102 research outputs found

    Le basi neurologiche del rapporto tra il consumatore e la marca. Il contributo del neuro-imaging alle ricerche di marketing

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    Consumer develop very tight relationships with brands. In many cases, consumers develop positive relationships with their preferred brands and goods. In some of these cases true “love” relationship may occur. Sometimes, also negative relationships arise, often as a reaction toward unsatisfactory experiences, bad practices, etc. Companies aim at developing strong and positive emotional relationships between their brands and their customers. When they succeed, the brand is immediately recognized, it elicits positive affective responses, it is more difficult to be substituted for by competitors. The aim of the present study is to measure behavioral and emotional brain responses to covert visual recognition of brands. Functional magnetic resonance imaging (fMRI) was used to measure brain activity in 15 healthy subjects (7 females, 23-33 years) that were exposed to four stimulus types: coloured scrambled pictures, coloured squares, brand logos, and IAPS pictures with positive and negative valence scores. Sixty-three popular brands were selected among 8 different product categories. Two specific patterns of activation emerged for like (amygdale) and dislike brands (anterior medial cingulate, left inferior frontal gyrus, left middle temporal gyrus, medial cuneus). Implications for interpreting the role of brands in consumer mental processes are given, with special reference to the asymmetry between positive and negative evaluations

    Human Cortical Excitability Increases with Time Awake

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    Prolonged wakefulness is associated not only with obvious changes in the way we feel and perform but also with well-known clinical effects, such as increased susceptibility to seizures, to hallucinations, and relief of depressive symptoms. These clinical effects suggest that prolonged wakefulness may be associated with significant changes in the state of cortical circuits. While recent animal experiments have reported a progressive increase of cortical excitability with time awake, no conclusive evidence could be gathered in humans. In this study, we combine transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to monitor cortical excitability in healthy individuals as a function of time awake. We observed that the excitability of the human frontal cortex, measured as the immediate (0-20 ms) EEG reaction to TMS, progressively increases with time awake, from morning to evening and after one night of total sleep deprivation, and that it decreases after recovery sleep. By continuously monitoring vigilance, we also found that this modulation in cortical responsiveness is tonic and not attributable to transient fluctuations of the level of arousal. The present results provide noninvasive electrophysiological evidence that wakefulness is associated with a steady increase in the excitability of human cortical circuits that is rebalanced during slee

    Spatiotemporal dynamics of single-letter reading: a combined ERP-FMRI study

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    This work investigates the neural correlates of single-letter reading by combining event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), thus exploiting their complementary spatiotemporal resolutions. Three externally-paced reading tasks were administered with an event-related design: passive observation of letters and symbols and active reading aloud of letters. ERP and fMRI data were separately recorded from 8 healthy adults during the same experimental conditions. Due to the presence of artifacts in the EEG signals, two subjects were discarded from further analysis. Independent Component Analysis was applied to ERPs, after dimensionality reduction by Principal Component Analysis: some independent components were clearly related to specific reading functions and the associated current density distributions in the brain were estimated with Low Resolution Electromagnetic Tomography Analysis method (LORETA). The impulse hemodynamic response function was modeled as a linear combination of linear B-spline functions and fMRI statistical analysis was performed by multiple linear regression. fMRI and LORETA maps were superimposed in order to identify the overlapping activations and the activated regions specifically revealed by each modality. The results showed the existence of neuronal networks functionally specific for letter processing and for explicit verbal-motor articulation, including the temporo-parietal and frontal regions. Overlap between fMRI and LORETA results was observed in the inferior temporal-middle occipital gyrus, suggesting that this area has a crucial and multifunctional role for linguistic and reading processes, likely because its spatial location and strong interconnection with the main visual and auditory sensory systems may have favored its specialization in grapheme-phoneme matching

