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1.
Child Dev ; 94(1): e57-e66, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36214376

RESUMO

We examined the relation between socioeconomic status (SES), vocabulary, and reading in middle childhood, during the transition from primary (elementary) to secondary (high) school. Children (N = 279, 163 girls) completed assessments of everyday and curriculum-related vocabulary, (non)word reading, and reading comprehension at five timepoints from age 10 to 13. Piecewise linear mixed-effects models showed significant growth in everyday vocabulary and word reading between every time point. Curriculum vocabulary and reading comprehension showed significant growth during the school year, but not during the summer holidays. There were significant effects of SES on all measures except word reading; yet, SES differences did not widen over time. Our findings motivate targeted reading and vocabulary support for secondary school students from lower SES backgrounds.


Assuntos
Compreensão , Vocabulário , Feminino , Humanos , Criança , Adolescente , Instituições Acadêmicas , Classe Social , Modelos Lineares
2.
Heliyon ; 7(7): e07518, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34296016

RESUMO

Despite substantial financial commitment to widening participation activities internationally, robust evidence demonstrating 'what works' in facilitating disadvantaged learners to access Higher Education (HE) is remarkably sparse. Much effort has been directed at measuring immediate post-intervention changes in the aspirations, attitudes and behaviours thought to drive access to HE, rather than actual access itself. Here, we present an innovative quasi-experimental study of a multi-intervention outreach programme (UniConnect) consisting of 1,386 learners from the Aimhigher West Midlands database whose HE application results were known, while controlling for multiple variables, including estimates of deprivation. The results showed that any engagement with UniConnect, no matter how limited, was associated with an improved chance of achieving a place in HE, but the type of engagement, the extent of engagement and the combination of types of engagement all mattered. The more learners engaged with UniConnect, the greater were their chances of HE acceptance, but the benefit of each additional engagement beyond five or six engagements was small. To our knowledge, these findings are the first to indicate the number, type and combinations of interventions that are most effective in supporting progression to HE. These results therefore have important implications for future practice, enabling funding for such work to be used for optimal impact. Furthermore, we found large differences in success between schools, even when controlling for several other variables; a finding which has important implications for future evaluation research.

3.
Dev Sci ; 24(1): e12986, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32412095

RESUMO

We reconcile competing theories of the role of phonological memory in reading development, by uncovering their dynamic relationship during the first 5 years of school. Phonological memory, reading and phoneme awareness were assessed in 780 phonics-educated children at age 4, 5, 6 and 9. Confirmatory factor analyses demonstrated that phonological memory loaded onto two factors: verbal short-term memory (verbal STM; phonological tasks that loaded primarily on serial order memory) and nonword repetition. Using longitudinal structural equation models, we found that verbal STM directly predicted early word-level reading from age 4 to 6, reflecting the importance of serial-order memory for letter-by-letter decoding. In contrast, reading had no reciprocal influence on the development of verbal STM. The relationship between nonword repetition and reading was bidirectional across the 5 years of study: nonword repetition and reading predicted each other both directly and indirectly (via phoneme awareness). Indirect effects from nonword repetition (and verbal STM) to reading support the view that phonological memory stimulates phonemically detailed representations through repeated encoding of complex verbal stimuli. Similarly, the indirect influence of reading on nonword repetition suggests that improved reading ability promotes the phoneme-level specificity of phonological representations. Finally, the direct influence from reading to nonword repetition suggests that better readers use orthographic cues to help them remember and repeat new words accurately. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=70LZfTR0BjE.


Assuntos
Fonética , Leitura , Criança , Pré-Escolar , Humanos , Estudos Longitudinais , Memória de Curto Prazo , Rememoração Mental
4.
Arch Gerontol Geriatr ; 91: 104232, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32827944

RESUMO

INTRODUCTION: Methods for measuring frailty over-emphasise physical health, and consensus for a more holistic approach is increasing. However, holistic tools have had mixed success in meeting the validation criteria required of a frailty index. We report on the further development and validation of a Frailty Tool designed for use in the community with a greater emphasis on psychological markers, Holland et al's Community-Oriented Frailty Index (COM-FI). METHOD: A total of 351 participants aged 58-96 were recruited from Retirement Villages and local communities across the West Midlands of the UK. Participants completed a series of measures designed to assess frailty and outcomes associated with frailty over a 2-year period. RESULTS: All three candidate items ('polypharmacy', 'exercise frequency', and the Coronary Heart Disease and Diabetes 'joint effect') were incorporated into the tool, and one variable, 'falls' was removed from the index. The revised COM-FI was shown to be valid and met Rockwood's validation criteria (Rockwood et al., 2006), with the exception that in this specific sample there was no significant gender difference and the index did not predict mortality. DISCUSSION: Overall, the COM-FI is a valid and reliable tool, although the capacity for the COM-FI to predict mortality over a 2-year period remains inconclusive given the small numbers of people at the higher ends of the frailty range. Prediction of need for social care was good, showing the utility of this community based tool.

