Episodic memory dysfunction and hypersynchrony in brain functional networks in cognitively intact subjects and MCI: a study of 379 individuals.

Delayed recall (DR) impairment is one of the most significant predictive factors in defining the progression to Alzheimer's disease (AD). Changes in brain functional connectivity (FC) could accompany this decline in the DR performance even in a resting state condition from the preclinical stages to the diagnosis of AD itself, so the characterization of the relationship between the two phenomena has attracted increasing interest. Another aspect to contemplate is the potential moderator role of the APOE genotype in this association, considering the evidence about their implication for the disease. 379 subjects (118 mild cognitive impairment (MCI) and 261 cognitively intact (CI) individuals) underwent an extensive evaluation, including MEG recording. Applying cluster-based permutation test, we identified a cluster of differences in FC and studied which connections drove such an effect in DR. The moderation effect of APOE genotype between FC results and delayed recall was evaluated too. Higher FC in beta band in the right occipital region is associated with lower DR scores in both groups. A significant anteroposterior link emerged in the seed-based analysis with higher values in MCI. Moreover, APOE genotype appeared as a moderator between beta FC and DR performance only in the CI group. An increased beta FC in the anteroposterior brain region appears to be associated with lower memory performance in MCI. This finding could help discriminate the pattern of the progression of healthy aging to MCI and the relation between resting state and memory performance.

A Systematic Review of Normative Data for Verbal Fluency Test in Different Languages.

Verbal fluency tests are easy and quick to use in neuropsychological assessments, so they have been counted among the most classical tools in this context. To date, several normative data for verbal fluency tests have been provided in different languages and countries. A systematic review was carried out with studies that provide normative data for verbal fluency tests. Studies were collected from Scopus, PubMed and Web of Science. 183 studies were retrieved from the database search, of which 73 finally met the inclusion criteria. An analysis of the risk of bias regarding samples selection/characterization and procedure/results reports is conducted for each article. Finally, a full description of the normative data characteristics, considering country and language, verbal fluency task characteristics (type of task) and sample characteristics (number of subjects, gender, age, education) is included. The current systematic review provides an overview and analysis of internationally published normative data that might help clinicians in their search for valid and useful norms on verbal fluency tasks, as well as updated information about qualitative aspects of the different options currently available.

Alpha-band power increases in posterior brain regions in attention deficit hyperactivity disorder after digital cognitive stimulation treatment: randomized controlled study.

The changes triggered by pharmacological treatments in resting-state alpha-band (8-14 Hz) oscillations have been widely studied in attention deficit hyperactivity disorder. However, to date, there has been no evidence regarding the possible changes in cognitive stimulation treatments on these oscillations. This paper sets out to verify whether cognitive stimulation treatments based on progressive increases in cognitive load can be effective in triggering changes in alpha-band power in attention deficit hyperactivity disorder. With this objective, we compared a cognitive stimulation treatment (n = 12) to a placebo treatment (n = 14) for 12 weeks (36 sessions of 15 min) in child patients (8-11 years old) with attention deficit hyperactivity disorder. Two magnetoencephalographic recordings were acquired for all participants. In order to extract the areas with changes in alpha power between both magnetoencephalographic recordings, the differences in the power ratio (pre/post-condition) were calculated using an analysis of covariance test adjusted for the age variable. The results show an increase in the post-treatment alpha power in the experimental group versus the placebo group (P < 0.01) in posterior regions. In addition, these changes were related to measures of attention, working memory and flexibility. The results seem to indicate that cognitive stimulation treatment based on progressive increases in cognitive load triggers alpha-band power changes in children diagnosed with attention deficit hyperactivity disorder in the direction of their peers without this disorder.

Neuropsychological networks in cognitively healthy older adults and dementia patients.

Neuropsychological tests have commonly been used to determine the organization of cognitive functions by identifying latent variables. In contrast, an approach which has seldom been employed is network analysis. We characterize the network structure of a set of representative neuropsychological test scores in cognitively healthy older adults and MCI and dementia patients using network analysis. We employed the neuropsychological battery from the National Alzheimer's Coordinating Center which included healthy controls (n = 7623), mild cognitive impairment patients (n = 5981) and dementia patients (n = 2040), defined according to the Clinical Dementia Rating. The results showed that, according to several network analysis measures, the most central cognitive function is executive function followed by attention, language, and memory. At the test level, the most central test was the Trail Making Test B, which measures cognitive flexibility. Importantly, these results and most other network measures, such as the community organization and graph representation, were similar across the three diagnostic groups. Therefore, network analysis can help to establish a ranking of cognitive functions and tests based on network centrality and suggests that this organization is preserved in dementia. Central nodes might be particularly relevant both from a theoretical and clinical point of view, as they are more associated with other nodes, and their disruption is likely to have a larger effect on the overall network than peripheral nodes. The present analysis may provide a proof of principle for the application of network analysis to cognitive data.

