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1.
Cogn Emot ; : 1-9, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38554265

RESUMO

Features of threatening cues and the associated context influence the perceived imminence of threat and the defensive responses evoked. To provide additional knowledge about how the directionality of a threat (i.e. directed-towards or away from the viewer) might impact defensive responses in humans, participants were shown pictures of a man carrying a gun (threat) or nonlethal object (neutral) directed-away from or towards the participant. Cardiac and electrodermal responses were collected. Compared to neutral images, threatening images depicting a gun directed-towards the participant induced sustained bradycardia and an increased electrodermal response, interpreted as immobility under attack. This defensive immobility reaction is evoked by high perceived threat and inescapable situations and indicates intense action preparation. Pictures of guns directed-away from the participant induced shorter bradycardia and no significant modulation of the electrodermal response compared to neutral pictures, which might be consistent with the perception of a less threatening situation. The results show that the directionality of threat stimuli is a key factor that prompts different patterns of defensive responses.

2.
Front Public Health ; 10: 891546, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35801235

RESUMO

Background: Ultra-processed foods (UPF) are becoming extensively available in the food environments. UPF are industrial formulations that are designed to maximize palatability and consumption through a combination of calorie-dense ingredients and chemical additives. UPFs are also aggressively marketed, which may make them more attractive than unprocessed/minimally processed foods (UMPF). Since consumers' purchase decisions are guided by food-evoked emotions, we aimed to provide evidence that UPF visual cues trigger higher emotional responses and approach motivation than UMPF visual cues, with potential impacts on individuals' intention to consume the UPF over the UMPF. Methods: Participants (n = 174; 144 women; mean age = 20.7 years; standard deviation = 4.35) performed two tasks. In the first task, 16 pictures of foods (8 UPF and 8 UMPF), and 74 pictures from other affective categories, were presented. After viewing each picture, the participants rated it along two basic dimensions of emotion through the Self-Assessment Manikin scale: pleasantness and arousal. In the second task, the participants viewed the same food pictures, and they rated their intention to consume the foods depicted in the pictures. Each picture was plotted in terms of its mean pleasantness and arousal ratings in a Cartesian plane, which resulted in an affective space. Results: Pictures of UPF and UMPF were positioned in the upper arm of the boomerang-shaped affective space that represents approach motivation. Pictures containing UPF triggered higher approach motivation and intention to consume than pictures containing UMPF. We also found a stronger association between emotional responses and intention to consume UPF relative to UMPF. Conclusion: These results shed new light on the role of ultra-processed foods evoked emotions that contribute to less healthy and sustainable food environments.


Assuntos
Manipulação de Alimentos , Motivação , Adulto , Ingestão de Energia , Fast Foods , Feminino , Humanos , Intenção , Adulto Jovem
3.
Front Psychol ; 13: 817699, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35465505

RESUMO

Proximity and interpersonal contact are prominent components of social connection. Giving affective touch to others is fundamental for human bonding. This brief report presents preliminary results from a pilot study. It explores if exposure to bonding scenes impacts the activity of specific muscles related to physical interaction. Fingers flexion is a very important component when performing most actions of affectionate contact. We explored the visuo-motor affective interplay by priming participants with bonding scenes and assessing the electromyographic activity of the fingers flexor muscle, in the absence of any overt movements. Photographs of dyads in social interaction and of the same dyads not interacting were employed. We examined the effects upon the electromyographical activity: (i) during the passive exposure to pictures, and (ii) during picture offset and when expecting the signal to perform a fingers flexion task. Interacting dyads compared to matched non-interacting dyads increased electromyographic activity of the fingers flexor muscle in both contexts. Specific capture of visual bonding cues at the level of visual cortex had been described in the literature. Here we showed that the neural processing of visual bonding cues reaches the fingers flexor muscle. Besides, previous visualization of bonding cues enhanced background electromyographic activity during motor preparation to perform the fingers flexion task, which might reflect a sustained leakage of central motor activity downstream leading to increase in firing of the respective motor neurons. These data suggest, at the effector level, an implicit visuo-motor connection in which social interaction cues evoke intrinsic dispositions toward affectionate social behavior.