7.
Neuropharmacology ; 119: 141-156, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28400257

RESUMO

In vivo, theta (4-7 Hz) and gamma (30-80 Hz) neuronal network oscillations are known to coexist and display phase-amplitude coupling (PAC). However, in vitro, these oscillations have for many years been studied in isolation. Using an improved brain slice preparation technique we have, using co-application of carbachol (10 µM) and kainic acid (150 nM), elicited simultaneous theta (6.6 ± 0.1 Hz) and gamma (36.6 ± 0.4 Hz) oscillations in rodent primary motor cortex (M1). Each oscillation showed greatest power in layer V. Using a variety of time series analyses we detected significant cross-frequency coupling in 74% of slice preparations. Differences were observed in the pharmacological profile of each oscillation. Thus, gamma oscillations were reduced by the GABAA receptor antagonists, gabazine (250 nM and 2 µM), and picrotoxin (50 µM) and augmented by AMPA receptor antagonism with SYM2206 (20 µM). In contrast, theta oscillatory power was increased by gabazine, picrotoxin and SYM2206. GABAB receptor blockade with CGP55845 (5 µM) increased both theta and gamma power, and similar effects were seen with diazepam, zolpidem, MK801 and a series of metabotropic glutamate receptor antagonists. Oscillatory activity at both frequencies was reduced by the gap junction blocker carbenoxolone (200 µM) and by atropine (5 µM). These data show theta and gamma oscillations in layer V of rat M1 in vitro are cross-frequency coupled, and are mechanistically distinct. The development of an in vitro model of phase-amplitude coupled oscillations will facilitate further mechanistic investigation of the generation and modulation of coupled activity in mammalian cortex.


Assuntos
Ritmo Gama/fisiologia , Córtex Motor/fisiologia , Ritmo Teta/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Animais Recém-Nascidos , Carbacol/farmacologia , Agonistas Colinérgicos/farmacologia , Relação Dose-Resposta a Droga , Agonistas de Aminoácidos Excitatórios , Ritmo Gama/efeitos dos fármacos , Técnicas In Vitro , Ácido Caínico/farmacologia , Masculino , Córtex Motor/efeitos dos fármacos , Neurotransmissores/farmacologia , Ratos , Ratos Wistar , Receptores de GABA/metabolismo , Ritmo Teta/efeitos dos fármacos
8.
Environ Res ; 150: 461-469, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27419367

RESUMO

BACKGROUND: Terrestrial Trunked Radio (TETRA) is a telecommunications system widely used by police and emergency services around the world. The Stewart Report on mobile telephony and health raised questions about possible health effects associated with TETRA signals. This study investigates possible effects of TETRA signals on the electroencephalogram and electrocardiogram in human volunteers. METHODS: Blinded randomized provocation study with a standardized TETRA signal or sham exposure. In the first of two experiments, police officers had a TETRA set placed first against the left temple and then the upper-left quadrant of the chest and the electroencephalogram was recorded during rest and active cognitive processing. In the second experiment, volunteers were subject to chest exposure of TETRA whilst their electroencephalogram and heart rate variability derived from the electrocardiogram were recorded. RESULTS: In the first experiment, we found that exposure to TETRA had consistent neurophysiological effects on the electroencephalogram, but only during chest exposure, in a pattern suggestive of vagal nerve stimulation. In the second experiment, we observed changes in heart rate variability during exposure to TETRA but the electroencephalogram effects were not replicated. CONCLUSIONS: Observed effects of exposure to TETRA signals on the electroencephalogram (first experiment) and electrocardiogram are consistent with vagal nerve stimulation in the chest by TETRA. However given the small effect on heart rate variability and the lack of consistency on the electroencephalogram, it seems unlikely that this will have a significant impact on health. Long-term monitoring of the health of the police force in relation to TETRA use is on-going.


