RESUMO
In view of the environmental issues caused by antibiotics, this research studies competitive adsorption/desorption for tetracycline (TC) and sulfadiazine (SDZ) in agricultural soils. Competitive adsorption was studied in binary systems (adding equal concentrations of both antibiotics). In addition, it was compared with results from simple systems. In all cases, batch-type adsorption/desorption experiments were carried out. In the binary systems, for the highest antibiotic concentration added, adsorption percentages were always higher for TC (close to 100%) than for SDZ (10-90%). In these systems, TC desorption was lower than 5% for all soils, and generally <10% for SDZ. Comparing TC and SDZ adsorption for the different systems, SDZ was clearly affected by the presence of TC, with SDZ adsorption percentages being was much higher (with differences generally above 65%) in the binary than in the simple systems. On the contrary, comparing the results of TC adsorption in simple and binary systems, TC was not affected by the presence of SDZ, obtaining similar adsorption percentages in both systems. Kd and KF values (in the Linear and Freundlich models), were higher in the simple systems in the case of TC, which could be due to competition with SDZ, while for SDZ Kd and KF were higher in the binary systems, with a synergistic effect of TC favoring SDZ adsorption. Regarding desorption, it reached 100% for SDZ in some soils in simple systems, dropping to 10% in the presence of TC. TC desorption was <4%, not affected by SDZ. The results indicate that environmental risks would be higher for SDZ, showing differences when both antibiotics are present. This can be considered relevant as regards public health and environmental preservation, in view of direct toxicities and the promotion of resistance to antibiotics associated with the presence of these contaminants in the environment.
Assuntos
Poluentes do Solo , Solo , Adsorção , Antibacterianos , Sulfadiazina , TetraciclinaRESUMO
The Electrophysiology Professional Interest Area (EPIA) and Global Brain Consortium endorsed recommendations on candidate electroencephalography (EEG) measures for Alzheimer's disease (AD) clinical trials. The Panel reviewed the field literature. As most consistent findings, AD patients with mild cognitive impairment and dementia showed abnormalities in peak frequency, power, and "interrelatedness" at posterior alpha (8-12 Hz) and widespread delta (< 4 Hz) and theta (4-8 Hz) rhythms in relation to disease progression and interventions. The following consensus statements were subscribed: (1) Standardization of instructions to patients, resting state EEG (rsEEG) recording methods, and selection of artifact-free rsEEG periods are needed; (2) power density and "interrelatedness" rsEEG measures (e.g., directed transfer function, phase lag index, linear lagged connectivity, etc.) at delta, theta, and alpha frequency bands may be use for stratification of AD patients and monitoring of disease progression and intervention; and (3) international multisectoral initiatives are mandatory for regulatory purposes.
Assuntos
Doença de Alzheimer/fisiopatologia , Ensaios Clínicos como Assunto , Eletroencefalografia/normas , Encéfalo/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Progressão da Doença , HumanosRESUMO
BACKGROUND: Frailty is a multidimensional clinical geriatric syndrome that may be reversed in its early stages. Most studies have paid attention to its physical or phenotypic boundaries, however, little is known about the social aspects surrounding this geriatric syndrome. The study examined the relationship between socio-demographic factors, social resources, quality of life and frailty in older adults. METHODS: This cross-sectional study included a representative sample (n = 749) of adults aged ≥65 years enrolled in forty-three senior centers located in North-West Spain. Socio-demographic data, social resources by the Older Americans Resources and Services Scale, quality of life by the World Health Organization's Quality of Life measure-brief version (WHOQOL-BREF), and frailty status diagnosed by the Frailty phenotype were measured. RESULTS: Female gender, age older than 75 years, single marital status, a poor quality of life, and low scores in the physical health domain of the WHOQOL-BREF were the main determinants of being non-robust. Together, these variables explained 24.4% of the variance. Age between 80 and 89 years, and a poor quality of life were the main determinants for non-robust men, whilst the physical health domain of the WHOQOL-BREF was the single main determinant for women. CONCLUSIONS: Our study found evidence that physical frailty is associated with social determinants and several quality of life domains. More research on this understudied topic is needed to avoid healthcare expenditures and improve the quality of life of non-robust elders.
