The effects of emotional stimuli on Word retrieval in people with aphasia

PURPOSE

Prior studies have shown that people with aphasia (PWA) have demonstrated superior language performance for emotional compared to nonemotional stimuli on a range of tasks, including auditory comprehension, verbal pragmatics, repetition, reading, and writing. However, studies on word retrieval, specifically, have suggested a possible interference effect of emotion on naming. The purpose of this study was to examine the effect of the emotional valence of stimuli on word retrieval in a series of naming tasks in PWA.

METHOD

Thirteen PWA and 13 neurotypical controls participated in four single-word naming tasks, including 1) object picture naming, 2) action picture naming, 3) category-member generation, and 4) verb generation. Each task included three valence sets of positively-, negatively-, and neutrally-rated pictures or words, which were obtained from the standardized International Affective Picture System (Lang et al., 2008) and the Affective Norms for Emotional Words (Bradley and Lang, 1999) databases. Accuracy and reaction time (RT) were measured and compared across groups, tasks, and valence sets.

RESULTS

Emotional stimuli, especially negative stimuli, resulted in worse naming performance, as measured by accuracy and RT, compared to nonemotional stimuli in PWA and neurotypical controls. This effect was relatively robust across the four naming tasks. In most cases, negative stimuli resulted in lower accuracy and slower RT than positive stimuli.

CONCLUSIONS

These findings suggest that stimulus valence may interfere with word retrieval for PWA and neurotypical adults and that this effect is robust across different types of naming tasks that vary by word class (nouns versus verbs) and stimulus type (pictures versus words). Negative stimuli resulted in worse naming performance than positive stimuli. These results suggest that emotionality of stimuli is an important variable to consider in word retrieval research.

Successful word retraining, maintenance and transference of practice to everyday activities: A single case experimental design in early onset alcohol-induced brain damage

Word retraining programs have been shown to improve naming ability post-stroke and in progressive aphasias. Here, we investigated benefits for a 22-year-old Danish man (DJ), whose difficulties followed brain damage from heavy alcohol misuse. Using a multiple baseline-across-behaviours design (target behaviour: retrieval of word list items), DJ completed a 4-week "Look, Listen, Repeat" program on a computer. Ninety personally relevant target words were selected to create three matched lists. List 1 was trained for 10 sessions over 2 weeks, followed by 9 sessions for List 2 over 2 weeks, while the third list remained untrained. Naming performance was evaluated at baseline, during the intervention, and at 1 and 4 months post-training. Naming improved following each intervention block (p < .001), with only one data point overlapping between the baseline and treatment phases for trained items. Untrained words remained unchanged (p = 1.00), with 50% of data points non-overlapping across baseline to treatment phases. Performance was maintained over time, and appeared to generalize, with DJ naming more trained objects in their natural setting (85%) than untrained items (64%). While more evidence is needed, brief (20-minute), intensive (5-day/week) word retraining programs may assist word retrieval for people with brain damage associated with alcohol misuse.

Word recall process and physiological activation in the tip-of-the-tongue state: Comparison of young and middle-aged groups

To clarify the feeling of knowing a name but not being able to recall it, known as having a "tip-of-the-tongue" (TOT) experience, we proposed a TOT model consisting of three stages combining a face recognition model and autonomic sympathetic nerve activity. Since TOT increases with age, we compared two age groups: young (N = 27, M = 20.4 ± 1.5 years) and middle-aged (N = 29, M = 58.5 ± 8.0 years). Experiment 1 showed that successfully naming low-frequency common names increased the skin conductance response (SCR) value, and the time to reach the maximum SCR value was longer. Experiment 2 was a naming task for face photographs. The younger group showed higher SCR values during successfully naming, while the middle-aged group showed similar SCR values for successfully naming and experiencing TOT. Both groups had the longest time to reach maximum SCR in TOT. In this study, physiological arousal of TOT was not affected by aging.

Poor Performer: A Distinct Entity in Cochlear Implant Users?

INTRODUCTION

Several factors are known to influence speech perception in cochlear implant (CI) users. To date, the underlying mechanisms have not yet been fully clarified. Although many CI users achieve a high level of speech perception, a small percentage of patients does not or only slightly benefit from the CI (poor performer, PP). In a previous study, PP showed significantly poorer results on nonauditory-based cognitive and linguistic tests than CI users with a very high level of speech understanding (star performer, SP). We now investigate if PP also differs from the CI user with an average performance (average performer, AP) in cognitive and linguistic performance.