Assuntos
Ondas de Rádio , Estimulação do Nervo Vago , Adolescente , Adulto , Método Duplo-Cego , Eletrocardiografia , Eletroencefalografia , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Polícia , Adulto Jovem
9.
Cognition ; 143: 178-86, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26176199

RESUMO

Phonological tasks are highly predictive of reading development but their complexity obscures the underlying mechanisms driving this association. There are three key components hypothesised to drive the relationship between phonological tasks and reading; (a) the linguistic nature of the stimuli, (b) the phonological complexity of the stimuli, and (c) the production of a verbal response. We isolated the contribution of the stimulus and response components separately through the creation of latent variables to represent specially designed tasks that were matched for procedure. These tasks were administered to 570 6 to 7-year-old children along with standardised tests of regular word and non-word reading. A structural equation model, where tasks were grouped according to stimulus, revealed that the linguistic nature and the phonological complexity of the stimulus predicted unique variance in decoding, over and above matched comparison tasks without these components. An alternative model, grouped according to response mode, showed that the production of a verbal response was a unique predictor of decoding beyond matched tasks without a verbal response. In summary, we found that multiple factors contributed to reading development, supporting multivariate models over those that prioritize single factors. More broadly, we demonstrate the value of combining matched task designs with latent variable modelling to deconstruct the components of complex tasks.


Assuntos
Desenvolvimento da Linguagem , Leitura , Percepção da Fala/fisiologia , Estimulação Acústica , Criança , Feminino , Humanos , Testes de Linguagem , Masculino
10.
Front Hum Neurosci ; 8: 528, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25104928

RESUMO

Altered state theories of hypnosis posit that a qualitatively distinct state of mental processing, which emerges in those with high hypnotic susceptibility following a hypnotic induction, enables the generation of anomalous experiences in response to specific hypnotic suggestions. If so then such a state should be observable as a discrete pattern of changes to functional connectivity (shared information) between brain regions following a hypnotic induction in high but not low hypnotically susceptible participants. Twenty-eight channel EEG was recorded from 12 high susceptible (highs) and 11 low susceptible (lows) participants with their eyes closed prior to and following a standard hypnotic induction. The EEG was used to provide a measure of functional connectivity using both coherence (COH) and the imaginary component of coherence (iCOH), which is insensitive to the effects of volume conduction. COH and iCOH were calculated between all electrode pairs for the frequency bands: delta (0.1-3.9 Hz), theta (4-7.9 Hz) alpha (8-12.9 Hz), beta1 (13-19.9 Hz), beta2 (20-29.9 Hz) and gamma (30-45 Hz). The results showed that there was an increase in theta iCOH from the pre-hypnosis to hypnosis condition in highs but not lows with a large proportion of significant links being focused on a central-parietal hub. There was also a decrease in beta1 iCOH from the pre-hypnosis to hypnosis condition with a focus on a fronto-central and an occipital hub that was greater in high compared to low susceptibles. There were no significant differences for COH or for spectral band amplitude in any frequency band. The results are interpreted as indicating that the hypnotic induction elicited a qualitative change in the organization of specific control systems within the brain for high as compared to low susceptible participants. This change in the functional organization of neural networks is a plausible indicator of the much theorized "hypnotic-state."

11.
Med Eng Phys ; 35(11): 1688-91, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23684580

RESUMO

We observed an anomaly in the human electroencephalogram (EEG) associated with exposure to terrestrial trunked radio (TETRA) Radiofrequency Fields (RF). Here, we characterize the time and frequency components of the anomaly and demonstrate that it is an artefact caused by TETRA RF interfering with the EEG recording equipment and not by any direct or indirect effect on the brain.


