scholarly journals Mid-level feature differences underlie early animacy and object size distinctions: Evidence from EEG decoding

2022 ◽  
Author(s):  
Ruosi Wang ◽  
Daniel Janini ◽  
Talia Konkle
Keyword(s):  
Temporal Processing ◽  
Large Scale ◽  
Object Size ◽  
Cortical Surface ◽  
Neural Processing ◽  
Neural Responses ◽  
Neural Basis ◽  
Topographical Organization ◽  
Explicit Recognition ◽  
Feature Information

Responses to visually-presented objects along the cortical surface of the human brain have a large-scale organization reflecting the broad categorical divisions of animacy and object size. Mounting evidence indicates that this topographical organization is driven by differences between objects in mid-level perceptual features. With regard to the timing of neural responses, images of objects quickly evoke neural responses with decodable information about animacy and object size, but are mid-level features sufficient to evoke these rapid neural responses? Or is slower iterative neural processing required to untangle information about animacy and object size from mid-level features? To answer this question, we used electroencephalography(EEG) to measure human neural responses to images of objects and their texform counterparts - unrecognizable images which preserve some mid-level feature information about texture and coarse form. We found that texform images evoked neural responses with early decodable information about both animacy and real-world size, as early as responses evoked by original images. Further, successful cross-decoding indicates that both texform and original images evoke information about animacy and size through a common underlying neural basis. Broadly, these results indicate that the visual system contains a mid-level feature bank carrying linearly decodable information on animacy and size, which can be rapidly activated without requiring explicit recognition or protracted temporal processing.

scholarly journals A mid-level organization of the ventral stream

2017 ◽  
Author(s):  
Bria Long ◽  
Chen-Ping Yu ◽  
Talia Konkle
Keyword(s):  
Large Scale ◽  
Texture Synthesis ◽  
Ventral Stream ◽  
Object Size ◽  
Neural Responses ◽  
Visual Stream ◽  
Visual Appearance ◽  
Explicit Recognition ◽  
High Level ◽  
Form Information

ABSTRACTHuman object-selective cortex shows a large-scale organization characterized by the high-level properties of both animacy and object-size. To what extent are these neural responses explained by primitive perceptual features that distinguish animals from objects and big objects from small objects? To address this question, we used a texture synthesis algorithm to create a novel class of stimuli—texforms—which preserve some mid-level texture and form information from objects while rendering them unrecognizable. We found that unrecognizable texforms were sufficient to elicit the large-scale organizations of object-selective cortex along the entire ventral pathway. Further, the structure in the neural patterns elicited by texforms was well predicted by curvature features and by intermediate layers of a deep convolutional neural network, supporting the mid-level nature of the representations. These results provide clear evidence that a substantial portion of ventral stream organization can be accounted for by coarse texture and form information, without requiring explicit recognition of intact objects.SIGNIFICANCE STATEMENTWhile neural responses to object categories are remarkably systematic across human visual cortex, the nature of these responses been hotly debated for the past 20 years. In this paper, a new class of stimuli (“texforms”) is used to examine how mid-level features contribute to the large-scale organization of the ventral visual stream. Despite their relatively primitive visual appearance, these unrecognizable texforms elicited the entire large-scale organizations of the ventral stream by animacy and object size. This work demonstrates that much of ventral stream organization can be explained by relatively primitive mid-level features, without requiring explicit recognition of the objects themselves.

scholarly journals The contribution of object size, manipulability, and stability on neural responses to inanimate objects

2020 ◽  
Author(s):  
Caterina Magri ◽  
Talia Konkle ◽  
Alfonso Caramazza
Keyword(s):  
Factor Analysis ◽  
Real World ◽  
Object Representation ◽  
Large Scale ◽  
Two Dimensions ◽  
List Type ◽  
Small Object ◽  
Object Size ◽  
Neural Responses ◽  
Large Object

AbstractIn human occipitotemporal cortex, brain responses to depicted inanimate objects have a large-scale organization by real-world object size. Critically, the size of objects in the world is systematically related to behaviorally-relevant properties: small objects are often grasped and manipulated (e.g., forks), while large objects tend to be less motor-relevant (e.g., tables), though this relationship does not always have to be true (e.g., picture frames and wheelbarrows). To determine how these two dimensions interact, we measured brain activity with functional magnetic resonance imaging while participants viewed a stimulus set of small and large objects with either low or high motor-relevance. The results revealed that the size organization was evident for objects with both low and high motor-relevance; further, a motor-relevance map was also evident across both large and small objects. Targeted contrasts revealed that typical combinations (small motor-relevant vs. large non-motor-relevant) yielded more robust topographies than the atypical covariance contrast (small non-motor-relevant vs. large motor-relevant). In subsequent exploratory analyses, a factor analysis revealed that the construct of motor-relevance was better explained by two underlying factors: one more related to manipulability, and the other to whether an object moves or is stable. The factor related to manipulability better explained responses in lateral small-object preferring regions, while the factor related to object stability (lack of movement) better explained responses in ventromedial large-object preferring regions. Taken together, these results reveal that the structure of neural responses to objects of different sizes further reflect behavior-relevant properties of manipulability and stability, and contribute to a deeper understanding of some of the factors that help the large-scale organization of object representation in high-level visual cortex.Highlights-Examined the relationship between real-world size and motor-relevant properties in the structure of responses to inanimate objects.-Large scale topography was more robust for contrast that followed natural covariance of small motor-relevant vs. large non-motor-relevant, over contrast that went against natural covariance.-Factor analysis revealed that manipulability and stability were, respectively, better explanatory predictors of responses in small- and large-object regions.

