Article

Engagement of Fusiform Cortex and Disengagement of Lateral Occipital Cortex in the Acquisition of Radiological Expertise

Exponent Failure Analysis, Bellevue, WA 98007, USA.
Cerebral Cortex (Impact Factor: 8.67). 04/2009; 19(11):2746-54. DOI: 10.1093/cercor/bhp051
Source: PubMed

ABSTRACT The human visual pathways that are specialized for object recognition stretch from lateral occipital cortex (LO) to the ventral surface of the temporal lobe, including the fusiform gyrus. Plasticity in these pathways supports the acquisition of visual expertise, but precisely how training affects the different regions remains unclear. We used functional magnetic resonance imaging to measure neural activity in both LO and the fusiform gyrus in radiologists as they detected abnormalities in chest radiographs. Activity in the right fusiform face area (FFA) correlated with visual expertise, measured as behavioral performance during scanning. In contrast, activity in left LO correlated negatively with expertise, and the amount of LO that responded to radiographs was smaller in experts than in novices. Activity in the FFA and LO correlated negatively in experts, whereas in novices, the 2 regions showed no stable relationship. Together, these results suggest that the FFA becomes more engaged and left LO less engaged in interpreting radiographic images over the course of training. Achieving expert visual performance may involve suppressing existing neural representations while simultaneously developing others.

