The aim of the present study was to examine receptive and expressive lexicon, as well as gesture production among children with and without developmental language disorder (DLD), Using the Swedish translation of the Picture Naming Game (PiNG). The parental evaluation Swedish Communicative Development Inventory III (SCDI III) was used to determine whether the results from PiNG and SCDI III were consistent. In this study, 10 children with DLD (study group) and 11 age-matched children with typical language development (control group) between 52 and 70 months of age participated. The participants were tested with PiNG, which is a test that examines reception and production of single nouns, verbs, adjectives, adverbs and prepositions. The guardians then completed SCDI III, which contains questions about the language abilities of the child. Gesture production in the form of deictic, iconic and conventional gestures was examined in conjunction with the use of PiNG. The results showed lower results for the study group on PiNG and SCDI III in comparison with the control group. The study group displayed a higher number of gestures than the control group, and in the former group, the use of gestures was positively correlated with the results from PiNG. In the study group, iconic gestures were used to compensate for language difficulties. The results from PiNG and SCDI III were not consistent. The age of the participants problably did not affect any results. The results from the present study indicate that PiNG may be useful when examining lexicon and gesture production among children with DLD. Both groups achieved high results on PiNG which may have affected the use of gestures and also possible correlations. For future studies, it is therefore recommended to apply PiNG on a group of younger children with DLD.

Syftet med föreliggande studie var att göra jämförelser mellan små barn med typisk språklig utveckling och små barn med språkstörning avseende impressivt och expressivt ordförråd samt användning av gester. Fyra barn med typisk språkutveckling rekryterades till studien. Dessa barn var köns- och åldersmatchade med redan insamlat material från fyra barn med språkstörning. Åldrarna på barnen (en flicka, tre pojkar) var 33–51 månader. Impressivt och expressivt ordförråd testades med Picture Naming Game (PiNG) och testsituationen videofilmades för att möjliggöra undersökning av barnens användning av deiktiska, ikoniska och emblematiska gester. Resultaten visar att barnen med typisk språklig utveckling på gruppnivå erhöll ett högre resultat på PiNG jämfört med de matchade barnen med språkstörning. Barnen med typisk utveckling utförde ett lägre antal totalt använda gester, ett lägre antal deiktiska och ikoniska gester samt hade färre gester synkroniserade med tal jämfört med barnen med språkstörning. Barnen med typisk språklig utveckling utförde fler emblematiska gester samt hade en högre andel gester synkroniserade med tal än barnen med språkstörning. Endast en av de uppmätta skillnaderna uppnådde statistisk signifikans vilket identifierades i användandet av emblem under expressiva testuppgifter där TD-gruppen använde signifikant fler emblem än barnen i DLD-gruppen. Då inga signifikanta skillnader förelåg mellan gruppernas totala PiNG-resultat och användning av gester gjordes en gemensam korrelationsanalys där en stark och signifikant negativ korrelation (p=0,01832) mellan barnens ålder och användning av ikoniska gester identifierades. Resultatet i föreliggande studie indikerar att gestanvändningen kan vara värdefull att inkludera vid bedömning av barn och utredning av eventuell språkstörning. Det finns dock behov av fler studier inom detta område och analys av en större mängd data behövs. / The purpose of the present study was to make comparisons between young children with typical language development and young children with developmental language disorder regarding impressive and expressive vocabulary and use of gestures. Four children with typical language development were recruited to the study. These children were sex- and age-matched with already collected data from four children with language impairment. The ages of the children (one girl, three boys) were 33- 51 months. Receptive and expressive vocabulary was tested with the Picture Naming Game (PiNG) and the test situation was video recorded to enable examination of the children's use of deictic, iconic and emblematic gestures. The results show that the children with typical language development at the group level obtained a higher result on the PiNG compared to the age- and gender matched children with a developmental language disorder. The children with typical development performed a lower number of total gestures, a lower number of deictic and iconic gestures as well as fewer gestures synchronized with speech in comparison to the children with developmental language disorder. The children with typical language development performed more emblematic gestures and had a higher percentage of gestures synchronized with speech than the children with language disorder. Only one significant difference was identified between the groups. Statistical significance was identified in the use of emblematic gestures during expressive tasks of PiNG where the children in the TD-group used significantly more emblematic gestures than the children in the DLD-group. As there were no significant differences between the groups regarding the total result of PiNG and the use of gestures, a joint correlation analysis was performed where a strong and significant negative correlation (p=0.01832) between the children's age and the use of iconic gestures was identified. The results of the present study indicate that the use of gestures can be valuable to include when assessing children and investigating possible language disorders. However, there is a need for more studies in this area and analysis of a larger amount of data is needed.