Assuntos
Idoso Fragilizado/psicologia , Fragilidade/epidemiologia , Fragilidade/psicologia , Vida Independente/psicologia , Relações Interpessoais , Qualidade de Vida/psicologia , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Fragilidade/diagnóstico , Avaliação Geriátrica/métodos , Humanos , Masculino , Exame Físico/métodos , Espanha/epidemiologia , Inquéritos e Questionários , Organização Mundial da SaúdeRESUMO
This exploratory study aimed to investigate the resting-state electroencephalographic (rsEEG) correlates of the cognitive reserve from a life span perspective. Current source density (CSD) and lagged-linear connectivity (LLC) measures were assessed to this aim. We firstly explored the relationship between rsEEG measures for the different frequency bands and a socio-behavioral proxy of cognitive reserve, the Cognitive Reserve Index (CRI). Secondly, we applied moderation analyses to assess whether any of the correlated rsEEG measures showed a moderating role in the relationship between age and cognitive function. Moderate negative correlations were found between the CRI and occipital CSD of delta and beta 2. Moreover, inter- and intrahemispheric LLC measures were correlated with the CRI, showing a negative association with delta and positive associations with alpha 1, beta 1, and beta 2. Among those correlated measures, just two rsEEG variables were significant moderators of the relationship between age and cognition: occipital delta CSD and right hemispheric beta 2 LLC between occipital and limbic regions. The effect of age on cognitive performance was stronger for higher values of both measures. Therefore, lower values of occipital delta CSD and lower beta 2 LLC between right occipital and limbic regions might protect or compensate for the effects of age on cognition. Results of this exploratory study might be helpful to allocate more preventive efforts to curb the progression of cognitive decline in adults with less CR, possibly characterized by these rsEEG parameters at a neural level. However, given the exploratory nature of this study, more conclusive work on these rsEEG measures is needed to firmly establish their role in the cognition-age relationship, for example, verifying if these measures moderate the relationship between brain structure and cognition.
RESUMO
Vascular contribution to cognitive impairment (VCI) and dementia is related to etiologies that may affect the neurophysiological mechanisms regulating brain arousal and generating electroencephalographic (EEG) activity. A multidisciplinary expert panel reviewed the clinical literature and reached consensus about the EEG measures consistently found as abnormal in VCI patients with dementia. As compared to cognitively unimpaired individuals, those VCI patients showed (1) smaller amplitude of resting state alpha (8-12 Hz) rhythms dominant in posterior regions; (2) widespread increases in amplitude of delta (< 4 Hz) and theta (4-8 Hz) rhythms; and (3) delayed N200/P300 peak latencies in averaged event-related potentials, especially during the detection of auditory rare target stimuli requiring participants' responses in "oddball" paradigms. The expert panel formulated the following recommendations: (1) the above EEG measures are not specific for VCI and should not be used for its diagnosis; (2) they may be considered as "neural synchronization" biomarkers to enlighten the relationships between features of the VCI-related cerebrovascular lesions and abnormalities in neurophysiological brain mechanisms; and (3) they may be tested in future clinical trials as prognostic biomarkers and endpoints of interventions aimed at normalizing background brain excitability and vigilance in wakefulness.