Electrophysiological Brain Changes Associated With Cognitive Improvement in a Pediatric Attention Deficit Hyperactivity Disorder Digital Artificial Intelligence-Driven Intervention: Randomized Controlled Trial.

BACKGROUND: Cognitive stimulation therapy appears to show promising results in the rehabilitation of impaired cognitive processes in attention deficit hyperactivity disorder. OBJECTIVE: Encouraged by this evidence and the ever-increasing use of technology and artificial intelligence for therapeutic purposes, we examined whether cognitive stimulation therapy implemented on a mobile device and controlled by an artificial intelligence engine can be effective in the neurocognitive rehabilitation of these patients. METHODS: In this randomized study, 29 child participants (25 males) underwent training with a smart, digital, cognitive stimulation program (KAD_SCL_01) or with 3 commercial video games for 12 weeks, 3 days a week, 15 minutes a day. Participants completed a neuropsychological assessment and a preintervention and postintervention magnetoencephalography study in a resting state with their eyes closed. In addition, information on clinical symptoms was collected from the child´s legal guardians. RESULTS: In line with our main hypothesis, we found evidence that smart, digital, cognitive treatment results in improvements in inhibitory control performance. Improvements were also found in visuospatial working memory performance and in the cognitive flexibility, working memory, and behavior and general executive functioning behavioral clinical indexes in this group of participants. Finally, the improvements found in inhibitory control were related to increases in alpha-band power in all participants in the posterior regions, including 2 default mode network regions of the interest: the bilateral precuneus and the bilateral posterior cingulate cortex. However, only the participants who underwent cognitive stimulation intervention (KAD_SCL_01) showed a significant increase in this relationship. CONCLUSIONS: The results seem to indicate that smart, digital treatment can be effective in the inhibitory control and visuospatial working memory rehabilitation in patients with attention deficit hyperactivity disorder. Furthermore, the relation of the inhibitory control with alpha-band power changes could mean that these changes are a product of plasticity mechanisms or changes in the neuromodulatory dynamics. TRIAL REGISTRATION: ISRCTN Registry ISRCTN71041318; https://www.isrctn.com/ISRCTN71041318.

Cognitive Control, Cognitive Biases and Emotion Regulation in Depression: A New Proposal for an Integrative Interplay Model.

Research traditions on cognition and depression focus on relatively unconnected aspects of cognitive functioning. On one hand, the neuropsychological perspective has concentrated on cognitive control difficulties as a prominent feature of this condition. On the other hand, the clinical psychology perspective has focused on cognitive biases and repetitive negative patterns of thinking (i.e., rumination) for emotional information. A review of the literature from both fields reveals that difficulties are more evident for mood-congruent materials, suggesting that cognitive control difficulties interact with cognitive biases to hinder cognitive switching, working memory updating, and inhibition of irrelevant information. Connecting research from these two traditions, we propose a novel integrative cognitive model of depression in which the interplay between mood-congruent cognitive control difficulties, cognitive biases, and rumination may ultimately lead to ineffective emotion-regulation strategies to downregulate negative mood and upregulate positive mood.

Emotional distraction in working memory: Bayesian-based evidence of the equivalent effect of positive and neutral interference.

Evidence has shown that negative distracting stimuli are most difficult to control when we are focused in a relevant task, while positive and neutral distractors might be equally overcome. Still, recent meta-analytic evidence has pointed out that differences in the ability to cope with positive or neutral distractors may be difficult to detect in healthy people and in laboratory sets. Here we re-analyse memory performance in four already published working memory experiments in which affective and non-affective distractors were used. We focused on the positive versus neutral contrast, which did not reveal differences in the original analysis, with the aim of quantifying evidence for the null hypothesis using a Bayesian approach. Bayes factor (BF) estimates show substantial evidence in favour to the absence of differences in three out of four datasets. Further, BF aggregated from the four studies shows stronger evidence for the null hypothesis. Results from this analysis show that WM performance after positive and neutral interference can be considered equivalent, suggesting that positive distractors can be overcome to the same extent as neutral ones.

Cognitive predictors of self-awareness in patients with acquired brain injury along neuropsychological rehabilitation.

