Lexical retrieval difficulties in post-COVID-19 syndrome: Insights from verbal fluency and naming tasks.

BACKGROUND: Although considerable research has been conducted on post-COVID-19 syndrome (PCS), cognitive symptoms, particularly those related to language, are still not well understood. AIMS: To provide a detailed quantitative and qualitative analysis of language performance in PCS patients using a comprehensive set of semantic and verbal production tasks. METHODS & PROCEDURES: The study involved 195 PCS patients aged 26-64 years and 50 healthy controls aged 25-61 years. Participants were assessed using two semantic tasks, three naming tasks and four types of verbal fluency tasks, designed to evaluate different aspects of language processing. OUTCOMES & RESULTS: PCS patients demonstrated significantly poorer performance compared with controls across all verbal fluency tasks. This was evident in both the total number of words generated and their types, with patients tending to choose more easily accessible words. In naming tasks, the pattern of errors was similar in both groups, although patients showed a higher number of non-responses and made more errors, reflecting difficulties in word retrieval. The analysis highlighted the impact of factors such as stimulus availability, educational level and cognitive reserve on performance. Notably, younger patients performed worse than older, a paradoxical trend also observed in previous research. CONCLUSIONS & IMPLICATIONS: These findings reveal significant word retrieval difficulties in PCS patients, suggesting that cognitive impairment related to language may be more pronounced than previously understood. The results underscore the need for a thorough evaluation of language functions in PCS patients and the development of more targeted and individualized language rehabilitation strategies to address these specific challenges. WHAT THIS PAPER ADDS: What is already known on the subject Studies on the cognitive characteristics of CPS have focused mainly on broad-spectrum neuropsychological assessments covering all cognitive functions. However, there are very few studies analysing oral production with specific lexical and semantic system tasks. Furthermore, no work has specifically included tasks assessing semantic processing or conducted qualitative analyses of the psycholinguistic variables affecting performance. Such analyses could undoubtedly help clarify the nature of the language impairments in patients with PCS. What this paper adds to the existing knowledge This study explores in depth the evaluation and analysis of the oral production of patients with PCS using several lexical and semantic tasks. In addition, psycholinguistic variables are analysed that could undoubtedly help clarify the nature of the language impairments in patients with PCS. What are the potential or actual clinical implications of this work? The study allows the identification of specific lexical-semantic deficits in the spoken language in patients with this PCS. A more detailed assessment of the oral language of these patients, keeping in mind the psycholinguistic variables that may affect the performance, will facilitate the design of more efficient and individualized rehabilitation programmes.

Reading fluency in Spanish patients with Parkinson's disease: A reading prosody examination.

BACKGROUND: The expressiveness during reading is essential for a fluent reading. Reading prosody has been scarcely studied in an experimental manner, owing to the difficulties in taking objective and direct measures of this reading skill. However, new technologies development has made it possible to analyse reading prosody in an experimental way. Prosodic patterns may vary, not being the same at the beginning of the reading learning process as in adulthood. They may also be altered in disorders such as dyslexia, but little is known about the prosodic characteristics and reading fluency of people with neurodegenerative diseases that cause language impairment, such as Parkinson's disease (PD). AIMS: The aim of this work was to study reading fluency in PD considering the prosodic characteristics of its reading. METHODS & PROCEDURES: The participants were 31 Spanish adults with PD and 31 healthy controls, aged 59-88 years. Two experimental texts were designed that included declarative, interrogative, and exclamatory sentences and experimental verbs and nouns. The manipulability level of the nouns and the motor content of the verbs were considered. The reading of the participants was recorded and analysed with Praat software. OUTCOMES & RESULTS: A longer reading duration and a greater number of pauses, especially in verbs, were found in the PD group, which also showed less pitch variation than the control group in the experimental sentences. The control group showed a big initial rise in declarative and interrogative sentences, as well as a stronger final declination in declarative and exclamatory ones, when compared to the PD group. CONCLUSIONS & IMPLICATIONS: The use of experimental methodologies for the analysis of reading fluency allows learning more about the prosodic characteristics of people with different pathologies, such as PD. Scarce pitch variability found in the analysis, together with the great number of pauses and the longer reading duration, leads to poorly expressive reading, which compromises fluency in PD. The exhaustive evaluation of the reading fluency of PD patients will make it possible to design more complete assessment methods that will favour the diagnosis and early detection of this pathology. WHAT THIS STUDY ADDS: What is already known on this subject • The speech of people with Parkinson's disease (PD) is often impaired by the appearance of hypokinetic dysarthria. The language of people with PD is usually affected with the progression of the disease, with lexico-semantic impairment which mainly affects verbs. Previous literature on reading fluency in PD usually considers reading speed and accuracy, neglecting prosody. Other neurodegenerative diseases with language impairment, such as Alzheimer's disease, commonly cause reading fluency problems. What this paper adds to existing knowledge • This study provides direct and objective measures of the reading fluency (speed, accuracy and prosody) in patients with PD, by the design of experimental texts. Reading fluency characteristics were found to be altered in these patients, especially in pitch variations and reading duration. The reading of Parkinson's patients showed a more flattened pitch. In addition, a greater number of pauses and longer reading durations were also found in the reading of verbs compared to the control group. What are the potential or actual clinical implications of this work? • The use of experimentally created texts makes it possible to analyse the influence of different psycholinguistic variables (frequency, length, motor content, manipulability) on reading fluency, and how the processing of these stimuli could be affected in PD. The objective analysis of the reading fluency characteristics in PD allows the design of more specific evaluation and diagnostic tasks. More complete assessment methods may allow the early detection of the disease. In the same way, it may favour a differential diagnosis with other neurodegenerative diseases.

