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.

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.

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.

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.

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.

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.

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.

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.

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.

Phonological recovery in Spanish developmental dyslexics through the tip-of-the-tongue paradigm / Recuperación fonológica en disléxicos evolutivos españoles mediante el paradigma de la punta de la lengua

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 (AU)

Antecedentes: los disléxicos evolutivos tienen dificultades para acceder y recuperar la forma fonológica de las palabras, sin presentar un déficit a nivel semántico. El propósito de este trabajo era estudiar, a través del paradigma del fenómeno de la punta de la lengua, los problemas de acceso léxico en niños con dislexia evolutiva y su posible relación con la conciencia fonológica. Método: un grupo de niños disléxicos (14) y otro grupo sin dificultades lectoras (14), con edades comprendidas entre 7 y 12 años, realizaron una tarea de denominación de dibujos de frecuencia media - baja y una tarea de conciencia fonológica. Resultados: los resultados indicaron que los niños disléxicos generalmente presentan mayor número de fenómenos de punta de la lengua que el grupo control. A pesar de ser capaces de dar información semántica acerca del dibujo, los disléxicos presentan dificultades para recuperar la información parcial fonológica. Conclusiones: los resultados indican que los disléxicos evolutivos tienen particular dificultad para acceder a la forma fonológica de las palabras. Esto puede ser interesante para desarrollar programas de intervención para estos niños (AU)

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.

[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.

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.

Tipos de trastornos anómicos en las afasias / Types of anomic disorders in aphasia

Los trastornos anómicos están presentes en todos los síndromes afásicos, pero son muy heterogéneos ya que las causas que los producen son muy variadas al ser muchos los procesos cognitivos que intervienen en la producción oral. En este estudio se analizó una muestra de 28 pacientes afásicos pertenecientes a diferentes síndromes (afasias de Broca, de Wernicke, etc.), pero todos con trastornos anómicos. El objetivo era comprobar las variedades de anomias existentes y si esas variedades están ligadas a los síndromes clásicos. A esos pacientes se les aplicaron ocho tareas léxico-semánticas, fundamentalmente de denominación de dibujos (objetos y acciones), semánticas (emparejamiento palabra-dibujo, asociación semántica, etc.) y fonológicas (repetición de palabras y pseudopalabras). Según los resultados en esas tareas se clasificó a los pacientes mediante análisis discriminante en varios grupos (anomia pura, semántica, fonológica y mixta) y se analizaron las principales disociaciones (recuerdo frente a reconocimiento, objetos frente a acciones, etc.) existentes entre ellos. También se hicieron correlaciones entre los resultados de las tareas para comprobar la capacidad de las pruebas de predecir los distintos tipos de anomias. Los resultados muestran la existencia de una gran variedad de trastornos anómicos, que además son independientes de los síndromes a los que pertenezcan los pacientes (AU)

Anomic disorders occur in all aphasic syndromes. Since many cognitive processes are involved in oral production, there are multiple causes of these disorders, which are consequently highly heterogeneous. This study analyzed a sample of 28 aphasic patients with distinct syndromes (Broca’s aphasia, Wernicke’s aphasia, etc.) but all with anomic disorders. The aim of this study was to determine the variety of anomias and their connection with classical syndromes. The patients performed eight lexical-semantic tasks, picture naming (objects and actions), semantic (word-picture matching, semantic association, etc.) and phonological tasks (words and pseudoword repetition). Based on the results on these tasks, the patients were classifi ed into several groups through a discriminant analysis (pure, semantic, phonological and mixed anomia) and the main dissociations between the groups were analyzed (recall vs. recognition, objects vs. actions, etc.). Correlations among the results of the tasks were analyzed to check the ability of the tasks to predict the different types of anomia. The results showed the existence of a wide variety of anomic disorders, which were independent of the type of syndrome found in each patient (AU)

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

El procedimiento generalmente empleado para diagnosticar a los pacientes afásicos consiste en analizar sus síntomas y en base a esos síntomas clasificarlos en uno de los síndromes clásicos. Sin embargo, esa taxonomía tiene algunos problemas importantes, el principal que no tiene en cuenta la variedad de pacientes afásicos existentes, ya que hay muchos más trastornos de los que recogen los síndromes. Con objeto de comprobar el grado de homogeneidad de una muestra de pacientes pertenecientes a diferentes síndromes, en este estudio se aplicaron nueve tareas de comprensión y producción oral a quince pacientes (cinco afásicos de Broca, cinco de Wernicke y cinco de Conducción) y a cinco personas sanas, con edades comprendidas entre 38 y 81 años. Los resultados muestran la existencia de una gran heterogeneidad entre los pacientes etiquetados bajo un mismo síndrome, tal como indica la variabilidad de puntuaciones dentro de los grupos en cada tarea. Por otra parte se observa un escaso ajuste al perfil esperado, ya que algunos pacientes presentan síntomas correspondientes a otros síndromes. Nuestros resultados sugieren la necesidad de estudiar a cada paciente de forma individual e interpretar sus trastornos independientemente de los síndromes (AU)

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 (AU)

Influencia de las variables psicolingüísticas sobre el efecto de generación / The influence of the psicholinguistic variables on the generation effect

El efecto de generación ha demostrado ser una técnica útil para mejorar el aprendizaje y el recuerdo de muy diversos tipos de materiales. Sin embargo no se ha encontrado este efecto en materiales sin significado, como las pseudopalabras, por lo que es lógico pensar que la familiaridad de los estímulos (su frecuencia y edad de adquisición) podría influir en la eficacia de esta técnica. Para comprobar esta hipótesis se llevaron a cabo dos experimentos en los que se manipulaban la frecuencia y la edad de adquisición. La potencia del efecto de generación impidió que se manifestaran los efectos de estas dos variables en la tarea de recuerdo libre, pero ambas influyeron en la tarea de reconocimiento. Así, se obtuvo "efecto espejo" tanto de frecuencia como de edad de adquisición, de manera que los estímulos menos familiares fueron mejor reconocidos que los más familiares (AU)

The generation effect has demonstrated to be an effective technique to improve learning and memory of several types of materials. However, this effect has not been found when meaningless materials are used, such as pseudo words. That is why it is logical to think that the familiarity of the stimuli (their frequency and age of acquisition) could influence the efficacy of this technique. To test this hypothesis two experiments, in which the frequency and the age of acquisition were manipulated, were carried out. The power of the generation effect did not allow the effects of these two variables to become evident in the recall task, but both influenced the recognition task. A "mirror effect" of frequency and age of acquisition was obtained, as the participants recognized the unfamiliar better than the familiar stimuli (AU)

Influencia de las variables psicolingüísticas sobre el efecto de generación / The influence of the psicholinguistic variables on the generation effect

El efecto de generación ha demostrado ser una técnica útil para mejorar el aprendizaje y el recuerdo de muy diversos tipos de materiales. Sin embargo no se ha encontrado este efecto en materiales sin significado, como las pseudopalabras, por lo que es lógico pensar que la familiaridad de los estímulos (su frecuencia y edad de adquisición) podría influir en la eficacia de esta técnica. Para comprobar esta hipótesis se llevaron a cabo dos experimentos en los que se manipulaban la frecuencia y la edad de adquisición. La potencia del efecto de generación impidió que se manifestaran los efectos de estas dos variables en la tarea de recuerdo libre, pero ambas influyeron en la tarea de reconocimiento. Así, se obtuvo "efecto espejo" tanto de frecuencia como de edad de adquisición, de manera que los estímulos menos familiares fueron mejor reconocidos que los más familiares (AU)

The generation effect has demonstrated to be an effective technique to improve learning and memory of several types of materials. However, this effect has not been found when meaningless materials are used, such as pseudo words. That is why it is logical to think that the familiarity of the stimuli (their frequency and age of acquisition) could influence the efficacy of this technique. To test this hypothesis two experiments, in which the frequency and the age of acquisition were manipulated, were carried out. The power of the generation effect did not allow the effects of these two variables to become evident in the recall task, but both influenced there cognition task. A "mirror effect" of frequency and age of acquisition was obtained, as the participants recognized the unfamiliar better than the familiar stimuli (AU)