“C ≠ A+B” A Gestalt de faces independe de demanda cognitiva: um estudo com bases eletrofisiológicas

Abstract

The phase-amplitude coupling (PAC) between the neuronal oscillations in the theta (3-6Hz) and gamma (30-90Hz) bands composes the basis of sensory integration, memory and attentional selection mechanism. In the present work, we present evidence through electroencephalography (EEG) that the PAC between theta and gamma in the prefrontal cortex (PFC) and posterior parietal cortex (PPC), respectively, is an underlying process in the perceptual closure in a recognition task holistic view of Mooney's Faces through the formulation of a Gestalt. The PAC Tetha-gamma was quantified using the modulation index (MI). The role played by executive functions in this process was verified through logistic regression analysis with measures of general intelligence (IQ) performance and working memory test. The results show a lower MI when the faces are presented in the canonical position (left hemispheres 1.4 ± 0.3x10-3 and right 1.4 ± 0.4x10-3, p <.001 in both) in relation to vertically inverted faces (left hemispheres 2.5 ± 0.5x10-3 and right 2.7 ± 0.7x10-3). However, the MI does not differ (p> .05) as to the success or failure to identify the images. No regression model tested allowed the prediction of success in the identification of faces based on measures of cognitive performance and MI. Thus, our study provides further evidence that PAC is adjacent to long-range communication between cortical areas and corroborates the discarding of the role of executive functions in supporting Gestalt's visual formulation in the parietal cortex.