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Bipolar patients (BD) in the euthymic phase show almost no symptoms, nevertheless possibility of relapse is still present. We expected to find a psychobiological trace of their vulnerability by analyzing a specific network-the Language Network (LN)-connecting many high-level processes and brain regions measured at rest. According to Crow's hypothesis on the key role of language in the origin of psychoses, we expected an altered asymmetry of the LN in euthymic BDs. Eighteen euthymic BD patients (10 females; age = 54.50 ± 11.38 years) and 16 healthy controls (HC) (8 females; age = 51.16 ± 11.44 years) underwent a functional magnetic resonance imaging scan at rest. The LN was extracted through independent component analysis. Then, LN time series was used to compute the fractional amplitude of the low-frequency fluctuation (fALFF) index, which was then correlated with clinical scales. Compared with HC, euthymic patients showed an altered LN with greater activation of Broca's area right homologous and anterior insula together with reduced activation of left middle temporal gyrus. The normalized fALFF analysis on BD patients' LN time series revealed that the Slow-5 fALFF band was positively correlated with residual mania symptoms but negatively associated with depression scores. In line with Crow's hypothesis postulating an altered language hemispheric asymmetry in psychoses, we revealed, in euthymic BD patients, a right shift involving both the temporal and frontal linguistic hubs. The fALFF applied to LN allowed us to highlight a number of significant correlations of this measure with residual mania and depression psychiatric symptoms.
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Transtorno Bipolar , Mapeamento Encefálico , Adulto , Idoso , Transtorno Bipolar/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Idioma , Imageamento por Ressonância Magnética , Mania , Pessoa de Meia-Idade , Projetos PilotoRESUMO
Although alterations of the default mode network (DMN) in schizophrenia (SZ) have been largely investigated, less research has been carried out on DMN alterations in different sub-phenotypes of this disorder. The aim of this pilot study was to compare DMN features among SZ patients with and without auditory verbal hallucinations (AVH). Three groups of 17 participants each were considered: patients with hallucinations (AVH-SZ), patients without hallucinations (nAVH-SZ) and age-matched healthy controls (HC). The DMN spatial pattern was similar between the nAVH-SZ and HC, but the comparison between these two groups and the AVH-SZ group revealed alterations in the left Angular Gyrus (lAG) node of the DMN. Using a novel approach based on normalized fractional Amplitude of Low-Frequency Fluctuations (fALFF), the AVH-SZ subgroup showed altered spectral activity in the DMN compared with the other two groups, especially in the lower-frequency bands (0.017-0.04 Hz). Significant positive correlations were found for both SZ groups collapsed, and for the nAVH-SZ group alone between delusional scores (PANSS-P1) and slow fALFF bands of the DMN. Narrowing the analysis to the ROI centered on the lAG, significant correlations were found in the AVH-SZ group for hallucination scores (PANSS-P3) and Slow-5 and Slow-4 (both positive), and Slow-3 (negative) fALFF bands. Our results reveal the central role of the lAG in relation to hallucinations, an important cortical area connecting auditory cortex with several hubs (including frontal linguistic centers) and involved in auditory process monitoring.
