Cerebral White Matter Mediation of Age-Related Differences in Picture Naming Across Adulthood

As people age, one of the most common complaints is difficulty with word retrieval. A wealth of behavioral research confirms such age-related language production deficits, yet the structural neural differences that relate to age-related language production deficits remains an open area of exploration. Therefore, the present study used a large sample of healthy adults across adulthood to investigate how age-related white matter differences in three key left-hemisphere language tracts may contribute to age-related differences in language ability. Specifically, we used diffusion tensor imaging (DTI) to measure fractional anisotropy (FA) and radial diffusivity (RD) which are indicators of white matter structure. We then used a series of path models to test whether white matter from the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the frontal aslant tract (FAT) mediated age-related differences in one form of language production, picture naming. We found that FA, as well as RD from the SLF and FAT mediated the relation between age and picture naming performance, whereas a control tract (corticospinal; CST) was not a mediator. Moreover, differences between mediation of picture naming and a control naming condition suggest that left SLF has a greater role in higher-order aspects of naming, such as semantic and lexical selection whereas left FAT is more sensitive to sensorimotor aspects of fluency or speech motor planning. These results suggest that dorsal white matter contributes to age-related differences in generating speech and may be particularly important in supporting word retrieval across adulthood.

Emotional Valence Affects Word Retrieval During Verb Fluency Tasks in Alzheimer’s Dementia

Individuals with amnestic Alzheimer’s disease (AD) often demonstrate preserved emotional processing skills despite the neurodegenerative disease that affects their limbic system. Emotional valence encompasses the encoding and retrieval of memory and it also affects word retrieval in healthy populations, but it remains unclear whether these effects are preserved in individuals with amnestic AD. Previous studies used a variety of encoding procedures and different retrieval methods that resulted in mixed findings. Therefore, the purpose of the current study is to investigate whether emotional enhancement of memory effects is observed in an experimental condition where the memory encoding process is not required, namely verb (action) fluency tasks. Seventeen participants who were cognitively healthy older adults (CHOA) and 15 participants with amnestic AD were asked to complete verb fluency tasks, and the relative degree of emotional valence observed in their responses was compared between the two groups. A neuropsychological test battery was administered to determine the participants’ cognitive and linguistic profiles, and correlational analyses were conducted to delineate relationships between emotional valence, verbal memory, and learning abilities. The results indicated that the participants with amnestic AD produced words with higher emotional valence (i.e., more pleasant words) compared to CHOA during action fluency testing. In addition, the degree of emotional valence in the words was negatively correlated with verbal memory and learning skills, showing that those with poorer memory skills tend to retrieve words with higher emotional valence. The findings are consistent with those previous studies that stressed that individuals with AD have preserved emotional enhancement of memory effects and may benefit from them for retrieval of information, which may offer some insight into the development of novel rehabilitative strategies for this population.

Facilitating Word Retrieval in Aphasia: Which Type of Cues for Which Aphasic Speakers?

Background: Even if both phonological and semantic cues can facilitate word retrieval in aphasia, it remains unclear if their respective effectiveness varies according to the underlying anomic profile.Aim: The aim of the present facilitation study is to compare the effect of phonological and semantic cues on picture naming accuracy and speed in different types of anomia.Methods: In the present within-subject design study, 15 aphasic persons following brain damage underwent picture naming paradigms with semantic cues (categorically- or associatively related) and phonological cues (initial phoneme presented auditorily, visually or both).Results: At the group level, semantic cueing was as effective as phonological cueing to significantly speed up picture naming. However, while phonological cues were effective regardless of the anomic profile, semantic cueing effects varied depending on the type of anomia. Participants with mixed anomia showed facilitation after both semantic categorical and associative cues, but individuals with lexical-phonological anomia only after categorical cues. Crucially, semantic cues were ineffective for participants with lexical-semantic anomia. These disparities were confirmed by categorical semantic facilitation decreasing when semantic/omission errors prevailed in the anomic profile, but increasing alongside phonological errors.Conclusion: The effectiveness of phonological vs semantic cues seems related to the underlying anomic profile: phonological cues benefit any type of anomia, but semantic cues only lexical-phonological or mixed anomia.

The critical role of the ventral temporal lobe in word retrieval

Deficits in word retrieval are a hallmark of a variety of neurological illnesses spanning from dementia to traumatic injuries. The role of the dominant temporal lobe in fluent naming has been characterized by lesional analyses, functional imaging, and intracranial recordings, but limitations of each of these measures preclude a clear assessment of which specific constituent of the temporal lobe is critical for naming. We studied a large cohort of patients undergoing surgical resections or laser ablations of the dominant temporal lobe for medically intractable epilepsy (n=95). These techniques are exceedingly effective for seizure control but often result in language declines, particularly in confrontation naming, which can be socio-economically disabling. We used a multivariate voxel-based lesion symptom mapping analysis to localize brain regions significantly associated with visual object naming deficits. We observed that posterior inferior temporal regions, centered around the middle fusiform gyrus, were significantly associated with a decline in confrontation naming. Furthermore, we found that the posterior margin of anterior temporal lobectomies was linearly correlated to a decline in visual naming with a clinically significant decline occurring once the resection extended 6 cm from the anterior tip of the temporal lobe. We integrated these findings with electrocorticography during naming in a subset of this population and found that the majority of cortical regions whose resection was associated with a significant decline overlapped with regions that were functionally most active prior to articulation. Importantly, these loci coincide with the sites of susceptibility artifacts during echo-planar imaging, which explains why this region has not previously been implicated. Taken together, these data highlight the crucial contribution of the posterior ventral temporal cortex in lexical access and its important role in the pathophysiology of anomia following temporal lobe resections. Surgical strategies, including the use of laser ablation to target the medial temporal lobe as well as microsurgical approaches, should attempt to preserve this region to mitigate postoperative language deficits.

