3], [4], [5], 
[6]. But most studies tested vocabulary in the context 
of short-term phonological memory. To our 
knowledge, there have been no investigations of the 
use of prosodic cues in children with Landau-Kleffner 
syndrome. We thus tested oral language 
perception/comprehension with linguistic and affective 
prosodic cues: rhythmic vs arrhythmic sentences and 
neutral vs anger sentences. With regard to linguistic 
prosody, we chose not to use the intonation pattern that 
distinguishes statements from questions because a) 
rhythm – the temporal organization of the prominences 
[7] – is also a very important prosodic element, b) 
most tests of prosody use this pattern [8], [9], [10], and 
c) more subtle prosodic elements need to be tested 
than statement vs question pattern in order to better 
examine language capacity in children who have 
already undergone speech-language therapies. With 
regard to affective prosody, the emotion anger was 
chosen for its precocity (even a baby gets angry when 
he doesn’t get what he wants immediately whereas we 
cannot be sure of sadness, for example, in a baby) and 
salient prosodic features compared with neutral. Given 
the clinical manifestation of LKS (word deafness), it is 
hypothesized that children with LKS would have 
fewer difficulties than healthy subjects in perceiving 
delexicalized sentences with affective prosody, i.e. 
sentences without semantic information.         
 
Materials and methods 
1. Subjects 
Twenty-two healthy children (M.A.: 7;7) in CE1 (2nd 
year of elementary school), twelve healthy adults 
(M.A.: 26;3), two children (9;9 and 8;4) and an 
adolescent (16;3) with Landau-Kleffner syndrome 
participated in this study. All participants were native 
French speakers and had normal hearing. None of the 
healthy subjects had any known history of audiological 
or neurological impairments. None of LKS 
participants had autism (one third of epileptics have 
autism) [11].  
 
2. Stimuli 
We used auditory visuo-motor tasks that consisted of 
auditory stimuli and visuo-motor responses for our 
protocol.  
Our battery of tests consists of two sets of tests of 
prosody: the first set focuses on linguistic prosody and 
the second on affective prosody. The first set of tests 
includes two groups of sentences, one delexicalized 
(with unintelligible lexical information) and the other 
non-delexicalized (with intelligible lexical 
information). Each of these sentence groups is 
subdivided into two subgroups, one with rhythm and 
the other without rhythm (no prominences). The 
second set of tests also comprises two groups of 
sentences, one delexicalized and the other non-
delexicalized. Each of these two groups is subdivided 
into two subgroups, one with sentences of neutral 
emotion prosody and the other with sentences 
containing prosodic cues for anger. 
 
2.1. Auditory stimuli 
The sentences were constructed using Novlex, a 
French lexical database for 7 to 8 year-old children. 
Novlex provides estimates of the lexical extent and 
frequency of the written vocabulary for primary 
students. Proper nouns, numbers, country names and 
onomatopoeias are not included in the database. The 
words used in our protocol have a frequency greater 
than 3000 per 100 million and each word has fewer 
than three syllables. The syntactic structures are either 
S-V-O or S-V-Adv without relative or conjunction 
clauses, and the sentences have from 6 up to 13 
syllables. The tenses used in our stimuli are the present, 
the compound past and the imperfect. To evaluate their 
suitability for the target age group, three 7 and 8 year-
old children were asked to judge the sentences by 
choosing one of the following five adjectives: 
comprehensible, difficile (difficult), rigolote (funny), 
bizarre and mal dite (incorrect). For the last choice, 
they were asked “Comment on le dit? (How would you 
say it)?” for a possible correction. The 140 selected 
sentences (90 neutral sentences and 50 anger sentences) 
were read by a 30 year-old actress and recorded with 
Apple Soundtrack Pro.  
Signal processing was carried out with Praat version 
5.1.03. To remove lexical (and thus semantic and 
syntactic) information, the fundamental frequency of 
the original signal was estimated and delexicalized in 
the form of sinusoids. As a result, the final stimulus 
was a pure sound which follows the structure of the 
original fundamental frequency. Certain artefacts 
resulting from delexicalization were eliminated by 
applying a low-pass filter at 400 Hz. To remove 
prosodic rhythm (the temporal organization of the 
prominences of each sentence), the duration of each 
syllable in all stimuli was modified so that each had 
the same duration (mean duration of syllables). Finally, 
all sentences were normalized in intensity to an 
equivalent RMS value.  
 
