Three-stage processing of category and variation information by entangled interactive mechanisms of peri-occipital and peri-frontal cortices

Abstract

Abstract-Invariant object recognition, which refers to the ability of precisely and rapidly recognizing objects in the presence of variations, has been a central question in human vision research. The general consensus is that the ventral and dorsal visual streams are the major processing pathways which undertake category and variation encoding in entangled layers. This overlooks the mounting evidence which support the role of peri-frontal areas in category encoding. These recent studies, however, have left open several aspects of visual processing in peri-frontal areas including whether these areas contributed only in active tasks, whether they interacted with peri-occipital areas or processed information independently and differently. To address these concerns, a passive EEG paradigm was designed in which subjects viewed a set of variation-controlled object images. Using multivariate pattern analysis, noticeable category and variation information were observed in occipital, parietal, temporal and prefrontal areas, supporting their contribution to visual processing. Using task specificity indices, phase and Granger causality analyses, three distinct stages of processing were identified which revealed transfer of information between peri-frontal and peri-occipital areas suggesting their parallel and . CC-BY-NC-ND 4.0 International license peer-reviewed) is the author/funder. It is made available under aThe copyright holder for this preprint (which was not . http://dx.doi.org/10.1101/189811 doi: bioRxiv preprint first posted online Jan. 10, 2018; 2 interactive processing of visual information. A brain-plausible computational model supported the possibility of parallel processing mechanisms in peri-occipital and peri-frontal areas. These findings, while advocating previous results on the role of prefrontal areas in object recognition, extend their contribution from active recognition, in which peri-frontal to peri-occipital feedback mechanisms are activated, to the general case of object and variation processing, which is an integral part of visual processing and play role even during passive viewing.

Perceptual difficulty modulates the direction of information flow in familiar face recognition

“…Our findings support theories suggesting that fronto-occipital information transfer may feedback (pre-existing) face templates, against which the input faces are compared for correct recognition (Bar et al, 2006;Summerfield et al, 2006). As an advantage to the previous results, which could not determine the content of the transferred signals (Bar et al, 2006;Summerfield et al, 2006;Goddard et al, 2016;Karimi-Rouzbahani et al, 2018;Karimi-Rouzbahani et al, 2019), using our novel connectivity analyses, we showed that the transferred signal contained information which contributed to the categorization of familiar and unfamiliar faces.…”

“…The RSA-based connectivity method used in this study further develops a recent shift towards multivariate brain connectivity methods (Anzellotti and Coutanche, 2018;Basti et al, 2020;Keitzmann et al, 2019;Goddard et al, 2016;Clarke et al, 2018;Karimi-Rouzbahani, 2018;Karimi-Rouzbahani et al, 2019;Karimi-Rouzbahani et al, 2020), and introduces several advantages over previous methods of connectivity analyses.…”

“…Specifically, we only observed feedback when the sensory evidence was lowest (high perceptual difficulty) in our face familairty categorization task. Although a large literature has provided evidence for the role of topdown feedback in visual perception, especially when sensory visual information is low, they generally evaluated the feedback mechanisms within the visual system (Ress et al, 2000;Lamme and Roelfsema, 2000;Super et al, 2001;Lamme et al, 2002;Pratte et al, 2013;Fenske et al, 2006;Lee and Mumford, 2003;Felleman et al, 1991;Delorme et al, 2004;Mohsenzadeh et al, 2018;Kietzmann et al, 2019) rather than across the frontooccpital brain networks (Bar et al, 2006;Summerfield et al, 2006;Goddard et al, 2016;Karimi-Rouzbahani et al, 2018;Karimi-Rouzbahani et al, 2019). Our findings support theories suggesting that fronto-occipital information transfer may feedback (pre-existing) face templates, against which the input faces are compared for correct recognition (Bar et al, 2006;Summerfield et al, 2006).…”

“…Such connectivity methods consider simultaneous (or time-shifted) correlated activations of different brain areas as connectivity, but they are unable to examine how (if at all) relevant information is transferred across those areas. Goddard et al (2016) developed an RSA-based connectivity method to solve these issues, which allowed us and others to track the millisecond transfer of stimulus information across peri-frontal and peri-occipital brain areas (Karimi-Rouzbahani, 2018;Karimi-Rouzbahani et al, 2019;Goddard et al, 2019;Keitzmann et al, 2019). This method, however, has the limitation that, it cannot tell us what aspects of the representation are transferred and modulated.…”

“…Typically, these studies use event-related paradigms, which evoke initial brain activations peaking at around 200 ms, whereas our dynamic masking paradigm releases the information gradually along the time course of the trial. Moreover, the extended (>200ms) static stimulation used in previous studies has been suggested to bias towards domination of feed-forward processing (Goddard et al, 2016;Karimi-Rouzbahani, 2018), because of the co-processing of the incoming sensory information and the recurrence of earlier windows of the same input (Kietzmann et al, 2019;Mohsenzadeh et al, 2018), making it hard to measure feedback. However, our paradigm, while providing a delayed processing profile compared to previous studies, avoids this and also slows down the process of evidence accumulation so that it becomes more trackable in time.…”