scholarly journals Using Live and Video Stimuli to Localize Face and Object Processing Regions of the Canine Brain

Animals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 108
Author(s):  
Kirsten D. Gillette ◽  
Erin M. Phillips ◽  
Daniel D. Dilks ◽  
Gregory S. Berns

Previous research to localize face areas in dogs’ brains has generally relied on static images or videos. However, most dogs do not naturally engage with two-dimensional images, raising the question of whether dogs perceive such images as representations of real faces and objects. To measure the equivalency of live and two-dimensional stimuli in the dog’s brain, during functional magnetic resonance imaging (fMRI) we presented dogs and humans with live-action stimuli (actors and objects) as well as videos of the same actors and objects. The dogs (n = 7) and humans (n = 5) were presented with 20 s blocks of faces and objects in random order. In dogs, we found significant areas of increased activation in the putative dog face area, and in humans, we found significant areas of increased activation in the fusiform face area to both live and video stimuli. In both dogs and humans, we found areas of significant activation in the posterior superior temporal sulcus (ectosylvian fissure in dogs) and the lateral occipital complex (entolateral gyrus in dogs) to both live and video stimuli. Of these regions of interest, only the area along the ectosylvian fissure in dogs showed significantly more activation to live faces than to video faces, whereas, in humans, both the fusiform face area and posterior superior temporal sulcus responded significantly more to live conditions than video conditions. However, using the video conditions alone, we were able to localize all regions of interest in both dogs and humans. Therefore, videos can be used to localize these regions of interest, though live conditions may be more salient.

2004 ◽  
Vol 16 (9) ◽  
pp. 1669-1679 ◽  
Author(s):  
Emily D. Grossman ◽  
Randolph Blake ◽  
Chai-Youn Kim

Individuals improve with practice on a variety of perceptual tasks, presumably reflecting plasticity in underlying neural mechanisms. We trained observers to discriminate biological motion from scrambled (nonbiological) motion and examined whether the resulting improvement in perceptual performance was accompanied by changes in activation within the posterior superior temporal sulcus and the fusiform “face area,” brain areas involved in perception of biological events. With daily practice, initially naive observers became more proficient at discriminating biological from scrambled animations embedded in an array of dynamic “noise” dots, with the extent of improvement varying among observers. Learning generalized to animations never seen before, indicating that observers had not simply memorized specific exemplars. In the same observers, neural activity prior to and following training was measured using functional magnetic resonance imaging. Neural activity within the posterior superior temporal sulcus and the fusiform “face area” reflected the participants' learning: BOLD signals were significantly larger after training in response both to animations experienced during training and to novel animations. The degree of learning was positively correlated with the amplitude changes in BOLD signals.


2019 ◽  
Vol 30 (2) ◽  
pp. 778-785 ◽  
Author(s):  
David Pitcher ◽  
Amy Pilkington ◽  
Lionel Rauth ◽  
Chris Baker ◽  
Dwight J Kravitz ◽  
...  

Abstract Neuroimaging studies show that ventral face-selective regions, including the fusiform face area (FFA) and occipital face area (OFA), preferentially respond to faces presented in the contralateral visual field (VF). In the current study we measured the VF response of the face-selective posterior superior temporal sulcus (pSTS). Across 3 functional magnetic resonance imaging experiments, participants viewed face videos presented in different parts of the VF. Consistent with prior results, we observed a contralateral VF bias in bilateral FFA, right OFA (rOFA), and bilateral human motion-selective area MT+. Intriguingly, this contralateral VF bias was absent in the bilateral pSTS. We then delivered transcranial magnetic stimulation (TMS) over right pSTS (rpSTS) and rOFA, while participants matched facial expressions in both hemifields. TMS delivered over the rpSTS disrupted performance in both hemifields, but TMS delivered over the rOFA disrupted performance in the contralateral hemifield only. These converging results demonstrate that the contralateral bias for faces observed in ventral face-selective areas is absent in the pSTS. This difference in VF response is consistent with face processing models proposing 2 functionally distinct pathways. It further suggests that these models should account for differences in interhemispheric connections between the face-selective areas across these 2 pathways.