2.2. Visuo-motor response mode 
Responses involved multiple-choice among drawings 
format (visual) and a with a button-press responses 
(motor). This type of response mode does not involve 
a heavy cognitive load thanks to the absence of written 
language, and this absence allows us to evaluate 
uniquely oral language perception/comprehension.  
Four images were proposed to subjects for each 
stimulus of linguistic prosody with semantic 
information. Each participant had to find the image 
depicting the sentence he/she had just listened to. The 
target words (subject & object) of the sentence were 
alternated with others (cf. Figure 1).  
 
  
Figure 1. ‘L’ours goûte le miel.’  
(The bear tastes honey.) 
 
For the tests of linguistic prosody tasks without 
semantic information in which the delexicalized 
sentences were either prosodic/rhythmic or 
aprosodic/arrhythmic, the children were asked to judge 
the sentences as being either flat (plates) or irregular 
(avec des pics vers le haut ou vers le bas)1 in their 
sound. To respond, subjects were asked to choose one 
of two drawings of line: one with peaks, the other was 
dotted and flat representing the patterns of each type of 
sentences. The position of the two lines was alternated 
(cf. Figure 2). 
For the tests of affective prosody either with or 
without semantic information, we used two smilies of 
                                                     
1
 Explained with example sounds & hand motions 
which one depicted a neutral expression, the other an 
angry one. These two emotions are expressed by the 
form of the mouth and the eyebrows. The position of 
the two smilies was alternated (cf. Figure 2).   
 
Figure 2. Lines for linguistic prosody (Left) & Smilies 
for affective prosody (Right) 
 
Subjects responded by pressing buttons that had been 
placed over the four keys on a USB numeric pad (7, 9, 
1 & 3 for the tests with 4 images, and 9 & 3 for the 
tests with 2 images). The other keys were covered with 
a board. The location of each button corresponded to 
that of each image. 
 
3. Procedure 
Children were screened with a pure tone audiometry in 
order to identify any auditory disorder. Only children 
without auditory deficits participated in this study. The 
stimuli were delivered using Presentation® on a 
Windows® XP interface. We administered randomly 
four series of tests (LP SEM+, LP SEM-, AP SEM+ & 
AP SEM-) 2 . Each series had thirty stimuli which 
included two sub-tests (cf. Table 1). 
 
 
Table 1. Structure of the battery of tests 
 
4. Analysis 
The raw response data recorded using the 
Presentation® platform was statistically analyzed 
using SPSS and Excel. Independent two-sample t-test 
(Levene’s test) was used to compare typically 
developing children (TDC) group with healthy adults. 
Paired sample t-tests were used in order to verify any 
discrepancy between two conditions within the same 
group. For each LKS child we calculated averages in 
different conditions and then compared them with the 
means of TDC +/- 2 standard deviations (p<0.05). A 
group comparison of TDC and LKS was not possible 
given the small number of subjects (n=3). We also 
used hierarchical clustering analysis (dendrogram) 
with 4 different types of distance (Ward, barycentre, 
                                                     
2
 LP = linguistic prosody, AP = affective prosody 
complete & median) to evaluate the distance between 
participants.  
 
Results 
1. Healthy children vs Adults 
Levene’s test demonstrated no significant difference in 
LP SEM+R+, LP SEM+R- and AP SEM+N. The rest 
of the tests had significant differences between the two 
groups (cf. Table 2).  When there is no semantic 
information, children’s performance is at chance level.  
 
Linguistic Prosody (LP) 
SEM+R+ SEM+R- SEM-R+ SEM-R- 
N.S. N.S. 0.001 0.004 
Affective Prosody (AP) 
SEM+N SEM+A SEM-N SEM-A 
N.S. 0.004 0.006 0.026 
 Table 2. TDC vs Adults (Levene’s test) 
 
In the TDC group no discrepancy was found in the 
paired sample t-tests. As for adults, a difference 
appeared between AP SEM-N and AP SEM-A 
(p=0.009) but no discrepancy between LP SEM+R+ 
and LP SEM+R-, LP SEM-R+ and LP SEM-R-, and 
AP SEM+N and AP SEM+A.  
 