Neuropsychological follow-up of a case of encephalitis by anti-nmda receptor.

Anti-NMDA receptor encephalitis is an autoimmune disease with psychiatric and cognitive symptoms. Our aim is to describe the cognitive follow-up of a patient diagnosed with the disease for 4 years. The results revealed severe cognitive impairment at the initial evaluation. At 3 months, memory and executive function deficits prevailed. At 9 months, only a deficit in verbal memory was found. At 4 years, she presented a mild memory deficit. These results revealed a significant short-term cognitive deficit. Subsequently, executive functions, memory and verbal fluency recovered, while a mild deficit in verbal memory persisted.

SpaVerb-WN-A megastudy of naming times for 4562 Spanish verbs: Effects of psycholinguistic and motor content variables.

Several studies have been carried out in various languages to explore the role of the main psycholinguistic variables in word naming, mainly in nouns. However, reading of verbs has not been explored to the same extent, despite the differences that have been found between the processing of nouns and verbs. To reduce this research gap, we present here SpaVerb-WN, a megastudy of word naming in Spanish, with response times (RT) for 4562 verbs. RT were obtained from at least 20 healthy adult participants in a reading-aloud task. Several research questions on the role of syllable frequency, word length, neighbourhood, frequency, age of acquisition (AoA), and the novel variable 'motor content' in verb naming were also examined. Linear mixed-effects model analyses indicated that (1) RT increase in with increasing word length and with decreasing neighbourhood size, (2) syllable frequency does not show a significant effect on RT, (3) AoA mediates the effect of motor content, with a positive slope of motor content at low AoA scores and a negative slope at high AoA scores, and (4) there is an interaction between word frequency and AoA, in which the AoA effect for low-frequency verbs gradually decreases as frequency increases. The results are discussed in relation to existing evidence and in the context of the consistency of the spelling-sound mappings in Spanish.

Motor content norms for 4,565 verbs in Spanish.

Embodiment theory suggests that, during the processing of words related to movement, as in the case of action verbs, somatotopic activation is produced in the motor and premotor cortices. In the same way, some studies have demonstrated that patients with frontal-lobe damage, such as Parkinson's patients, have difficulties processing that kind of stimulus. At the moment, no standardized data exist concerning the motor content of Spanish verbs. Therefore, the aim of the present research was to develop a database of 4,565 verbs in Spanish through a survey filled out by 152 university students. The value for the motor content was obtained by calculating the average value from the answers of the participants. In addition, the reliability of the results was estimated, as well as their convergent validity, using diverse correlation coefficients. The database and the raw responses of the participants can be downloaded from this website: https://inco.grupos.uniovi.es/enlaces.

Effects of the psycholinguistic variables on the lexical decision task in Spanish: a study with 2,765 words.