Previous research has identified a critical role of executive function and memory in self-awareness, a metacognitive capacity often impaired in acquired brain injury. Through this observational study, we aimed to explore the effect of cognitive rehabilitation on the predictive value of these variables, as also whether any of them can predict the level of self-awareness once the cognitive rehabilitation is completed. 69 patients underwent a neuropsychological assessment, including self-awareness, at admission to and discharge from a cognitive rehabilitation process. Regression analysis was performed at these two moments and a third one was conducted to evaluate whether any of the variables at admission predicted the level of self-awareness at discharge. Verbal fluency was found to be the best predictor of self-awareness, both at admission and discharge. In addition, inhibition and cognitive flexibility, as well as episodic memory, appeared as significant predictors of post-rehabilitation self-awareness. Finally, verbal fluency was revealed as the unique pre-rehabilitation predictor of subsequent level of self-awareness following rehabilitation. While post-acute self-awareness is predicted by non-specific executive measures, the cognitive improvement putatively induced by neuropsychological rehabilitation reveals the contribution of more specific executive and memory functions. Importantly, pre-rehabilitation verbal fluency scores predicted the level of self-awareness after cognitive rehabilitation.

Self-Awareness Moderates the Association Between Executive Dysfunction and Functional Independence After Acquired Brain Injury.

OBJECTIVE: Impaired self-awareness (SA) is a common symptom after suffering acquired brain injury (ABI) which interferes with patient's rehabilitation and their functional independence. SA is associated with executive function and declarative memory, two cognitive functions that are related to participants' daily living functionality. Through this observational study, we aim to explore whether SA may play a moderator role in the relation between these two cognitive processes and functional independence. METHOD: A sample of 69 participants with ABI completed a neuropsychological assessment focused on executive function and declarative memory which also included a measure of SA and functional independence. Two separated linear models were performed including functional independence, SA, and two neuropsychological factors (declarative memory and executive function) derived from a previous principal component analysis. RESULTS: Moderation analysis show a significant interaction between SA and executive function, reflecting an association between lower executive functioning and poorer functional outcome, only in participants with low levels of SA. Notwithstanding, declarative memory do not show a significant interaction with SA, even though higher declarative memory scores were associated with better functional independence. CONCLUSIONS: SA seems to play a moderator effect between executive function, but not declarative memory, and functional independence. Accordingly, participants with executive deficits and low levels of SA might benefit from receiving specific SA interventions in the first instance, which would in turn positively impact on their functional independence.

Conciencia de déficit como proceso clave en la rehabilitación de pacientes con daño cerebral adquirido: revisión sistemática / Self-awareness as a key process for rehabilitation of patients with acquired brain injury: a systematic review

Introducción: La afectación de la conciencia de déficit es un síntoma habitual de los pacientes que sufren una lesión cerebral, que afecta al proceso rehabilitador y a los logros en términos de independencia funcional del paciente. Pacientes y métodos: Se realizó una revisión sistemática en las bases bibliográficas Scopus y PubMed de los trabajos científicos que han abordado la conciencia de déficit en pacientes con daño cerebral entre 2000 y 2019. Finalmente se revisaron 65 artículos. Resultados: La conciencia de déficit como proceso metacognitivo está ligada a otros procesos cognitivos de orden superior, como las funciones ejecutivas y la memoria. En los últimos años, se han diseñado e implementado programas de intervención específicos sobre conciencia de déficit que han demostrado su eficacia mediante la incorporación de diferentes técnicas (por ejemplo, psicoeducación y feedback). Ante la necesidad de evaluar el éxito de la intervención sobre la conciencia de déficit en términos de mejora funcional, algunos trabajos han estudiado la generalización y la trasferencia de los resultados de la intervención sobre la conciencia de déficit a las actividades de la vida diaria. Conclusiones: La investigación en conciencia de déficit en pacientes con daño cerebral se ha desarrollado de forma significativa en los últimos años, considerando los factores neuropsicológicos, psicológicos y sociales de este fenómeno. Su futuro prometedor apunta hacia su incorporación como cribado en los protocolos de evaluación y, en su caso, su intervención de forma específica, lo que contribuirá a una rehabilitación eficaz que repercuta en la calidad de vida de los pacientes