METHODS

Seventeen adult postlingually deafened CI users with speech perception scores in quiet of 55 (9.32) % (AP) on the German Freiburg monosyllabic speech test at 65 dB underwent neurocognitive (attention, working memory, short- and long-term memory, verbal fluency, inhibition) and linguistic testing (word retrieval, lexical decision, phonological input lexicon). The results were compared to the performance of 15 PP (speech perception score of 15 [11.80] %) and 19 SP (speech perception score of 80 [4.85] %). For statistical analysis, U-Test and discrimination analysis have been done.

RESULTS

Significant differences between PP and AP were observed on linguistic tests, in Rapid Automatized Naming (RAN: p = 0.0026), lexical decision (LexDec: p = 0.026), phonological input lexicon (LEMO: p = 0.0085), and understanding of incomplete words (TRT: p = 0.0024). AP also had significantly better neurocognitive results than PP in the domains of attention (M3: p = 0.009) and working memory (OSPAN: p = 0.041; RST: p = 0.015) but not in delayed recall (delayed recall: p = 0.22), verbal fluency (verbal fluency: p = 0.084), and inhibition (Flanker: p = 0.35). In contrast, no differences were found hereby between AP and SP. Based on the TRT and the RAN, AP and PP could be separated in 100%.

DISCUSSION

The results indicate that PP constitute a distinct entity of CI users that differs even in nonauditory abilities from CI users with an average speech perception, especially with regard to rapid word retrieval either due to reduced phonological abilities or limited storage. Further studies should investigate if improved word retrieval by increased phonological and semantic training results in better speech perception in these CI users.

No negative impact of word retraining on vocabulary use or clarity of communication in semantic dementia

Word retraining techniques can improve picture naming of treated items in people with semantic dementia (SD). The utility of this, however, has been questioned given the propensity for under- and overgeneralization errors in naming in SD. Few studies have investigated the occurrence of such errors. This study examined whether, following tailored word retraining: (1) misuse of words increases, (2) the type of naming errors changes, and/or (3) clarity of communication is reduced. Performance on trained and untrained word naming from nine participants with SD who completed a word retraining programme were analysed. Responses from baseline and post-intervention assessments were coded for misuse (i.e., trained word produced for another target item), error type, and communication clarity. All participants showed significant improvement for trained vocabulary. There was no significant increase in misuse of words, with such errors occurring rarely. At a group level, there was an increased tendency toward omission errors for untrained items, and a reduction in semantically related responses. However, this did not impact on clarity scores with no consistent change across participants. In sum, we found no negative impacts following tailored word retraining, providing further evidence of the benefit of these programmes for individuals with SD.

Effects of concurrent action and object naming treatment on naming skills and functional brain activation patterns in primary progressive aphasia: An fMRI study with a case-series design

Individuals with primary progressive aphasia (PPA) exhibit differential impairment patterns in noun and verb naming, but it remains unclear whether anomia treatment results in similar improvements in noun and verb naming. Therefore, we examined the immediate and long-term (3-months post-treatment) behavioral and neural effects of an anomia treatment on object and action naming skills in PPA. A case-series design was utilized involving two individuals with PPA. Object and action words were trained concurrently and probed regularly using word lists matched on a number of lexical characteristics. One participant showed improvements in all word categories with different effect sizes whereas the other participant demonstrated improved naming only on trained object words. Treatment-induced fMRI changes were found in both hemispheres, with distinct patterns observed across participants. Further research is needed to better understand the effects of residual language and cognitive skills on behavioral and neurophysiological outcomes following anomia treatment for PPA.

Methodological Considerations for Incorporating Clinical Data Into a Network Model of Retrieval Failures

Difficulty retrieving information (e.g., words) from memory is prevalent in neurogenic communication disorders (e.g., aphasia and dementia). Theoretical modeling of retrieval failures often relies on clinical data, despite methodological limitations (e.g., locus of retrieval failure, heterogeneity of individuals, and progression of disorder/disease). Techniques from network science are naturally capable of handling these limitations. This paper reviews recent work using a multiplex lexical network to account for word retrieval failures and highlights how network science can address the limitations of clinical data. Critically, any model we employ could impact clinical practice and patient lives, harkening the need for theoretically well-informed network models.