In einer multiplen Einzelfallstudie mit zehn aphasischen Patienten wurde die Wirksamkeit eines semantischen und eines phonologischen Therapieansatzes zur Behandlung von Wortabrufstörungen verglichen. Detaillierte Einzelfalluntersuchungen ermöglichten die Diagnose der zugrundeliegenden funktionalen Störungen bei jedem Patienten. Auf diese Weise konnten die erzielten Therapieeffekte auf die individuellen kognitiv-neurolinguistischen Störungsmuster bezogen werden. Im Vordergrund der Therapie stand in beiden Ansätzen das mündliche Benennen von Objektabbildungen mit unterschiedlichen Arten von Hilfen. Während in der semantischen Therapie Teilaspekte des semantischen Zielkonzepts als Benennhilfen eingesetzt wurden, handelte es sich bei den phonologischen Hilfen um Teilinformationen der Zielwortform. Bei der Erhebung von spezifischen Therapieeffekten wurde zwischen itemspezifischen und itemübergreifenden Verbesserungen sowie kurz- und langfristigen Effekten auf die mündlichen Benennleistungen unterschieden. Dabei wurden neben den quantitativen Verbesserungen (% korrekt) auch die qualitativen Effekte (Fehlertypen) der beiden Ansätze berücksichtigt, und es wurden Transfereffekte in die Spontansprache der Patienten untersucht. Zusätzlich wurden auch die Soforteffekte der verschiedenen Benennhilfen in den Therapiesitzungen erhoben. Im Methodenvergleich zeigte sich, dass die phonologische Therapiephase kurzfristig bei der Mehrzahl der Patienten signifikante Verbesserungen beim Bildbenennen bewirkte, diese Effekte haben sich jedoch überwiegend als nicht stabil erwiesen. Im Gegensatz dazu erwies sich die semantische Therapiephase auch als langfristig effektiv. Im Unterschied dazu erwiesen sich die phonologischen Benennhilfen bei fast allen Patienten als unmittelbar effektiver als die semantischen Benennhilfen. Somit waren die Soforteffekte der Hilfetypen in den Therapiesitzungen kein sicherer Indikator für die Dauer der Gesamteffekte einer Therapiephase. Außerdem zeigte sich nicht bei allen Patienten ein direkter Zusammenhang zwischen der Art ihrer zugrundeliegenden funktionalen Störung und den erzielten Therapieeffekten. Einerseits profitierten Patienten mit erhaltenen semantischen Verarbeitungsleistungen von der semantischen Therapie, andererseits zeigten sich signifikante phonologische Therapieeffekte bei Patienten mit zentral-semantischen Störungen. Die Wirkmechanismen der beiden Therapieansätze werden unter Berücksichtigung unterschiedlicher kognitiv-neurolinguistischer Theorien zum mündlichen Wortabrufprozess beim Bildbenennen interpretiert. / This study compared semantic and phonological treatments of word retrieval in ten aphasic patients using a multiple single case paradigm. The patients' single word processing was investigated before therapy, so that specific treatment effects could be interpreted with regard to underlying functional deficit(s) in each patient. In both treatments, the main task was spoken picture naming with different types of cues. In the semantic treatment, different aspects of the semantic target concept were used as a cue in picture naming, in the phonological treatment, different types of word-form specific information were provided as a cue. Treatment effects were assessed in terms of both short- and long-lasting effects on spoken picture naming accuracy in each patient. Both quantitative (proportion of correct responses) and qualitative (error types) improvements were evaluated. Furthermore, generalisation to untreated pictures (control items) and related tasks and transfer effects into spontaneous speech were examined. In addition, the immediate effects of the different types of prompts in the phonological and semantic treatment sessions were analysed. Regarding the stability of effects, different outcomes were found for semantic versus phonological treatments. The phonological treatment phase produced only short-lasting effects in most of the patients. In contrast, the semantic treatment phase produced more stable effects in some participants. With regard to the immediate effects of the different types of cues in the treatment sessions, it turned out that the phonological cues produced stronger effects than the semantic cues in most of the participants. Nevertheless, the effects of the semantic treatment phase were more stable than the phonological treatment effects. Specific effects of the phonological and the semantic treatment were not directly linked to the underlying functional disorder in each patient. Patients with preserved and with impaired semantic processing of concrete nouns could profit from both methods. The underlying mechanisms of effectiveness of the two treatment methods are interpreted in the framework of different cognitive-neuropsychological theories of spoken picture naming.

