The purpose of the present study was to explore the ways that spouses of persons with ABI experience a process of change in roles, routine, and overall lifestyle and the subsequent implications for their support needs. The present study used a qualitative narrative inquiry methodology to examine the process of the experiences of this population of spouses. In-depth semi-structured interviews were conducted with 15 spouses, each of whom was engaged in a heterosexual relationship. There were 10 female and five male participants whose ages ranged from 40 to 61. Twelve of the participants were formally married, and three were in a common law relationship. In the interviews, the participants were asked about the changes in their lives after the onset of their spouses’ brain injuries. The data analysis was informed by narrative inquiry with attention paid to the structure of the participants’ stories. A three phase trajectory of caregiving emerged from the analysis which provided details regarding the process of change in the spousal caregiving role and how various role transitions within this role were intertwined with stressors and other feelings. The research highlighted three phases of caregiving including an Embryonic, Immersed and Modified Caregiver phase. The findings were theoretically important for identifying: how these spouses situate themselves within role transitions; coping strategies; various support needs; and future directions for research in this area.

This study utilized the moving-window self-paced reading paradigm to investigate the processing of English morphemes by native speakers of English, Chinese, and Korean. The morphemes belonged to three distinct theoretical types: Stratum 1 derivation ({-ALADJ}, {-ITY}, and {-OUSADJ}), Stratum 2 derivation ({-NESS}, {-FULADJ}, and {-ERAGENT}), and inflection ({-SPL}, {-EDPAST}, and {-S3RDSGPRES}). Participants were presented with either (1) fully grammatical sentences which contained words featuring these morphemes or (2) ungrammatical sentences in which one word form lacked one of the morphemes when it was obligatory (e.g., Canada is one of the most *prosper and developed countries in the world). Half the sentences were presented with a concurrent working memory load, which consisted of remembering the result of a simple calculation (e.g., subtracting 3 from 95) while processing a sentence and reporting the number immediately thereafter. Reading times for the target word and the three words immediately following it were used as the main dependent variable. The background measures included a C-Test of English proficiency, a reading span task, a digits-forward task, a digits-backward task, and a detailed background questionnaire. In agreement with previous research, it was found that morphological violations tended to cause slowdowns in processing. Conversely, the presence of a concurrent memory load tended to cause speedups. Native speakers differed from non-native speakers by: (1) showing an early sensitivity to violations of Stratum 2 derivational morphology; (2) exhibiting a delayed response to violations of Stratum 1 derivation; and (3) not slowing down after violations of inflectional morphology. In addition, native speakers were the only group exhibiting no relationship between morphological processing on one side and short term-memory, working memory, and C-Test scores on the other. Overall, the similarity between native and non-native speakers was the greatest in the processing of Stratum 1 derivation. Crucially, the temporal pattern of the Korean participants’ responses to morphological violations in English placed them in an intermediate position between the English and Chinese native speakers, which was interpreted as evidence of L1 – L2 transfer in morphological processing. Notably, this transfer occurred between an agglutinative L1 and an unrelated mixed-type L2.

Deception is not only part of daily life for adults, but it is also part of typical development throughout childhood. Research has shown that the ability to deceive improves with age and has been found to be related to the development of cognitive skills such as executive functioning processes, theory of mind, and intelligence. However for some children, lie-telling becomes problematic and atypical. For children with conduct problems, deception is one of the most common presenting symptoms and has been found to be pervasive across childhood and into adolescence. While most studies analyze the lying behaviours of these children based on parent and teacher reports, no studies have yet empirically evaluated the actual deceptive behaviours of children with severe conduct problems. The current study investigated the antisocial and prosocial deception rates and abilities of children with and without severe conduct problems. Additionally, cognitive measures and parental reports of lying and parenting styles were considered in order to determine how such variables may be related to deception. A total of 66 children participated in the current study with half of the sample originating from a community agency for children with behaviour problems and the other half consisting of an age- and gender-matched control sample. Results demonstrated that compared to their typically developing counterparts, children with conduct problems were more likely to behave antisocially by committing antisocial transgressions, and subsequently lying. These children were also less likely to tell prosocial lies. Consistent with previous research, many cognitive measures, such as Executive Functioning (e.g., inhibition) and Theory of Mind (1st and 2nd Order) were found to be related to deception for the typically developing sample, though fewer and different cognitive measures were found to be predictive of deception within the clinical sample. Parent ratings of lie-telling frequency were not predictive of antisocial or prosocial deception, though they were predictive of antisocial lie-telling sophistication. Parenting styles were minimally predictive of deception. Results suggest that the mechanisms used by children with conduct problems during deception differ from a typically developing sample. Limitations as well as implications are discussed.

