Mechanisms of orientation sensitivity of human visual system: Part II. Neural patterns of early processing of information about line orientation

Psychophysical analysis of three separate anisotropic patterns in vision : putting visual reference frames in conflict to study the class 1 and 2 oblique effects and the horizontal effect.

“…In an orientation categorization task, Mikhailova, Gerasimenko, Krylova, Izyurov and Slavutskaya (2015) found no orientation selectivity in early evoked potentials at P1 in the occipital cortex, but did in the parietal cortex, which is known to process spatial information. At N1, which occurs 150 to 200ms post-stimulus there was a difference in the occipital cortex, though this most likely occurred due to feedback as there was no difference found in this lobe at the earlier (100ms post-stimulus), P1, component.…”

“…It has been suggested that the Class 2 oblique effect occur at a processing stage where information is represented categorically based on the cardinal coordinate system, but is not modality specific, (Baud-Bovy & Gentaz, 2012;Smyrnis et al, 2014). Others have looked at the parietal cortex as a possible location as it is known to process spatial information (Izyurov & Slavutskaya, 2015). The inferior parietal cortex receives vestibular afferents and is a multisensory area that includes processing of spatial orientation (Brandt, Dieterich & Daneck, 1994).…”

“…should also look at later effects in the occipital lobe, as Mikhailova et al (2015) found a delayed response in the occipital cortex after original signal differences in the parietal cortex (possible feedback). Tasks that elicit the Class 2 oblique effect should be used, such as orientation categorization and memory tasks.…”