Verbbenämning innebär förmågan att benämna en bild utifrån den aktivitet som bilden illustrerar. I tidigare studier har det visat sig att barn tidigt i språkutvecklingen har svårare för verbbenämning än substantivbenämning (Gentner, 1982; Kauschke, Lee & Pae, 2007). Detta förklaras delvis av att verb är mer lingvistiskt komplexa än vad som är fallet för substantiv (Gentner & Boroditsky, 2001), samt att de är svårare att illustrera (Masterson, Druks & Gallienne, 2008). För att undersöka benämningsförmåga används oftast bildbenämningstest och för verb saknas ett svenskt test för barn. Föreliggande studie syftade till att undersöka verbbenämningsförmågan hos svenska barn samt att utröna om den svenska översättningen av Action Naming Test (ANT) är tillämplig på svenska barn. Deltagarna testades både med ANT samt Boston Naming test (BNT), för att få ett mått på de deltagande barnens benämningsförmåga av såväl verb som substantiv, och för att möjliggöra en jämförelse dem emellan. I den föreliggande studien deltog 116 barn i åldern 3;6 till 5;5 år uppdelade i fyra åldersgrupper. Resultaten på ANT visade att barnen fick högre testpoäng med stigande ålder. En felsvarsansalys visade att de vanligaste felsvaren var semantiskt relaterade (ord tillhörande samma eller en överordnad semantisk kategori) eller perceptuellt relaterade (visuell feltolkning) till målordet. En jämförelse av resultaten på ANT och BNT visade genomgående högre andel rätta svar på ANT. Det finns flera tänkbara förklaringar till detta. En förklaring är att barnen har passerat den ålder då substantiv är lättare att benämna än verb. En annan förklaring är att de helt enkelt har lättare att benämna verb än substantiv. Mer troligt är att testresultaten inte är jämförbara med varandra. Med några ändringar kan ANT bli ett användbart verbbenämningstest för svenska förskolebarn. / Verb naming comprises the ability to name an activity illustrated in a picture. Previous studies have shown that pre-school children have more difficulties in the naming of verbs than in naming of nouns (Gentner, 1982; Kauschke, Lee & Pae, 2007). This is explained as being partly due to the greater linguistical complexity of verbs compared to nouns (Gentner & Boroditsky, 2001) and that verbs are more difficult to illustrate (Masterson, Druks & Gallienne, 2008). Picture naming tests are frequently used in order to investigate naming ability but today a verb naming test is not available for Swedish children. The present study aimed to investigate naming ability of verbs in Swedish children, and to evaluate if the Swedish translation of the Action Naming Test (ANT) is applicable on children. In addition, all participants were tested with both ANT and the Boston Naming Test (BNT) in order to evaluate the participating children’s naming ability of verbs and nouns in order to make a comparison between the two of them. In the present study 116 children aged 3;6 to 5;5 years divided into four age groups participated. The results on the ANT showed continuously higher scores with increasing age. The error analysis showed that the most frequently occurring error categories were either semantically related (words within the same or superordinate category) or perceptually related (misinterpretation of the picture). When comparing the results between the ANT and the BNT higher scores were shown on the ANT in all age groups. This could imply that the participating children are beyond the age when nouns are easier to name than verbs, or that unlike previous studies, verbs are easier to learn. More likely, the test results are not comparable with each other. With some adjustments, the ANT is considered applicable for Swedish pre-school children.