The Effect of Combining Attention Training Program into Language-based Treatment of Anomia on Word Retrieval: A Case Report

Introduction: The present study is a case report of a 50-year-old man (SM) with aphasia whose word retrieval was severely impaired. The aim of the study was to compare the effect of a combined treatment program (attention training and language treatment) and a single program (language treatment alone) on the naming picture materials. Materials and Methods: This case was affected by a hemorrhagic cerebrovascular accident in the territory of Middle Cerebral Artery branches of the left hemisphere. Two naming treatments, i.e. the single and combined treatments sequentially, were provided for SM; during each of them a 50-item wordlist was practiced (Lists A and B). 12 treatment sessions were implemented for him during each treatment program. These two lists along with another list (List C), left for assessment of generalization of treatments to untrained items, were probed 6 times during and after each program. The whole picture set was normalized in another study described in the text. Results: Our patient’s naming ability progressed during the treatment programs. However, this progression was more salient in combined treatment program. More specifically, List B had the mean score of 34.25 in combined treatment program that was higher than mean of List A in single treatment program (14.5). The slope of List B scores was also higher than that of List A (3.7 vs 1.2). List C showed more generalization of combined treatment to untrained items than single treatment based on its mean scores (27 vs 18.5). Conclusion: the observed improvements of naming ability were felt to be the result of combining attention training into the language treatment which is lead to sustained attention, less distraction and more concentration.

Treatment Approaches for Word Retrieval Deficits in Persons with Aphasia: Recent Advances

Word retrieval deficit is found to be one of the most persistent symptoms reported among the constellation of symptoms exhibited by persons with aphasia (PWAs). This deficit restraints the persons with aphasia to perform with ease across day-to-day conversations. As a consequence, PWAs fail to communicate their desired ideas or thoughts. Word retrieval is an intricate process as it entails various levels of processing. In addition, word retrieval breakdown can occur at multiple levels (semantic level or lexical-semantic level, or phonological level). Thus, there is a need for speech-language pathologists (SLPs) to treat this deficit through effective treatment approaches. In recent decades, semantic feature analysis, verb network strengthening treatment, and phonological component analysis have received greater focus and importance in treating word retrieval deficits. Many studies confirmed that the use of these treatment approaches on PWAs possesses a pivotal role in remediating word retrieval deficits.

Effects of Rhythmic Interventions on Cognitive Abilities in Parkinson’s Disease

<b><i>Objective:</i></b> The objective of this study is to compare 2 different rhythmic, high-intensive interventions, that is, rhythmic speech-language therapy (rSLT) versus rhythmic balance-mobility training (rBMT), against a no-therapy (NT) condition in patients with Parkinson’s disease and against healthy controls (HCs) with regard to the change in or enhancement of cognitive abilities. <b><i>Methods:</i></b> The 4 groups (rSLT: <i>N</i> = 16; rBMT: <i>N</i> = 10; NT: <i>N</i> = 18; and HC: <i>N</i> = 17) were matched for age, sex, and educational level and were tested in 6 cognitive domains: working memory, executive function, visuo-construction, episodic memory, attention, and word retrieval. Assessments took place at baseline, at 4 weeks (T1), and at 6 months (T2). Rhythmic interventions were provided 3 times per week for 4 weeks in total. To analyze true intervention effects between groups and across time, statistical analyses included <i>reliable change index.</i> Intergroup differences were assessed with multivariate assessment of variance, while differences within groups were assessed with 95% confidence intervals of mean difference. <b><i>Results:</i></b> The rSLT improved <i>working memory</i> and <i>word retrieval</i> (<i>p</i> &#x3c; 0.05), possibly a beneficial transfer effect of the training method per se. In contrast, the NT group worsened in <i>phonemic</i> and <i>semantic shifting</i> (<i>p</i> &#x3c; 0.01). Observed improvements in <i>flexibility</i> and in <i>episodic memory</i> in the HC may be linked to training effects of retesting. <b><i>Conclusions:</i></b> Rhythmic cues are resistant to neurodegeneration and have a strong motivating factor. As thus, these may facilitate high-intensive and demanding training. Although both trainings were superior to NT, the improvement of cognitive abilities depends on the specific training method. Further, therapy may be more effective when delivered by a therapist rather than by an impersonal computer program.

Do Cues Facilitate Retrieval of Verbs in Persons with Bilingual Aphasia?

Word retrieval difficulty is commonly seen in persons with aphasia. The cues would repair word retrieval difficulty. The effect of cues during verb retrieval was gauged via Action Naming Test (ANT) in Kannada and English languages in persons with aphasia (PWAs). A total of eight persons with bilingual Aphasia (Broca's, conduction, and isolation type) were recruited for the study. The participants were expected to have a minimum quantum of verbal output were considered for the study. Specifically, the study used phonemic, semantic, and verbal contextual cues to assess verb retrieval abilities. The result of the study manifested that all participants of the study were able to perform better with phonemic cues followed by semantic and verbal contextual cues in both Kannada and English languages.