Naslov
Attention modulates the earliest visual neuromagnetic responses

Autori
Sušac, Ana ; Josef Golubić, Sanja ; Bubić, Andreja ; Huonker, Ralph ; Götz, Theresa ; Haueisen, Jens ; Supek, Selma

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts 4th Croatian Congress of Neuroscience / - Zagreb : Hrvatsko društvo za neuroznanost ; Hrvatski institut za istraživanje mozga Medicinskog fakulteta Sveučilišta u Zagrebu, 2013, 58-58

Skup
4th Croatian Congress of Neuroscience

Mjesto i datum
Zagreb, Hrvatska, 20.09.2013. - 21.09.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
C1 (earliest visual response); V1 (primary visual cortex); attentional modulation; MEG

Sažetak
The selective attention effects in the primary visual area were first demonstrated using the neurodynamic method of magnetoencephalography (MEG) [1], after which they were repeatedly confirmed by fMRI [2] and numerous EEG/fMRI studies. Aine et al. [1] showed that the attentional modification that causes V1 reactivation at the latency of 150 ms may be attributed to feedback connections. Specifically, unlike the methods relying on slow hemodynamic responses, MEG and EEG are able to track the evoked extracranial and cortical dynamics with millisecond resolution, and provide valuable insights into the dynamics of activated and reactivated areas. Recent results have shown attentional effects even at the level of the earliest C1 component of the measured evoked responses triggered around 50-100 ms after the presentation of the visual stimulus [3, 4]. In this study, we used MEG and spatio-temporal source localization in order to determine the location and timing of the earliest visual attention modifications. Using multiple current dipoles we modeled the earliest neuromagnetic responses to visual stimuli displayed in different parts of the visual fields. During the experiment participants attended: 1) always at the same part of the visual field in the first experimental condition, and 2) always at different parts of the visual field that were cued prior to each trial in the second condition. The attentional effects in both experimental conditions were determined by comparing the neuromagnetic responses to the same stimuli for the attended and non-attended locations of their presentation. The evoked visual responses were measured on 14 subjects using Elekta Neuromag 306-channel MEG system at the Biomagnetic Center in Jena. MEG data were analyzed using the MRIVIEW Calibrated Start Spatio-Temporal (CSST) multi-start inverse procedure for spatio-temporal source localization. The spatio-temporal localization of neuromagnetic sources indicated an attentional modulation of the dynamics of the occipital contralateral source that was identified 70-100 ms after the stimulus presentation. Both types of cueing resulted in the attentional modulation. [1] Aine et al. (1995) Temporal dynamics of visual-evoked neuromagnetic sources: effects of stimulus parameters and selective attention. Int J Neurosci 80:79–104. [2] Tootell et al. (1998) The retinotopy of visual spatial attention. Neuron 21:1409–1422. [3] Kelly et al. (2008) Spatial attention modulates initial afferent activity in human primary visual cortex. Cereb Cortex 18:2629–2636. [4] Poghosyan et al. (2008) Attention modulates earliest responses in the primary auditory and visual cortices. Neuron 58:802–813.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Temeljne medicinske znanosti

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