Η εξελικτική δυσλεξία είναι μια ειδική μαθησιακή δυσκολία στην κατάκτηση του γραπτού λόγου που δεν σχετίζεται με χαμηλό νοητικό δυναμικό, ελλιπείς εκπαιδευτικές ευκαιρίες ή κάποιο εμφανές αισθητηριακό ή νευρολογικό πρόβλημα. Σύμφωνα με την «υπόθεση των φωνολογικών αναπαραστάσεων», που έχει υποστηριχθεί από δεδομένα στην αγγλική γλώσσα, τα άτομα με δυσλεξία παρουσιάζουν δυσκολία στην επαρκή αποθήκευση και ανάσυρση ακολουθιών ήχων που απαρτίζουν λέξεις, δηλαδή στη διαμόρφωση επαρκών «φωνολογικών αναπαραστάσεων». Στην παρούσα εργασία εξετάστηκε συστηματικά η παραπάνω υπόθεση. Δύο ομάδες 25 (επιλεγμένων από την κοινή τάξη) και 20 (με επίσημη διάγνωση από το ΚΕΔΔΥ) δυσλεξικών μαθητών εξετάστηκαν παράλληλα με δύο ομάδες ελεγχου: η πρώτη ίδιας χρονολογικής ηλικίας και καλής αναγνωστικής ικανότητας και η δεύτερη μικρότερης χρονολογικής ηλικίας και ανάλογης αναγνωστικής ικανότητας με τους δυσλεξικούς. Διαπιστώθηκαν ήπιες δυσκολίες των δυσλεξικών αναφορικά με την ποιότητα των φωνολογικών τους αναπαραστάσεων, όπως αξιολογήθηκε από την ικανότητά τους στην κατονομασία εικόνων. Από την άλλη, οι συσχετίσεις της επίδοσής τους στην κατονομασία εικόνων με επιδόσεις σε δοκιμασίες επεξεργασίας εξερχόμενης και εισερχόμενης φωνολογικής πληροφορίας, αλλά και φωνολογικής επίγνωσης, βασισμένων μάλιστα στα ίδια στοιχεία του λεξικού με εκείνα που είχαν χρησιμοποιηθεί στη δοκιμασία κατονομασίας εικόνων, δεν ήταν σε όλες τις περιπτώσεις ιδιαίτερα ισχυρές. Πιθανοί αιτιολογικοί παράγοντες για τις δυσκολίες των δυσλεξικών μαθητών στο φωνολογικό επίπεδο διερευνήθηκαν τόσο σε γνωστικό όσο και σε αντιληπτικό επίπεδο. Σε γνωστικό επίπεδο, ο παράγοντας της «συχνότητας» της φωνολογικής αναπαράστασης φάνηκε να σχετίζεται ισχυρότερα με την ποιότητα των φωνολογικών αναπαραστάσεων όλων των μαθητών ανεξάρτητα από το επίπεδο αναγνωστικής ικανότητας, σε σχέση με τον παράγοντα του «αριθμού των συλλαβών». Τέλος, σε αντιληπτικό επίπεδο εξετάστηκαν δύο παράμετροι της ακουστικής αντίληψης ως πιθανοί αιτιολογικοί παράγοντες των δυσκολιών των δυσλεξικών στη φωνολογική επεξεργασία: α. η αντίληψη ταχύτατα παρουσιαζόμενων ακουστικών ερεθισμάτων (Tallal) και β. η αντίληψη του κέντρου του ακουστικού ερεθίσματος (p-center, Goswami). Τα αποτελέσματα δεν φαίνεται να υποστηρίζουν τις υποθέσεις για πιθανά ελλείμματα στις συγκεκριμένες παραμέτρους ακουστικής αντίληψης που εξετάστηκαν. / Developmental dyslexia is a specific learning difficulty in acquiring literacy skills that manifests despite normal IQ, adequate educational opportunity and in the absence of any obvious sensory or neurological damage. According to the “Phonological Representations Hypothesis”, a hypothesis that has been supported by research in English, a core deficit for individuals with dyslexia is a difficulty in accurately storing and retrieving the sound sequences that make up words, or “phonological representations”. In this thesis the “Phonological Representations Hypothesis” of dyslexia was tested and elaborated. Two groups of 25 (chosen from normal classes) and 20 (with formal diagnosis from the National Center of Diagnosis, Differential Diagnosis and Educational Support of Greece) dyslexics were assessed alongside chronological age and reading ability matched groups. Mild difficulties of dyslexics were found as far as the quality of the phonological representations is concerned, as indexed by picture naming. Assossiations between performance in picture naming and performance on related input and output phonological processing tasks and phonological awareness taks were not in all cases strong. Possible reasons for dyslxexic’s phonological difficulties were investigated at both cognitive and perceptual levels. As far as the cognitive level is concerned, “frequency” rather than “ length” of the phonological representation was found to be associated more strongly with the quality of the phonological representation of all students independently of their reading ability. As far as the perceptual level is concerned, two different explanatory factors for dyslexic’s difficulties in phonological processing were assessed: a. perception of rapidly presented auditory stimuli (Tallal, 1980) and b. perception of the perceptual center of acoustic signals (p-center, Goswami, 2002). Results are not stronlgy supportive of the two hypotheses tested concerning deficits in parameters of perception of acoustic stimuli.

