Early onset of neural synchronization in the contextual associations network

Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 02/2011; 108(8):3389-94. DOI: 10.1073/pnas.1013760108
Source: PubMed


Objects are more easily recognized in their typical context. However, is contextual information activated early enough to facilitate the perception of individual objects, or is contextual facilitation caused by postperceptual mechanisms? To elucidate this issue, we first need to study the temporal dynamics and neural interactions associated with contextual processing. Studies have shown that the contextual network consists of the parahippocampal, retrosplenial, and medial prefrontal cortices. We used functional MRI, magnetoencephalography, and phase synchrony analyses to compare the neural response to stimuli with strong or weak contextual associations. The context network was activated in functional MRI and preferentially synchronized in magnetoencephalography (MEG) for stimuli with strong contextual associations. Phase synchrony increased early (150-250 ms) only when it involved the parahippocampal cortex, whereas retrosplenial-medial prefrontal cortices synchrony was enhanced later (300-400 ms). These results describe the neural dynamics of context processing and suggest that context is activated early during object perception.

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Available from: Maximilien Chaumon, Sep 30, 2015
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    • "Moshe Bar's " visual prediction theory " is consistent with perception–action coupling in the visual domain and points to specific cortical areas likely central to differentiating experts from novices. Specifically , Bar (Bar, 2009a,b; Cheung and Bar, 2012; Kveraga et al., 2011) notes the role of the orbitofrontal cortex (OFC) in multimodal associations and links this capability with heightened prediction capability in visual experts. He furthermore provides evidence that the OFC is part of a larger visual expertise network that includes the fusiform face area (FFA). "
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    NeuroImage 08/2015; 123. DOI:10.1016/j.neuroimage.2015.08.028 · 6.36 Impact Factor
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    • "Tentatively, such sensorimotor integration could be enabled by oscillatory synchrony, i.e., rhythmic millisecond-range temporal correlations of neuronal activity (Womelsdorf et al., 2007; Singer, 2009). Previous MEG and EEG studies have revealed that the level of inter-areal phase synchrony within the alpha (8–14 Hz), beta (14–30 Hz) and gamma (30–80 Hz) frequency bands correlates with various perceptual, attention, and working memory task performances (Kujala et al., 2007; Palva et al., 2010; Hipp et al., 2011; Kveraga et al., 2011; Huang et al., 2014), therefore supporting the hypothesis that coordinated operation between task-relevant brain regions is reflected as strengthened oscillatory synchrony (for a review, see Palva and Palva, 2012). "
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    Frontiers in Psychology 05/2014; 5:394. DOI:10.3389/fpsyg.2014.00394 · 2.80 Impact Factor
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    • "This would be particularly true because high personal harm images would be construed as motivationally salient, and motivational salience is important to modulating amygdala response (Cunningham and Brosch, 2012). In contrast, images representing unpleasant situations that are lower in the likelihood of personal harm would be associated with increased activation within the latter regions as well as engage the association-processing regions (the parahippocampal, retrosplenial and medial prefrontal cortices; Bar and Aminoff, 2003; Davachi, 2006; Bar et al., 2008; Peters et al., 2009; Kveraga et al., 2011) to a greater extent. The brain regions involved in representing and regulating unpleasant subjective feelings [orbitofrontal cortex (OFC), ventromedial prefrontal cortex (vmPFC) and lateral PFC; Kringelbach and Rolls, 2004; Ochsner and Gross, 2005; Touroutoglou et al., 2012; Wilson-Mendenhall et al., 2013] should be engaged by all evocative negative images (threatening and Merely Negative) to assess and resolve the presence or absence of threat and its spatial and temporal characteristics. "
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