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Esquizofrenia , Rede de Modo Padrão , Alucinações/diagnóstico por imagem , Alucinações/etiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Projetos Piloto , Esquizofrenia/complicações , Esquizofrenia/diagnóstico por imagemRESUMO
In recent years, many studies have focused on resting-state brain activity, and especially on functional connectivity (FC), an approach that typically describes the statistical interdependence of activity in distant brain regions through specific networks. Our aim was to study the neurophysiological correlates of emotion dysregulation. Therefore, we expected that both the Default Mode Network (DMN), and the Ventral Attention Network (VAN) would have been involved. Indeed, the latter plays a role in the automatic orienting of attention towards biologically salient stimuli and includes key regions for emotion control and modulation. Starting from a community sample of 422 female students, we selected 25 women with high traits of emotion dysregulation (HD group) and 25 with low traits (LD group). They underwent a 64-channel EEG recording during a five-minute resting state with eyes open. Seed-based FC was computed on the EEG Alpha band (8-13 Hz) as a control band, and on EEG Gamma power (30-50 Hz) as the relevant measure. The power within each network and inter-network connectivity (Inter-NC) was also calculated. Analysis of the EEG Gamma band revealed, in the HD group, higher levels of Inter-NC between the VAN and all other resting-state networks as compared with the LD group, while no differences emerged in the Alpha band. Concerning correlations, Alpha power in the VAN was negatively correlated in the HD group with affective lability (ALS-18 questionnaire), both for total score (ρ = -0.52, p FDR < 0.01) and the Depression/Elation subscale) ρ = -0.45, p FDR < 0.05). Consistent with this, in the Gamma band, a positive correlation was found between VAN spectral power and the Depression/Elation subscale of ALS-18, again in the HD group only (ρ = 0.47, p FDR < 0.05). In conclusion, both resting state FC and network power in the VAN were found to be related to high emotion dysregulation, even in our non-clinical sample with high traits. Emotion dysregulation was characterized, in the EEG gamma band, by a VAN strongly connected to all other networks, a result that points, in women prone to emotion dysregulation, to a strong automatic orienting of attention towards their internal state, bodily sensations, and emotionally intense related thoughts.
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Films, compared with emotional static pictures, represent true-to-life dynamic stimuli that are both ecological and effective in inducing an emotional response given the involvement of multimodal stimulation (i.e., visual and auditory systems). We hypothesized that a direct comparison between the two methods would have shown greater efficacy of movies, compared to standardized slides, in eliciting emotions at both subjective and neurophysiological levels. To this end, we compared these two methods of emotional stimulation in a group of 40 young adults (20 females). Electroencephalographic (EEG) Alpha rhythm (8-12 Hz) was recorded from 64 scalp sites while participants watched (in counterbalanced order across participants) two separate blocks of 45 slides and 45 clips. Each block included three groups of 15 validated stimuli classified as Erotic, Neutral and Fear content. Greater self-perceived arousal was found after the presentation of Fear and Erotic video clips compared with the same slide categories. sLORETA analysis showed a different lateralization pattern: slides induced decreased Alpha power (greater activation) in the left secondary visual area (Brodmann Area, BA, 18) to Erotic and Fear compared with the Neutral stimuli. Instead, video clips elicited reduced Alpha in the homologous right secondary visual area (BA 18) again to both Erotic and Fear contents compared with Neutral ones. Comparison of emotional stimuli showed smaller Alpha power to Erotic than to Fear stimuli in the left precuneus/posterior cingulate cortex (BA 7/31) for the slide condition, and in the left superior parietal lobule (BA 7) for the clip condition. This result matched the parallel analysis of the overlapped Mu rhythm (corresponding to the upper Alpha band) and can be interpreted as Mu/Alpha EEG suppression elicited by greater motor action tendency to Erotic (approach motivation) compared to Fear (withdrawal motivation) stimuli. Correlation analysis found lower Alpha in the left middle temporal gyrus (BA 21) associated with greater pleasantness to Erotic slides (r 38 = -0.62, p = 0.009), whereas lower Alpha in the right supramarginal/angular gyrus (BA 40/39) was associated with greater pleasantness to Neutral clips (r 38 = -0.69, p = 0.012). Results point to stronger emotion elicitation of movies vs. slides, but also to a specific involvement of the two hemispheres during emotional processing of slides vs. video clips, with a shift from the left to the right associative visual areas.