The purpose of the present study was to explore the ways that spouses of persons with ABI experience a process of change in roles, routine, and overall lifestyle and the subsequent implications for their support needs. The present study used a qualitative narrative inquiry methodology to examine the process of the experiences of this population of spouses. In-depth semi-structured interviews were conducted with 15 spouses, each of whom was engaged in a heterosexual relationship. There were 10 female and five male participants whose ages ranged from 40 to 61. Twelve of the participants were formally married, and three were in a common law relationship. In the interviews, the participants were asked about the changes in their lives after the onset of their spouses’ brain injuries. The data analysis was informed by narrative inquiry with attention paid to the structure of the participants’ stories. A three phase trajectory of caregiving emerged from the analysis which provided details regarding the process of change in the spousal caregiving role and how various role transitions within this role were intertwined with stressors and other feelings. The research highlighted three phases of caregiving including an Embryonic, Immersed and Modified Caregiver phase. The findings were theoretically important for identifying: how these spouses situate themselves within role transitions; coping strategies; various support needs; and future directions for research in this area.

This study utilized the moving-window self-paced reading paradigm to investigate the processing of English morphemes by native speakers of English, Chinese, and Korean. The morphemes belonged to three distinct theoretical types: Stratum 1 derivation ({-ALADJ}, {-ITY}, and {-OUSADJ}), Stratum 2 derivation ({-NESS}, {-FULADJ}, and {-ERAGENT}), and inflection ({-SPL}, {-EDPAST}, and {-S3RDSGPRES}). Participants were presented with either (1) fully grammatical sentences which contained words featuring these morphemes or (2) ungrammatical sentences in which one word form lacked one of the morphemes when it was obligatory (e.g., Canada is one of the most *prosper and developed countries in the world). Half the sentences were presented with a concurrent working memory load, which consisted of remembering the result of a simple calculation (e.g., subtracting 3 from 95) while processing a sentence and reporting the number immediately thereafter. Reading times for the target word and the three words immediately following it were used as the main dependent variable. The background measures included a C-Test of English proficiency, a reading span task, a digits-forward task, a digits-backward task, and a detailed background questionnaire. In agreement with previous research, it was found that morphological violations tended to cause slowdowns in processing. Conversely, the presence of a concurrent memory load tended to cause speedups. Native speakers differed from non-native speakers by: (1) showing an early sensitivity to violations of Stratum 2 derivational morphology; (2) exhibiting a delayed response to violations of Stratum 1 derivation; and (3) not slowing down after violations of inflectional morphology. In addition, native speakers were the only group exhibiting no relationship between morphological processing on one side and short term-memory, working memory, and C-Test scores on the other. Overall, the similarity between native and non-native speakers was the greatest in the processing of Stratum 1 derivation. Crucially, the temporal pattern of the Korean participants’ responses to morphological violations in English placed them in an intermediate position between the English and Chinese native speakers, which was interpreted as evidence of L1 – L2 transfer in morphological processing. Notably, this transfer occurred between an agglutinative L1 and an unrelated mixed-type L2.

Age-related declines in hearing abilities are common and can be attributed to changes in the peripheral and central levels of the auditory system. Although central auditory processing is enhanced in younger musicians, the influence of lifelong musicianship on age-related decline in central auditory processing has not yet been investigated. Therefore, the purpose of this dissertation was to investigate whether lifelong musicianship can mitigate age-related decline in central auditory processing. In the first experiment, age-related declines on four hearing assessments were compared between musicians and non-musicians. Speech-in-noise and gap-detection thresholds were found to decline at a slower rate in musicians, providing an increasing advantage with age. Furthermore, musicians had a lifelong advantage in detecting a mistuned harmonic, although the rate of age-related decline was similar for both musicians and non-musicians. Importantly, there was no significant effect of musicianship on pure-tone thresholds, suggesting that lifelong musicianship can mitigate age-related decline in central but not peripheral auditory processing. To test this hypothesis, a second experiment compared auditory evoked responses (AERs) between groups of older and younger musicians and non-musicians. Results indicated that exogenous neural activity was enhanced in musicians, but that age-related changes were similar between musicians and nonmusicians. Furthermore, endogenous, attention-dependent neural activity was enhanced in older adults, suggesting a compensatory cognitive strategy. Importantly, endogenous activity was preferentially enhanced in older musicians, suggesting that lifelong musicianship enhanced cognitive processes related to auditory perception. In the final experiment, the ability to segregate simultaneous sounds was tested in older and younger musicians and non-musicians by using a mistuned harmonic paradigm, where AERs to harmonic complexes were compared to AERs when one of the harmonics was mistuned. Results indicated that musical training in older adults has little effect on early automatic registration of the mistuned harmonic. In contrast, late attention-dependent activity, associated with the perception of the mistuned harmonic as a separate sound, was influenced by musical training in older adults, suggesting that lifelong musicianship preserves or enhances cognitive components of concurrent sound segregation. In summary, musical training was found to reduce age-related decline in hearing abilities due to enhanced central processing of auditory information.