In order to explore the role of the main psycholinguistic variables on visual word recognition, several mega-studies have been conducted in English in recent years. Nevertheless, because the effects of these variables depend on the regularity of the orthographic system, studies must also be done in other languages with different characteristics. The goal of this work was to conduct a lexical decision study in Spanish, a language with a shallow orthography and a high number of words. The influence of psycholinguistic variables on latencies corresponding to 2,765 words was assessed by means of linear mixed-effects modeling. The results show that some variables, such as frequency or age of acquisition, have significant effects on reaction times regardless of the type of words used. Other variables, such as orthographic neighborhood or imageability, were significant only in specific groups of words. Our results highlight the importance of taking into account the peculiarities of each spelling system in the development of reading models.

Neuropsychological Rehabilitation Improves Memory and Action Naming in Patients With Post-COVID-19 Syndrome.

PURPOSE: Post-COVID-19 syndrome (PCS-19) is a condition characterized by both physical and cognitive alterations in patients who have overcome COVID-19. Despite the high incidence of this disorder and the inconveniences it produces to those affected, there are few studies investigating the efficacy of cognitive stimulation in these patients. The aim of this study was to compare two groups of patients with PCS-19. One of them was treated with neuropsychological intervention for 6 months, whereas the other did not receive treatment. Both groups shared similar clinical characteristics and cognitive profiles. METHOD: The study included 15 participants. Eight (seven women and one man, with a mean age of 50.13 years) made up the experimental group and received neuropsychological rehabilitation sessions once a week with the aim of recovering or compensating for their impaired functions. The control group consisted of seven patients (six women and one man, with a mean age of 52.86 years) who did not undergo neuropsychological rehabilitation sessions. The neuropsychological assessment protocol included tests for all cognitive domains. RESULTS: In comparison with the assessment prior to the neuropsychological intervention, significant differences were found in the experimental group both in verbal memory and in the action naming task. As for the control group, improvements in action fluency performance were observed. Neither group showed significant improvement in pre- versus posttest Stroop scores. However, the control group did perform higher than the treatment group in the final assessment. CONCLUSION: Despite the small sample size, our results suggest that patients with PCS-19 may benefit from neuropsychological rehabilitation, as it may help them to improve several cognitive functions that do not recover spontaneously.

Development of criteria for cognitive dysfunction in post-COVID syndrome: the IC-CoDi-COVID approach.

BACKGROUND: We aimed to develop objective criteria for cognitive dysfunction associated with the post-COVID syndrome. METHODS: Four hundred and four patients with post-COVID syndrome from two centers were evaluated with comprehensive neuropsychological batteries. The International Classification for Cognitive Disorders in Epilepsy (IC-CoDE) framework was adapted and implemented. A healthy control group of 145 participants and a complementary data-driven approach based on unsupervised machine-learning clustering algorithms were also used to evaluate the optimal classification and cutoff points. RESULTS: According to the developed criteria, 41.2% and 17.3% of the sample were classified as having at least one cognitive domain impaired using -1 and -1.5 standard deviations as cutoff points. Attention/processing speed was the most frequently impaired domain. There were no differences in base rates of cognitive impairment between the two centers. Clustering analysis revealed two clusters, although with an important overlap (silhouette index 0.18-0.19). Cognitive impairment was associated with younger age and lower education levels, but not hospitalization. CONCLUSIONS: We propose a harmonization of the criteria to define and classify cognitive impairment in the post-COVID syndrome. These criteria may be extrapolated to other neuropsychological batteries and settings, contributing to the diagnosis of cognitive deficits after COVID-19 and facilitating multicenter studies to guide biomarker investigation and therapies.

Cognitive impairment in young adults with post COVID-19 syndrome.

In this study, we aimed to examine different cognitive domains in a large sample of patients with post COVID-19 syndrome. Two hundred and fourteen patients, 85.04% women, ranged 26 to 64 years (mean = 47.48 years) took part in this investigation. Patients' processing speed, attention, executive functions and various language modalities were examined online using a comprehensive task protocol designed for this research. Alteration in some of the tasks was observed in 85% of the participants, being the attention and executive functions tests the ones that show the highest percentage of patients with severe impairment. Positive correlations were observed between the age of the participants in almost all the tasks assessed, implying better performance and milder impairment with increasing age. In the comparisons of patients according to age, the oldest patients were found to maintain their cognitive functions relatively preserved, with only a mild impairment in attention and speed processing, while the youngest showed the most marked and heterogeneous cognitive impairment. These results confirm the subjective complaints in patients with post COVID-19 syndrome and, thanks to the large sample size, allow us to observe the effect of patient age on performance, an effect never reported before in patients with these characteristics.