Assuntos
Eletrocardiografia/instrumentação , Rádio/instrumentação , Adulto , Artefatos , Eletrodos , Feminino , Humanos , Pessoa de Meia-Idade , Imagens de Fantasmas , Fatores de Tempo , Adulto Jovem
12.
Front Hum Neurosci ; 7: 881, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24399948

RESUMO

EEG Hyperscanning is a method for studying two or more individuals simultaneously with the objective of elucidating how co-variations in their neural activity (i.e., hyperconnectivity) are influenced by their behavioral and social interactions. The aim of this study was to compare the performance of different hyper-connectivity measures using (i) simulated data, where the degree of coupling could be systematically manipulated, and (ii) individually recorded human EEG combined into pseudo-pairs of participants where no hyper-connections could exist. With simulated data we found that each of the most widely used measures of hyperconnectivity were biased and detected hyper-connections where none existed. With pseudo-pairs of human data we found spurious hyper-connections that arose because there were genuine similarities between the EEG recorded from different people independently but under the same experimental conditions. Specifically, there were systematic differences between experimental conditions in terms of the rhythmicity of the EEG that were common across participants. As any imbalance between experimental conditions in terms of stimulus presentation or movement may affect the rhythmicity of the EEG, this problem could apply in many hyperscanning contexts. Furthermore, as these spurious hyper-connections reflected real similarities between the EEGs, they were not Type-1 errors that could be overcome by some appropriate statistical control. However, some measures that have not previously been used in hyperconnectivity studies, notably the circular correlation co-efficient (CCorr), were less susceptible to detecting spurious hyper-connections of this type. The reason for this advantage in performance is discussed and the use of the CCorr as an alternative measure of hyperconnectivity is advocated.

13.
PLoS One ; 7(9): e45630, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23049827

RESUMO

Although event-related potentials (ERPs) are widely used to study sensory, perceptual and cognitive processes, it remains unknown whether they are phase-locked signals superimposed upon the ongoing electroencephalogram (EEG) or result from phase-alignment of the EEG. Previous attempts to discriminate between these hypotheses have been unsuccessful but here a new test is presented based on the prediction that ERPs generated by phase-alignment will be associated with event-related changes in frequency whereas evoked-ERPs will not. Using empirical mode decomposition (EMD), which allows measurement of narrow-band changes in the EEG without predefining frequency bands, evidence was found for transient frequency slowing in recognition memory ERPs but not in simulated data derived from the evoked model. Furthermore, the timing of phase-alignment was frequency dependent with the earliest alignment occurring at high frequencies. Based on these findings, the Firefly model was developed, which proposes that both evoked and induced power changes derive from frequency-dependent phase-alignment of the ongoing EEG. Simulated data derived from the Firefly model provided a close match with empirical data and the model was able to account for i) the shape and timing of ERPs at different scalp sites, ii) the event-related desynchronization in alpha and synchronization in theta, and iii) changes in the power density spectrum from the pre-stimulus baseline to the post-stimulus period. The Firefly Model, therefore, provides not only a unifying account of event-related changes in the EEG but also a possible mechanism for cross-frequency information processing.


Assuntos
Sincronização Cortical/fisiologia , Eletroencefalografia/métodos , Adulto , Algoritmos , Animais , Simulação por Computador , Eletrodos , Potenciais Evocados/fisiologia , Feminino , Vaga-Lumes , Humanos , Masculino , Memória , Modelos Estatísticos , Modelos Teóricos , Neurônios/metabolismo , Oscilometria/métodos , Reconhecimento Visual de Modelos , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído
14.
J Pers Soc Psychol ; 102(5): 910-24, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22229459

RESUMO

Anxiety and fear are often confounded in discussions of human emotions. However, studies of rodent defensive reactions under naturalistic conditions suggest anxiety is functionally distinct from fear. Unambiguous threats, such as predators, elicit flight from rodents (if an escape-route is available), whereas ambiguous threats (e.g., the odor of a predator) elicit risk assessment behavior, which is associated with anxiety as it is preferentially modulated by anti-anxiety drugs. However, without human evidence, it would be premature to assume that rodent-based psychological models are valid for humans. We tested the human validity of the risk assessment explanation for anxiety by presenting 8 volunteers with emotive scenarios and asking them to pose facial expressions. Photographs and videos of these expressions were shown to 40 participants who matched them to the scenarios and labeled each expression. Scenarios describing ambiguous threats were preferentially matched to the facial expression posed in response to the same scenario type. This expression consisted of two plausible environmental-scanning behaviors (eye darts and head swivels) and was labeled as anxiety, not fear. The facial expression elicited by unambiguous threat scenarios was labeled as fear. The emotion labels generated were then presented to another 18 participants who matched them back to photographs of the facial expressions. This back-matching of labels to faces also linked anxiety to the environmental-scanning face rather than fear face. Results therefore suggest that anxiety produces a distinct facial expression and that it has adaptive value in situations that are ambiguously threatening, supporting a functional, risk-assessing explanation for human anxiety.


