Heightened Responses of the Parahippocampal and Retrosplenial Cortices during Contextualized Recognition of Congruent Objects.

Daina Crafa,Colin Hawco,Mathieu B Brodeur

doi:10.3389/fnbeh.2017.00232

Abstract

Context sometimes helps make objects more recognizable. Previous studies using functional magnetic resonance imaging (fMRI) have examined regional neural activity when objects have strong or weak associations with their contexts. Such studies have demonstrated that activity in the parahippocampal cortex (PHC) generally corresponds with strong associations between objects and their spatial contexts while retrosplenial cortex (RSC) activity is linked with episodic memory. However these studies investigated objects viewed in associated contexts, but the direct influence of scene on the perception of visual objects has not been widely investigated. We hypothesized that the PHC and RSC may only be engaged for congruent contexts in which the object could typically be found but not for neutral contexts. While in an fMRI scanner, 15 participants rated the recognizability of 152 photographic images of objects, presented within congruent and incongruent contexts. Regions of interest were created to examine PHC and RSC activity using a hypothesis-driven approach. Exploratory analyses were also performed to identify other regional activity. In line with previous studies, PHC and RSC activity emerged when objects were viewed in congruent contexts. Activity in the RSC, inferior parietal lobe (IPL) and fusiform gyrus also emerged. These findings indicate that different brain regions are employed when objects are meaningfully contextualized.

Highlights

Objects in daily life are not always immediately recognized or known to the viewer, but they generally are easier to identify when the contextual information surrounding them is taken into account
Kirk et al (2009) reported that frontal activity was related to a bias of judgment induced by the context. While these results show that the PHC and retrosplenial cortex (RSC) activity are influenced by objectscene congruity, they showed that other brain areas, including the frontal and the parietal areas, are involved as well
The recognition rate of objects presented in congruent context was significantly higher (71%, scenes and 29% (SD): 14%) than the recognition of objects presented in neutral context (53%, SD: 15%)

Summary

Introduction

Objects in daily life are not always immediately recognized or known to the viewer, but they generally are easier to identify when the contextual information surrounding them is taken into account. Higher activity in the PHC is mostly observed when objects with strong scene context associations are viewed; the PHC appears to process place-related contextual information for objects with strong associations (Bar and Aminoff, 2003; Gronau et al, 2008; Kveraga et al, 2010). One study shows that even non-spatial scene associations congruently engage the PHC, which may suggest that the PHC is engaged with context processing more generally (Aminoff et al, 2007). A few studies have reported that the RSC shows heighted activity for objects with strong associations and point to broader neuroscience literature linking RSC activity with episodic memory; theorizing that the RSC accesses past memories when evaluating contextual associations (Bar and Aminoff, 2003; Vann et al, 2009). The relationships between RSC activity and context have not been directly examined in humans

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