Reading Fluency in Spanish Patients with Alzheimer's Disease.

BACKGROUND: Reading fluency is essential for our functioning in the literate society in which we live. Reading expressiveness or prosody, along with speed and accuracy, are considered key aspects of fluent reading. Prosodic patterns may vary, not being the same in children learning to read as in adulthood. But little is known about the prosodic characteristics and reading fluency of people with neurodegenerative diseases that causes language impairment and reading difficulties, such as Alzheimer's disease (AD). OBJECTIVE: The aim of this work was to study reading fluency in AD, considering reading speed, accuracy and reading prosody. METHODS: The participants were 20 healthy elderly Spanish adults, and 20 AD patients, aged 64-88 years. An experimental text was designed, that included declarative, exclamatory, and interrogative sentences, words with different stresses and low-frequency words. The reading of the participants was recorded and analyzed using Praat software. RESULTS: The AD group showed significantly longer reading duration, both at the syllable level and at the word and sentence level. These patients also committed more pauses between words, which were also longer, and more reading errors. The control group showed a variation of the syllabic F0 in the three types of sentences, while these variations only appeared in declarative ones in the AD group. CONCLUSION: The pauses, along with the slight pitch variations and the longer reading times and errors committed, compromise the reading fluency of people with AD. Assessment of this reading feature could be interesting as a possible diagnostic marker for the disease.

[Syndromes or symptoms in the assessment of aphasic patients?]. / ¿Síndromes o síntomas en la evaluación de los pacientes afásicos?

The procedure generally used to diagnose aphasic patients consists of classifying them in one of the classic syndromes on the basis of the analysis of their symptoms. However, this taxonomy has several important problems, the main one being that it does not take into account the variability of aphasic patients, as there are many more disorder profiles than those included in the syndromes. In order to test the homogeneity of a sample of patients diagnosed with the classic taxonomy, 15 aphasic patients (5 Broca, 5 Wernicke and 5 Conduction) and 5 healthy controls were tested with nine comprehension and production tasks. Participants were aged 38 to 81 years old. The results indicate the existence of great variability in patients labeled with the same diagnosis, as revealed by the differences in within-group scores in each task, and a limited adjustment to the expected profile, with some patients showing symptoms allegedly corresponding to other syndromes. Our results call attention to the need to study each patient individually and interpret their disorders regardless of the syndromes.

Evolution of Writing Impairment in Spanish Patients with Alzheimer's Disease.

BACKGROUND: Although some studies suggest that writing difficulties may be one of the early symptoms of Alzheimer's disease (AD), they have been scarcely studied compared to oral language. Particularly noteworthy is the paucity of longitudinal studies that enable the observation of writing impairment as cognitive decline progresses. OBJECTIVE: The aim of this study was to examine the characteristics of writing in patients with AD and to monitor the deterioration of their performance over a follow-up period. METHODS: Sixty-four participants (half with AD and half healthy elderly) were compared in a word and pseudo-word dictation task. Patients were evaluated every 6 months over a 2.5 year follow-up period. RESULTS: The evolution of patient performance and error profile shows a typical pattern of deterioration, with early damage to the lexical pathway, which later extends to the phonological pathway and eventually affects peripheral processes. CONCLUSION: These results confirm the presence of writing difficulties from the early stages of AD, supporting the value of this task for early diagnosis. Furthermore, it allows us to explain the contradictory data obtained in previous investigations.

[Variability in the semantic errors produced by brain-injured patients]. / Variabilidad en los errores semánticos producidos por pacientes con daño cerebral.