Assuntos
Ansiedade/psicologia , Emoções , Expressão Facial , Medição de Risco , Adolescente , Adulto , Idoso , Animais , Nível de Alerta , Comportamento Animal , Modelos Animais de Doenças , Medo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Psicológicos , Reprodutibilidade dos Testes , Roedores , Reino Unido
15.
Psychopharmacology (Berl) ; 216(4): 545-56, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21390504

RESUMO

OBJECTIVES: Ecstasy is a recreational drug whose active ingredient, 3,4-methylenedioxymethamphetamine (MDMA), acts predominantly on the serotonergic system. Although MDMA is known to be neurotoxic in animals, the long-term effects of recreational Ecstasy use in humans remain controversial but one commonly reported consequence is mild cognitive impairment particularly affecting verbal episodic memory. Although event-related potentials (ERPs) have made significant contributions to our understanding of human memory processes, until now they have not been applied to study the long-term effects of Ecstasy. The aim of this study was to examine the effects of past Ecstasy use on recognition memory for both verbal and non-verbal stimuli using ERPs. METHODS: We compared the ERPs of 15 Ecstasy/polydrug users with those of 14 cannabis users and 13 non-illicit drug users as controls. RESULTS: Despite equivalent memory performance, Ecstasy/polydrug users showed an attenuated late positivity over left parietal scalp sites, a component associated with the specific memory process of recollection. CONCLUSIONS: [corrected] This effect was only found in the word recognition task which is consistent with evidence that left hemisphere cognitive functions are disproportionately affected by Ecstasy, probably because the serotonergic system is laterally asymmetrical. Experimentally, decreasing central serotonergic activity through acute tryptophan depletion also selectively impairs recollection, and this too suggests the importance of the serotonergic system. Overall, our results suggest that Ecstasy users, who also use a wide range of other drugs, show a durable abnormality in a specific ERP component thought to be associated with recollection.


Assuntos
Potenciais Evocados/efeitos dos fármacos , Alucinógenos/efeitos adversos , Memória/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Adolescente , Adulto , Estudos de Casos e Controles , Cognição/efeitos dos fármacos , Feminino , Humanos , Masculino , Reconhecimento Psicológico/efeitos dos fármacos , Serotonina/metabolismo , Fatores de Tempo , Adulto Jovem
16.
Neuroreport ; 17(2): 205-8, 2006 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-16407772

RESUMO

This study sought to explore whether the so-called 'paradoxical' task-related increases in the alpha bandwidth of the human electroencephalogram result from increases in evoked (phase locked), as opposed to induced (non-phase locked), activity. The electroencephalograms of 18 participants were recorded while they engaged in both auditory sensory-intake tasks (listening to randomly generated 'tunes') and internally directed attention tasks (imagining the same randomly generated tunes) matched for auditory input. Measures of evoked (phase locked) and induced (non-phase locked) activity were compared between tasks. Increases in induced alpha power were found during internal attention. No experimental effects were observed for evoked activity. These results are not entirely consistent with proposals that 'paradoxical' alpha indexes the evoked inhibition of task irrelevant processing.


Assuntos
Ritmo alfa , Atenção/fisiologia , Mapeamento Encefálico , Potenciais Evocados Auditivos/fisiologia , Estimulação Acústica/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desempenho Psicomotor/fisiologia
17.
Int J Psychophysiol ; 48(1): 35-42, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12694899

RESUMO

One developing theme in consciousness research is that consciousness is not the product of any specific component of the brain, rather it is an emergent property of the changing patterns of connectivity between different specialised functional components. For example, the dynamic core hypothesis proposes that conscious experience requires high levels of neural complexity, where complexity is defined in terms of functional connectivity. To test this hypothesis, electroencephalography was recorded while participants were shown random dot-stereograms. Consistent with the dynamic core hypothesis, neural complexity increased as the participants changed from simply viewing the stereogram to consciously perceiving the hidden 3D image.