Assuntos
Encéfalo/fisiopatologia , Disfunção Cognitiva/diagnóstico , Demência Vascular/diagnóstico , Eletroencefalografia/métodos , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/fisiopatologia , Demência Vascular/etiologia , Demência Vascular/fisiopatologia , Potenciais Evocados/fisiologia , Humanos , Descanso/fisiologiaRESUMO
Physical frailty is closely associated with cognitive impairment. We aim to investigate the neuropsychological profiles of prefrail and non-frail dementia-free community-dwelling older adults using a comprehensive neuropsychological evaluation, and to examine the association between specific frailty criteria and clinical and neuropsychological scores. Participants completed a comprehensive standardized neuropsychological evaluation (covering cognitive domains such as memory, executive functions, language and attention), and frailty assessment. Frailty was assessed according to biological criteria: unintentional weight loss, exhaustion, low physical activity, slowness, and weakness. The sample comprised 60 dementia-free community-dwelling adults, aged 65 years or older (range 65-89 years; 60.0% women). Forty-two participants were classified as robust (no frailty criteria present), and 18 as prefrail (1 or 2 frailty criteria present). We explored neurocognitive differences between the groups and examined the association between specific criteria of frailty phenotype and clinical and neuropsychological outcomes with bivariate tests and multivariate models. Prefrail participants showed poorer cognitive performance than non-frail participants in both memory and non-memory cognitive domains. However, delayed episodic memory was the only cognitive subdomain that remained significant after controlling for age, gender, and educational level. Gait speed was significantly associated with general cognitive performance, immediate memory, and processing speed, while grip strength was associated with visual episodic memory and visuoconstructive abilities. Both gait speed and grip strength were negatively associated with depressive scores. Our results suggest that prefrailty is associated with cognitive dysfunction. The fact that specific cognitive domains may be susceptible to subclinical states of physical frailty may have important clinical implications. Indeed, early detection of specific cognitive dysfunctions may allow opportunities for reversibility.
RESUMO
BACKGROUND: We explored sex-related differences in sociodemographic, medical, psychological, and functional conditions in older adults attending to senior citizens' centers. MATERIALS AND METHODS: An exploratory study was conducted as part of the VERISAÚDE project, a cross-sectional population-based study of individuals aged ≥65 years enrolled in senior community centers located in Galicia, Northwest of Spain (n = 749). A comprehensive gerontological evaluation was used to assess the social, medical, psychological, and functional characteristics of the sample. RESULTS: Women presented a higher prevalence of frailty (p = 0.017), a higher risk of malnutrition (p = 0.029), more medication consumption (p = 0.002), and polypharmacy (p = 0.008), higher depressive scores (p = 0.007), and lower cognitive scores (p = 0.045) than men, who showed a higher prevalence of hearing impairment (p = 0.034), toxic habits (all ps = 0.0001), and comorbidity (p = 0.002), and better quality of life (p = 0.030), and social resources (p = 0.002). Participants considered that attending and being involved in senior centers has a positive influence on their health and promotes successful aging. DISCUSSION: Important differences were found between women and men in health variables, suggesting that sex exerts a powerful influence on health status in older age. These differences should be identified and taking into account when designing interventions to promote active aging and to improve the quality of life of older adults. Taking a sex perspective during the evaluation process could lead to a higher number of older people being effectively treated in clinical practice.
RESUMO
Mild cognitive impairment (MCI) is considered an intermediate transitional stage for the development of dementia, especially Alzheimer's disease. The identification of neurophysiological biomarkers for MCI will allow improvement in detecting and tracking the progression of cognitive impairment. The primary objective of this study was to compare cortical auditory evoked potentials between older adults with and without probable MCI to identify potential neurophysiological indicators of cognitive impairment. We applied a temporal-spatial principal component analysis to the evoked potentials achieved during the processing of pure tones and speech sounds, to facilitate the separation of the components of the P1-N1-P2 complex. The probable MCI group showed a significant amplitude increase in a factor modeling N1b for speech sounds (Cohen's d = .84) and a decrease in a factor around the P2 time interval, especially for pure tones (Cohen's d = 1.17). Moreover, both factors showed a fair discrimination value between groups (area under the curve [AUC] = .698 for N1b in speech condition; AUC = .746 for P2 in tone condition), with high sensitivity to detect MCI cases (86% and 91%, respectively). The results for N1b suggest that MCI participants may suffer from a deficit to inhibit irrelevant speech information, and the decrease of P2 amplitude could be a signal of cholinergic hypoactivation. Therefore, both components could be proposed as early biomarkers of cognitive impairment.
