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Details

  • Name

    José Vasconcelos Raposo
  • Cluster

    Computer Science
  • Role

    Research Coordinator
  • Since

    01st April 2015
Publications

2018

The effects of body position on Reflexive Motor Acts and the sense of presence in virtual environments

Authors
Bessa, M; Melo, M; de Sousa, AA; Raposo, JV;

Publication
Computers and Graphics (Pergamon)

Abstract
The purpose of this study was to measure the subject's sense of presence while they performed a task (riding a bicycle downhill) in a virtual reality (VR) environment and to compare it by body position (standing vs. sitting) and gender. The sample consisted of 35 subjects (19 male and 16 female) between 17 and 33 years of age. A translated and validated Portuguese version of the Igroup Presence Questionnaire (IPQp) and the Reflexive Motor Acts (RMAs), based on direct observation, were used as metrics. The results showed significant differences between body position at the level of Experienced Realism, Spatial Presence and Overall Sense of Presence. When measuring RMAs, it was demonstrated that people in the sitting position presented a higher frequency. We concluded that body position influences perceptions of credibility, which has an impact on the sense of presence. No differences were identified between the genders. © 2017 Elsevier Ltd

2017

Presence and cybersickness in immersive content: Effects of content type, exposure time and gender

Authors
Melo, M; Raposo, JV; Bessa, M;

Publication
Computers & Graphics

Abstract

2017

Monoamines and cortisol as potential mediators of the relationship between exercise and depressive symptoms

Authors
Carneiro, LSF; Mota, MP; Vieira Coelho, MA; Alves, RC; Fonseca, AM; Vasconcelos Raposo, J;

Publication
EUROPEAN ARCHIVES OF PSYCHIATRY AND CLINICAL NEUROSCIENCE

Abstract
A randomized controlled trial was conducted to assess the effects of exercise plus pharmacotherapy on monoamine neurotransmitters (dopamine, noradrenaline, adrenaline, serotonin) and cortisol levels. A total of 26 women with clinical depression were randomly assigned to one of the two groups: aerobic exercise plus pharmacotherapy or only pharmacotherapy. The exercise program consisted of aerobic exercise, 45-50 min/session, three times/week, for 16 weeks. The biological parameters were measured before and after the exercise program. Adding exercise to pharmacotherapy had no additional effects on monoamines and cortisol plasma levels. These data are preliminary outcomes from a small sample and should be replicated.

2016

Adaptation and Validation of the Igroup Presence Questionnaire (IPQ) in a Portuguese Sample

Authors
Vasconcelos Raposo, J; Bessa, M; Melo, M; Barbosa, L; Rodrigues, R; Teixeira, CM; Cabral, L; Sousa, AA;

Publication
PRESENCE-TELEOPERATORS AND VIRTUAL ENVIRONMENTS

Abstract
The present study aims (a) to translate and adapt the Igroup Presence Questionnaire (IPQ) to the Portuguese context (semantic equivalence/ conceptual and content validity) and (b) to examine its psychometric properties (reliability and factorial validity). The sample consisted of 478 subjects (285 males and 193 females). The fidelity of the factors varied between 0.53 and 0.83. The confirmatory factor analysis results produced a 14-item version of IPQ-PT, accepting covariance between residual errors of some items of the instrument, as the best structural representation of the data analyzed. The CFA was conducted based on a three-variable model. The fit indexes obtained were X-2/df = 2.647, GFI = .948, CFI = .941, RSMEA = .059, and AIC = 254. These values demonstrate that the proposed Portuguese translation of the IPQ maintains its original validity, demonstrating it to be a robust questionnaire to measure the sense of presence in virtual reality studies. It is therefore recommended for use in presence research when using Portuguese samples.

2016

Sexting: Adaptation of sexual behavior to modern technologies

Authors
Silva, RBR; Teixeira, CM; Vasconcelos Raposo, J; Bessa, M;

Publication
COMPUTERS IN HUMAN BEHAVIOR

Abstract
This is the first research that aim to analyze the practice of Sexting in Portugal. The goals of this study included comparing the differences between the Sexting dimensions and independent factors (gender, age, literacy qualifications, profession, residence, marital status, existence of a stable relationship, most used media, place of frequent use of the media, most commonly used technological device, security perception of communication technology, number of text messages sent per day, recipients of text messages) and corroborating the existence of correlations between the Sexting dimensions. The study sample consisted of 301 individuals aged between 18 and 52 years (158 adults and 143 young adults) and included both females (169) and males (132). The instruments used included a translated and adapted version of the Sex and Tech Survey, created by The National Campaign to Prevent Teen and Unplanned Pregnancy, and the elaboration of 7 social and demographic questions and 6 questions about media consumption and daily technology use. The results showed that environment exposure was higher in males as well as in the group of individuals of both sexes who sent approximately 76-90 written messages per day. By contrast, positive emotions and the development of greater interest in Sexting were higher in women. Positive emotions were higher in young adults, students of both sexes and unemployed persons.