Introduction: Self-awareness impairment is a common symptom of patients after suffering acquired brain injury, affecting the rehabilitation process and achievements in terms of patients’s daily living functionality. Patients and methods: A systematic review was performed using Scopus and PubMed databases of scientific articles that address self-awareness in patients with brain injury between 2000 and 2019. Finally, 65 articles were reviewed. Results. As a metacognitive process, self-awareness is linked to other higher order cognitive domains such an executive functions and memory. In recent years, specific intervention programs for self-awareness have been developed and implemented, and have proved their effectiveness, by using different techniques (i.e. psychoeducation and feedback). Considering the importance of assessing the success of the self-awareness interventions in terms of functional improvement, some studies have explored the generalization and transfer of results from those interventions to activities of daily living. Conclusions: Research in self-awareness in patients with acquired brain injury has developed significantly in recent years, considering the neuropsychological, psychological and social factors of this phenomenon. The promising future of research in this field points at its inclusion as screening tool in the assessment protocols and, if applicable, its individualized intervention, contributing to an effective global rehabilitation that affects patient's quality of life

The differential effect of background music on memory for verbal and visuospatial information.

Background music is a part of our everyday activities. Considerable evidence suggests that listening to music while performing cognitive tasks may negatively influence performance. However, other studies have shown that it can benefit memory when the music played during the encoding of information is also provided during the retrieval of that information, in the so-called context dependent memory effect. Since controversial results may be attributed to the nature of the material to be memorized, the aim of the present study is to compare the potential effect of consistent background music on the immediate and long-term recall of verbal and visuospatial information. Experiment 1 showed that instrumental background music does not benefit nor decrease recall of a list of unrelated words, both at the immediate and the 48-hours-delayed tests. By contrast, Experiment 2 revealed that the same background music can impair immediate and therefore long-term memory for visuospatial information. Results are interpreted in terms of competition for neurocognitive resources, with tasks mostly relying on the same brain hemisphere competing for a limited set of resources. Hence, background music might impair visuospatial memory to a greater extent than verbal memory, in the context of limited capacity cognitive system. In conclusion, the nature of the material to be learnt must be considered to fully understand the effect of background music on memory.

Trends in the scientific literature on atypical antipsychotic drugs in the United Kingdom: a bibliometric study.

OBJECTIVE: A bibliometric study was undertaken of peer-reviewed publications on atypical antipsychotic drugs (AADs) from the United Kingdom and the findings are presented herein. METHODS: We selected the documents from the Scopus database. We applied several production and dispersion bibliometric indicators, including Price's law on the growth of the scientific literature, and Bradford's law. We also calculated a so-called 'participation index' across different countries. The bibliometric data were thereafter correlated with social and health data from the UK, including total per capita expenditure on health and gross domestic expenditure. RESULTS: A total of 4156 original manuscripts were published within the timeframe 1967-2015. Our results are in accord with Price's law, with scientific output demonstrating exponential growth (r = 0.9227, as against an r = 0.8766 after adjustment). The drugs most widely evaluated were clozapine (465 documents), olanzapine (263) and risperidone (248). Stratification into Bradford zones produced a nucleus represented by the Journal of Psychopharmacology (168 articles) and British Journal of Psychiatry (159 articles). A total of 1250 different journals were evaluated. CONCLUSIONS: Publications on AADs in the UK have shown exponential growth across the studied period, which is in line with the progressively burgeoning novel AAD releases. No evidence of a saturation point was observed.

A Bibliometric Analysis of Scientific Production on Second-Generation Anti-Psychotic Drugs in Malaysia.

OBJECTIVE: We carried out a bibliometric study on the scientific papers related to second-generation antipsychotic drugs (SGAs) in Malaysia. METHODS: With the SCOPUS database, we selected those documents made in Malaysia whose title included descriptors related to SGAs. We applied bibliometric indicators of production and dispersion, as Price's law and Bradford's law, respectively. We also calculated the participation index of the different countries. The bibliometric data were also been correlated with some social and health data from Malaysia (total per capita expenditure on health and gross domestic expenditure on R&D). RESULTS: We found 105 original documents published between 2004 and 2016. Our results fulfilled Price's law, with scientific production on SGAs showing exponential growth (r = 0.401, vs. r = 0.260 after linear adjustment). The drugs most studied are olanzapine (9 documents), clozapine (7), and risperidone (7). Division into Bradford zones yields a nucleus occupied by the Medical Journal of Malaysia, Singapore Medical Journal, Australian and New Zealand Journal of Psychiatry, and Pharmacogenomics. Totally, 63 different journals were used, but only one in the top four journals had an impact factor being greater than 3. CONCLUSION: The publications on SGAs in Malaysia have undergone exponential growth, without evidence a saturation point.