Assuntos
Envelhecimento/fisiologia , Percepção Auditiva/fisiologia , Disfunção Cognitiva/fisiopatologia , Eletroencefalografia/métodos , Potenciais Evocados Auditivos/fisiologia , Potenciais Evocados/fisiologia , Inibição Psicológica , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Análise Espaço-Temporal , Percepção da Fala/fisiologiaRESUMO
OBJECTIVES: Greater understanding of changes in the degree of frailty is important for clarifying the natural history of frailty and may help clinical decision-making regarding preventive interventions. The objectives of this study were to explore natural frailty transition rates at 1-year follow-up and to identify the main determinants of such transitions. STUDY DESIGN: Prospective longitudinal study covering a representative sample of community-dwelling older adults aged ≥65 years (n = 749) at baseline, and transition information at 1-year follow-up (n = 537). MEAN OUTCOME MEASURES: The assessment of frailty status was based on phenotypic criteria (unintentional weight loss, weakness, exhaustion, slow walking speed, low physical activity). Frailty transitions (progressed, regressed, no change, or death) and associated factors were assessed. RESULTS: Most participants remained unchanged from their baseline status (57.1% non-frail, 83.4% pre-frail, 66.7% frail). Regarding frailty transitions, 42.9% of non-frail older adults at baseline had progressed to a pre-frail status by the 1-year follow-up, and 7.9% of pre-frail older adults had become frail. Importantly, 33.3% of frail older adults regressed to a pre-frail status and 8.7% of pre-frail adults had regressed to a non-frail status. Non-frail females tended to progress to pre-frailty significantly more than males (p = 0.006), and mortality was higher among participants classified as frail at baseline (10.7%). Logistic regression showed that the main determinants of worsening frailty were hearing impairment (OR 3.180; 95% CI 1.078-9.384), congestive heart failure (OR 10.864; 95% CI 1.379-85.614), and polypharmacy (OR 2.572, 95% CI 1.096-6.037). CONCLUSION: Our results confirm the dynamic of frailty and the bidirectional nature of frailty transitions, and indicate the need for preventing and treating these conditions in later life in order to minimize the burden of frailty.
Assuntos
Fragilidade/epidemiologia , Fragilidade/fisiopatologia , Perda Auditiva/epidemiologia , Insuficiência Cardíaca/epidemiologia , Polimedicação , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Progressão da Doença , Feminino , Fragilidade/mortalidade , Avaliação Geriátrica , Humanos , Vida Independente , Estudos Longitudinais , Masculino , Estudos Prospectivos , Recuperação de Função Fisiológica , Remissão Espontânea , Espanha/epidemiologiaRESUMO
BACKGROUND: Multisensory stimulation and individualized music have shown to be good in handling the psychological and behavioral symptoms in people with severe dementia. OBJECTIVE: Explore the effects of two nonpharmacological interventions, multisensory stimulation environment (MSSE) in a Snoezelen room and individualized music sessions, on mood, behavior, and biomedical parameters of institutionalized elderly patients with severe dementia. METHODS: Randomized trial of 21 patients aged ≥65 years randomly assigned to two groups (MSSE and individualized music). Interventions administered in two-weekly sessions lasted 30 minutes for a period of 12 weeks. Main outcomes were recorded before, during, and at the end of the intervention. RESULTS: Both groups had immediate positive effects on mood and behavior. Participants were more happy/more content (pâ<â0.001), talked more spontaneously (pâ=â0.009), related to people better (pâ=â0.002), were more attentive to/focused on their environment (pâ<â0.001), enjoyed themselves (pâ=â0.003), were less bored/inactive (pâ=â0.004), and more relaxed/content (pâ=â0.003). The MSSE group performed a better visual follow-up of the stimuli (pâ=â0.044), and the music group were more relaxed and happy (pâ=â0.003). A decrease in heart rate (pâ=â0.013) and an increase in oxygen saturation (pâ=â0.011) were observed from before to after interventions in both groups, with no significant differences between them. CONCLUSIONS: Both interventions seem to be effective at managing mood and behavioral disturbances in the short term and at improving physiological rates, highlighting the efficacy of nonpharmacological treatments in patients with severe dementia.