4.
Psychol Res Behav Manag ; 14: 1359-1369, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512046

RESUMO

PURPOSE: Growing evidence suggests that peritraumatic tonic immobility, an involuntary defensive response that involves extreme physical immobility and the perceived inability to escape, is a significant predictor of post-traumatic stress disorder (PTSD) symptomatology. However, this issue has not been specifically addressed in adolescents. Here, we investigated whether tonic immobility response experienced during the worst childhood or adolescent trauma is associated with PTSD symptom severity in a non-clinical student sample. METHODS: The sample was composed of students in 9th grade who were attending public and private schools. Symptoms of post-traumatic stress and tonic immobility were assessed using questionnaires. We performed bivariate and multivariate negative binomial regressions to examine whether tonic immobility was associated with PTSD symptomatology after controlling for confounders (peritraumatic dissociation, peritraumatic panic reactions, gender, age and time since trauma). RESULTS: We found an association between tonic immobility and PTSD symptom severity, even after controlling for confounders. Therefore, tonic immobility is associated with PTSD symptoms in trauma-exposed adolescents. CONCLUSION: These findings highlight tonic immobility as a possible risk factor that could be used to provide direction for more targeted trauma interventions for individuals, particularly those at risk for developing PTSD. Therefore, it contributes to preventing and reducing the psychiatric burden in adolescence and later in life.

5.
Front Psychol ; 12: 671481, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335385

RESUMO

The editors of several major journals have recently asserted the importance of combating racism and sexism in science. This is especially relevant now, as the COVID-19 pandemic may have led to a widening of the gender and racial/ethnicity gaps. Implicit bias is a crucial component in this fight. Negative stereotypes that are socially constructed in a given culture are frequently associated with implicit bias (which is unconscious or not perceived). In the present article, we point to scientific evidence that shows the presence of implicit bias in the academic community, contributing to strongly damaging unconscious evaluations and judgments of individuals or groups. Additionally, we suggest several actions aimed at (1) editors and reviewers of scientific journals (2) people in positions of power within funding agencies and research institutions, and (3) members of selection committees to mitigate this effect. These recommendations are based on the experience of a group of Latinx American scientists comprising Black and Latina women, teachers, and undergraduate students who participate in women in science working group at universities in the state of Rio de Janeiro, Brazil. With this article, we hope to contribute to reflections, actions, and the development of institutional policies that enable and consolidate diversity in science and reduce disparities based on gender and race/ethnicity.

6.
Front Psychol ; 12: 772916, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35069355

RESUMO

Background: Evidence indicates that the processing of facial stimuli may be influenced by incidental factors, and these influences are particularly powerful when facial expressions are ambiguous, such as neutral faces. However, limited research investigated whether emotional contextual information presented in a preceding and unrelated experiment could be pervasively carried over to another experiment to modulate neutral face processing. Objective: The present study aims to investigate whether an emotional text presented in a first experiment could generate negative emotion toward neutral faces in a second experiment unrelated to the previous experiment. Methods: Ninety-nine students (all women) were randomly assigned to read and evaluate a negative text (negative context) or a neutral text (neutral text) in the first experiment. In the subsequent second experiment, the participants performed the following two tasks: (1) an attentional task in which neutral faces were presented as distractors and (2) a task involving the emotional judgment of neutral faces. Results: The results show that compared to the neutral context, in the negative context, the participants rated more faces as negative. No significant result was found in the attentional task. Conclusion: Our study demonstrates that incidental emotional information available in a previous experiment can increase participants' propensity to interpret neutral faces as more negative when emotional information is directly evaluated. Therefore, the present study adds important evidence to the literature suggesting that our behavior and actions are modulated by previous information in an incidental or low perceived way similar to what occurs in everyday life, thereby modulating our judgments and emotions.