Efficacy of an intervention programme for rehabilitation of awareness of deficit after acquired brain injury: A pilot study.

BACKGROUND: Impaired Awareness of Deficit (AD) is a frequent symptom after suffering acquired brain injury (ABI) that severely influences patients' daily lives. PRIMARY OBJECTIVE: Pilot study to assess the effectiveness of a structured intervention programme which was developed from a biopsychosocial approach, and relied on common therapeutic strategies of proven effectiveness. METHODS: We assessed the effectiveness of our intervention on a sample of 60 patients with ABI, 30 of whom received the specific AD intervention programme, while the other 30 followed an equivalent rehabilitation approach where they received no specific intervention on AD. AD were assessed before and after the specific intervention on AD through an ad-hoc designed questionnaire. RESULTS: This study reports that patients who received the proposed programme demonstrated significant improvement in their level of AD, as compared to the control group. This improvement was observable on all the proposed dimensions of awareness. Interestingly, results from correlation analysis also showed that patients with lower initial AD were those who exhibited a greater degree of improvement following the intervention. CONCLUSIONS: This research provides evidence in favour of the effectiveness of implementing an intervention programme for AD in the context a global rehabilitation process for patients with ABI.

Tracking the effect of emotional distraction in working memory brain networks: Evidence from an MEG study.

The active maintenance of information in visual working memory (WM) is known to rely on the sustained activity over functional networks including frontal, parietal, occipital, and temporal cortices. Previous studies have described interference-based disturbances in the functional coupling between prefrontal and posterior cortices, and that such disturbances can be restored for a successful WM performance after the presentation of the interfering stimulus. However, very few studies have applied functional connectivity measures to the analysis of the brain dynamics involved in overriding emotional distraction, and all of them have limited their analysis to the particular connections between the amygdala and prefrontal cortex. In this study, we used magnetoencephalography (MEG) to characterize the mutual information-based functional connectivity dynamics among regions of interest located over the prefrontal, the parietal, the temporal, and the occipital cortex. Our results show that the detection of emotional distraction at early latencies (50-150 ms) induces a reduction of functional connectivity involving parietal and temporal cortices that are part of the frontoposterior WM network, while functional coupling among prefrontal areas and between them and posterior cortices is strengthened during the detection of emotional distractors. Later in the processing of the distractor (250-350 and 360-460 ms), the frontoposterior coupling is reestablished for a successful performance, while the orbitofrontal and ventrolateral prefrontal cortex become strongly connected to posterior cortices as a mechanism to cope with emotional distractors.

Interference Impacts Working Memory in Mild Cognitive Impairment.

Mild cognitive impairment (MCI) is considered a transitional stage between healthy aging and dementia, specifically Alzheimer's disease (AD). The most common cognitive impairment of MCI includes episodic memory loss and difficulties in working memory (WM). Interference can deplete WM, and an optimal WM performance requires an effective control of attentional resources between the memoranda and the incoming stimuli. Difficulties in handling interference lead to forgetting. However, the interplay between interference and WM in MCI is not well-understood and needs further investigation. The current study investigated the effect of interference during a WM task in 20 MCIs and 20 healthy elder volunteers. Participants performed a delayed match-to-sample paradigm which consisted in two interference conditions, distraction and interruption, and one control condition without any interference. Results evidenced a disproportionate impact of interference on the WM performance of MCIs, mainly in the presence of interruption. These findings demonstrate that interference, and more precisely interruption, is an important proxy for memory-related deficits in MCI. Thus, the current findings reveal novel evidence regarding the causes of WM forgetting in MCI patients, associated with difficulties in the mechanisms of attentional control.

Early detection and late cognitive control of emotional distraction by the prefrontal cortex.

Unpleasant emotional distraction can impair the retention of non-emotional information in working memory (WM). Research links the prefrontal cortex with the successful control of such biologically relevant distractors, although the temporal changes in this brain mechanism remain unexplored. We use magnetoencephalography to investigate the temporal dynamics of the cognitive control of both unpleasant and pleasant distraction, in the millisecond (ms) scale. Behavioral results demonstrate that pleasant events do not affect WM maintenance more than neutral ones. Neuroimaging results show that prefrontal cortices are recruited for the rapid detection of emotional distraction, at early latencies of the processing (70-130 ms). Later in the processing (360-450 ms), the dorsolateral, the medial and the orbital sections of the prefrontal cortex mediate the effective control of emotional distraction. In accordance with the behavioral performance, pleasant distractors do not require higher prefrontal activity than neutral ones. These findings extend our knowledge about the brain mechanisms of coping with emotional distraction in WM. In particular, they show for the first time that overriding the attentional capture triggered by emotional distractors, while maintaining task-relevant elements in mind, is based on the early detection of such linked-to-survival information and on its later cognitive control by the prefrontal cortex.