    Transmissão do laser de baixa potência através de filmes plásticos de PVC

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    Low-intensity laser application is used in physical therapy in view of accelerating wound repair processes. In clinical practice, a PVC film is commonly used covering the laser pen’s tip to avoid contamination of the wound by the equipment, mainly on mucosa and cruent areas. From the therapeutic point of view, it is important to evaluate whether the PVC film interferes in the transmitted dosimetry to the tissue, minimizing therapy effects. The aim of this study was to evaluate the percentage of energy transmission of two laser equipments used in physical therapy clinics. Laser wavelengths were 632.8 nm for the HeNe (helium-neon) and 830 nm for the GaAlAs (gallium-aluminium arsenide) laser. For each wavelength a total of 150 measures were evaluated: 50 with direct irradiation (control group, CG) and with two different kinds of PVC film on the laser pen (experimental groups G1 and G2). Both PVC films were 0.01 mm thick. Results showed that the HeNe laser had the following losses when compared to CG: G1, 0.9% and G2, 0.8%; for the AsGaAl laser, the losses were G1, 2.3% and G2, 1.3%. In spite of statistically significant differences, the percentages of loss were small, showing that the film does not interfere in laser transmission. The PVC film can thus be used in clinical practice with no interference in laser dosimetry.O laser de baixa potência é utilizado na fisioterapia na cicatrização de lesões, para acelerar a reparação tecidual. Um filme de PVC na ponteira do equipamento é comumente usado na prática clínica para evitar a contaminação da lesão pelo equipamento, principalmente em mucosas e áreas cruentas. Este estudo visou avaliar se a membrana de PVC interfere na dosimetria transmitida à área tratada, minimizando os efeitos da aplicação. Foi utilizado um medidor de potência para avaliar as medidas percentuais da transmissão de energia de dois equipamentos de laser comumente usados na prática clínica, com os seguintes comprimentos de onda: laser de HeNe (hélio-neônio), 632,8 nm e de AsGaAl (arsenato de gálio alumínio), 830 nm. Para cada comprimento de onda foram avaliadas 150 medidas: 50 com irradiação direta (grupo controle, GC) e 100 com dois tipos diferentes de filmes de PVC transparentes na ponteira do laser (grupos experimentais G1 e G2). Ambos os filmes de PVC tinham 0,01 mm de espessura. Os resultados mostram que, comparando os valores de transmissão do GC com os dos grupos experimentais, o laser de HeNe teve as seguintes perdas: G1, 0,9% e G2, 0,8%; para o laser de AsGaAl, as perdas foram G1, 2,3% e G2, 1,3%. Apesar de a diferença estatística ter sido significativa, as porcentagens de perdas foram pequenas, mostrando que o filme de PVC transparente não interfere de forma significativa na transmissão da onda laser, podendo ser usado eficazmente na aplicação clínica

    Estratégias para ensino de hábitos posturais em crianças: história em quadrinhos versus experiência prática

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    This experimental study assessed the effects of a posture education program comparing two teaching strategies: by means of a comic strip (CS) and through practical experience (PE), in which children experienced each correct and incorrect posture. The posture education program was applied to 2nd- and 3rd-grade students aged 7-to-11 in three teaching meetings. The sample consisted of 40 boys and 40 girls evenly distributed into two groups, each taught by one teaching strategy: CS group and PE group. Questionnaires were applied before program onset and six months after the end of the program, in order to assess participants' postural habits. Correct postures taught were standing, sitting, knapsack carrying, bending down, moving objects, and sleeping posture. Results showed significant improvement in learning and memorizing correct postures by all subjects; no significant differences were found between the groups in all variables assessed. Both comic strip and practical experience teaching strategies were thus efficient in teaching boys and girls healthy postural habits.Este estudo experimental verificou os efeitos de um programa de educação postural comparando duas estratégias de ensino, a utilização de uma história em quadrinhos (HQ) e a experiência prática de posturas corretas e incorretas (EP). O programa de educação postural foi aplicado em três encontros com escolares das 2ª e 3ª séries, com idades entre 7 e 11 anos; 40 meninas e 40 meninos foram divididos igualmente em dois grupos, cada um submetido a uma estratégia de ensino: GHQ e GEP. O conhecimento dos hábitos posturais foi verificado por meio de questionários aplicados antes e após 6 meses do término das sessões. Foram ensinadas as posturas corretas em pé, sentado, de transportar mochilas, de abaixar, de mudar objetos de lugar e jeito de dormir. Os resultados do estudo indicaram que, para todas as variáveis estudadas houve aumento significativo no aprendizado e memorização dos hábitos posturais corretos em ambos os grupos, e que não houve diferença significativa entre as duas estratégias educativas. Não foram detectadas diferenças no aprendizado e memorização dos hábitos posturais corretos em crianças de ambos os sexos submetidas às duas metodologias de ensino