Word finding difficulties (WFD) and slowing down both in linguistic comprehension and production are standard characteristics of people as they grow older. WFD also commonly occur in aphasia and are considered one of the most pervasive symptoms affecting stroke participants’ everyday communication. Research on older adults’ WFD has traditionally focused on production of single words when completing picture naming tasks, while very little is known about how much these WFD can compromise connected speech. Similarly, while picture naming tasks have typically been used for assessing and treating word finding problems in clinical practice, there is a dearth of studies in the aphasiological literature investigating the relationship between confrontation naming and connected speech tasks. The thesis investigated whether a newly-developed method/treatment targeting both speed and accuracy (‘repeated increasingly speeded presentation’ - RISP) in picture naming was more effective in (a) speeding up participants without compromising accuracy, and (b) improving the use of the trained/treated names in connected speech, compared to a standard method/therapy (‘standard presentation’ - SP) which targeted accuracy alone. English-speaking, elderly participants (n=27 at Chapter 3, n= 21 at Chapter 4) and participants with aphasia of varying severity and subtype (n=5 at Chapter 5 and n=20 at Chapter 6) were asked to carry out picture naming tasks/picture naming treatments and composite picture description tasks where the composite pictures included the trained/treated items. As for the neurotypical participants, words which were retrieved more quickly in picture naming tasks were also those which were more readily available and produced in connected speech tasks. Compared to SP, RISP was found to be significantly more effective in significantly reducing picture naming latencies without inducing a speed-accuracy trade-off and with lasting effects. Finally, SP was as effective in promoting retrieval in connected speech as RISP. As for the clinical population, compared to SP, RISP was significantly more effective in improving picture naming accuracy and in maintaining the reduced RTs in the long term. In comparison to the SP, RISP crucially led to significantly higher carry-over of targeted items to connected speech. The thesis findings underlined the effectiveness of a more demanding single word training method/treatment in improving lexical retrieval in confrontation naming for neurotypical participants and in enhancing connected speech for participants with aphasia.

Föreliggande studie syftar till att skapa en ordlista med tillhörande bildmaterial som kan utgöra ett underlag för att bedöma den fonologiska förmågan hos finskspråkiga barn. Ytterligare undersöks huruvida de utvalda målorden ingår i det aktiva ordförrådet hos finskspråkiga barn mellan 3-5 år och kan bli eliciterade utifrån de valda bilderna. Slutligen presenteras förbättringsförslag för det framtagna materialet. Ordlistan består utav 80 ord och utgår frånBirutés och Stembergers (2010) principer för att möjliggöra en ickelinjär analys. Samtliga fonemi det finska språket är representerade, med ett par undantag vad gäller marginella fonem.Ytterligare ingår ett stort antal diftonger, konsonantsekvenser och andra stavelse- och ordstrukturer. I studien deltog sammanlagt 24 finsktalande barn med ett åldersspann mellan 3–5år. Barnen delades in i två åldersgrupper för att möjliggöra en jämförelse mellan de yngre (3;0–3;11 år) och de äldre (4;0–4;9 år) barnen. Barnens svar kategoriserades utefter typen av promting och eliciteringsstrategier som användes för att elicitera målordet. Dessa kategorier var spontan benämning, semantisk promting, fonologisk promting, alternativ, eftersägning och utebliven produktion. Signifikant fler ord eliciterades genom spontan produktion hos barn i den äldre gruppen än i den yngre. För den yngre gruppen eliciterades signifikant fler ord inom semantisk promting, alternativ och eftersägning. Antalet ord där produktionen uteblev (utebliven produktion) var signifikant fler hos den yngre gruppen. Ytterligare noterades användning av oförväntade böjningsformer och varianter för respektive barn. Resultatet indikerade att fler av målorden förefaller finnas i de äldre barnens aktiva ordförråd än de yngres. Slutsatser från denna studie är att majoriteten av de framtagna orden och tillhörande bilder fungerar för elicitering men att ändringar behöver göras i det existerande materialet. Studiens resultat indikerar att 14 antal ord och 11 antal bilder inte fungerar för elicitering. Föreslagna ändringar är att 11 ord byts ut, tretas bort och 10 läggs till. Ytterligare föreslås att 10 bilder byts ut. / The aim of this present study was to create a word list and select appropriate pictures that can be used in a picture naming test to assess phonological abilities in Finnish speaking children.Further this study investigates whether the selected target words are present in the expressive vocabulary of Finnish speaking children aged 3-5 years and if they can be elicited with the chosen pictures. Suggestions for further improvement of the material are discussed. The wordlist includes 80 words that were chosen according to criteria for a phonological assessment material presented by Bérubé and Stemberger (2010) and enables a non-linear analysis. In the created material all phonemes in the Finnish language are represented with few exceptions regardingmarginal phonemes. Many different diphthongs, consonant sequences and other syllable and word structures are also included. The participants in this study consisted of 24 Finnish speaking children aged between 3-5 years. The children were divided into two age groups to enable comparisons between younger (3;0-3;11 years) and older (4;0-4;9 years) children. The children's answers were categorized according to the type of prompting or elicitation strategies that were needed to elicit the target word. These categories were spontaneous production, semantic prompting, phonological prompting, alternatives, imitation, and unproduced words.Significantly more words were elicited by spontaneous production among the older children than the younger children. In the younger group, significantly more words were elicited by semantic prompting, alternatives, and imitation. The number of unproduced words were significantly higher in the younger group. No significant differences were found for the remaining categories. Production of unexpected inflectional forms and other variations were also noted. The result indicates that a large amount of the target words was present in the older group's expressive vocabulary compared to the younger group. Conclusions of this study are that most of the selected words and pictures are appropriate in picture naming context, but that some alterations to the existing material are needed since 14 words and 11 pictures cannot be elicited to asufficient extent. Suggested alterations are that 11 words are exchanged, three removed, and tenadded, to improve the existing wordlist. A further suggestion is that ten pictures are exchanged.

The aim of the present study was to examine receptive and expressive lexicon, as well as gesture production among children with and without developmental language disorder (DLD), using the Swedish translation of the Picture Naming Game (PiNG). The parental evaluation Swedish Communicative Development Inventory III (SCDI III) was used to determine whether the results from PiNG and SCDI III were consistent. In this study, 10 children with DLD (study group) and 11 age-matched children with typical language development (control group) between 52 and 70 months of age participated. The participants were tested with PiNG, which is a test that examines reception and production of single nouns, verbs, adjectives, adverbs and prepositions. The guardians then completed SCDI III, which contains questions about the language abilities of the child. Gesture production in the form of deictic, iconic and conventional gestures was examined in conjunction with the use of PiNG. The results showed lower results for the study group on PiNG and SCDI III in comparison with the control group. The study group displayed a higher number of gestures than the control group, and in the former group, the use of gestures was positively correlated with the results from PiNG. In the study group, iconic gestures were used to compensate for language difficulties. The results from PiNG and SCDI III were not consistent. The age of the participants problably did not affect any results. The results from the present study indicate that PiNG may be useful when examining lexicon and gesture production among children with DLD. Both groups achieved high results on PiNG which may have affected the use of gestures and also possible correlations. For future studies, it is therefore recommended to apply PiNG on a group of younger children with DLD.