2004 ◽  
Vol 4 (8) ◽  
pp. 131-131 ◽  
Author(s):  
G. Golarai ◽  
D. G. Ghahremani ◽  
J. L. Eberhardt ◽  
K. Grill-Spector ◽  
G. D. E. Gabrieli

2017 ◽  
Author(s):  
Michal Bernstein ◽  
Yaara Erez ◽  
Idan Blank ◽  
Galit Yovel

AbstractFaces convey rich information including identity, gender and expression. Current neural models of face processing suggest a dissociation between the processing of invariant facial aspects such as identity and gender, that engage the fusiform face area (FFA) and the processing of changeable aspects, such as expression and eye gaze, that engage the posterior superior temporal sulcus face area (pSTS-FA). Recent studies report a second dissociation within this network such that the pSTS-FA, but not the FFA, shows much stronger response to dynamic than static faces. The aim of the current study was to test a unified model that accounts for these two major functional characteristics of the neural face network. In an fMRI experiment, we presented static and dynamic faces while subjects judged an invariant (gender) or a changeable facial aspect (expression). We found that the pSTS-FA was more engaged in processing dynamic than static faces and changeable than invariant facial aspects, whereas the OFA and FFA showed similar response across all four conditions. Our results reveal no dissociation between the processing of changeable and invariant facial aspects, but higher sensitivity to the processing of changeable facial aspects by the motion-sensitive face area in the superior temporal sulcus.


Author(s):  
James H. Austin

This chapter examines the structure and multiple functions of the angular gyrus, the parahippocampal gyrus, and the superior temporal sulcus (STS). It also distinguishes between the fusiform face area (FFA) and the parahippocampal place area (PPA).


2010 ◽  
Vol 22 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Jia Liu ◽  
Alison Harris ◽  
Nancy Kanwisher

fMRI studies have reported three regions in human ventral visual cortex that respond selectively to faces: the occipital face area (OFA), the fusiform face area (FFA), and a face-selective region in the superior temporal sulcus (fSTS). Here, we asked whether these areas respond to two first-order aspects of the face argued to be important for face perception, face parts (eyes, nose, and mouth), and the T-shaped spatial configuration of these parts. Specifically, we measured the magnitude of response in these areas to stimuli that (i) either contained real face parts, or did not, and (ii) either had veridical face configurations, or did not. The OFA and the fSTS were sensitive only to the presence of real face parts, not to the correct configuration of those parts, whereas the FFA was sensitive to both face parts and face configuration. Further, only in the FFA was the response to configuration and part information correlated across voxels, suggesting that the FFA contains a unified representation that includes both kinds of information. In combination with prior results from fMRI, TMS, MEG, and patient studies, our data illuminate the functional division of labor in the OFA, FFA, and fSTS.


2011 ◽  
Vol 23 (12) ◽  
pp. 3949-3958 ◽  
Author(s):  
Marijke Brants ◽  
Johan Wagemans ◽  
Hans P. Op de Beeck

Some of the brain areas in the ventral temporal lobe, such as the fusiform face area (FFA), are critical for face perception in humans, but what determines this specialization is a matter of debate. The face specificity hypothesis claims that faces are processed in a domain-specific way. Alternatively, the expertise hypothesis states that the FFA is specialized in processing objects of expertise. To disentangle these views, some previous experiments used an artificial class of novel objects called Greebles. These experiments combined a learning and fMRI paradigm. Given the high impact of the results in the literature, we replicated and further investigated this paradigm. In our experiment, eight participants were trained for ten 1-hr sessions at identifying Greebles. We scanned participants before and after training and examined responses in FFA and lateral occipital complex. Most importantly and in contrast to previous reports, we found a neural inversion effect for Greebles before training. This result suggests that people process the “novel” Greebles as faces, even before training. This prediction was confirmed in a postexperimental debriefing. In addition, we did not find an increase of the inversion effect for Greebles in the FFA after training. This indicates that the activity in the FFA for Greebles does not depend on the degree of expertise acquired with the objects but on the interpretation of the stimuli as face-related.


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