SciELO - Scientific Electronic Library Online

 
vol.8 número1Más allá de la obediencia: reanálisis de la investigación de MilgramLa percepción de peligro y competencia como factores predictores del prejuicio hacia diferentes grupos sociales índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

  • Em processo de indexaçãoCitado por Google
  • Não possue artigos similaresSimilares em SciELO
  • Em processo de indexaçãoSimilares em Google

Compartilhar


Escritos de Psicología (Internet)

versão On-line ISSN 1989-3809versão impressa ISSN 1138-2635

Resumo

FARRAS-PERMANYER, Laia; GUARDIA-OLMOS, Joan  e  PERO-CEBOLLERO, Maribel. Effect of kernel size for BOLD signal smoothing in functional paradigms (fMRI). Escritos de Psicología [online]. 2015, vol.8, n.1, pp.21-29. ISSN 1989-3809.  https://dx.doi.org/10.5231/psy.writ.2015.1212.

Smoothing is a filtering technique that is essential for brain signal analysis and consists in calculating and comparing the average activation of a voxel to that of its neighbours. Several authors have proposed alternatives or modifications to this process; nonetheless, articles that compare the effect of different sizes of smoothing remain scarce. Thus, the aim of this study was to investigate the effect of applying different smoothing sizes and to highlight the importance of choosing the correct smoothing size. Five smoothing criteria were applied to brain images obtained during an easy motor task performed by five adult participants. Significant differences were found between different smoothing sizes, mainly between the non-smoothing application and the smallest smoothing size versus the two largest smoothing sizes. The signals from the most activated brain areas did not disappear with increased smoothing, whereas signals from less active or smaller areas disappeared. Despite the study sample size, the results suggest that smoothing is relevant in functional magnetic resonance image processing and that the optimum smoothing size is 2.5 and 3.

Palavras-chave : Functional Magnetic Resonance Imaging (fMRI); Filtering; Smoothing.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )

 

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons