Poster #: 65
Topic: Memory and perception
Thursday, Sep 10, 2015
The interplay of the magno- and parvocellular visual pathways in visual MMN
1Royal Holloway, University of London, Egham, United Kingdom
2Institute of Cognitive Neuroscience and Psychology, RCNS HAS, Budapest, Hungary
3Institute of Cognitive Neuroscience and Psychology, Hungarian Academy of Sciences, Research Centre for Natural Sciences, Budapest, Hungary
Two main components of the visual system, the magnocellular (M) and parvocellular (P) pathways, have different characteristics such as spatial frequency selectivity, contrast and colour sensitivity and processing speed (fast M and slower P activity). A dissociation of responses has been shown according to whether M and P biased stimuli are presented, using reaction times and fMRI. According to some theories (see e.g. Bar et al., 2006, Kveraga et al., 2007), the M system has a role in forming the gist of visual scenes. This process is fast and automatic, resulting in top down control of fine-grade pattern analysis. VMMN is an early ERP component that may reflect pattern detection in the scene, which may provide ERP based correlates of this difference in contribution of the two streams. Additionally it should be able to reflect the latency differential that the slow integration time of fMRI cannot. We investigate the relative contributions of the two systems to VMMN by pesenting M and P biased standards and deviants in an unattended tyipical oddball stimulus. Low contrast, low spatial frequency Gabor patches are used to target the M sytem and high contrast, high spatial freqency the P. We find that P biased deviants paired with M biased standards result in a larger mismatch negativity with a different latency profile than in the reverse situation. We explain our results by investigating to what extent there is adaptation across the two types of stimuli and to what extent predictive processes are at play.