Thèse de doctorat présenté en vue de l'obtention du doctorat en psychologie - recherche intervention, option neuropsychologie clinique (Ph.D) / Il est de plus en plus communément admis que la plupart des fonctions cognitives chez l’humain sont organisées sous forme de réseaux cérébraux distribués plutôt que strictement sous forme de modules anatomiques ségrégués et localisés. Parmi ces fonctions cognitives, nos capacités à nommer des objets ou à formuler des idées sont fondamentales dans la communication verbale et une perturbation de ces capacités peut mener à des limitations significatives au quotidien (ex. manque de fluidité, discours vide de sens, paraphasies et difficultés à se faire comprendre). La combinaison multimodale des données en imagerie par résonance magnétique (IRM) est une façon d’étudier ces réseaux cérébraux. Elle permet d’investiguer simultanément plusieurs pans de l’architecture neurobiologique qui forme ces réseaux cérébraux (ex. les dynamiques fonctionnelles qu’entretiennent les différentes aires cérébrales et leurs connexions anatomiques sous-jacentes). L’intégration de l’IRM fonctionnelle (IRMf) pour guider la tractographie représente une combinaison multimodale pertinente pour étudier le réseau fonctionnel (aires cérébrales) et structurel (fibre de matière blanche) qui permet la dénomination d’images chez l’humain. Néanmoins, la combinaison de ces modalités est complexe et il n’existe à ce jour aucune documentation strictement dédiée à l’intégration l’IRMf pour guider la tractographie (ex. procédurier, bonnes pratiques, etc.). Le premier objectif de cette thèse consistait donc à effectuer une synthèse intégrative des aspects méthodologiques associés à l’intégration de l’IRMf pour guider la tractographie via une étude de la portée (article/étude #1). Nos résultats sont organisés en 19 constats qui concernent les défis méthodologiques associés à cette méthode de combinaison multimodale. Nous y proposons également des recommandations, des pistes de solution et avons identifié des lacunes dans les connaissances associées à cette méthodologie. Le second objectif de cette thèse visait à cartographier le réseau cérébral impliqué dans la dénomination d’images en intégrant l’IRMf pour guider la tractographie auprès de jeunes adultes en santé (article/étude #2). En appliquant les connaissances de l’article/étude #1 dans le cadre d’une étude empirique, nous avons pu proposer un modèle neurocognitif de la dénomination d’images. Dans ce modèle, nous validons la présence d’une voie ventrale et dorsale du traitement de l’information. Les résultats suggèrent aussi que les parties postérieures du cortex inférotemporal et du gyrus temporal supérieur peuvent servir d’interface entre ces deux voies du traitement de l’information. Cette étude appuie également la suggestion d'une voie ventrale indirecte qui transige par le lobe temporal antérieur. Finalement, cette thèse propose un outil fort utile pour les chercheurs qui désirent utiliser cette méthode intégrative, avancer les connaissances ou encore développer de nouveaux outils méthodologiques. Grâce à a l’intégration de l’IRMf pour guider la tractographie et la triangulation des données issues d’autres méthodes, cette thèse offre une analyse détaillée des processus cognitifs et des bases neurobiologiques impliqués dans la dénomination d’images. Il s’agit encore ici d’un outil très pertinent pour tous les cliniciens qui ont recours à la dénomination d’images dans le cadre de leur pratique. / It has become more and more consensual that most cognitive functions in humans are organized in distributed brain networks rather than simply segregated and localized modules. Amongst these cognitive functions, our ability to name objects and elaborate ideas is fundamental for verbal communication as naming impairments can lead to significant limitations (i.e., lack of fluidity, empty speech, paraphasias and struggles to be understood). Multimodal magnetic resonance imaging (MRI) data combination provide opportunities for studying brain networks. It allows us to simultaneously investigate different aspects of the neurobiological architecture that forms brain networks (i.e., the functional dynamics that brain areas maintain together and their underlying anatomical connections). The integration of functional MRI (fMRI) to guide diffusion MRI (dMRI) tractography therefore represents an interesting way of combining multimodal MRI to study functional networks (brain areas) and white matter structures that allow picture naming abilities in humans. However, combining different MRI modalities remains a complex challenge and, up to this date, there is no documentation strictly dedicated to the integration of fMRI to guide dMRI tractography (i.e. bests practices, step-by-step guide, recommendations, etc.). The first objective of this thesis was to provide an integrative synthesis of the methodological aspects related to the integration of fMRI to guide dMRI tractography through a scoping review (article/study #1). Our results are organized in 19 findings which concern the methodological challenges associated with this multimodal combination technique. We there offer recommendations, solutions and identify gaps in the literature. The second objective of this thesis was to map the brain network involved in picture naming by integrating fMRI to guide dMRI tractography in healthy young adults (article/study #2). By applying the knowledge obtained from article/study #1 in the context of an experimental study, we were able to propose a neurocognitive model of picture naming. In this model, we confirm the presence of a ventral and dorsal information processing pathway. Our results also suggest that the posterior parts of the inferotemporal cortex and superior temporal gyrus may serve as an interface between these two information processing pathways. This study also supports the hypothesis of an indirect ventral pathway that relays through the anterior temporal lobe. Finally, this thesis offers a useful tool for researchers who wish to use this multimodal integrative method, advance knowledge or develop new methodological tools. Thanks to the integration of fMRI to guide dMRI tractography and the triangulation of data from other methods, this thesis was able to offer a complex and comprehensive look at the cognitive processes and neurobiological basis involved in picture naming. Again, this is also a very relevant tool for all clinicians who use picture naming in their everyday practice.