Users of cochlear implants typically have difficulty differentiating talkers, identifying vocal expressions of emotion, and recognizing familiar melodies because of the degraded spectral cues provided by conventional implants. This thesis examined these abilities in a small, relatively privileged sample of young bilateral implant users. In Study 1 child implant users and a control sample of hearing children were required to judge whether various utterances were produced by a man, woman, or girl (Experiment 1) and to identify the voices of cartoon characters from familiar television programs (Experiment 2). Child implant users’ performance on talker classification was comparable to that of hearing children. Their identification of cartoon characters’ voices was less accurate than that of hearing children but well above chance levels. These findings challenge conventional wisdom about the talker identification difficulties of implant users. In Study 2 the children were required to indicate whether semantically neutral utterances (Experiment 1) or classical piano excerpts (Experiment 2) sounded “happy” or “sad”. In both cases, implant users performed less accurately than hearing children but well above chance levels. Although the findings on emotion recognition in music are in line with those of previous research, the findings on emotion in speech are at odds with claims that young implant users are insensitive to vocal affect. In Study 3 the children were required to identify the theme songs from familiar television programs on the basis of combined timing and pitch cues as well as timing or pitch cues alone. Implant users’ performance was comparable to that of hearing children except when the cues were restricted to pitch relations, which resulted in performance at chance levels. The findings suggest that the musical representations of young implanted listeners include precise information about timing and coarser information about pitch. They also demonstrate, for the first time, that children, both implant users and those with normal hearing, can identify familiar music on the basis of timing cues alone. Overall, the findings highlight the importance of timing cues for implant users, the range of individual differences, and habilitation possibilities for the recognition of talkers, emotion, and music.

The dentate gyrus is a region that hosts most of the hippocampal cells in mammals. Nevertheless, its role in spatial memory remains poorly understood, especially in light of the recently-studied phenomenon of adult hippocampal neurogenesis and its possible role in aging and chronic brain disease. We found that chronic over-expression of transforming growth factor beta1 (TGFbeta1), a cytokine involved in neurodegenerative disease, results in several modifications of brain structure, including volumetric changes and persistent astrogliosis. Furthermore, TGFbeta1 over-expression affects the generation of new neurons, leading to an increased number of neurons in the dentate gyrus and deficits in spatial memory acquisition and storage in aged mice. Nonetheless, reducing neurogenesis via pharmacological treatment impairs spatial memory in juvenile mice but not in adult or aged mice. This suggests that the addition of new cells to hippocampal circuitry, and not the increased plasticity of these cells, is the most relevant role of neurogenesis in spatial memory. We tested this idea by modifying proliferation in the dentate gyrus at several ages using multiple techniques and evaluating the incorporation of newborn neurons into hippocampal circuitry. We found that all granule neurons, recently generated or not, have the same probability of being incorporated. Therefore, the number of new neurons participating in memory circuits is proportional to their availability. Our conclusion is that adult-generated cells have the same functional relevance as those generated during development. Together, our data show that the dentate gyrus is important for memory processing and that adult neurogenesis may be relevant to its functionality by optimizing the number of neurons for memory processing. The equilibrium between neurogenesis and optimal dentate gyrus size is disrupted when TGFbeta1 is chronically increased, which occurs in neurodegenerative pathologies, leading to cognitive impairment in aged animals.