2. LKS group 
J (9;9) and A(8;4) were compared with TDC, and T 
(16;3) was compared with adults. Participant J’s 
performance fell within 2 SD of the one of TDC group. 
Participant A showed better performance than the 
TDC in AP SEM-A with over 2 SD distance and a 
trend in AP SEM-N. It was notable that for T scores 
were much lower than that of adults’ one with over 2 
SD distance in LP SEM-R-, AP SEM+A, AP SEM-N 
& AP SEM-A. In fact, his performance was 
comparable with TDC rather than adults’ one. The 
dendrogram shows that T was far away from adults 
whatever the clustering method we used (cf. Figure 3).  
 
Figure 3. Dendrogram of adults using Ward’s distance, 
T. is encircled in red  
 
All participants were better at SEM+ tasks with 
varying degrees in both prosody tests (cf. Figure 4).  
Adults (1) maintained high scores with very little 
difference in both LP and AP tests whereas other 
participants’ score (2, 3 & 5) dramatically dropped in 
SEM- tasks except A. (4) whose high score was 
maintained in AP tests. 
 
 
Figure 4. Estimated marginal means of scores 
SEM+ = with semantic information 
SEM- = without semantic information 
 
Discussion 
Healthy children at the age of 7 to 8 showed chance 
level performance in SEM- tasks. This may be due to 
specificity of language development in children [12]: 
The function of language for children is to indicate an 
intention to ‘make do things with words’. They 
emphasize the use of language rather than its form, in 
other words, it is rather the communicative function of 
language that interests children than language itself. In 
the absence of communicative function, children 
cannot identify emotions. It could be argued that 
children acquire lexicon, semantics, syntax, pragmatics, 
etc. at the expense of primary elements of language 
such as prosodic features that they had used before 
they started speaking. These primary elements of 
language will resurface when children will be able to 
manipulate correctly lexicon, semantics, syntax, 
pragmatics, etc. Once one has mastered arbitrarily 
coded semantics and syntax, he has no trouble in 
understanding the relational aspects of language and 
its paralinguistic forms [13]. Adults can distinguish 
emotions without semantic information because they 
can apply elements of other situations to the context of 
tests. Besides, it is no longer only the communicative 
function of language that they are interested in, but 
they can ‘manipulate’ its form. That is why we observe 
good performance in adults regardless of the task. 
 
Our study did not show any significant difference 
between conditions in the healthy children group. 
Children at the age of 7 to 8 use contents 
(semantic/lexical information) rather than 
paralinguistic cues in oral comprehension [14]. This 
fact can explain the reason of paired sample t-test 
results in the typically developing children group. In 
the adults group, only between AP SEM-N and AP 
SEM-A was found a significant difference (p=0.009). 
When some anger sentences were not strongly enough 
imbued with anger characteristics, adults judged them 
neutral for lack of semantic information. The fact that 
no discrepancy was found between AP SEM+N and 
AP SEM+A may be due to the ceiling effect observed 
in this group (14.67/15 for N vs 15/15 for A). 
Participant J has performance as good as TDC (M.A. 7 
years 7 months), but given his age, 9 years 9 months, 
we cannot rule out slightly delayed language 
development. Since he is still getting speech-language 
therapy weekly, this possible delay could get 
remediated.  
As for the participant T, in spite of his age (16;3) he 
had quite poor performance comparable with that of 7-
8 year-old children. He had obvious difficulties in 
perceiving prosodic cues. This may be due to the 
premature termination of speech-language therapy: T 
stopped all therapies at the age of 11. This case may 
demonstrate the importance of long-term speech-
language therapies for children with LKS. 
The results from A confirm our hypothesis: her 
performance was as good as that of adults in AP SEM- 
tasks. In contrast she was comparable with typically 
developing children in the rest of our tests. Participant 
A has recovered from LKS for 2 years, her recovery is 
more recent than J’s and T’s. Her recent recovery may 
explain the persistence of affective prosody. We 
hypothesized that children with LKS would use 
prosodic cues to understand others in their everyday 
life while they are aphasic. These primary elements of 
language would be the only way that they rely on to 
try to be in oral communication.  
 
Future research 
Although one participant’s results could confirm our 
hypothesis, it doesn’t allow generalization or deeper 
understanding on language outcomes in children with 
LKS. In order to verify our hypothesis – the primary 
elements of language (prosody) would persist in 
children with Landau-Kleffner syndrome and they 
would use the prosodic cues for communication, it will 
be interesting to test children with LKS either in their 
aphasic phase or shortly after their recovery. The 
results obtained from our test battery could allow us to 
better understand language development in children 
and it could be helpful for speech-language therapists 
to have another type of check-up of language capacity 
to better frame therapies for patients.  
We initially included a group of children with ASD 
with an opposite hypothesis to the one of this study 
considering their clinical manifestation (problems in 
understanding others’ emotions): children with ASD 
would be better at linguistic prosody tasks with 
semantic information. Data analysis of this group is 
ongoing.  
    