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BACKGROUND: The strong and long lockdown adopted by the Italian government to limit COVID-19 spreading represents the first threat-related mass isolation in history that can be studied in depth by scientists to understand individuals' emotional response to a pandemic. METHODS: We investigated the effects on individuals' mental wellbeing of this long-term isolation by means of an online survey on 71 Italian volunteers. They completed the Positive and Negative Affect Schedule and Fear of COVID-19 Scale and judged valence, arousal, and dominance of words either related or unrelated to COVID-19, as identified by Google search trends. RESULTS: Emotional judgments changes from normative data varied depending on word type and individuals' emotional state, revealing early signals of individuals' mental distress to COVID-19 confinement. All individuals judged COVID-19-related words to be less positive and dominant. However, individuals with more negative feelings and COVID-19 fear also judged COVID-19-unrelated words to be less positive and dominant. Moreover, arousal ratings increased for all words among individuals with more negative feelings and COVID-19 fear but decreased among individuals with less negative feelings and COVID-19 fear. DISCUSSION: Our results show a rich picture of emotional reactions of Italians to tight and 2-month long confinement, identifying early signals of mental health distress. They are an alert to the need for intervention strategies and psychological assessment of individuals potentially needing mental health support following the COVID-19 situation.
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Bipolar disorder (BD) is a psychiatric condition causing acute dysfunctional mood states and emotion regulation. Specific neuropsychological features are often present also among patients in euthymic phase, who do not show clear psychotic symptoms, and for whom the characterization from functional magnetic resonance imaging (fMRI) is very limited. This study aims at identifying the neural and behavioral correlates of the default mode network (DMN) using the fractional amplitude of low frequency fluctuations (fALFF). Eighteen euthymic BD patients (10 females; age = 54.50 ± 11.38 years) and sixteen healthy controls (HC) (8 females; age = 51.16 ± 11.44 years) underwent a 1.5T fMRI scan at rest. The DMN was extracted through independent component analysis. Then, DMN time series was used to compute the fALFF, which was correlated with clinical scales. From the between-group comparison, no significant differences emerged in correspondence to regions belonging to the DMN. For fALFF analysis, we reported significant increase of low-frequency fluctuations for lower frequencies, and decreases for higher frequencies compared to HC. Correlations with clinical scales showed that an increase in higher frequency spectral content was associated with lower levels of mania and higher levels of anxious symptoms, while an increase in lower frequencies was linked to lower depressive symptoms. Starting from our findings on the DMN in euthymic BD patients, we suggest that the fALFF derived from network time series represents a viable approach to investigate the behavioral correlates of resting state networks, and the pathophysiological mechanisms of different psychiatric conditions.
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Transtorno Bipolar , Adulto , Idoso , Transtorno Bipolar/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Rede de Modo Padrão , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-IdadeRESUMO
This study aimed to investigate emotional alterations in a community sample with primary psychopathic traits. Sixty males selected from a larger sample and divided in two groups, High (HP) and Low (LP) primary Psychopathy, watched 15 validated emotional movies divided in five categories (Erotic, Neutral, Fear, and the new Scenery and Compassion). Subjective responses and cortical activity in the EEG Gamma band (30-49 Hz) were recorded. Concerning self-reports, HP participants felt less anxious and anguished in response to Fear clips and less sad, touched and anguished by Compassion excerpts. Negative clips induced larger EEG Gamma activity in both groups compared to neutral and erotic movies, but Gamma activity to Fear movies was reduced in HP. This group showed also a small cortical response to positive Scenery movies, at the level of the Neutral ones. Source analysis showed in HP participants a reduced cortical activation to Fear in a large brain network, comprising the right prefrontal and temporal cortices and bilateral inferior parietal cortex. Results showed that primary psychopathy, in addition to the impaired response to Fear, was associated with a reduced response also to other specific categories of emotional stimuli, suggesting an altered affect on a broader scale.