Assuntos
Sintomas Comportamentais/etiologia , Demência/complicações , Transtornos do Humor/etiologia , Transtornos do Humor/reabilitação , Musicoterapia/métodos , Estimulação Acústica , Idoso , Idoso de 80 Anos ou mais , Demência/psicologia , Demência/reabilitação , Emoções/fisiologia , Feminino , Seguimentos , Frequência Cardíaca Fetal/fisiologia , Humanos , Masculino , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between "seen" trials and "not seen" trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expression, and written words). Results showed the typical visual ERP components in both "seen" and "not seen" trials. There was no statistical difference in the ERP peak latencies between the "seen" and "not seen" trials, suggesting a similar timing of the cortical neural synchronization regardless the primary visual consciousness. In contrast, ERP sources showed differences between "seen" and "not seen" trials. For the visuospatial stimuli, the primary consciousness was related to higher activity in dorsal occipital and parietal sources at about 400 ms post-stimulus. For the emotional face expressions, there was greater activity in parietal and frontal sources at about 180 ms post-stimulus. For the written letters, there was higher activity in occipital, parietal and temporal sources at about 230 ms post-stimulus. These results hint that primary visual consciousness is associated with an enhanced cortical neural synchronization having entirely different spatiotemporal characteristics as a function of the features of the visual stimuli and possibly, the relative qualia (i.e., visuospatial, face expression, and words). In this framework, the dorsal visual stream may be synchronized in association with the primary consciousness of visuospatial and emotional face contents. Analogously, both dorsal and ventral visual streams may be synchronized in association with the primary consciousness of linguistic contents. In this line of reasoning, the ensemble of the cortical neural networks underpinning the single visual features would constitute a sort of multi-dimensional palette of colors, shapes, regions of the visual field, movements, emotional face expressions, and words. The synchronization of one or more of these cortical neural networks, each with its peculiar timing, would produce the primary consciousness of one or more of the visual features of the scene.
RESUMO
Previous studies have shown abnormal power and functional connectivity of resting state electroencephalographic (EEG) rhythms in groups of Alzheimer's disease (AD) compared to healthy elderly (Nold) subjects. Here we tested the best classification rate of 120 AD patients and 100 matched Nold subjects using EEG markers based on cortical sources of power and functional connectivity of these rhythms. EEG data were recorded during resting state eyes-closed condition. Exact low-resolution brain electromagnetic tomography (eLORETA) estimated the power and functional connectivity of cortical sources in frontal, central, parietal, occipital, temporal, and limbic regions. Delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz) were the frequency bands of interest. The classification rates of interest were those with an area under the receiver operating characteristic curve (AUROC) higher than 0.7 as a threshold for a moderate classification rate (i.e., 70%). Results showed that the following EEG markers overcame this threshold: (i) central, parietal, occipital, temporal, and limbic delta/alpha 1 current density; (ii) central, parietal, occipital temporal, and limbic delta/alpha 2 current density; (iii) frontal theta/alpha 1 current density; (iv) occipital delta/alpha 1 inter-hemispherical connectivity; (v) occipital-temporal theta/alpha 1 right and left intra-hemispherical connectivity; and (vi) parietal-limbic alpha 1 right intra-hemispherical connectivity. Occipital delta/alpha 1 current density showed the best classification rate (sensitivity of 73.3%, specificity of 78%, accuracy of 75.5%, and AUROC of 82%). These results suggest that EEG source markers can classify Nold and AD individuals with a moderate classification rate higher than 80%.
RESUMO
Previous studies have suggested that older adults with age-associated memory impairment (AAMI) may show a significant decline in attentional resource capacity and inhibitory processes in addition to memory impairment. In the present paper, the potential attentional capture by task-irrelevant stimuli was examined in older adults with AAMI compared to healthy older adults using scalp-recorded event-related brain potentials (ERPs). ERPs were recorded during the execution of a visual search task, in which the participants had to detect the presence of a target stimulus that differed from distractors by orientation. To explore the automatic attentional capture phenomenon, an irrelevant distractor stimulus defined by a different feature (color) was also presented without previous knowledge of the participants. A consistent N2pc, an electrophysiological indicator of attentional deployment, was present for target stimuli but not for task-irrelevant color stimuli, suggesting that these irrelevant distractors did not attract attention in AAMI older adults. Furthermore, the N2pc for targets was significantly delayed in AAMI patients compared to healthy older controls. Together, these findings suggest a specific impairment of the attentional selection process of relevant target stimuli in these individuals and indicate that the mechanism of top-down suppression of entirely task-irrelevant stimuli is preserved, at least when the target and the irrelevant stimuli are perceptually very different.
