Spatiotemporal analysis of category and target-related information processing in the brain during object detection

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

“…Second, whether higher-order frontal brain areas contribute to familiar face recognition, as they do to object recognition (Bar et al,. 2006; Summerfield et al, 2006; Goddard et al, 2016; Karimi-Rouzbahani et al, 2019), and whether levels of face familiarity and perceptual difficulty (as has been suggested previously (Woolgar et al, 2011; Woolgar et al, 2015)) impact the involvement of frontal cognitive areas 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). Previous results 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). Here, 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 follows a recent shift towards informational 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, 2020a), and introduces a few distinct features compared to previous methods of connectivity analyses. Specifically, traditional connectivity methods examine inter-area interactions through indirect measures such as gamma-band synchronization (Gregoriou et al, 2009), shifting power (Bar et al, 2006) or causality in the activity patterns (Summerfield et al, 2006; Fan et al, 2020).…”

“…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 Granger connectivity method to solve this issue, 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). This was followed by another informational connectivity method, which was similar but used regression instead of correlation in implementation (Keitzmann et al, 2019).…”

“…This in turn facilitates the flow of familiar face information in a bottom-up feed-forward manner from the occipito-temporal to the frontal areas for recognition (di Oleggio Castello and Gobbini, 2015; Ramon et al, 2015; Ellis et al, 1979; Young and Burton, 2018). On the other hand, studies have also shown the role of frontal brain areas in facilitating the processing of visual inputs (Bar et al, 2006; Kveraga et al, 2007; Goddard et al, 2016; Karimi-Rouzbahani et al, 2019), such as faces (Kramer et al, 2018; Summerfield et al, 2006), by feeding back signals to the face-selective areas in the occipito-temporal visual areas, particularly when the visual input is ambiguous (Summerfield et al, 2006) or during face imagery (Mechelli et al, 2004; Johnson et al, 2007). These top-down mechanisms, which were localized in medial prefrontal cortex (MPFC), have been suggested (but not quantitatively supported) to reflect feedback of (pre-existing) face templates, against which the input faces are compared for correct recognition (Summerfield et al, 2006) in a recollection procedure (Brown and Banks, 2015).…”