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Filmes Cinematográficos , Transtorno da Personalidade Antissocial , Eletroencefalografia , Medo , Humanos , MasculinoRESUMO
BACKGROUND: Reading is a unique human skill. Several brain networks involved in this complex skill mainly involve the left hemisphere language areas. Nevertheless, nonlinguistic networks found in the right hemisphere also seem to be involved in sentence and text reading. These areas do not deal with phonological information, but are involved in verbal and nonverbal pattern information processing. The right hemisphere is responsible for global processing of a scene, which is needed for developing reading skills. AIMS: Caffeine seems to affect global pattern processing specifically. Consequently, our aim was to discover if it could enhance text reading skill. METHODS: In two mechanistic studies (n=24 and n=53), we tested several reading skills, global and local perception, alerting, spatial attention and executive functions, as well as rapid automatised naming and phonological memory, using a double-blind, within-subjects, repeated-measures design in typical young adult readers. RESULTS: A single dose of 200 mg caffeine improved global processing, without any effect on local information processing, alerting, spatial attention and executive or phonological functions. This improvement in global processing was accompanied by faster text reading speed of meaningful sentences, whereas single word/pseudoword or pseudoword text reading abilities were not affected. These effects of caffeine on reading ability were enhanced by mild sleep deprivation. CONCLUSIONS: These findings show that a small quantity of caffeine could improve global processing and text reading skills in adults.
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Cafeína/farmacologia , Processos Mentais/efeitos dos fármacos , Leitura , Percepção Visual/efeitos dos fármacos , Adulto , Atenção/efeitos dos fármacos , Método Duplo-Cego , Função Executiva/efeitos dos fármacos , Feminino , Humanos , Masculino , Memória/efeitos dos fármacos , Adulto JovemRESUMO
The need for a validated set of emotional clips to elicit emotions in more ecological experiments is increasing. Here we present the validation of a new database of emotional films, named E-MOVIE, which includes, in this first validation phase, 39 excerpts arranged in six categories, three negative (Fear, Sadness and Compassion), two positive (Erotic and Scenery) and a Neutral category. Notably, Compassion and Scenery are new in the field as they were not included in other databases. The clips in E-MOVIE are characterized by homogenous durations of approximately two minutes, which make them suitable for psychophysiological research. In order to study the affective profile prompted by each category 174 participants (112 women) rated the movies on multiple dimensions, namely valence and arousal, intensity and discreteness of the induction of one of the six basic emotions and, finally, intensity of the experience of the emotional states defined by a series of emotional adjectives. Erotic clips were effective in the elicitation of a positive emotional state, characterized by high levels of arousal and excitement. On the other hand, Fear clips (selected without blood to avoid disgust reaction) prompted an affect characterized by high arousal, low valence and high levels of reported fear and anxiety. Women reported greater unpleasantness, distress, anxiety and jittery than men to the three negative categories. Compassion clips, characterized by the depiction of crying characters, were able to induce an affective state dominated by sadness and feeling touched, consistent with an empathic reaction to emotional sufferance. Sadness clips, instead, elicited an affective state characterized by sadness together with distress and angst. We also demonstrated that clips depicting natural environments (i.e. Scenery) prompted in the viewer a surprised, inspired affective state, characterized by high valence and arousal (especially in males), a result which suggests that their past categorization as neutral stimuli was inaccurate and problematic.
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Bases de Dados como Assunto , Emoções , Filmes Cinematográficos , Neurociências , Caracteres Sexuais , Nível de Alerta/fisiologia , Feminino , Humanos , Masculino , Reconhecimento Psicológico , Adulto JovemRESUMO
The present study sought to investigate how differences in trait empathy can influence emotional reactivity to a specific set of affective categories. Forty-one female students, divided in High (HE, nâ¯=â¯20) and Low (LE, nâ¯=â¯21) trait empathy, watched eight validated movie clips divided in four emotional categories (Erotic, Fear, Compassion and Neutral) while subjective evaluation of emotion and EEG gamma activity were recorded. Analysis of self-reports revealed that HE compared to LE exhibited an increased arousal level to all emotional clips. Concerning EEG data, the HE group showed a greater cortical gamma to all the emotional categories compared to the Neutral, while the LE group had greater response only to the negative clips. Participants in the HE group also showed a strong positive correlation between subjective arousal and cortical activity in response to Fear and Compassion clips. The greatest correlation was found to Compassion clips and was located in the right inferior parietal lobe (r(18)â¯=â¯0.63), an important hub for both sensory-emotion integration and empathic sharing of others' emotions. Results suggest that high empathy was associated with enhanced gamma activity and greater self-reported arousal to all emotional stimuli. Furthermore, in this group, scenes with crying characters prompted a distinctive and localized cortical processing.