Contexte : Les répercussions de l’alcool au niveau des fonctions cognitives sont bien documentées. Certaines hypothèses suggèrent que l’alcool affecte des fonctions cognitives spécifiques alors que d’autres avancent l’hypothèse de déficits diffus. Cependant, une ambigüité persiste concernant quelles fonctions cognitives sont le plus touchées par l’alcool, et à quel point la durée d’abstinence affecte la récupération cognitive. Nous avons procédé à une des premières méta-analyses qui s’intéresse aux différentes fonctions cognitives touchées par la consommation problématique d’alcool et à la durée d’abstinence requise pour une récupération au niveau des cognitions. Méthodes : Une recherche de la littérature a permis d’identifier 62 études évaluant les cognitions chez les personnes présentant des troubles liés à l’utilisation d’alcool. Les estimations de la taille d’effet ont été calculées avec la Comprehensive Meta Analysis –V2 pour les 12 domaines cognitifs suivants : quotient intellectuel, fluidité verbale/langage, vitesse de traitement de l’information, mémoire de travail, attention, résolution de problème/fonctions exécutives, inhibition/impulsivité, apprentissage verbal, mémoire verbale, apprentissage visuel, mémoire visuelle, habiletés visuo-spatiales. Parmi ces 12 domaines cognitifs, 3 estimations de la taille d’effet ont été calculées selon les durées d’abstinences suivantes : court- (<1 mois), moyen- (2 à 12 mois) et long- (>1 an) termes. Résultats : Les résultats ont révélé la présence de dysfonctions modérées dans 11 domaines cognitifs durant l’abstinence à court terme, et dans 10 domaines cognitifs pour le moyen-terme. Des dysfonctions cognitives minimales furent notées durant l’abstinence à long-terme. Conclusions : Ces résultats révèlent des déficits cognitifs significatifs et diffus durant la première année d’abstinence. Déficits qui se normalisent après un an. Ces résultats soutiennent l’hypothèse de déficits cognitifs diffus reliés à l’alcoolisme et suggèrent que la cognition devrait faire partie intégrante du traitement d’alcoolisme. / Background: The cognitive repercussions of alcoholism are well documented. However, the literature remains somewhat ambiguous with which distinct cognitive functions are more susceptible to impairment in alcoholism and to how duration of abstinence affects cognitive recovery. Some theories claim alcohol negatively affects specific cognitive functions while others assert that deficits are more diffuse in nature. We performed the first meta-analysis to examine cognition in alcoholism and how duration of abstinence affects cognitive recovery. Methods: A literature search yielded 62 studies assessing cognitive dysfunction among alcoholics. Effect size estimates were calculated using the Comprehensive Meta-Analysis V2, for the following 12 cognitive domains: intelligence quotient, verbal fluency/language, speed of processing, working memory, attention, problem solving/executive functions, inhibition/impulsivity, verbal learning, verbal memory, visual learning, visual memory, and visuo-spatial abilities. Within these 12 domains, 3 effect size estimates were calculated based on abstinence duration and partitioned into short- (<1 month), intermediate- (2 to 12 months) and long- (>1 year) term abstinence. Results: Findings revealed moderate impairment across 11 cognitive domains during short term abstinence with moderate impairment across 10 domains during intermediate term abstinence, and overall small effect size estimates during long term abstinence. Conclusions: Results suggest significant cognitive dysfunction during the first year following abstinence from alcohol and that long term abstinence yields near normalisation of cognitive function. These findings support the diffuse brain deficits hypothesis. Clinical implications suggest that cognition may need to be considered an integral part of the treatment of alcoholism.

Speaker identification is a challenge for cochlear implant users because their prosthesis restricts access to the cues that underlie natural voice quality. The present thesis examined speaker recognition in the context of spectrally degraded sentences. The listeners of interest were child implant users who were prelingually deaf as well as hearing children and adults who listened to speech via vocoder simulations of implant processing. Study 1 focused on child implant users' identification of a highly salient speaker—the mother (identified as mother)—and unfamiliar speakers varying in age and gender (identified as man, woman, or girl). In a further experiment, children were required to differentiate their mother's voice from the voices of unfamiliar women. Young hearing children were tested on the same tasks and stimuli. Although child implant users performed more poorly than hearing children overall, they successfully differentiated their mother's voice from other voices. In fact, their performance surpassed expectations based on previous studies of child and adult implant users. Even when natural variations in speaking style were reduced, child implant users successfully identified the speakers. The findings imply that person-specific differences in articulatory style contributed to implanted children's successful performance. Study 2 used vocoder simulations of cochlear implant processing to vary the spectral content of sentences produced by the man, woman, and girl from Study 1. The ability of children (5-7 years and 10-12 years) and adults with normal hearing to identify the speakers was affected by the level of spectral degradation and by the gender of the speaker. Female voices were more difficult to identify than was the man's voice, especially for the younger children. In some respects, hearing individuals' identification of degraded voices was poorer than that of child implant users in Study 1. In a further experiment, hearing children and adults were required to provide verbatim repetitions of spectrally degraded sentences. Their performance on this task greatly exceeded their performance on speaker identification at comparable levels of spectral degradation. The present findings underline the importance of ecologically valid materials and methods when assessing speaker identification, especially in children. Moreover, they raise questions about the efficacy of vocoder models for the study of speaker identification in cochlear implant users.