7.
Neuroimage ; 224: 117404, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32971264

RESUMO

Victims of urban violence are at risk of developing Posttraumatic Stress Disorder (PTSD), one of the most debilitating consequences of violence. Considering that PTSD may be associated with inefficient selection of defensive responses, it is important to understand the relation between motor processing and PTSD. The present study aims to investigate the extent to which the severity of posttraumatic stress symptoms (PTSS) is related to motor preparation against visual threat cues in victims of urban violence. Participants performed a choice reaction time task while ignoring a picture that could be threating or neutral. The EEG indices extracted were the motor-related amplitude asymmetry (MRAA) in the alpha frequency range, and the lateralized readiness potential (LRP). We observed a linear relation between longer LRP latency and a slower reaction time, selectively during threat processing (compared to neutral) in low PTSS, but not in high PTSS participants. Alpha MRAA suppression and the PTSS were also linearly related: the smaller the alpha MRAA suppression in the threat condition relative to neutral, the greater the PTSS. These results provide evidence that threatening cues affect motor processing that is modulated by the severity of PTSS in victims of urban violence.


Assuntos
Variação Contingente Negativa/fisiologia , Sinais (Psicologia) , Córtex Motor/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Violência , Ritmo alfa/fisiologia , Encéfalo/fisiopatologia , Eletroencefalografia , Sincronização de Fases em Eletroencefalografia , Feminino , Humanos , Masculino , Atividade Motora , Estimulação Luminosa , Tempo de Reação , Adulto Jovem
8.
Front Psychol ; 10: 191, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30804849

RESUMO

Threatening cues and surrounding contexts trigger specific defensive response patterns. Posturography, a technique for measuring postural strategies, has been used to evaluate motor defensive reactions in humans. When exposed to gun pointed pictures, humans were shown to exhibit an immobility reaction. Short and long-term exposure to violent video games was shown to be a causal risk factor for increased violent and aggressive behavior. Assaultive violence with a gun is a major trigger for motor defensive reactions, and post-traumatic stress disorder (PTSD) is the most characteristic psychiatric sequelae. Recent studies point to links between PTSD symptoms and emotional shortfalls in non-clinical trauma-exposed samples. The present study investigated defensive reactions to gun threat and PTSD symptoms in heavy players of violent video games compared to non-players. Male university students were screened according to use of violent video games and divided in three groups: non-players, moderate players, and heavy players. Stimuli were pictures depicting a man pointing a gun directed at the participant. In matched control pictures, non-lethal objects replaced the gun. Posturography was recorded and PTSD symptoms were assessed. When exposed to the threat pictures, non-players exhibited the expected reduction in amplitude of body sway (immobility), heavy players presented atypical augmented amplitude of body sway, and moderate players showed intermediate reactivity. Heavy players presented a significant distinct reaction compared to non-players. They also scored significantly higher in PTSD symptoms than non-players. Disadvantageous defensive reactions and higher vulnerability to PTSD symptoms, revealed in the present study, add to other shortcomings for heavy players.

9.
Front Hum Neurosci ; 13: 469, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32038201

RESUMO

Dynamic cognitive control adjustments are important for integrating thoughts and actions that take place during dynamic changes of environmental demands and support goal-directed behavior. We investigated, in a working memory (WM) paradigm, whether dynamic adjustments in cognitive control based on previous trial load influence the neural response to neutral or unpleasant distracters. We also investigated whether individual self-reported abilities in controlling thoughts influence this effect. Participants performed a WM change detection task with low or high WM-related cognitive demands. An unpleasant or a neutral distractive image was presented at the beginning of each trial, prior to the WM task. We tested for control adjustments that were associated with the load level of the preceding trial task (N-1) on the neural response to the subsequent distractive image. We found an effect of the prior WM task load on a parieto-occipital waveform event-related potential (ERP) that appeared between 200 and 300 ms after the neutral distracter onset. This effect was not observed for the unpleasant distracter. Individual ability for controlling thoughts may influence the effect of cognitive control adjustments on distracter processing during the unpleasant condition. These findings provide evidence that: (1) dynamic cognitive control adjustments are impaired by unpleasant distracters; and (2) the ability to control unpleasant thoughts is linked to individual differences in flexible cognitive control adjustments and shielding of WM representations from unpleasant distracters.