Emotional interference-based forgetting in short-term memory. Cognitive inhibition of pleasant but not unpleasant biologically relevant distractors.

Emotional stimuli automatically recruit attentional resources. Although this usually brings more adaptive responses, it may suppose a disadvantage when emotional information is task-irrelevant and should be ignored. Previous studies have shown how emotional stimuli with a negative content exert a greater interference than neutral stimuli during a concurrent working memory (WM) task. However, the impact of positively valenced stimuli as interference has not been addressed to date. In three experiments and one re-analysis we explore the impact of pleasant and unpleasant emotional distractors during WM maintenance. The results suggest that our cognitive control can cope with the interference posed by pleasant distractors as well as with the interference posed by neutral stimuli. However, unpleasant distractors are harder to control in the context of WM maintenance. As unpleasant stimuli usually convey relevant information that we should not to ignore, our executive control seems to be less able to reallocate cognitive resources after unpleasant distraction.

State anxiety in healthy pople can increase their vulnerability to neutral but not to unpleasant distraction in working memory / La ansiedad estado en personas sanas puede aumentar su vulnerabilidad a la distracción neutra pero no a la desagradable en la memoria de trabajo

Unpleasant irrelevant events are known to negatively affect our capacity to maintain neutral but taskrelevant nformation in working memory (WM). In parallel, anxiety biases our attentional responses to those stimuli that may be potentially threatening in order to adaptively enhance their detection andassessment. In this study, we investigated differences between healthy anxious and non-anxious volunteers while they performed a WM task in which neutral and unpleasant pictures were presented as distractors. Our results revealed that state anxiety could increase the interfering effect of neutral but not unpleasant distractors. These findings are discussed in regard to previous studies suggesting that anxiety and acute stress can decrease the level of specificity in the vigilance mechanism that serves to optimize the detection and evaluation of threats

Se sabe que los hechos desagradables irrelevantes influyen negativamente en nuestra capacidad para mantener en la memoria de trabajo información no emocional aunque importante para la tarea. Paralelamente, la ansiedad sesga nuestras respuestas atencionales a aquellos estímulos potencialmente amenazadores para, de este modo, mejorar adaptativamente su detección y valoración. En este trabajo hemos investigado las diferencias entre voluntarios sanos y ansiosos mientras realizaban una tarea de memoria de trabajo en la que se presentaban como distractores imágenes neutras y desagradables. Los resultados muestran que la ansiedad estado puede aumentar el efecto de interferencia de los distractores neutros pero no de los desagradables. Se comentan dichos resultados en relación a estudios anteriores que concluyen que la ansiedad y el estrés agudo pueden disminuir el nivel de especificidad en el mecanismo de vigilancia que sirve para optimizar la detección y evaluación de las amenazas

Early prefrontal activation as a mechanism to prevent forgetting in the context of interference.

OBJECTIVE: Recent research has focused on interference resolution deficits as the main cause of short-term memory decreases in aging. To determine whether activation of brain compensatory mechanisms occur during the encoding process in older people. Moreover, two different levels of interference (distraction and interruption) were presented during the maintenance period to examine how they modulate brain activity profiles. DESIGN: A delayed match-to-sample task with two experimental conditions: distraction and interruption. PARTICIPANTS: Twenty-seven young adults from Complutense University of Madrid and 20 healthy older adults from Complutense Elderly University of Madrid. MEASUREMENTS: Magnetoencephalography scans were recorded during the execution of a working memory interference task. Brain activity sources from younger and older adults during the encoding stage were compared in each condition using minimum norm estimation analyses. RESULTS: The elderly showed enhancement of prefrontal activity during early latencies of the encoding process in both conditions. In the distraction condition, enhanced activity was located in left ventrolateral prefrontal regions, whereas in the interruption condition, enhanced activity was observed in the right ventral prefrontal areas and anterior cingulate cortex. CONCLUSION: Increased recruitment of prefrontal regions in the elderly might be related to the processing depth of information, encoding of new information and semantic associations that are successfully recalled, and with interference resolution and preparatory control when the level of interference becomes higher. These prefrontal modulations during early latencies might reflect a higher top-down control of the encoding process in normal aging to prevent forgetting.