Assuntos
Percepção de Profundidade/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Visual/fisiologia , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Rede Nervosa/fisiologia
18.
Int J Psychophysiol ; 47(1): 65-74, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12543447

RESUMO

Although slow waves of the electroencephalogram (EEG) have been associated with attentional processes, the functional significance of the alpha component in the EEG (8.1-12 Hz) remains uncertain. Conventionally, synchronisation in the alpha frequency range is taken to be a marker of cognitive inactivity, i.e. 'cortical idling'. However, it has been suggested that alpha may index the active inhibition of sensory information during internally directed attentional tasks such as mental imagery. More recently, this idea has been amended to encompass the notion of alpha synchronisation as a means of inhibition of non-task relevant cortical areas irrespective of the direction of attention. Here we test the adequacy of the one idling and two inhibition hypotheses about alpha. In two experiments we investigated the relation between alpha and internally vs. externally directed attention using mental imagery vs. sensory-intake paradigms. Results from both experiments showed a clear relationship between alpha and both attentional factors and increased task demands. At various scalp sites alpha amplitudes were greater during internally directed attention and during increased load, results incompatible with alpha reflecting cortical idling and more in keeping with suggestions of active inhibition necessary for internally driven mental operations.


Assuntos
Ritmo alfa/métodos , Atenção/fisiologia , Inibição Psicológica , Estimulação Acústica/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Estatísticas não Paramétricas
19.
Int J Psychophysiol ; 46(2): 91-100, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12433386

RESUMO

We examined two subjectively distinct memory states that are elicited during recognition memory in humans and compared them in terms of the gamma oscillations (20-60 Hz) in the electroencepahalogram (EEG) that they induced. These subjective states, 'recollection' and 'familiarity' both entail correct recognition but one involves a clear and conscious recollection of the event including memory for contextual detail whilst the other involves a sense of familiarity without clear recollection. Here we show that during a verbal recognition memory test, the subjective experience of 'recollection' induced higher amplitude gamma oscillations than the subjective experience of 'familiarity' in the time period 300-500 ms after stimulus presentation. Recollection, but not familiarity, was also associated with greater functional connectivity in the gamma frequency range between frontal and parietal sites. Furthermore, the magnitude of the gamma functional connectivity varied over time and was modulated at 3 Hz. Previous studies in animals have shown local theta frequency modulation (3-7 Hz) of gamma-oscillations but this is the first time that a similar effect has been reported in the human EEG.


Assuntos
Eletroencefalografia , Rememoração Mental/fisiologia , Adulto , Análise de Variância , Potenciais Evocados Visuais/fisiologia , Feminino , Lobo Frontal/fisiologia , Humanos , Masculino , Modelos Psicológicos , Lobo Parietal/fisiologia , Teoria Psicológica , Tempo de Reação , Reconhecimento Psicológico/fisiologia
20.
J Altern Complement Med ; 8(4): 427-35, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12230903

RESUMO

OBJECTIVES: Exposure to active mobile phones (MP) has been shown to affect human neural function as shown by the electroencephalogram (EEG). Although it has not been determined whether such effects are harmful, a number of devices have been developed that attempt to minimize these MP-related effects. One such device, the Q Link Ally (QL; Clarus Products, International, L.L.C., San Rafael, CA), is argued to affect the human organism in such a way as to attenuate the effect of MPs. The present pilot study was designed to determine whether there is any indication that QL does alter MP-related effects on the human EEG. DESIGN: Twenty-four (24) subjects participated in a single-blind, fully counterbalanced crossover design in which subjects' resting EEG and phase-locked neural responses to auditory stimuli were assessed under conditions of either active MP or active MP plus QL. RESULTS: The addition of QL to the MP condition increased resting EEG in the gamma range and did so as a function of exposure duration, and it attenuated MP-related effects in the delta and alpha range (at trend-level). The addition of the QL also affected phase-locked neural responses, with a laterality reversal in the alpha range and an alteration to changes over time in the delta range, a reduction of the MP-related beta decrease over time at fronto-posterior sites, and a global reduction in the gamma range that increased as a function of exposure duration. No unambiguous relations were found between these changes and either performance or psychologic state. CONCLUSIONS: This pilot study suggests that the addition of the QL to active MP-exposure does affect neural function in humans, altering both resting EEG patterns and the evoked neural response to auditory stimuli, and that there is a tendency for some MP-related changes to the EEG to be attenuated by the QL.


Assuntos
Estimulação Acústica , Eletroencefalografia , Potenciais Evocados Auditivos , Telefone , Estimulação Acústica/métodos , Adulto , Estudos Cross-Over , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Método Simples-Cego
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