    Archeologia delle alte quote sulla montagna veneta: la campagna di ricognizione di superficie 2019 a Recoaro Terme (Vicenza)

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    In this paper we present the preliminary results of the 2019 field survey conducted in the framework of the project \u201cBeyond the border. Study and enhancement of the highlands between Veneto and Trentino\u201d. The aim of this overarching project, which applies a multidisciplinary approach, is threefold: to detect in this mountain landscape the main activity areas and reconstruct possible connections between them; to analyse the long-term relationships between Trentino and Prealpine Veneto from prehistory to the present day; and to study the evolving function of this frontier area during periods of conflict/interaction. Several methods were employed to shed light on the above-mentioned research aims: field-walking survey, analysis of aerial photos, ethnographic and archival research, GIS-based landscape analysis and predictive modelling, and LiDAR data for feature detection in wooded areas. The combined use of all these approaches allowed us to identify long-term exploitation activities, which are documented also by both the ethnographic and archaeological data. The major periods of conflict in these areas are also highlighted in the archaeological record. The 2019-survey campaign opens up new research directions such as the future excavation of Bronze Age occupation zones; network and connectivity analysis between Prealpine Veneto and Trentino; hillforts and their interaction with the highlands

    EEG Responses to TMS Are Sensitive to Changes in the Perturbation Parameters and Repeatable over Time

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    BACKGROUND: High-density electroencephalography (hd-EEG) combined with transcranial magnetic stimulation (TMS) provides a direct and non-invasive measure of cortical excitability and connectivity in humans and may be employed to track over time pathological alterations, plastic changes and therapy-induced modifications in cortical circuits. However, the diagnostic/monitoring applications of this technique would be limited to the extent that TMS-evoked potentials are either stereotypical (non-sensitive) or random (non-repeatable) responses. Here, we used controlled changes in the stimulation parameters (site, intensity, and angle of stimulation) and repeated longitudinal measurements (same day and one week apart) to evaluate the sensitivity and repeatability of TMS/hd-EEG potentials. METHODOLOGY/PRINCIPAL FINDINGS: In 10 volunteers, we performed 92 single-subject comparisons to evaluate the similarities/differences between pairs of TMS-evoked potentials recorded in the same/different stimulation conditions. For each pairwise comparison, we used non-parametric statistics to calculate a Divergence Index (DI), i.e., the percentage of samples that differed significantly, considering all scalp locations and the entire post-stimulus period. A receiver operating characteristic analysis showed that it was possible to find an optimal DI threshold of 1.67%, yielding 96.7% overall accuracy of TMS/hd-EEG in detecting whether a change in the perturbation parameters occurred or not. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that the EEG responses to TMS essentially reflect deterministic properties of the stimulated neuronal circuits as opposed to stereotypical responses or uncontrolled variability. To the extent that TMS-evoked potentials are sensitive to changes and repeatable over time, they may be employed to detect longitudinal changes in the state of cortical circuits