 
References 
[1] Landau, WM. & Kleffner, FR. (1957) Syndrome of 
acquired aphasia with convulsive disorder in children. 
Neurology 7, 523-530 
[2] Metz-Lutz, MN. Développement des capacités 
verbales dans les suites d’une aphasie acquise de 
l’enfant. Compréhension verbale en présence d’un 
déficit de la mémoire phonologique. Rapport de fin de 
recherche, COG 48  
[3] Coutinho dos Santos, L. et al. (2002) Landau-
Kleffner syndrome: Study of four cases. Arquivos de 
Neuro-Psiquiatria 60, No.2A 
[4] Grote, CL. (1999) Language outcome following 
multiple subpial transection for Landau–Kleffner 
syndrome. Brain 122, 561-566 
[5] Robinson, RO. et al. (2001) Landau-Kleffner 
syndrome: course and correlates with outcome. 
Developmental medicine and child neurology 43, 243-
247  
[6] Birch, IK. (2001) Multiple subpial transection in 
Landau-Kleffner syndrome. Developmental medicine 
and child neurology 43, 248-252 
[7] Astésano, C. (2001) Rythme et accentuation en 
français – Invariance et variabilité stylistique. 
L’Harmattan 
[8] McCann, J. et al. (2003) Profiling Elements of 
Prosodic Systems – Children (PEPS-C). Queen 
Margaret University College 
[9] Meister et al. (2008) Conception and realization of 
a prosody test battery. HNO 56, N°3, 340-348 
[10] Bowers et al. Florida Affective Battery. Not 
published 
[11] Tuchman, R. (2006) Autism and epilepsy: What 
has regression got to do with it? Epilepsy Currents 6, 
No. 4, 107–111 
[12] Bruner, JS. (1998) Le développement de l’enfant : 
savoir faire, savoir dire. PUF 
[13] Levy, RI. (1982) On the nature and functions of 
the emotions: An anthropological perspective. Social 
science information 21, 511-528  
[14] Morton, JB. et al. (2001) Children’s 
understanding of emotion in speech. Child 
development 72, No.3, 834-843 


Perception and comprehension of linguistic and affective prosody in children with Landau-Kleffner syndrome