Support for an inhibitory model of word retrieval

Word retrieval may involve an inhibitory process in which a target word is activated and related words are suppressed. In the current functional magnetic resonance imaging (fMRI) study, we examined the inhibition of language processing cortex by the left dorsolateral prefrontal cortex (DLPFC) during word retrieval using an anagram-solving paradigm. Participants were presented with a distractor that was read aloud followed by a to-be-solved anagram. Distractor types were defined relative to orthographic overlap with the subsequent anagram solution and included related words with one letter different (e.g., "gripe" for the anagram of "price"), related pseudo-words, and unrelated words (i.e., all five letters were different). The anagram solution reaction time was slower in both the related word and related pseudo-word distractor conditions as compared to the unrelated word distractor condition, which can be attributed to greater inhibition following related distractors. The contrast of related words and unrelated words produced one activation in the left DLPFC, a region that has been associated with memory inhibition. To identify the regions that were negatively correlated with activity in the left DLPFC for related distractors, we conducted a functional connectivity analysis between this left DLPFC region and the rest of the brain. We found negatively correlated activity between the DLPFC and language processing cortex for the related word distractor condition (and the related pseudo-word distractor condition at a relaxed threshold). These findings suggest that that the left DLPFC may inhibit related word (and pseudo-word) representations in language processing cortex.

Quantifying the Interplay of Semantics and Phonology During Failures of Word Retrieval by People With Aphasia Using a Multiplex Lexical Network

Investigating instances where lexical selection fails can lead to deeper insights into the cognitive machinery and architecture supporting successful word retrieval and speech production. In this paper, we used a multiplex lexical network approach that combines semantic and phonological similarities among words to model the structure of the mental lexicon. Network measures at different levels of analysis (degree, network distance, and closeness centrality) were used to investigate the influence of network structure on picture naming accuracy and errors by people with Anomic, Broca's, Conduction, and Wernicke's aphasia. Our results reveal that word retrieval is influenced by the multiplex lexical network structure in at least two ways-(a) the accuracy of production and error type on incorrect productions were influenced by the degree and closeness centrality of the target word, and (b) error type also varied in terms of network distance between the target word and produced error word. Taken together, the analyses demonstrate that network science techniques, particularly the use of the multiplex lexical network to simultaneously represent semantic and phonological relationships among words, reveal how the structure of the mental lexicon influences language processes beyond traditionally examined psycholinguistic variables. We propose a framework for how the multiplex lexical network approach allows for understanding the influence of mental lexicon structure on word retrieval processes, with an eye toward a better understanding of the nature of clinical impairments, like aphasia.

Mapping psycholinguistic features to the neuropsychological and lesion profiles in aphasia

Naming and word retrieval deficits are two of the most persistent symptoms in chronic post-stroke aphasia. Naming success or failure on specific words can sometimes be predicted by the psycholinguistic properties of the word. Despite a wealth of literature investigating the influence of psycholinguistic properties in neuro-typical and clinical language processing, the underlying structure of these properties and their relation to the fundamental language components and neural correlates are unexplored. In this study, a multivariate data-decomposition approach was used to identify the underlying structure within a collection of psycholinguistic properties (word imageability, frequency, age-of-acquisition, familiarity, length, semantic diversity and phonological neighbourhood density) and their influence on naming accuracy was explored in a cohort of 42 participants with a diverse range of chronic post-stroke aphasia classifications and severities. The results extracted three principal psycholinguistic factors, which were best described as 'lexical usage', 'semantic clarity' and 'phonological complexity'. Furthermore, a novel approach was used to systematically relate the influence of these psycholinguistic properties to participants' neuropsychological and lesion profiles. The findings did not show a one-to-one mapping between psycholinguistic features and core language components. 'Lexical usage' was the only factor that showed a significant difference between fluent versus non-fluent aphasia groups in terms of the influence of this lexical factor on successful naming, and it was the only factor that was related to the pattern of patients' brain lesions. Voxel-wise whole brain lesion-symptom mapping identified left frontal regions, aligning with previous evidence that these regions are related to language production functions, including word retrieval and repetition. The evidence from the current study suggests that the functional locus of psycholinguistic properties is distributed across multiple language components rather than being localised to a single language element.