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    • "It is worth noting the absence of any expertise effect for cars in EVC, in contrast to Harel et al. (2010). While it is a null effect, it is obtained in the context of clear expertise effects in other areas, and it is consistent with a number of prior studies of expertise where early visual cortex was part of the field of the view (Gauthier et al., 1999, 2000; Xu, 2005; Harley et al., 2009; Bilalic et al., 2011; McGugin et al., 2014). This suggests that expertise individuating objects in homogeneous categories does not recruit V1 and that expertise effects for cars in Harel et al. (2010) may have been due to differences in size between cars and control images, as supported by their finding more activity for cars in V1 even for novices (although these effects were not statistically significant). "
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    ABSTRACT: The fusiform face area (FFA) is one of several areas in occipito-temporal cortex whose activity is correlated with perceptual expertise for objects. Here, we investigate the robustness of expertise effects in FFA and other areas to a strong task manipulation that increases both perceptual and attentional demands. With high-resolution fMRI at 7Telsa, we measured responses to images of cars, faces and a category globally visually similar to cars (sofas) in 26 subjects who varied in expertise with cars, in (a) a low load 1-back task with a single object category and (b) a high load task in which objects from two categories rapidly alternated and attention was required to both categories. The low load condition revealed several areas more active as a function of expertise, including both posterior and anterior portions of FFA bilaterally (FFA1/FFA2 respectively). Under high load, fewer areas were positively correlated with expertise and several areas were even negatively correlated, but the expertise effect in face-selective voxels in the anterior portion of FFA (FFA2) remained robust. Finally, we found that behavioral car expertise also predicted increased responses to sofa images but no behavioral advantages in sofa discrimination, suggesting that global shape similarity to a category of expertise is enough to elicit a response in FFA and other areas sensitive to experience, even when the category itself is not of special interest. The robustness of expertise effects in right FFA2 and the expertise effects driven by visual similarity both argue against attention being the sole determinant of expertise effects in extrastriate areas.
    Neuropsychologia 09/2014; 63. DOI:10.1016/j.neuropsychologia.2014.08.029 · 3.45 Impact Factor
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    • "Here, we reassess the shared variance between face and object recognition and provide the first demonstration that expressing this ability depends on experience. Experts with extensive real-world experience individuating objects in nonface categories (e.g., birds, cars) also demonstrate a variety of behavioral (Curby, Glazek, & Gauthier, 2009; McGugin, McKeeff, Tong, & Gauthier, 2010) and neural (Gauthier, Curran, Curby, & Collins, 2003; Harley et al., 2009; Xu, 2005) markers of face perception in their domain of expertise. We hypothesize that subjects with more individuating experience will show more similar performance for faces and nonface objects than those with less individuating experience. "
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    ABSTRACT: SOME RESEARCH FINDS THAT FACE RECOGNITION IS LARGELY INDEPENDENT FROM THE RECOGNITION OF OTHER OBJECTS; A SPECIALIZED AND INNATE ABILITY TO RECOGNIZE FACES COULD THEREFORE HAVE LITTLE OR NOTHING TO DO WITH OUR ABILITY TO RECOGNIZE OBJECTS WE PROPOSE A NEW FRAMEWORK IN WHICH RECOGNITION PERFORMANCE FOR ANY CATEGORY IS THE PRODUCT OF DOMAIN-GENERAL ABILITY AND CATEGORY-SPECIFIC EXPERIENCE IN EXPERIMENT 1, WE SHOW THAT THE OVERLAP BETWEEN FACE AND OBJECT RECOGNITION DEPENDS ON EXPERIENCE WITH OBJECTS IN 256 SUBJECTS WE MEASURED FACE RECOGNITION, OBJECT RECOGNITION FOR EIGHT CATEGORIES, AND SELF-REPORTED EXPERIENCE WITH THESE CATEGORIES EXPERIENCE PREDICTED NEITHER FACE RECOGNITION NOR OBJECT RECOGNITION BUT MODERATED THEIR RELATIONSHIP FACE RECOGNITION PERFORMANCE IS INCREASINGLY SIMILAR TO OBJECT RECOGNITION PERFORMANCE WITH INCREASING OBJECT EXPERIENCE IF A SUBJECT HAS A LOT OF EXPERIENCE WITH OBJECTS AND IS FOUND TO PERFORM POORLY, THEY ALSO PROVE TO HAVE A LOW ABILITY WITH FACES IN A FOLLOW-UP SURVEY, WE EXPLORED THE DIMENSIONS OF EXPERIENCE WITH OBJECTS THAT MAY HAVE CONTRIBUTED TO SELF-REPORTED EXPERIENCE IN EXPERIMENT 1 DIFFERENT DIMENSIONS OF EXPERIENCE APPEAR TO BE MORE SALIENT FOR DIFFERENT CATEGORIES, WITH GENERAL SELF-REPORTS OF EXPERTISE REFLECTING JUDGMENTS OF VERBAL KNOWLEDGE ABOUT A CATEGORY MORE THAN JUDGMENTS OF VISUAL PERFORMANCE THE COMPLEXITY OF EXPERIENCE AND CURRENT LIMITATIONS IN ITS MEASUREMENT SUPPORT THE IMPORTANCE OF AGGREGATING ACROSS MULTIPLE CATEGORIES OUR FINDINGS IMPLY THAT BOTH FACE AND OBJECT RECOGNITION ARE SUPPORTED BY A COMMON, DOMAIN-GENERAL ABILITY EXPRESSED THROUGH EXPERIENCE WITH A CATEGORY AND BEST MEASURED WHEN ACCOUNTING FOR EXPERIENCE:
    Journal of Vision 07/2014; 14(8). DOI:10.1167/14.8.7 · 2.73 Impact Factor
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    • "The work discussed so far has focused on the activation differences between experts and novices at a group level. However, recently it has also been suggested that the critical test of the involvement of a region in object expertise is whether its response to objects of expertise correlates with the degree of expertise (Gauthier et al., 2005; Harley et al., 2009). Using this criterion, McGugin et al. (2012b), in a high-resolution fMRI study at 7T, reported that car selectivity in FFA correlates with car expertise (but see Grill-Spector et al., 2004 for a conflicting result). "
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    ABSTRACT: Real-world expertise provides a valuable opportunity to understand how experience shapes human behavior and neural function. In the visual domain, the study of expert object recognition, such as in car enthusiasts or bird watchers, has produced a large, growing, and often-controversial literature. Here, we synthesize this literature, focusing primarily on results from functional brain imaging, and propose an interactive framework that incorporates the impact of high-level factors, such as attention and conceptual knowledge, in supporting expertise. This framework contrasts with the perceptual view of object expertise that has concentrated largely on stimulus-driven processing in visual cortex. One prominent version of this perceptual account has almost exclusively focused on the relation of expertise to face processing and, in terms of the neural substrates, has centered on face-selective cortical regions such as the Fusiform Face Area (FFA). We discuss the limitations of this face-centric approach as well as the more general perceptual view, and highlight that expert related activity is: (i) found throughout visual cortex, not just FFA, with a strong relationship between neural response and behavioral expertise even in the earliest stages of visual processing, (ii) found outside visual cortex in areas such as parietal and prefrontal cortices, and (iii) modulated by the attentional engagement of the observer suggesting that it is neither automatic nor driven solely by stimulus properties. These findings strongly support a framework in which object expertise emerges from extensive interactions within and between the visual system and other cognitive systems, resulting in widespread, distributed patterns of expertise-related activity across the entire cortex.
    Frontiers in Human Neuroscience 12/2013; 7(10):885. DOI:10.3389/fnhum.2013.00885 · 2.90 Impact Factor
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