One of the most common types of errors produced by aphasic patients during oral word production is semantic errors. However, although aphasia semantic errors are often treated as a single homogenous group, there are, in fact, several subtypes defined by the nature of the error-target relationship: paradigmatic, if the two words are category coordinates; syntagmatic, if they are associatively related but from different semantic categories; and superordinate, if the meaning of the error is broader than the meaning of the target. The goal of this study was to investigate whether or not these various subtypes of semantic errors have a similar processing origin. With this objective, we compared the patterns of semantic errors made by a group of Alzheimer patients in a picture-naming task with those made by a group of aphasic patients. We examined the percentages of the different error types, the degree of association between target and error, and the frequency values both of errors and targets. The results suggest that the three subtypes of semantic errors have different origins: the superordinate appear to arise at the semantic level, the syntagmatic at the lexical level, and the paradigmatic at both levels of processing.

Oral and Written Naming in Alzheimer's Disease: A Longitudinal Study.

BACKGROUND: The expressive difficulties in patients with Alzheimer's dementia have been extensively studied, mainly in oral language. However, the deterioration of their writing processes has received much less attention. OBJECTIVE: The present study aims to examine the decline of the performance of patients with Alzheimer's disease in both oral and written picture-naming tasks. METHOD: Sixty-four participants (half with Alzheimer's disease and half healthy elderly) were compared in the oral and written versions of a picture-naming task. Follow-up lasted two and a half years and patients were evaluated every six months. RESULTS: Cross-sectional data indicate that the controls performed better than the patients, and both groups showed a different pattern of errors. In terms of longitudinal data, the results show a similar pattern of deterioration in both tasks. In terms of errors, lexical-semantics were the most numerous at the beginning and their number remained constant throughout all evaluations. In the case of non-responses, there was a significant increase in the last session, both in oral and written naming. CONCLUSION: These results replicate those found in previous studies and highlight the utility of the naming task to detect minimal changes in the evolution of patients with Alzheimer's disease.

Phonological recovery in Spanish developmental dyslexics through the tip-of-the-tongue paradigm.

BACKGROUND: Developmental dyslexics have difficulties accessing and retrieving the phonological form of words, in the absence of a deficit at the semantic level. The aim of this work was to study, through the Tip-of-the-tongue (TOT) paradigm, the problems of lexical access in Spanish-speaking developmental dyslexics and the relationship with their phonological awareness. METHOD: A group of developmental dyslexics (14) and other children without reading difficulties (14), aged 7 to 12, performed a picture naming task of medium and low frequency and a task of phonological awareness. RESULTS: The results indicated that dyslexic children generally show a greater number of TOT phenomena than the control group. Despite being able to provide semantic information of the drawing, they had difficulties retrieving partial phonological information. CONCLUSIONS: These results indicate that developmental dyslexic children have particular difficulty in accessing the phonological form of words, which may be interesting for the development of intervention programs for these children.

The generation effect in patients with mild cognitive impairment.

The generation effect (GE) has been proven as an effective technique to improve learning and memory in healthy and clinical populations. However, it has not been found with meaningless materials such as pseudowords. Several hypotheses postulate the participation of semantic memory in the information-generating process. There is indeed a clear decrease in the effect in patients with serious semantic memory disorders, such as Alzheimer's disease (AD) but, if this is correct, other patients whose memory disorders are not so serious, such as mild cognitive impairment (MCI), should show GE to some extent. To test this hypothesis, we examined 54 participants (18 healthy adults, 18 patients with AD, and 18 with MCI) in a task involving reading and completion of phrases. Results show a decreased (although obvious) GE in patients with MCI. Likewise, results indicate that greater semantic damage will lead to poorer performance with less familiar stimuli or low-frequency words.

Determinants of lexical access in speech production: role of word frequency and age of acquisition.

The main determinants of lexical access in speech are considered to be a word's age of acquisition (AoA) and its frequency of occurrence in a speaker's experience. It is unclear whether and how these variables interact, although they are commonly observed to be correlated, for the few studies that address the issue have reported inconsistent findings. An influential view of AoA in lexical processing (Ellis and Lambon Ralph, 2000) predicts stronger frequency effects for items acquired later in life than for those acquired at an early age. Five experiments were designed to investigate the possible interaction of AoA and frequency effects in speech. We found that the interaction between word frequency and AoA was not robust and that, contrary to expectation, the effect of word frequency was greater for words acquired earlier in life than for those acquired later. The implications of our findings are discussed.