Test-retest reliability in an fMRI study of naming in dementia

fMRI has been used as an outcome measure in dementia treatment studies, with many previous studies comparing only single pre- and post-treatment fMRI scans to determine treatment-induced neural changes, while utilizing single subject experimental designs. The purpose of the current study was to evaluate fMRI test-retest reliability in dementia patients and typical older adults using noun and verb confrontation naming to evaluate the validity of using a single pre/post-treatment scan comparison. Seven individuals with dementia and 9 control participants were tested three times over two months using the same fMRI procedures. Differences in individual and group level activation patterns were observed that varied across time. Additionally, the extent of variability fluctuated across individuals, groups, and the grammatical category of target words. Our findings suggested that one time fMRI scanning may inadequately represent an individual's typical brain activation pattern, particularly an individual with dementia. Thus, multiple imaging baselines are recommended.

Self-reported inner speech relates to phonological retrieval ability in people with aphasia

Many individuals with aphasia report the ability to say words in their heads despite spoken naming difficulty. Here, we examined individual differences in the experience of inner speech (IS) in participants with aphasia to test the hypotheses that self-reported IS reflects intact phonological retrieval and that articulatory output processing is not essential to IS. Participants (N = 53) reported their ability to name items correctly internally during a silent picture-naming task. We compared this measure of self-reported IS to spoken picture naming and a battery of tasks measuring the underlying processes required for naming (i.e., phonological retrieval and output processing). Results from three separate analyses of these measures indicate that self-reported IS relates to phonological retrieval and that speech output processes are not a necessary component of IS. We suggest that self-reported IS may be a clinically valuable measure that could assist in clinical decision-making regarding anomia diagnosis and treatment.

Tip of the Tongue States Increase Under Evaluative Observation

We tested the frequent assumption that the difficulty of word retrieval increases when a speaker is being observed and evaluated. We modified the Trier Social Stress Test (TSST) so that participants believed that its evaluative observation components continued throughout the duration of a subsequent word retrieval task, and measured participants' reported tip of the tongue (TOT) states. Participants in this TSST condition experienced more TOTs than participants in a comparable, placebo TSST condition in which there was no suggestion of evaluative observation. This experiment provides initial evidence confirming the assumption that evaluative observation by a third party can be disruptive to word retrieval. We interpret our findings by proposing an extension to a well-supported theoretical model of TOTs.

Mild Cognitive Impairments Moderate the Effect of Time on Verbal Fluency Performance

OBJECTIVES

Mild cognitive impairments (MCI) is a transitional state in aging associated with increased risk of incident dementia. The current study investigated whether MCI status moderated the effect of time on word generation during verbal fluency tasks. Specifically, the objective was to determine whether MCI status had differential effects on initial automatic or latter more effortful retrieval processes of fluency tasks.

METHODS

Participants were community residing older adults enrolled in a longitudinal cohort study. Of the 408 participants, 353 were normal (age=76.06±6.61; %female=57.8) and 55 were diagnosed with MCI (age=78.62±7.00; %female=52.7). Phonemic and category fluency were each administered for 60 s, but performance was recorded at three consecutive 20-s intervals (0-20 s [T1], 21-40 s [T2], 41-60 s [T3]. Separate linear mixed effects models for each fluency task were used to determine the effects of group, time, and their interaction on word generation.

RESULTS

In both fluency tasks, word generation declined as a function of time. Individuals with MCI generated fewer words compared to controls during the first 20 s of phonemic (beta=-1.56; p<.001; d=0.28) and category fluency (beta=-1.85; p<.001; d=0.37). Group by time interactions revealed that individuals with MCI demonstrated attenuated declines in word generation from the first to the second and third time intervals of both phonemic ([T1 vs. T2] beta=2.17, p=.001; d=0.41; [T1 vs. T3]beta=2.28, p=.001; d=0.45) and category ([T1 vs. T2] beta= 2.22, p=.002; d=0.50; [T1 vs. T3]beta=3.16, p<.001; d=0.71) fluency.

CONCLUSIONS

Early automatic retrieval processes in verbal fluency tasks are compromised in MCI. (JINS, 2017, 23, 44-55).

Age-Related Increases in Verbal Knowledge Are Not Associated With Word Finding Problems in the Cam-CAN Cohort: What You Know Won't Hurt You

Objective:

We tested the claim that age-related increases in knowledge interfere with word retrieval, leading to word finding failures. We did this by relating a measure of crystallized intelligence to tip-of-the-tongue (TOT) states and picture naming accuracy.