Scientific Publications of the University of Toulouse II Le Mirail

Perception and comprehension of linguistic & affective prosody in children with Landau-Kleffner syndrome  Deok-Hee Kim-Dufor1*, Emmanuel Ferragne2, Olivier Dufor3, Corine Astésano1 and Jean-Luc Nespoulous1 1 Laboratoire Jacques Lordat-OCTOGONE, Université de Toulouse II Le Mirail, France 2 Laboratoire Dynamique du langage-UMR 5596 CNRS, Université Lyon Lumière, France 3 CogNeuro Research Lab, Johns Hopkins University, Baltimore, MD, USA *Corresponding author: deok-hee.kim@univ-tlse2.fr  Keywords: linguistic prosody, affective prosody, auditory tests, Landau-Kleffner syndrome, language development/outcome  Introduction Landau-Kleffner syndrome, aka acquired epileptic aphasia in children, is a type of epilepsy in which the most characteristic symptom is word deafness (aphasia) evolving into auditory agnosia and/or mutism. Since Landau-Kleffner syndrome was discovered by Dr. Landau and Dr. Kleffner in 1957 [1], there have been some case studies examining language outcomes in children suffering from this disease [2], [3], [4], [5], [6]. But most studies tested vocabulary in the context of short-term phonological memory. To our knowledge, there have been no investigations of the use of prosodic cues in children with Landau-Kleffner syndrome. We thus tested oral language perception/comprehension with linguistic and affective prosodic cues: rhythmic vs arrhythmic sentences and neutral vs anger sentences. With regard to linguistic prosody, we chose not to use the intonation pattern that distinguishes statements from questions because a) rhythm – the temporal organization of the prominences [7] – is also a very important prosodic element, b) most tests of prosody use this pattern [8], [9], [10], and c) more subtle prosodic elements need to be tested than statement vs question pattern in order to better examine language capacity in children who have already undergone speech-language therapies. With regard to affective prosody, the emotion anger was chosen for its precocity (even a baby gets angry when he doesn’t get what he wants immediately whereas we cannot be sure of sadness, for example, in a baby) and salient prosodic features compared with neutral. Given the clinical manifestation of LKS (word deafness), it is hypothesized that children with LKS would have fewer difficulties than healthy subjects in perceiving delexicalized sentences with affective prosody, i.e. sentences without semantic information.          Materials and methods 1. Subjects Twenty-two healthy children (M.A.: 7;7) in CE1 (2nd year of elementary school), twelve healthy adults (M.A.: 26;3), two children (9;9 and 8;4) and an adolescent (16;3) with Landau-Kleffner syndrome participated in this study. All participants were native French speakers and had normal hearing. None of the healthy subjects had any known history of audiological or neurological impairments. None of LKS participants had autism (one third of epileptics have autism) [11].   2. Stimuli We used auditory visuo-motor tasks that consisted of auditory stimuli and visuo-motor responses for our protocol.  Our battery of tests consists of two sets of tests of prosody: the first set focuses on linguistic prosody and the second on affective prosody. The first set of tests includes two groups of sentences, one delexicalized (with unintelligible lexical information) and the other non-delexicalized (with intelligible lexical information). Each of these sentence groups is subdivided into two subgroups, one with rhythm and the other without rhythm (no prominences). The second set of tests also comprises two groups of sentences, one delexicalized and the other non-delexicalized. Each of these two groups is subdivided into two subgroups, one with sentences of neutral emotion prosody and the other with sentences containing prosodic cues for anger.  2.1. Auditory stimuli The sentences were constructed using Novlex, a French lexical database for 7 to 8 year-old children. Novlex provides estimates of the lexical extent and frequency of the written vocabulary for primary students. Proper nouns, numbers, country names and onomatopoeias are not included in the database. The words used in our protocol have a frequency greater than 3000 per 100 million and each word has fewer than three syllables. The syntactic structures are either S-V-O or S-V-Adv without relative or conjunction clauses, and the sentences have from 6 up to 13 syllables. The tenses used in our stimuli are the present, the compound past and the imperfect. To evaluate their suitability for the target age group, three 7 and 8 year-old children were asked to judge the sentences by choosing one of the following five adjectives: comprehensible, difficile (difficult), rigolote (funny), bizarre and mal dite (incorrect). For the last choice, they were asked “Comment on le dit? (How would you say it)?” for a possible correction. The 140 selected sentences (90 neutral sentences and 50 anger sentences) were read by a 30 year-old actress and recorded with Apple Soundtrack Pro.  Signal processing was carried out with Praat version 5.1.03. To remove lexical (and thus semantic and syntactic) information, the fundamental frequency of the original signal was estimated and delexicalized in the form of sinusoids. As a result, the final stimulus was a pure sound which follows the structure of the original fundamental frequency. Certain artefacts resulting from delexicalization were eliminated by applying a low-pass filter at 400 Hz. To remove prosodic rhythm (the temporal organization of the prominences of each sentence), the duration of each syllable in all stimuli was modified so that each had the same duration (mean duration of syllables). Finally, all sentences were normalized in intensity to an equivalent RMS value.   