RESUMO
OBJECTIVE: The purpose of this study was to evaluate the efficacy of a multimedia and interactive cognitive program on cognition and depressive symptomatology in healthy older adults. METHODS: Adults aged ≥65 years were randomly assigned to two groups: the experimental group in which the participants received a computerized cognitive training application; and the control group in which the participants received no intervention during the protocol. Performance on the mini-mental state examination (MMSE) and the short-form of the geriatric depression scale (GDS-SF) were analysed using a three-way repeated-measure analysis of variance. RESULTS: To determine cognition after the training, the cognitive program was used and the results were assessed using the MMSE, indicating that the significant time effects within the groups reflected the score for cognitive assessment that was significantly better after the intervention in the experimental group. No significant differences were observed with regard to the depressive symptomatology or between the groups according to sex or educational level on the two dimensions previously established (cognition and depressive symptomatology). CONCLUSION: The development of technological applications for intervention in older adults is increasing. Based on the established objective, we can conclude that the computerized intervention may constitute a good alternative to enhance the cognitive status in older people.
Assuntos
Transtornos Cognitivos/prevenção & controle , Cognição/fisiologia , Computadores , Depressão/prevenção & controle , Aprendizagem , Memória , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Testes NeuropsicológicosRESUMO
OBJECTIVE: The prevalence of dementia is increasing and consequently the demands from families, institutions and healthcare system. Although a substantial amount of research on caregiving has emphasized the negative aspects of caregiving, specifically on caregiver burden and depression, less attention has been paid to the positive aspects of caregiving. The aim of the present work was to study the phenomenon of caregiving satisfaction in informal caregivers of people with dementia by assessing their likely predictors. METHODS: A stress process model was used to study caregiver's satisfaction (measured using the Revised Caregiving Satisfaction Scale) on 101 informal caregivers of patients with dementia in relation to the caregiver's background and context, stress-related factors, and mediators. RESULTS: The regression model has an adjusted R(2) of 0.20, which indicates that having a consanguinity relationship with the care recipient, suffering from lower levels of subjective burden, and managing individuals with severe cognitive impairment are the most important predictors of higher caregiving satisfaction. CONCLUSION: Interventions focused on the enhancement of the caregiving satisfaction by increasing the understanding of the disease, should be especially addressed to caregivers without a consanguinity relationship and with high levels of subjective burden, and to those managing care recipients with mild or moderate stages of dementia.
Assuntos
Cuidadores/psicologia , Demência/enfermagem , Assistência Domiciliar/psicologia , Satisfação Pessoal , Adaptação Psicológica , Adulto , Demência/psicologia , Depressão , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Estresse PsicológicoRESUMO
Long-term effects of multisensory stimulation were assessed using a "Snoezelen" room on older residents with dementia. Thirty patients were randomly assigned to 3 groups: multisensory stimulation environment (MSSE) group, individualized activities (activity) group, and control group. The MSSE and activity groups participated in two 30-minute weekly individualized intervention sessions over 16 weeks. Pre-, mid-, posttrial, and 8-week follow-up behavior, mood, cognitive, and functional impairment in basic activities of daily living were registered. Items included in the physically nonaggressive behavior factor improved significantly in post- versus pretrial in the MSSE group compared to the activity group, with no significant differences between MSSE and control groups. The MSSE and activity groups demonstrated behavior improvements and higher scores on the Cohen-Mansfield agitation inventory, verbal agitated behavior factor, and Neuropsychiatric Inventory-Nursing Home, with no significant differences between groups. The MSSE could have long-term positive effects on such neuropsychiatric symptoms in older people with dementia.