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Afeto/fisiologia , Emoções/fisiologia , Empatia/fisiologia , Ritmo Gama/fisiologia , Filmes Cinematográficos , Personalidade , Adolescente , Eletroencefalografia , Medo , Feminino , Humanos , Autorrelato , Mulheres , Adulto JovemRESUMO
Spontaneous blinking is a non-invasive indicator known to reflect dopaminergic influence over frontal cortex and attention allocation in perceptual tasks. 38 participants watched eighteen short film clips (2â¯min), designed to elicit specific affective states, and arranged in six different emotional categories, while their eye movements were recorded from the vertical electroculogram. The largest blink rate inhibition, reflecting greater attention allocation to the movie, was observed during the presentation of Erotic clips, excerpts on wilderness depicting beautiful landscapes (Scenery), as well as clips showing crying characters (Compassion). Instead, the minimum blink rate inhibition was found for Fear clips, which induced a defensive response with stimulus rejection. Blink rate across time evidenced how Compassion clips elicited early inhibition while Sadness clips induced a slower, later inhibition. Correlation analyses also revealed a negative correlation (râ¯<â¯-0.40) between total blink rate recorded during Erotic and Compassion clips and self-reported interest. Overall, the main variable explaining blink rate was emotional Valence. Results suggest that blink modulation is related with the motivational relevance and biological significance of the stimuli, tracking their differential recruitment of attentional resources. Furthermore, they provide a solid background for studying the emotion-attention patterns and their deficits also in clinical samples (e.g., neurological and psychiatric patients) using spontaneous blinking as a not-interfering psychophysiological measure.
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Atenção/fisiologia , Piscadela/fisiologia , Emoções/fisiologia , Adulto , Afeto/fisiologia , Nível de Alerta/fisiologia , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Motivação/fisiologia , Estimulação Luminosa , Adulto JovemRESUMO
AIM: The ability to discern commonalities and differences in the neurobiology of functional psychoses represents a key element to unmasking shared vulnerability across different psychiatric conditions. The present study sought to compare the automatic visual attention mechanisms in three psychiatric disorders considered to distribute along the continuum of psychosis severity: schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD). To this end, the visual P1 event-related potential component, a cortical correlate of automatic visual attention, was measured during an ecological task based on visual word pair presentation. METHODS: Four samples of participants, 18 SCZ, 20 BD, 28 MDD, and 30 healthy controls, were recruited and submitted to the same procedure and stimuli. The P1 evoked by visual word presentation was recorded through a 38-electrode electroencephalography cap. Words were presented on a computer screen serially as pairs, and participants had to decide whether they rhymed or not. RESULTS: P1 was larger at posterior sites in SCZ compared with BD, healthy control, and MDD participants. BD patients showed the lowest P1 compared with all other groups. Positive Pearson's correlations were found in SCZ patients between P1 amplitude on left posterior sites and both hallucination severity and worse task performance. CONCLUSION: The three investigated psychiatric samples showed different automatic visual attention patterns: SCZ patients exhibited the greatest cognitive impairment correlated with the amplitude of P1, MDD patients revealed a normal component, and BD showed a compensated euthymic response different from results of past literature in untreated patients.
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Atenção/fisiologia , Transtorno Bipolar/fisiopatologia , Córtex Cerebral/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Potenciais Evocados/fisiologia , Esquizofrenia/fisiopatologia , Percepção Visual/fisiologia , Adulto , Idoso , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
A lack of empathy, interpersonal dominance, aggression and the exploitation of others are the key features of both narcissism and psychopathic disorders. With the aim to better capture the shared facets of these traits, this study developed a new tool named the Capability to Influence Others (CIO) Inventory, which is based on the pleasantness evaluation of ten items-verbs presented in the infinitive form. The inventory, characterized by very quick submission, was administered to 67 males and 100 females and was correlated with the concurrent Narcissistic Personality Inventory (NPI) and Levenson Self-Report Psychopathy Scale (LSRP). An exploratory factor analysis supported the presence of only one factor in both the male and female groups. Internal consistency of the CIO was very good for both men (Cronbach's alphaâ¯=â¯0.85; 95% CIs: 0.80-0.90) and women (Cronbach's alphaâ¯=â¯0.83; 95% CIs: 0.77-0.87). Further statistics showed a high correlation between the CIO and the LSRP-F1 (primary psychopathy) in both genders (râ¯>â¯0.47). Clear gender differences were found in the correlation between the CIO and the NPI: the correlation was high (râ¯=â¯0.58) in males and absent in females. The CIO may represent a quick and low demanding tool for a preliminary screening of individuals with high psychopathic/narcissistic traits from community samples, forensic institutions, high schools and company personnel.
