scholarly journals Increased Activation in the Fusiform Face Area to Greebles is a Result of Expertise Training, Not by its Face-likeness

2021 ◽  
Author(s):  
Kuo Liu ◽  
Chiu-Yueh Chun ◽  
Le-Si Wang ◽  
Chun-Chia Kung

In 2011, Brants, Wagemans, & Op de Beeck (JOCN 23:12, pp. 3949-3958) trained eight individuals to become Greeble experts, and found neuronal inversion effects [NIEs; i.e., higher Fusiform Face Area (FFA) activity for upright, rather than inverted Greebles]. These effects were also found for faces, both before and after training. By claiming to have replicated the seminal Greeble training study (i.e., Gauthier, Tarr, Anderson, Skudlarski, & Gore, 1999, Nat Neurosci, 2, 568-573), Brants et al. interpreted these results as participants viewing Greebles as faces throughout training, contrary to the original argument of subjects becoming Greeble experts only after training. However, such a claim presents two issues. First, the behavioral training results of Brants et al. did not replicate those of Gauthier et al (1999), raising concerns of whether the right training regime had been adopted. Second, both a literature review and meta-analysis of NIE in the FFA suggest its unreliability as an index of face(-like) processing. To empirically evaluate these issues, the present study compared two documented training paradigms (i.e., Gauthier & Tarr, 1997, Vision Res, 37, 1673-1682; and Gauthier, Williams, Tarr, & Tanaka, 1998, Vision Res, 38, 2401-2428) and explored their impact on the FFA. The results showed significant increases in the FFA for Greebles, and a clear neural "adaptation" (i.e., decreased activity for faces following Greebles, but not following non-face objects, in the FFA) both only in the Gauthier97 group, and only after training, reflecting clear modulation of expertise following "appropriate" training. In both groups, no clear NIE for faces nor Greebles were found. Collectively, these data invalidate the two assumptions behind the Brants et al. findings, and provide not only the updated support, but also the new evidence, for the perceptual expertise hypothesis of FFA.

2010 ◽  
Vol 104 (1) ◽  
pp. 336-345 ◽  
Author(s):  
Alison Harris ◽  
Geoffrey Karl Aguirre

Although the right fusiform face area (FFA) is often linked to holistic processing, new data suggest this region also encodes part-based face representations. We examined this question by assessing the metric of neural similarity for faces using a continuous carryover functional MRI (fMRI) design. Using faces varying along dimensions of eye and mouth identity, we tested whether these axes are coded independently by separate part-tuned neural populations or conjointly by a single population of holistically tuned neurons. Consistent with prior results, we found a subadditive adaptation response in the right FFA, as predicted for holistic processing. However, when holistic processing was disrupted by misaligning the halves of the face, the right FFA continued to show significant adaptation, but in an additive pattern indicative of part-based neural tuning. Thus this region seems to contain neural populations capable of representing both individual parts and their integration into a face gestalt. A third experiment, which varied the asymmetry of changes in the eye and mouth identity dimensions, also showed part-based tuning from the right FFA. In contrast to the right FFA, the left FFA consistently showed a part-based pattern of neural tuning across all experiments. Together, these data support the existence of both part-based and holistic neural tuning within the right FFA, further suggesting that such tuning is surprisingly flexible and dynamic.


2010 ◽  
Vol 10 (7) ◽  
pp. 493-493 ◽  
Author(s):  
D. D. Dilks ◽  
E. Dechter ◽  
C. Triantafyllou ◽  
B. Keil ◽  
L. L. Wald ◽  
...  

2012 ◽  
Vol 24 (4) ◽  
pp. 1006-1017 ◽  
Author(s):  
Sara C. Verosky ◽  
Nicholas B. Turk-Browne

A quintessential example of hemispheric specialization in the human brain is that the right hemisphere is specialized for face perception. However, because the visual system is organized contralaterally, what happens when faces appear in the right visual field and are projected to the nonspecialized left hemisphere? We used divided field presentation and fMRI adaptation to test the hypothesis that the left hemisphere can recognize faces, but only with support from the right hemisphere. Consistent with this hypothesis, facial identity adaptation was observed in the left fusiform face area when a face had previously been processed by the right hemisphere, but not when it had only been processed by the left hemisphere. These results imply that facial identity information is transferred from the right hemisphere to the left hemisphere, and that the left hemisphere can represent facial identity but is less efficient at extracting this information by itself.


2019 ◽  
Vol 19 (10) ◽  
pp. 115a
Author(s):  
Edwin J Burns ◽  
Cindy Bukach

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Xiaoxu Fan ◽  
Fan Wang ◽  
Hanyu Shao ◽  
Peng Zhang ◽  
Sheng He

Although face processing has been studied extensively, the dynamics of how face-selective cortical areas are engaged remains unclear. Here, we uncovered the timing of activation in core face-selective regions using functional Magnetic Resonance Imaging and Magnetoencephalography in humans. Processing of normal faces started in the posterior occipital areas and then proceeded to anterior regions. This bottom-up processing sequence was also observed even when internal facial features were misarranged. However, processing of two-tone Mooney faces lacking explicit prototypical facial features engaged top-down projection from the right posterior fusiform face area to right occipital face area. Further, face-specific responses elicited by contextual cues alone emerged simultaneously in the right ventral face-selective regions, suggesting parallel contextual facilitation. Together, our findings chronicle the precise timing of bottom-up, top-down, as well as context-facilitated processing sequences in the occipital-temporal face network, highlighting the importance of the top-down operations especially when faced with incomplete or ambiguous input.


Endoscopy ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 6-14 ◽  
Author(s):  
Shashank Garg ◽  
Jesse Xie ◽  
Sumant Inamdar ◽  
Sheila L. Thomas ◽  
Arvind J. Trindade

Background Dysplasia in Barrett’s esophagus (BE) is focal and difficult to locate. The aim of this meta-analysis was to understand the spatial distribution of dysplasia in BE before and after endoscopic ablation therapy. Methods A systematic search was performed of multiple databases to July 2019. The location of dysplasia prior to ablation was determined using a clock-face orientation (right or left half of the esophagus). The location of the dysplasia post-ablation was classified as within the tubular esophagus or at the top of the gastric folds (TGF). Results 13 studies with 2234 patients were analyzed. Pooled analysis from six studies (819 lesions in 802 patients) showed that before ablation, dysplasia was more commonly located in the right half versus the left half (odds ratio [OR] 4.3; 95 % confidence interval [CI] 2.33 – 7.93; P < 0.001). Pooled analysis from seven studies showed that dysplasia after ablation recurred in 101 /1432 patients (7.05 %; 95 %CI 5.7 % – 8.4 %). Recurrence of dysplasia was located more commonly at the TGF (n = 68) than in the tubular esophagus (n = 34; OR 5.33; 95 %CI 1.75 – 16.21; P = 0.003). Of the esophageal lesions, 90 % (27 /30) were visible, whereas only 46 % (23 /50) of the recurrent dysplastic lesions at the TGF were visible (P < 0.001). Conclusion Before ablation, dysplasia in BE is found more frequently in the right half of the esophagus versus the left. Post-ablation recurrence is more commonly found in the TGF and is non-visible, compared with the tubular esophagus, which is mainly visible.


2009 ◽  
Vol 172 (3) ◽  
pp. 184-191 ◽  
Author(s):  
Sebastian Walther ◽  
Andrea Federspiel ◽  
Helge Horn ◽  
Piero Bianchi ◽  
Roland Wiest ◽  
...  

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