2.2. Visuo-motor response mode Responses involved multiple-choice among drawings format (visual) and a with a button-press responses (motor). This type of response mode does not involve a heavy cognitive load thanks to the absence of written language, and this absence allows us to evaluate uniquely oral language perception/comprehension.  Four images were proposed to subjects for each stimulus of linguistic prosody with semantic information. Each participant had to find the image depicting the sentence he/she had just listened to. The target words (subject & object) of the sentence were alternated with others (cf. Figure 1).     Figure 1. ‘L’ours goûte le miel.’  (The bear tastes honey.)  For the tests of linguistic prosody tasks without semantic information in which the delexicalized sentences were either prosodic/rhythmic or aprosodic/arrhythmic, the children were asked to judge the sentences as being either flat (plates) or irregular (avec des pics vers le haut ou vers le bas)1 in their sound. To respond, subjects were asked to choose one of two drawings of line: one with peaks, the other was dotted and flat representing the patterns of each type of sentences. The position of the two lines was alternated (cf. Figure 2). For the tests of affective prosody either with or without semantic information, we used two smilies of                                                      1 Explained with example sounds & hand motions which one depicted a neutral expression, the other an angry one. These two emotions are expressed by the form of the mouth and the eyebrows. The position of the two smilies was alternated (cf. Figure 2).    Figure 2. Lines for linguistic prosody (Left) & Smilies for affective prosody (Right)  Subjects responded by pressing buttons that had been placed over the four keys on a USB numeric pad (7, 9, 1 & 3 for the tests with 4 images, and 9 & 3 for the tests with 2 images). The other keys were covered with a board. The location of each button corresponded to that of each image.  3. Procedure Children were screened with a pure tone audiometry in order to identify any auditory disorder. Only children without auditory deficits participated in this study. The stimuli were delivered using Presentation® on a Windows® XP interface. We administered randomly four series of tests (LP SEM+, LP SEM-, AP SEM+ & AP SEM-) 2 . Each series had thirty stimuli which included two sub-tests (cf. Table 1).   Table 1. Structure of the battery of tests  4. Analysis The raw response data recorded using the Presentation® platform was statistically analyzed using SPSS and Excel. Independent two-sample t-test (Levene’s test) was used to compare typically developing children (TDC) group with healthy adults. Paired sample t-tests were used in order to verify any discrepancy between two conditions within the same group. For each LKS child we calculated averages in different conditions and then compared them with the means of TDC +/- 2 standard deviations (p<0.05). A group comparison of TDC and LKS was not possible given the small number of subjects (n=3). We also used hierarchical clustering analysis (dendrogram) with 4 different types of distance (Ward, barycentre,                                                      2 LP = linguistic prosody, AP = affective prosody complete & median) to evaluate the distance between participants.   Results 1. Healthy children vs Adults Levene’s test demonstrated no significant difference in LP SEM+R+, LP SEM+R- and AP SEM+N. The rest of the tests had significant differences between the two groups (cf. Table 2).  When there is no semantic information, children’s performance is at chance level.   Linguistic Prosody (LP) SEM+R+ SEM+R- SEM-R+ SEM-R- N.S. N.S. 0.001 0.004 Affective Prosody (AP) SEM+N SEM+A SEM-N SEM-A N.S. 0.004 0.006 0.026  Table 2. TDC vs Adults (Levene’s test)  In the TDC group no discrepancy was found in the paired sample t-tests. As for adults, a difference appeared between AP SEM-N and AP SEM-A (p=0.009) but no discrepancy between LP SEM+R+ and LP SEM+R-, LP SEM-R+ and LP SEM-R-, and AP SEM+N and AP SEM+A.   2. LKS group J (9;9) and A(8;4) were compared with TDC, and T (16;3) was compared with adults. Participant J’s performance fell within 2 SD of the one of TDC group. Participant A showed better performance than the TDC in AP SEM-A with over 2 SD distance and a trend in AP SEM-N. It was notable that for T scores were much lower than that of adults’ one with over 2 SD distance in LP SEM-R-, AP SEM+A, AP SEM-N & AP SEM-A. In fact, his performance was comparable with TDC rather than adults’ one. The dendrogram shows that T was far away from adults whatever the clustering method we used (cf. Figure 3).   Figure 3. Dendrogram of adults using Ward’s distance, T. is encircled in red   All participants were better at SEM+ tasks with varying degrees in both prosody tests (cf. Figure 4).  Adults (1) maintained high scores with very little difference in both LP and AP tests whereas other participants’ score (2, 3 & 5) dramatically dropped in SEM- tasks except A. (4) whose high score was maintained in AP tests.   