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Transtorno da Personalidade Antissocial/diagnóstico , Narcisismo , Personalidade , Inquéritos e Questionários/estatística & dados numéricos , Adulto , Exibicionismo/psicologia , Feminino , Humanos , Masculino , Inventário de Personalidade/estatística & dados numéricos , Psicometria , Valores de Referência , Reprodutibilidade dos TestesRESUMO
Blink rate is a behavioral index highly correlated with frontostriatal dopaminergic activity. The present research was aimed at studying the modulation of spontaneous blink rate in function of the increasing attentional load induced by the Mackworth Clock Test. Since blinking interferes with sensory processing, we expected a decreasing blink rate with increasing attentional demand. Three tasks of 7-min each and different difficulties were administered: the Mackworth had a red dot moving in a circle with intervals varying from 500ms, 350ms to 200ms, corresponding to increasing task difficulty. Participant had to detect the rare jumps of one position by the red dot (targets). The blink rate was recorded from thirty-three female students starting from vertical oculogram recording of the right eye. The time course of blink rate across the 7-min task was also analyzed to test the hypothesis that fatigue arises also during brief tasks depending on the difficulty level. Results showed that the Hard task (200ms dot intervals) was associated with greater percentage of missed targets, faster response times and smaller blink rates with respect to the Medium and Easy ones. Analysis of the time course within the task revealed an increase of blink rate, indexing larger fatigue, starting in the 4th minute, independent from the difficulty level. In addition, trial-by-trial analysis showed that under strong attentional demand dopamine-related blink activity was inhibited throughout the whole task. Results point to the use of blink rate as an ecological index of dopaminergic component of attentional load and fatigue and revealed how human attention drops after relatively brief intervals of about 4min.
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Atenção/fisiologia , Piscadela/fisiologia , Dopamina/fisiologia , Fadiga/fisiopatologia , Desempenho Psicomotor/fisiologia , Ritmo Ultradiano/fisiologia , Adulto , Eletroculografia , Feminino , Humanos , Adulto JovemRESUMO
The present research investigated the hypothesis that elderly and horizontal body position contribute to impair learning capacity. To this aim, 30 young (mean age: 23.2 years) and 20 elderly women (mean age: 82.8 years) were split in two equal groups, one assigned to the Seated Position (SP), and the other to the horizontal Bed Rest position (hBR). In the Learning Phase, participants were shown 60 words randomly distributed, and in the subsequent Recognition Phase they had to recognize them mixed with a sample of 60 new words. Behavioral analyses showed age-group effects, with young women exhibiting faster response times and higher accuracy rates than elderly women, but no interaction of body position with age group was found. Analysis of the RP component (250-270ms) revealed greater negativity in the left Occipital gyrus/Cuneus of both sitting age-groups, but significantly left-lateralized RP in left Lingual gyrus only in young bedridden women. Elderly hBR women showed a lack of left RP lateralization, the main generator being located in the right Cuneus. Young participants had the typical old/new effect (450-800ms) in different portions of left Frontal gyri/Uncus, whereas elderly women showed no differences in stimulus processing and its location. EEG alpha activity analyzed during a 3min resting state, soon after the recognition task, revealed greater alpha amplitude (i.e., cortical inhibition) in posterior sites of hBR elderly women, a result in line with their inhibited posterior RP. In elderly women the left asymmetry of RP was positively correlated with both greater accuracy and faster responses, thus pointing to a dysfunctional role, rather than a compensatory shift, of the observed right RP asymmetry in this group. This finding may have important clinical implications, with particular regard to the long-term side-effects of forced Bed Rest on elderly patients.