2016

Exercise Improves Depression: Gold Strategies to Treatment Adherence?

Authors
Carneiro, LSF; Fonseca, AM; Vieira coelho, MA; Mota, MP; Vasconcelos raposo, J;

Publication
EARLY INTERVENTION IN PSYCHIATRY

Abstract

2016

Exercise for adults with depressive symptoms: Beyond the weight loss paradigm

Authors
Carneiro, LSF; Mota, MP; Vieira Coelho', MA; Rosenbaum, S; Fonseca, AM; Vasconcelos Raposo, J;

Publication
PSYCHIATRY RESEARCH

Abstract

2016

Impact of physical exercise on catechol-O-methyltransferase activity in depressive patients: A preliminary communication

Authors
Carneiro, LSF; Fonseca, AM; Serrao, P; Mota, MP; Vasconcelos Raposo, J; Vieira Coelho, MA;

Publication
JOURNAL OF AFFECTIVE DISORDERS

Abstract
Background: Catechol-O-methyltransferase (COMT) is a catabolic enzyme involved in the degradation of bioactive molecules including the neurotransmitters epinephrine, norepinephrine, and dopamine. Higher COMT activity in depressive patients in comparison to non-depressed individuals has been reported. The effect of aerobic exercise on depressive patients has been studied and a number of researchers and clinicians believe it to be effective in the treatment of depression and to be involved in several molecular underlying mechanisms. However, the effect of physical exercise on this enzyme activity is unknown, and it remains to be elucidated if chronic exercise changes COMT activity. This randomized control trial evaluates the effects of chronic exercise on peripheral COMT (S-COMT) activity in women with depressive disorder. Methods: Fourteen women (aged: 51.4 + 10.5 years) diagnosed with depression (according to International Classification of Diseases-10) were randomized to one of two groups: pharmacotherapy plus physical exercise (n=7) or only pharmacotherapy (n=7). The aerobic exercise program was supervised, lasting between 45-50 min/session, three times/week for 16 weeks. Erythrocyte soluble COMT were assessed prior to and after the exercise program. Results: Exercise group when compared to a control group presented a significant decrease (p=0.02, r=-0.535) in S-COMT activity between baseline and post-intervention. Limitations: These data are preliminary outcomes from a small sample and should be replicated. Conclusions: Chronic exercise therapy combined with pharmacotherapy leads to significant decrease in S-COMT activity. Our results provide evidence that exercise interferes with S-COMT activity, a molecular mechanism involved in depression. (C) 2016 Published by Elsevier B.V.

2015

Effects of structured exercise and pharmacotherapy vs. pharmacotherapy for adults with depressive symptoms: A randomized clinical trial

Authors
Carneiro, LSF; Fonseca, AM; Vieira Coelho, MA; Mota, MP; Vasconcelos Raposo, J;

Publication
JOURNAL OF PSYCHIATRIC RESEARCH

Abstract
Objective: Physical exercise has been consistently documented as a complementary therapy in the treatment of depressive disorders. However, despite a higher prevalence among women compared to men, the trials developed in women are scarce. In addition, the optimal dosage of exercise capable of producing benefits that reduce depressive symptoms remains unclear. This clinical trial is designed to measure the effect of a structured physical exercise program as a complement to antidepressant medication in the treatment of women with depression. Methods: From July 2013 to May 2014, we implemented a randomized controlled trial (HAPPY BRAIN study). A total of 26 women (aged 50.16 +/- 12.08) diagnosed with clinical depression were randomized either to a supervised aerobic exercise group (45-50 min/week three times a week for four months) plus pharmacotherapy (intervention group), or only antidepressant medication (control group). Results: The exercise group presented a decrease in BDI-II and DASS-21 total score scales. Relatively to DASS-21, it showed a significant decrease in anxiety and stress. The exercise group when compared to a control group showed improvement in relation to physical functioning parameters between baseline and post-intervention. Moreover, anthropometric parameters presented only significant differences between groups in fat mass percentage. Nonetheless, no differences were found between groups in weight, body mass index, waist circumference, and self-esteem. Conclusion: Our results showed that supervised structured aerobic exercise training could be an effective adjuvant therapy for treating women with depression, reducing depressive symptomatology and improving physical fitness. A key factor of this improvement included strict control of exercise workload parameters and adjustment to each subject's capacity. In our study, due to the sample size there is an increase in the probability of type II errors.