Assuntos
Terapias Complementares/métodos , Demência/reabilitação , Agitação Psicomotora/reabilitação , Sensação/fisiologia , Idoso , Idoso de 80 Anos ou mais , Terapias Complementares/instrumentação , Feminino , Humanos , Estudos Longitudinais , Masculino , Resultado do TratamentoRESUMO
A famous-face naming task was used to establish the electrophysiological characterization of the tip-of-the-tongue (TOT) state, successful naming (K), and nonrecognition (DK). The differences in the direct event-related potentials (ERPs) and in the lateralized readiness potential between those categories were studied. The ERP correlates of recognition and access to semantic and lexical information were similar between K and TOT, but showed amplitude differences with respect to DK. A delayed onset of the response selection was obtained in TOT in comparison with K, suggesting an insufficient activation of phonological information from 360 ms onwards. The continuous search for the name and the conflict monitoring in TOT led to differences in ERP amplitudes between TOT and the other categories from 750 ms onwards as well as to a delayed onset of response preparation, indicating a continuous engagement of processing resources.
Assuntos
Potenciais Evocados/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Fala/fisiologia , Adolescente , Adulto , Cognição/fisiologia , Eletroencefalografia , Face , Feminino , Humanos , Masculino , Nomes , Estimulação Luminosa , Tempo de Reação/fisiologiaRESUMO
In the present study a face naming reaction time task was employed in order to evaluate the effect of age on performance and on movement related cortical potentials (MRCPs). In addition, the effect of three response categories with different cognitive demands (DON'T KNOW-don't know the name-, KNOW-correct naming- and TOT-tip-of the-tongue state) on performance and on MRCPs in a sample of older adults was evaluated. The same MRCPs found in a previous study in a sample of young adults were identified in older adults. The results indicated that older participants were generally slower at providing responses than young adults, and that both age groups showed longer reaction time in TOT than in DON'T KNOW and KNOW categories. The first component of readiness potential (1st-RP) showed larger amplitude and longer duration in older than in young adults, especially in the TOT category, which would explain the generally slower responses provided by older participants. In addition, in older adults, the 1st-RP was larger in TOT than in the DON'T KNOW category, but a slope reduction and stabilization were observed in TOT from the more demanding stages of stimulus processing. These results may reflect a lengthening in the preparation period in the TOT category, which probably explains the behavioural slowing in this category. The data of the present study suggest differences in the allocation of processing resources between groups, indicating that the sensoriomotor performance should be compromised more in older than in young adults in tasks with high cognitive load.
Assuntos
Envelhecimento/fisiologia , Córtex Cerebral/fisiologia , Potencial Evocado Motor/fisiologia , Face , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Reconhecimento Psicológico/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Adulto JovemRESUMO
The aim of the present study was evaluate the movement-related cortical potentials (MRCPs) associated with manual and speech movements during a face naming task carried out by the same participants as in a previous study, in order to: 1) determine whether the slowing down of the reaction time observed in the tip-of-the-tongue (TOT) state was caused by motor processes; 2) compare the MRCPs among the three response categories (tip-of-the-tongue, successful retrieval and not knowing the name); and 3) determine whether the MRCPs modulated the differences in amplitude of the late negative wave among response categories. The first component of readiness potential, the negative slope, the motor potential and the reafferent potential associated with the manual response, and two components associated with the verbal responses-the speech-related motor potential and the speech-related reafferent potential-were identified. The slowing down of reaction time observed in the TOT category may be due to a temporal interruption in the motor programming of the responses due to the TOT state. The longer latency in speech-related components in the KNOW with respect to the TOT category can be attributed to the greater cognitive demands involved in the retrieval of proper names in the former category. The brain activity associated with the preparation and execution of the responses had a differential modulatory effect on the amplitude of the LNW component, which may partially explain the differences between the categories observed in the previous study by Díaz et al. [Díaz, F., Lindín, M., Galdo-Alvarez, S., Facal, D., Juncos-Rabadán, O., 2007. An event-related potentials study of face identification and naming: the tip-of-the-tongue state. Psychophysiology 44, 50-68].