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Fatores Etários , Aprendizagem/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Decúbito Dorsal/fisiologia , Análise e Desempenho de Tarefas , Idoso de 80 Anos ou mais , Eletroencefalografia , Feminino , Humanos , Postura/fisiologia , Tempo de Reação/fisiologia , Adulto JovemRESUMO
Horizontal body position is a posture typically adopted for sleeping or during brain imaging recording in both neuroscience experiments and diagnostic situations. Recent literature showed how this position and similar ones with head down are associated to reduced plasticity, impaired pain and emotional responses. The present study aimed at further understanding the decrease of cortical activity associated with horizontal body position by measuring high-frequency EEG bands - typically associated with high-level cognitive activation - in a resting state experimental condition. To this end, two groups of 16 female students were randomly assigned to either sitting control (SC) or 2-h horizontal Bed Rest condition (hBR) while EEG was recorded from 38 scalp recording sites. The hBR group underwent several body transitions, from sitting to supine, and from supine to sitting. Results revealed a clear effect of horizontal posture: the hBR group showed, compared to its baseline and to SC, reduced High-Beta and Gamma EEG band amplitudes throughout the 2-h of hBR condition. In addition, before and after the supine condition, hBR group as well as SC exhibited a greater left vs. right frontal activation in both EEG bands while, on the contrary, the supine position induced a bilateral and reduced activation in hBR participants. The cortical sources significantly more active in SC compared with hBR participants included the left Inferior Frontal Gyrus and left Insula. Results are discussed in relation to the differences among neuroimaging methods (e.g., fMRI, EEG, NIRS), which can be partially explained by posture-induced neural network changes.
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Past studies have shown consistent evidence that body position significantly affects brain activity, revealing that both head-down and horizontal bed-rest are associated with cortical inhibition and altered perceptual and cognitive processing. The present study investigates the effects of body position on spontaneous, open-eyes, resting-state EEG cortical activity in 32 young women randomly assigned to one of two conditions, seated position (SP) or horizontal bed rest (BR). A between-group repeated-measure experimental design was used, EEG recordings were made from 38 scalp locations, and low-frequency (delta and alpha) amplitudes of the two groups were compared in four different conditions: when both groups (a) were seated (T0), (b) assumed two different body positions (seated vs. supine conditions, immediate [T1] and 120min later [T2]), and (c) were seated again (T3). Overall, the results showed no a priori between-group differences (T0) before experimental manipulation. As expected, delta amplitude, an index of cortical inhibition in awake resting participants, was significantly increased in group BR, revealing both rapid (T1) and mid-term (T2) inhibitory effects of supine or horizontal positions. Instead, the alpha band was highly sensitive to postural transitions, perhaps due to baroreceptor intervention and, unlike the delta band, underwent habituation and decreased after a 2-h bed rest. These results indicate clear-cut differences at rest between the seated and supine positions, thus supporting the view that the role of body position in the differences found between brain metabolic methods (fMRI and PET) in which participants lie horizontally, and EEG-MEG-TMS techniques with participants in a seated position, has been largely underestimated so far.
