title: Effects of emotional valence and three-dimensionality of visual stimuli on brain activation: an fMRI study.
abstract: BACKGROUND
  Examining changes in brain activation linked with emotion-inducing stimuli is essential to the study of emotions. Due to the ecological potential of techniques such as virtual reality (VR), inspection of whether brain activation in response to emotional stimuli can be modulated by the three-dimensional (3D) properties of the images is important.
  
  
  OBJECTIVE
  The current study sought to test whether the activation of brain areas involved in the emotional processing of scenarios of different valences can be modulated by 3D. Therefore, the focus was made on the interaction effect between emotion-inducing stimuli of different emotional valences (pleasant, unpleasant and neutral valences) and visualization types (2D, 3D). However, main effects were also analyzed.
  
  
  METHODS
  The effect of emotional valence and visualization types and their interaction were analyzed through a 3 × 2 repeated measures ANOVA. Post-hoc t-tests were performed under a ROI-analysis approach.
  
  
  RESULTS
  The results show increased brain activation for the 3D affective-inducing stimuli in comparison with the same stimuli in 2D scenarios, mostly in cortical and subcortical regions that are related to emotional processing, in addition to visual processing regions.
  
  
  CONCLUSIONS
  This study has the potential of clarify brain mechanisms involved in the processing of emotional stimuli (scenarios' valence) and their interaction with three-dimensionality.
authors.affiliation: Institute of Biomedical Sciences Abel Salazar, University of Porto (ICBAS-UP), Psychosocial Rehabilitation Lab, Faculty of Psychology and Educational Sciences, University of Porto/School of Allied Health Sciences, Polytechnic of Porto (LABRP, ESTSP-IPP/FPCEUP), Porto, Portugal.
authors.forename: A R
authors.initials: AR
authors.lastname: Dores
authors.affiliation: Brain Imaging Network Portugal/National Association of Functional Brain Imaging (BING/ANIFC), Coimbra, Portugal.
authors.forename: I
authors.initials: I
authors.lastname: Almeida
authors.affiliation: Faculty of Psychology and Educational Sciences, University of Porto (FPCEUP), Porto, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Barbosa
authors.affiliation: Brain Imaging Network Portugal/National Association of Functional Brain Imaging (BING/ANIFC), Coimbra, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Castelo-Branco
authors.affiliation: Advanced Institute of Health Sciences - North (CESPU), Paredes, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Monteiro
authors.affiliation: Service of Computerized Medical Imaging SA (SMIC), Porto, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Reis
authors.affiliation: Institute of Biomedical Sciences Abel Salazar, University of Porto (ICBAS-UP), Porto, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: de Sousa
authors.affiliation: Institute of Health Sciences, Portuguese Catholic University (ICS-UCP), Lisboa, Portugal.
authors.forename: A Castro
authors.initials: AC
authors.lastname: Caldas
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D000077463:Carbamide Peroxide; D003867:Depth Perception / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010545:Peroxides / Q000097:blood; D010775:Photic Stimulation; D014508:Urea / Q000031:analogs & derivatives / Q000097:blood; D055815:Young Adult
chemical_list: D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea
keywords: 3D/2D visual stimuli; Emotional valence (pleasant, unpleasant, neutral); functional Magnetic Resonance Imaging (fMRI)