%0 Journal Article
%@ 0167-8760
%A  Rokszin Adrienn Aranka
%A  Győri-Dani Dóra
%A  Nyúl László Gábor
%A  Csifcsák Gábor
%D 2016
%F publicatio:8871
%J INTERNATIONAL JOURNAL OF PSYCHOPHYSIOLOGY
%P 19-27
%T Electrophysiological correlates of top-down effects facilitating natural image categorization are disrupted by the attenuation of low spatial frequency information
%U http://publicatio.bibl.u-szeged.hu/8871/
%V 100
%X The modulatory effects of low and high spatial frequencies on  the posterior C1, P1 and N1 event-related potential (ERP)  amplitudes have long been known from previous  electrophysiological studies. There is also evidence that  categorization of complex natural images relies on top-down  processes, probably by facilitating contextual associations  during the recognition process. However, to our knowledge, no  study has investigated so far how such top-down effects are  manifested in scalp ERPs, when presenting natural images with  attenuated low or high spatial frequency information. Twenty- one healthy subjects participated in an animal vs. vehicle  categorization task with intact grayscale stimuli and images  predominantly containing high (HSF) or low spatial  frequencies (LSF). ERP scalp maps and amplitudes/latencies  measured above occipital, parietal and frontocentral sites  were compared among the three stimulus conditions. Although  early occipital components (C1 and P1) were modulated by  spatial frequencies, the time range of the N1 was the  earliest to show top-down effects for images with unmodified  low spatial frequency spectrum (intact and LSF stimuli). This  manifested in ERP amplitude changes spreading to anterior  scalp sites and shorter posterior N1 latencies. Finally, the  frontocentral N350 and the centroparietal LPC were  differently influenced by spatial frequency filtering, with  the LPC being the only component to show an amplitude and  latency modulation congruent with the behavioral responses  (sensitivity index and reaction times). Our results  strengthen the coarse-to-fine model of object recognition and  provide electrophysiological evidence for low spatial  frequency-based top-down effects within the first 200 ms of  visual processing.
%Z FELTÖLTŐ: Rokszin Adrienn Aranka - rokszinadrienn@gmail.com  FELTÖLTÉSI MEGJEGYZÉS: A kiadói fájl (rokszin_et_al_2016_int_j_of_psychophy) nem tehető nyilvánossá.