10.
Front Hum Neurosci ; 12: 448, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30483083

RESUMO

Background: Despite several attempts to review and explain how meditation alters the brain and facilitates emotion regulation, the extent to which meditation and emotion regulation strategies share the same neural mechanisms remains unclear. Objective: We aim to understand the influence of meditation on the neural processing of negative emotional stimuli in participants who underwent meditation interventions (naive meditators) and long-term meditators. Methodology: A systematic review was conducted using standardized search operators that included the presence of terms related to emotion, meditation and neuro-imaging techniques in PsycInfo, PubMed, Scopus, and Web of Science databases. Results: Searches identified 882 papers, of which 11 were eligible for inclusion. Results showed a predominance of greater prefrontal/frontal activity related to meditation, which might indicate the increased recruitment of cognitive/attentional control resources in naïve and long-term meditators. This increased frontal activity was also observed when participants were asked to simply react to negative stimuli. Findings from emotion-related areas were scarce but suggested increased insular activity in meditators, potentially indicating that meditation might be associated with greater bodily awareness. Conclusions: Meditation practice prompts regulatory mechanisms when participants face aversive stimuli, even without an explicit request. Moreover, some studies reported increased insular activity in meditators, consistent with the hypothesis that meditation helps foster an interoceptive awareness of bodily and emotional states.

11.
Front Psychol ; 9: 1228, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30072937

RESUMO

Some studies have demonstrated a beneficial role of Positive Affect on working memory (WM) by either applying protocols of mood induction or assessing naturally occurring state Positive Affect. However, there are no studies directly linking Positive Affect as a stable personality-like trait with WM. We aimed to address this potential relationship using the Positive and Negative Affect Schedule scale and contra-lateral delay activity (CDA) as measures of trait Positive Affect and WM Capacity, respectively. We also sought to investigate the impact of a neutral or unpleasant emotional state on this relationship. Participants performed a change detection task, while a neutral or an unpleasant emotional state was induced. Our results showed a positive robust correlation between trait Positive Affect and WM Capacity for both neutral and unpleasant emotional states, as revealed by the neuroelectrophysiological gold-standard measure of WM, namely, CDA. These data suggest a tangible role of trait Positive Affect in the cognitive ability of maintaining goal-relevant information in WM, such that even a highly disruptive state is not sufficient to corrupt this relationship.

12.
Public Health Nutr ; 21(3): 543-557, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29173214

RESUMO

OBJECTIVE: The present study aimed to (i) assess the appetitive drives evoked by the visual cues of ultra-processed food and drink products and (ii) investigate whether text warnings reduce appetitive drives and consumers' reported intentions to eat or drink ultra-processed products. DESIGN: In Study I, a well-established psychometric tool was applied to estimate the appetitive drives associated with ultra-processed products using sixty-four image representations. Sixteen product types with four exemplars of a given product were included. Pictures from the International Affective Picture System (IAPS) served as controls. The two exemplars of each product type rated as more appetitive were selected for investigation in the second study. Study II assessed the impact of textual warnings on the appetitive drive towards these thirty-two exemplars. Each participant was exposed to two picture exemplars of the same product type preceded by a text warning or a control text. After viewing each displayed picture, the participants reported their emotional reactions and their intention to consume the product. SETTING: Controlled classroom experiments SUBJECTS: Undergraduate students (Study I: n 215, 135 women; Study II: n 98, 52 women). RESULTS: In Study I, the pictures of ultra-processed products prompted an appetitive motivation associated with the products' nutritional content. In Study II, text warnings were effective in reducing the intention to consume and the appetitive drive evoked by ultra-processed products. CONCLUSIONS: This research provides initial evidence favouring the use of text warnings as a public policy tool to curb the powerful influence of highly appetitive ultra-processed food cues.


Assuntos
Apetite , Sinais (Psicologia) , Fast Foods , Comportamento Alimentar/psicologia , Promoção da Saúde/métodos , Intenção , Envio de Mensagens de Texto , Adolescente , Adulto , Comunicação , Emoções , Feminino , Alimentos , Manipulação de Alimentos , Humanos , Masculino , Motivação , Valor Nutritivo , Psicometria , Estudantes , Adulto Jovem
13.
Soc Cogn Affect Neurosci ; 12(6): 984-992, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28402534

RESUMO

Emotional states can guide the actions and decisions we make in our everyday life through their influence on cognitive processes such as working memory (WM). We investigated the long-lasting interference that an unpleasant emotional state had on goal-relevant WM representations from an electrophysiological perspective. Participants performed a change detection task that was preceded by the presentation of unpleasant or neutral task-irrelevant pictures in a blocked fashion. We focused on the contralateral delay activity (CDA), an event-related potential that is sensitive to the number of task-relevant items stored in WM. We found that the asymptotic limit for the CDA amplitude was lower during the unpleasant emotional state than during the neutral one; that is, an emotional state was capable of reducing how many task-relevant items the participants could hold in WM. Furthermore, both the individuals who experienced more intrusive thoughts and those who were dispositionally anxious were more susceptible to the influence of the emotional state. We provide evidence that an unpleasant emotional state diminished visual WM for task-relevant items, particularly in susceptible individuals. These results open new avenues to uncover the emotional-cognitive processing that underlies maladaptive WM representations and the role of such processing in the development of mental illness.


Assuntos
Emoções/fisiologia , Memória de Curto Prazo/fisiologia , Ansiedade/psicologia , Eletroencefalografia , Fenômenos Eletrofisiológicos , Potenciais Evocados , Feminino , Humanos , Masculino , Estimulação Luminosa , Substância Branca/fisiologia , Adulto Jovem
14.
Behav Brain Res ; 302: 252-62, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26802729

RESUMO

Threatening cues and surrounding contexts trigger specific defensive response patterns. Potential threat evokes attentive immobility; attack evokes flight when escape is available and immobility when escape is blocked. Tonic immobility installs when threat is overwhelming and life-risky. In humans, reduced body sway characterizes attentive and tonic immobility, the former with bradycardia, and the later with expressive tachycardia. Here, we investigate human defensive strategies in the presence or absence of an escape route. We employed pictures depicting a man carrying a gun and worked with participants exposed to urban violence. In pictures simulating more possibility of escape, the gun was directed away from the observer; in those simulating higher risk and less chance of escape, the gun was directed toward the observer. Matched control pictures depicted similar layouts, but a non-lethal object substituted the gun. Posturographic and electrocardiographic recordings were collected. Amplitude of sway and heart rate were higher for gun directed-away and lower for gun direct-toward. Compared to their respective matched controls, there was a general increase in the amplitude of sway for the gun directed-away pictures; and a reduction in back-and-forth sway and in heart rate for gun directed-toward pictures. Taken together, those measures suggest that, when exposed to threat invading their margin of safety in a context indicating possible escape route, humans, as non-human species, engage in active escape, resembling the flight stage of the defensive cascade. When facing threat indicating less possibility of escape, humans present an immobile response with bradycardia.


Assuntos
Sinais (Psicologia) , Mecanismos de Defesa , Reação de Fuga/fisiologia , Percepção Visual/fisiologia , Adulto , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Fixação Ocular/fisiologia , Reação de Congelamento Cataléptica/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Movimento , Estimulação Luminosa , Estatísticas não Paramétricas , Estudantes , Universidades , Adulto Jovem
15.
Psicol. teor. pesqui ; 32(2): e322216, 2016. graf
Artigo em Inglês | LILACS | ID: biblio-955912

RESUMO

ABSTRACT This pilot study assessed the effects of a five day focused meditation training on the interplay between emotional interference and anxiety in a non clinical sample randomized into two groups (experimental=13; control=18). Emotional interference was indexed comparing the reaction times in an attention span task with negative or neutral distracting images. Anxiety experienced during the task was also assessed through self-report. Only in the control group higher anxiety levels interacted with greater emotional interference and a worse evaluation of valence and arousal of emotional images. These preliminary findings suggest that meditation may help modulating anxiety effects on bias to negative stimuli, and that even a short training may facilitate self-regulatory processes.