Method:

Participants were from a large (N = 708), cross-sectional (aged 18–88 years), population-based sample from the Cambridge Centre for Ageing and Neuroscience cohort (Cam-CAN; www.cam-can.com). They completed (a) the Spot-the-Word Test (STW), a measure of crystallized intelligence in which participants circled the real word in word/nonword pairs, (b) a TOT-inducing task, and (c) a picture naming task.

Results:

Age and STW independently predicted TOTs, with higher TOTs for older adults and for participants with lower STW scores. Tests of a moderator model examining interactions between STW and age indicated that STW was a significant negative predictor of TOTs in younger adults, but with increasing age, the effect size gradually approached zero. Results using picture naming accuracy replicated these findings.

Discussion:

These results do not support the hypothesis that lifelong knowledge acquisition leads to interference that causes an age-related increase in TOTs. Instead, crystallized intelligence supports successful word retrieval, although this relationship weakens across adulthood.

Lexical conflict resolution in children with specific language impairment

The aim of our study is to examine the effect of conflict on naming latencies in children with specific language impairment (SLI) and typically developing (TD) children and to explore whether deficits in conflict resolution contribute to lexical problems in SLI. In light of previous results showing difficulties with inhibitory functions in SLI, we expected higher semantic conflict effect in the SLI than in the TD group. To investigate this question 13 children with SLI and 13 age- and gender-matched TD children performed a picture naming task in which the level of conflict was manipulated and naming latencies were measured. Children took longer to name pictures in high conflict conditions than in low conflict conditions. This effect was equally present in the SLI and TD groups. Our results suggest that word production is more effortful for children when conflict resolution is required but children with SLI manage competing lexical representations as efficiently as TD children. This result contradicts studies, which found difficulties with inhibitory functions and is in line with findings of intact inhibitory abilities in children with SLI. Further studies should rule out the possibility that in SLI lower level of conflict resulting from weaker lexical representations masks impairments in inhibition, and investigate the effect of linguistic conflict in other areas.

Neuroanatomical correlates of verbal fluency in early Alzheimer's disease and normal aging

Verbal fluency (VF) impairments occur early in Alzheimer's disease (AD) and to a lesser extent also in normal aging. However, the neural underpinnings of these impairments are not fully understood. The present study evaluated whether VF impairments in early AD and normal aging rely upon common or different neuroanatomical correlates. We examined the association between VF performance and brain structure in 18 mild AD patients and 24 healthy elderly. Linear regressions were performed between accuracy and time intervals in VF scores and structural measurements of cerebral gray matter (GM) and white matter (WM) using MRI. Results showed that semantic VF correlated exclusively with GM in cerebellum, left temporal fusiform cortex, and WM in uncinate fasciculus, inferior fronto-occipital fasciculus and corpus callosum. Phonemic VF showed unique associations between intervals and WM in left-hemisphere tracts. The association between GM in hippocampus, subcortical structures and semantic accuracy differentiated patients from controls. Results showed that VF impairments are primarily associated with same structural brain changes in AD as in healthy elderly but at exaggerated levels. However, specific VF deficiencies and their underlying neural correlates exist and these clearly differentiate the initial stages of AD.

Single-word predictions of upcoming language during comprehension: Evidence from the cumulative semantic interference task

Comprehenders predict upcoming speech and text on the basis of linguistic input. How many predictions do comprehenders make for an upcoming word? If a listener strongly expects to hear the word "sock", is the word "shirt" partially expected as well, is it actively inhibited, or is it ignored? The present research addressed these questions by measuring the "downstream" effects of prediction on the processing of subsequently presented stimuli using the cumulative semantic interference paradigm. In three experiments, subjects named pictures (sock) that were presented either in isolation or after strongly constraining sentence frames ("After doing his laundry, Mark always seemed to be missing one…"). Naming sock slowed the subsequent naming of the picture shirt - the standard cumulative semantic interference effect. However, although picture naming was much faster after sentence frames, the interference effect was not modulated by the context (bare vs. sentence) in which either picture was presented. According to the only model of cumulative semantic interference that can account for such a pattern of data, this indicates that comprehenders pre-activated and maintained the pre-activation of best sentence completions (sock) but did not maintain the pre-activation of less likely completions (shirt). Thus, comprehenders predicted only the most probable completion for each sentence.