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Ritmo alfa/fisiologia , Córtex Cerebral/fisiologia , Ritmo Delta/fisiologia , Inibição Neural/fisiologia , Decúbito Dorsal/fisiologia , Análise de Variância , Mapeamento Encefálico , Eletroencefalografia , Feminino , Análise de Fourier , Humanos , Adulto JovemRESUMO
The present study aimed to investigate gender differences in the emotional evaluation of 18 film clips divided into six categories: Erotic, Scenery, Neutral, Sadness, Compassion, and Fear. 41 female and 40 male students rated all clips for valence-pleasantness, arousal, level of elicited distress, anxiety, jittery feelings, excitation, and embarrassment. Analysis of positive films revealed higher levels of arousal, pleasantness, and excitation to the Scenery clips in both genders, but lower pleasantness and greater embarrassment in women compared to men to Erotic clips. Concerning unpleasant stimuli, unlike men, women reported more unpleasantness to the Compassion, Sadness, and Fear compared to the Neutral clips and rated them also as more arousing than did men. They further differentiated the films by perceiving greater arousal to Fear than to Compassion clips. Women rated the Sadness and Fear clips with greater Distress and Jittery feelings than men did. Correlation analysis between arousal and the other emotional scales revealed that, although men looked less aroused than women to all unpleasant clips, they also showed a larger variance in their emotional responses as indicated by the high number of correlations and their relatively greater extent, an outcome pointing to a masked larger sensitivity of part of male sample to emotional clips. We propose a new perspective in which gender difference in emotional responses can be better evidenced by means of film clips selected and clustered in more homogeneous categories, controlled for arousal levels, as well as evaluated through a number of emotion focused adjectives.
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Nível de Alerta/fisiologia , Emoções/fisiologia , Caracteres Sexuais , Gravação em Vídeo , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Mental imagery has the potential to influence perception by directly altering sensory, cognitive, and affective brain activity associated with imagined content. While it is well established that mental imagery can both exacerbate and alleviate acute and chronic pain, it is currently unknown how imagery mechanisms regulate pain perception. For example, studies to date have been unable to determine whether imagery effects depend upon a general redirection of attention away from pain or focused attentional mechanisms. To address these issues, we recorded subjective, behavioral and ERP responses using 64-channel EEG while healthy human participants applied a mental imagery strategy to decrease or increase pain sensations. When imagining a glove covering the forearm, participants reported decreased perceived intensity and unpleasantness, classified fewer high-intensity stimuli as painful, and showed a more conservative response bias. In contrast, when imagining a lesion on the forearm, participants reported increased pain intensity and unpleasantness, classified more low-intensity stimuli as painful, and displayed a more liberal response bias. Using a mass-univariate approach, we further showed differential modulation of the N2 potentials across conditions, with inhibition and facilitation respectively increasing and decreasing N2 amplitudes between 122 and 180 ms. Within this time window, source localization associated inhibiting vs. facilitating pain with neural activity in cortical regions involved in cognitive inhibitory control and in the retrieval of semantic information (i.e., right inferior frontal and temporal regions). In contrast, the main sources of neural activity associated with facilitating vs. inhibiting pain were identified in cortical regions typically implicated in salience processing and emotion regulation (i.e., left insular, inferior-middle frontal, supplementary motor and precentral regions). Overall, these findings suggest that the content of a mental image directly alters pain-related decision and evaluative processing to flexibly produce hypoalgesic and hyperalgesic outcomes.
Assuntos
Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Função Executiva/fisiologia , Hiperalgesia/fisiopatologia , Imaginação/fisiologia , Inibição Psicológica , Percepção da Dor/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The present study examined linguistic plastic reorganization of language through Evoked Potentials in a group of 17 non-fluent aphasic patients who had suffered left perisylvian focal lesions, and showed a good linguistic recovery. Language reorganisation was probed with three linguistic tasks (Phonological, Semantic, Orthographic), the early word recognition potential (N150) and the later phonological-related component (N350). Results showed the typical left-lateralised posterior N150 in healthy controls (source: left Fusiform Gyrus), that was bilateral (Semantic) or right sided (Phonological task) in patients (sources: right Inferior/Middle Temporal and Fusiform Gyri). As regards N350, controls revealed different intra- and inter-hemispheric linguistic activation across linguistic tasks, whereas patients exhibited greater activity in left intact sites, anterior and posterior to the damaged area, in all tasks (sources: Superior Frontal Gyri). A comprehensive neurofunctional model is presented, describing how complete intra- and inter-hemispheric reorganisation of the linguistic networks occurs after aphasic damage in the strategically dominant left perisylvian linguistic centres.