RESUMO Este estudo piloto avaliou os efeitos de cinco dias de meditação focada na relação entre interferência emocional e ansiedade em amostra não clínica randomizada em dois grupos (experimental=13; controle=18). A interferência emocional foi indexada comparando os tempos de reação em uma tarefa de atenção com imagens distratoras negativas ou neutras. Também foi avaliado o autorrelato da ansiedade durante a tarefa. Apenas no grupo controle uma maior ansiedade interagiu com uma maior interferência emocional e uma pior avaliação de valência e alerta (arousal) das imagens emocionais. Esses achados preliminares sugerem que a meditação pode ajudar a modular o efeito da ansiedade no viés para estímulos negativos, e que mesmo um treino breve pode facilitar processos autorregulatórios.

16.
Front Hum Neurosci ; 9: 107, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25788883

RESUMO

The role of attention in emotional processing is still the subject of debate. Recent studies have found that high positive affect in approach motivation narrows attention. Furthermore, the positive affect trait has been suggested as an important component for determining human variability in threat reactivity. We employed functional magnetic resonance imaging to investigate whether different states of attention control would modulate amygdala responses to highly unpleasant pictures relative to neutral and whether this modulation would be influenced by the positive affect trait. Participants (n = 22, 12 male) were scanned while viewing neutral (people) or unpleasant pictures (mutilated bodies) flanked by two peripheral bars. They were instructed to (a) judge the picture content as unpleasant or neutral or (b) to judge the difference in orientation between the bars in an easy condition (0 or 90(∘) orientation difference) or (c) in a hard condition (0 or 6(∘) orientation difference). Whole brain analysis revealed a task main effect of brain areas related to the experimental manipulation of attentional control, including the amygdala, dorsolateral prefrontal cortex, and posterior parietal cortex. Region of interest analysis showed an inverse correlation (r = -0.51, p < 0.01) between left amygdala activation and positive affect level when participants viewed unpleasant stimuli and judged bar orientation in the easy condition. This result suggests that subjects with high positive affect exhibit lower amygdala reactivity to distracting unpleasant pictures. In conclusion, the current study suggests that positive affect modulates attention effect on unpleasant pictures, therefore attenuating emotional responses.

17.
Front Psychol ; 6: 16, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25674068

RESUMO

It is assumed that social bonds in humans have consequences for virtually all aspects of behavior. Social touch-based contact, particularly hand caressing, plays an important role in social bonding. Pre-programmed neural circuits likely support actions (or predispositions to act) toward caressing contacts. We searched for pre-set motor substrates toward caressing by exposing volunteers to bonding cues and having them gently stroke a very soft cloth, a caress-like movement. The bonding cues were pictures with interacting dyads and the control pictures presented non-interacting dyads. We focused on the readiness potential, an electroencephalographic marker of motor preparation that precedes movement execution. The amplitude of the readiness potential preceding the grasping of pleasant emotional-laden stimuli was previously shown to be reduced compared with neutral ones. Fingers flexor electromyography measured action output. The rationale here is that stroking the soft cloth when previously exposed to bonding cues, a compatible context, would result in smaller amplitudes of readiness potentials, as compared to the context with no such cues. Exposure to the bonding pictures increased subjective feelings of sociability and decreased feelings of isolation. Participants who more frequently engage in mutual caress/groom a "significant other" in daily life initiated the motor preparation earlier, reinforcing the caress-like nature of the task. As hypothesized, readiness potentials preceding the caressing of the soft cloth were significantly reduced under exposure to bonding as compared to control pictures. Furthermore, an increased fingers flexor electromyographic activity was identified under exposure to the former as compared to the latter pictures. The facilitatory effects are likely due to the recruitment of pre-set cortical motor repertoires related to caress-like movements, emphasizing the distinctiveness of neural signatures for caress-like movements.