    TAAC - TMS Adaptable Auditory Control: A universal tool to mask TMS clicks

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    Background: Coupling transcranial magnetic stimulation with electroencephalography (TMS-EEG) allows recording the EEG response to a direct, non-invasive cortical perturbation. However, obtaining a genuine TMS- evoked EEG potential requires controlling for several confounds, among which a main source is represented by the auditory evoked potentials (AEPs) associated to the TMS discharge noise (TMS click). This contaminating factor can be in principle prevented by playing a masking noise through earphones. New method: Here we release TMS Adaptable Auditory Control (TAAC), a highly flexible, open-source, Matlab®- based interface that generates in real-time customized masking noises. TAAC creates noises starting from the stimulator-specific TMS click and tailors them to fit the individual, subject-specific click perception by mixing and manipulating the standard noises in both time and frequency domains. Results: We showed that TAAC allows us to provide standard as well as customized noises able to effectively and safely mask the TMS click. Comparison with existing methods: Here, we showcased two customized noises by comparing them to two standard noises previously used in the TMS literature (i.e., a white noise and a noise generated from the stimulator-specific TMS click only). For each, we quantified the Sound Pressure Level (SPL; measured by a Head and Torso Simulator - HATS) required to mask the TMS click in a population of 20 healthy subjects. Both customized noises were effective at safe (according to OSHA and NIOSH safety guidelines) and lower SPLs with respect to standard noises. Conclusions: At odds with previous methods, TAAC allows creating effective and safe masking noises specifically tailored on each TMS device and subject. The combination of TAAC with tools for the real-time visualization of TEPs can help control the influence of auditory confounds also in non-compliant patients. Finally, TAAC is a highly flexible and open-source tool, so it can be further extended to meet different experimental requirements

    Bistability breaks-off deterministic responses to intracortical stimulation during non-REM sleep

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    During non-rapid eye movement (NREM) sleep (stage N3), when consciousness fades, cortico-cortical interactions are impaired while neurons are still active and reactive. Why is this? We compared cortico-cortical evoked-potentials recorded during wakefulness and NREM by means of time-frequency analysis and phase-locking measures in 8 epileptic patients undergoing intra-cerebral stimulations/recordings for clinical evaluation. We observed that, while during wakefulness electrical stimulation triggers a chain of deterministic phase-locked activations in its cortical targets, during NREM the same input induces a slow wave associated with an OFF-period (suppression of power > 20 Hz), possibly reflecting a neuronal down-state. Crucially, after the OFF-period, cortical activity resumes to wakefulness-like levels, but the deterministic effects of the initial input are lost, as indicated by a sharp drop of phase-locked activity. These findings suggest that the intrinsic tendency of cortical neurons to fall into a down-state after a transient activation (i.e. bistability) prevents the emergence of stable patterns of causal interactions among cortical areas during NREM. Besides sleep, the same basic neurophysiological dynamics may play a role in pathological conditions in which thalamo-cortical information integration and consciousness are impaired in spite of preserved neuronal activity. (C) 2015 The Authors. Published by Elsevier Inc.Peer reviewe

    The spectral features of EEG responses to transcranial magnetic stimulation of the primary motor cortex depend on the amplitude of the motor evoked potentials

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    Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) can excite both cortico-cortical and cortico-spinal axons resulting in TMS-evoked potentials (TEPs) and motor-evoked potentials (MEPs), respectively. Despite this remarkable difference with other cortical areas, the influence of motor output and its amplitude on TEPs is largely unknown. Here we studied TEPs resulting from M1 stimulation and assessed whether their waveform and spectral features depend on the MEP amplitude. To this aim, we performed two separate experiments. In experiment 1, single-pulse TMS was applied at the same supra-threshold intensity on primary motor, prefrontal, premotor and parietal cortices and the corresponding TEPs were compared by means of local mean field power and time-frequency spectral analysis. In experiment 2 we stimulated M1 at resting motor threshold in order to elicit MEPs characterized by a wide range of amplitudes. TEPs computed from high-MEP and low-MEP trials were then compared using the same methods applied in experiment 1. In line with previous studies, TMS of M1 produced larger TEPs compared to other cortical stimulations. Notably, we found that only TEPs produced by M1 stimulation were accompanied by a late event-related desynchronization (ERD-peaking at ~300 ms after TMS), whose magnitude was strongly dependent on the amplitude of MEPs. Overall, these results suggest that M1 produces peculiar responses to TMS possibly reflecting specific anatomo-functional properties, such as the re-entry of proprioceptive feedback associated with target muscle activation
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