Thèse présentée en vue de l’obtention du grade de Ph. D. recherche et intervention en psychologie, option neuropsychologie clinique / L’aphasie survient le plus souvent à la suite d’un accident vasculaire cérébral (AVC) ischémique touchant l’artère cérébrale moyenne (ACM) gauche et représente l’une des conséquences les plus dévastatrices d’un AVC. La présente thèse vise à répondre à deux lacunes scientifiques importantes dans le domaine de l’aphasie secondaire à l’AVC impliquant l’ACM gauche, la première, plus fondamentale, et la seconde, plus clinique. Dans un premier temps, alors que les effets de l’AVC ischémique sur la matière grise ont été largement documentés dans les études précédentes, les mécanismes sous-tendant les dommages à la matière blanche cérébrale demeurent peu étudiés. Ainsi, le premier article inclus dans cette thèse vise à décrire le patron d’évolution longitudinale des propriétés microstructurelles de la matière blanche ipsilésionnelle après un AVC ischémique impliquant l’ACM gauche, en utilisant l’imagerie par résonance magnétique de diffusion. Nos résultats suggèrent que différents mécanismes pathophysiologiques s’opèrent pendant les stades aigu, subaigu précoce et chronique de l’AVC, avec la matière blanche lésionnelle et la matière blanche périlésionnelle affectée par l’ischémie à différents degrés et selon un décours temporel différent. Nous montrons que la considération d’une combinaison de mesures de diffusion à différents temps de mesure peut nous informer par rapport à la nature des différents mécanismes pathophysiologiques en cours, incluant l’oedème cellulaire, les dommages axonaux et la dégradation de la gaine de myéline. Une autre question qui demeure peu explorée dans la littérature sur l’aphasie post-AVC concerne la façon dont l’anomie, son symptôme cardinal, est reflétée dans la production de discours aux stades précoces du trouble. Le second article de cette thèse vise donc à évaluer la relation entre les mesures quantitatives de la production de discours et la performance dans le contexte de tâches de dénomination d’images au stade subaigu précoce de l’aphasie post-AVC impliquant l’ACM gauche (8-14 jours post-AVC). Nos résultats montrent la présence d’atteintes pour plusieurs mesures micro- et macrolinguistiques du discours chez les personnes avec aphasie et indiquent que l’informativité du discours (unités de contenu sémantique) est la mesure discursive la plus fortement corrélée aux capacités de dénomination. Nos résultats contribuent à une meilleure compréhension de la façon dont l’anomie est reflétée dans le contexte de la production de discours continu chez les personnes avec aphasie post-AVC dans la phase précoce du trouble. Ils suggèrent également que l’évaluation quantitative du discours peut offrir de l’information unique et potentiellement plus complexe à propos des atteintes langagières précoces, laquelle ne peut être entièrement captée par une tâche de dénomination d’images. / Post-stroke aphasia most frequently occurs after an ischemic stroke involving the left middle cerebral artery (MCA) and represents one of the most devastating consequences of a stroke. This thesis aims to address two major scientific gaps in the field of post-stroke aphasia: the first one is more fundamental, and the second one, more clinical. First, while the effects of ischemic stroke on cerebral grey matter have been thoroughly described in previous literature, the mechanisms of ischemic white matter injury remain far less understood. The first article of this thesis aims to characterize the longitudinal evolution of the microstructural properties of ipsilesional white matter after an ischemic stroke involving the left MCA, using diffusion magnetic resonance imaging. Our findings suggest that various pathophysiological mechanisms are at play after the ischemic stroke, with the lesional white matter and perilesional white matter tissue affected by ischemia at different rates and to different extents. We show that the examination of multiple diffusivity metrics may inform us about the mechanisms occurring at different time points, including cellular edema, axonal damage, and myelin loss. Another scientific gap in the post-stroke aphasia literature is that we do not know how anomia, its cardinal feature, is reflected in connected speech production during the early stages of the disease. The second article included in the thesis aims to assess the relationship between quantitative measures of connected speech production and performance in confrontation naming in people with aphasia in the early subacute stage following an ischemic stroke involving the left MCA (8–14 days post-stroke). We provide evidence for the presence of impairments in an array of micro- and macrolinguistic measures of speech in individuals with post-stroke aphasia and we show that confrontation naming abilities most strongly relate to informativeness in a picture description task. Our findings contribute to a better understanding of how anomia impacts connected speech production in the first days after stroke onset and suggest that quantitative discourse analysis may provide unique, possibly more complex information that isn’t entirely captured by picture naming tasks.