18.
Biol Psychol ; 103: 233-41, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25258033

RESUMO

Despite the impressive progress in the biological research of posttraumatic stress disorder (PTSD), little is known about the neurobiological correlates of emotional reactions in healthy people with posttraumatic stress symptoms (PTSS). The present study investigated whether PTSS are related to the electrocortical processing of unpleasant pictures in a sample of undergraduate students. Participants were instructed to judge whether images were unpleasant or neutral while an EEG was taken. The late positive potential (LPP) to unpleasant relative to neutral was more positive for people with high PTSS than with low PTSS. Additionally, a temporospatial principal components analysis (PCA) for the whole sample identified positivities that were directly correlated with PTSS. These results provide evidence that brain reactivity to unpleasant cues would predict PTSS intensity and thus be a biomarker of PTSS severity.


Assuntos
Encéfalo/fisiopatologia , Potenciais Evocados/fisiologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Adolescente , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Análise de Componente Principal , Índice de Gravidade de Doença , Adulto Jovem
19.
Front Psychol ; 5: 1514, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25566169

RESUMO

Tonic immobility is an involuntary, last-ditch defensive reaction characterized by physical inactivity in a context of inescapable threat that has been described in many species, including humans. The occurrence of this defensive response is a predictor of the severity of psychiatric disorders and may be considered as an index of an intense reaction to a traumatic event. Here, we investigated whether the retrospective reports of peritraumatic tonic immobility reaction in participants exposed to a traumatic event would modify their cardiac responses to pictures related to their trauma. Using a questionnaire of life-threating events, we selected students who experienced violent crime as their most intense trauma and students who had never experienced a violent crime trauma, but experienced other traumatic events. All participants completed a questionnaire that estimated the intensity of tonic immobility during their most intense trauma. Electrocardiographic recordings were collected during exposure to pictures. Participants viewed emotional pictures (human attack with guns) and neutral pictures. These emotional stimuli were selected to be trauma-relevant to the violent crime group and non trauma-relevant to the no violent crime trauma group. Violent crime group showed a positive correlation between heart rate changes after viewing trauma-related pictures and tonic immobility scores. We observed that low tonic immobility scores were associated with bradycardia and high scores with tachycardia in response to trauma-relevant pictures. For the no violent crime group, no significant correlation was detected. These results suggest that the relevance of the stimuli and the magnitude of the defensive response during a previous trauma event were important factors triggering more intense defensive responses.

20.
Front Hum Neurosci ; 7: 632, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24115925

RESUMO

The prioritization of processing emotional stimuli usually produces deleterious effects on task performance when it distracts from a task. One common explanation is that brain resources are consumed by emotional stimuli, diverting resources away from executing the task. Viewing unpleasant stimuli also generates defensive reactions, and these responses may be at least partially responsible for the effect of the emotional modulation observed in various reaction time (RT) paradigms. We investigated whether modulatory effects on RT vary if we presented threat stimuli to prompt different defensive responses. To trigger different responses, we manipulated threat perception by moving the direction of threatening stimuli. Threatening or neutral stimuli were presented as distractors during a bar orientation discrimination task. The results demonstrated that threat stimuli directed toward the observer produced a decrease in RT; in contrast, threat stimuli directed away from the observer produced an increase in RT, when compared to neutral stimuli. Accelerated RT during directed toward threat stimuli was attributed to increased motor preparation resulting from strong activation of the defense response cascade. In contrast, directed away threat stimuli likely activated the defense cascade, but less intensively, prompting immobility. Different threat stimuli produced varying effects, which was interpreted as evidence that the modulation of RT by emotional stimuli represents the summation of attentional and motivational effects. Additionally, participants who had been previously exposed to diverse types of violent crime were more strongly influenced by threat stimuli directed toward the observer. In sum, our data support the concept that emotions are indeed action tendencies.

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