Figure 4. Estimated marginal means of scores SEM+ = with semantic information SEM- = without semantic information  Discussion Healthy children at the age of 7 to 8 showed chance level performance in SEM- tasks. This may be due to specificity of language development in children [12]: The function of language for children is to indicate an intention to ‘make do things with words’. They emphasize the use of language rather than its form, in other words, it is rather the communicative function of language that interests children than language itself. In the absence of communicative function, children cannot identify emotions. It could be argued that children acquire lexicon, semantics, syntax, pragmatics, etc. at the expense of primary elements of language such as prosodic features that they had used before they started speaking. These primary elements of language will resurface when children will be able to manipulate correctly lexicon, semantics, syntax, pragmatics, etc. Once one has mastered arbitrarily coded semantics and syntax, he has no trouble in understanding the relational aspects of language and its paralinguistic forms [13]. Adults can distinguish emotions without semantic information because they can apply elements of other situations to the context of tests. Besides, it is no longer only the communicative function of language that they are interested in, but they can ‘manipulate’ its form. That is why we observe good performance in adults regardless of the task.  Our study did not show any significant difference between conditions in the healthy children group. Children at the age of 7 to 8 use contents (semantic/lexical information) rather than paralinguistic cues in oral comprehension [14]. This fact can explain the reason of paired sample t-test results in the typically developing children group. In the adults group, only between AP SEM-N and AP SEM-A was found a significant difference (p=0.009). When some anger sentences were not strongly enough imbued with anger characteristics, adults judged them neutral for lack of semantic information. The fact that no discrepancy was found between AP SEM+N and AP SEM+A may be due to the ceiling effect observed in this group (14.67/15 for N vs 15/15 for A). Participant J has performance as good as TDC (M.A. 7 years 7 months), but given his age, 9 years 9 months, we cannot rule out slightly delayed language development. Since he is still getting speech-language therapy weekly, this possible delay could get remediated.  As for the participant T, in spite of his age (16;3) he had quite poor performance comparable with that of 7-8 year-old children. He had obvious difficulties in perceiving prosodic cues. This may be due to the premature termination of speech-language therapy: T stopped all therapies at the age of 11. This case may demonstrate the importance of long-term speech-language therapies for children with LKS. The results from A confirm our hypothesis: her performance was as good as that of adults in AP SEM- tasks. In contrast she was comparable with typically developing children in the rest of our tests. Participant A has recovered from LKS for 2 years, her recovery is more recent than J’s and T’s. Her recent recovery may explain the persistence of affective prosody. We hypothesized that children with LKS would use prosodic cues to understand others in their everyday life while they are aphasic. These primary elements of language would be the only way that they rely on to try to be in oral communication.   Future research Although one participant’s results could confirm our hypothesis, it doesn’t allow generalization or deeper understanding on language outcomes in children with LKS. In order to verify our hypothesis – the primary elements of language (prosody) would persist in children with Landau-Kleffner syndrome and they would use the prosodic cues for communication, it will be interesting to test children with LKS either in their aphasic phase or shortly after their recovery. The results obtained from our test battery could allow us to better understand language development in children and it could be helpful for speech-language therapists to have another type of check-up of language capacity to better frame therapies for patients.  We initially included a group of children with ASD with an opposite hypothesis to the one of this study considering their clinical manifestation (problems in understanding others’ emotions): children with ASD would be better at linguistic prosody tasks with semantic information. Data analysis of this group is ongoing.       References [1] Landau, WM. & Kleffner, FR. (1957) Syndrome of acquired aphasia with convulsive disorder in children. Neurology 7, 523-530 [2] Metz-Lutz, MN. Développement des capacités verbales dans les suites d’une aphasie acquise de l’enfant. Compréhension verbale en présence d’un déficit de la mémoire phonologique. Rapport de fin de recherche, COG 48  [3] Coutinho dos Santos, L. et al. (2002) Landau-Kleffner syndrome: Study of four cases. Arquivos de Neuro-Psiquiatria 60, No.2A [4] Grote, CL. (1999) Language outcome following multiple subpial transection for Landau–Kleffner syndrome. Brain 122, 561-566 [5] Robinson, RO. et al. (2001) Landau-Kleffner syndrome: course and correlates with outcome. Developmental medicine and child neurology 43, 243-247  [6] Birch, IK. (2001) Multiple subpial transection in Landau-Kleffner syndrome. Developmental medicine and child neurology 43, 248-252 [7] Astésano, C. (2001) Rythme et accentuation en français – Invariance et variabilité stylistique. L’Harmattan [8] McCann, J. et al. (2003) Profiling Elements of Prosodic Systems – Children (PEPS-C). Queen Margaret University College [9] Meister et al. (2008) Conception and realization of a prosody test battery. HNO 56, N°3, 340-348 [10] Bowers et al. Florida Affective Battery. Not published [11] Tuchman, R. (2006) Autism and epilepsy: What has regression got to do with it? Epilepsy Currents 6, No. 4, 107–111 [12] Bruner, JS. (1998) Le développement de l’enfant : savoir faire, savoir dire. PUF [13] Levy, RI. (1982) On the nature and functions of the emotions: An anthropological perspective. Social science information 21, 511-528  [14] Morton, JB. et al. (2001) Children’s understanding of emotion in speech. Child development 72, No.3, 834-843 

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Perception and comprehension of linguistic and affective prosody in children with Landau-Kleffner syndrome

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