scholarly journals Mid-level visual features underlie the high-level categorical organization of the ventral stream

2018 ◽  
Vol 115 (38) ◽  
pp. E9015-E9024 ◽  
Author(s):  
Bria Long ◽  
Chen-Ping Yu ◽  
Talia Konkle
Keyword(s):  
Large Scale ◽  
Texture Synthesis ◽  
Ventral Stream ◽  
Neural Responses ◽  
Intermediate Layers ◽  
Coarse Texture ◽  
Explicit Recognition ◽  
Ventral Pathway ◽  
High Level ◽  
Form Information

Human object-selective cortex shows a large-scale organization characterized by the high-level properties of both animacy and object size. To what extent are these neural responses explained by primitive perceptual features that distinguish animals from objects and big objects from small objects? To address this question, we used a texture synthesis algorithm to create a class of stimuli—texforms—which preserve some mid-level texture and form information from objects while rendering them unrecognizable. We found that unrecognizable texforms were sufficient to elicit the large-scale organizations of object-selective cortex along the entire ventral pathway. Further, the structure in the neural patterns elicited by texforms was well predicted by curvature features and by intermediate layers of a deep convolutional neural network, supporting the mid-level nature of the representations. These results provide clear evidence that a substantial portion of ventral stream organization can be accounted for by coarse texture and form information without requiring explicit recognition of intact objects.

scholarly journals Evidence accumulation relates to perceptual consciousness and monitoring

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Pereira ◽  
Pierre Megevand ◽  
Mi Xue Tan ◽  
Wenwen Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Detection Threshold ◽  
Task Demands ◽  
Neuron Activity ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Neural Basis ◽  
Perceptual Consciousness ◽  
Evidence Accumulation ◽  
Posterior Parietal

AbstractA fundamental scientific question concerns the neural basis of perceptual consciousness and perceptual monitoring resulting from the processing of sensory events. Although recent studies identified neurons reflecting stimulus visibility, their functional role remains unknown. Here, we show that perceptual consciousness and monitoring involve evidence accumulation. We recorded single-neuron activity in a participant with a microelectrode in the posterior parietal cortex, while they detected vibrotactile stimuli around detection threshold and provided confidence estimates. We find that detected stimuli elicited neuronal responses resembling evidence accumulation during decision-making, irrespective of motor confounds or task demands. We generalize these findings in healthy volunteers using electroencephalography. Behavioral and neural responses are reproduced with a computational model considering a stimulus as detected if accumulated evidence reaches a bound, and confidence as the distance between maximal evidence and that bound. We conclude that gradual changes in neuronal dynamics during evidence accumulation relates to perceptual consciousness and perceptual monitoring in humans.

Position Selectivity in Scene- and Object-Responsive Occipitotemporal Regions

2007 ◽  
Vol 98 (4) ◽  
pp. 2089-2098 ◽  
Author(s):  
Sean P. MacEvoy ◽  
Russell A. Epstein
Keyword(s):  
Large Scale ◽  
Scene Perception ◽  
Receptive Fields ◽  
Neural Responses ◽  
Retinal Position ◽  
Vertical Meridian ◽  
Retinal Stimulation ◽  
Natural Vision ◽  
Visual Hemifields ◽  
Insight Into

Complex visual scenes preferentially activate several areas of the human brain, including the parahippocampal place area (PPA), the retrosplenial complex (RSC), and the transverse occipital sulcus (TOS). The sensitivity of neurons in these regions to the retinal position of stimuli is unknown, but could provide insight into their roles in scene perception and navigation. To address this issue, we used functional magnetic resonance imaging (fMRI) to measure neural responses evoked by sequences of scenes and objects confined to either the left or right visual hemifields. We also measured the level of adaptation produced when stimuli were either presented first in one hemifield and then repeated in the opposite hemifield or repeated in the same hemifield. Although overall responses in the PPA, RSC, and TOS tended to be higher for contralateral stimuli than for ipsilateral stimuli, all three regions exhibited position-invariant adaptation, insofar as the magnitude of adaptation did not depend on whether stimuli were repeated in the same or opposite hemifields. In contrast, object-selective regions showed significantly greater adaptation when objects were repeated in the same hemifield. These results suggest that neuronal receptive fields (RFs) in scene-selective regions span the vertical meridian, whereas RFs in object-selective regions do not. The PPA, RSC, and TOS may support scene perception and navigation by maintaining stable representations of large-scale features of the visual environment that are insensitive to the shifts in retinal stimulation that occur frequently during natural vision.

scholarly journals Subjective social status and neural processing of race in Mexican American adolescents

2018 ◽  
Vol 30 (5) ◽  
pp. 1837-1848 ◽  
Author(s):  
Keely A. Muscatell ◽  
Ethan McCormick ◽  
Eva H. Telzer
Keyword(s):  
Social Status ◽  
Mexican American ◽  
Educational Background ◽  
Subjective Social Status ◽  
Sensitive Period ◽  
Neural Processing ◽  
Neural Responses ◽  
Black And White ◽  
Face Area ◽  
Mexican American Adolescents

AbstractAdolescence is a sensitive period for sociocultural development in which facets of social identity, including social status and race, become especially salient. Despite the heightened importance of both social status and race during this developmental period, no known work has examined how individual differences in social status influence perceptions of race in adolescents. Thus, in the present study, we investigated how both subjective social status and objective socioeconomic status (SES) influence neural responses to race. Twenty-three Mexican American adolescents (15 females; mean age = 17.22 years) were scanned using functional magnetic resonance imaging while they viewed Black and White faces in a standard labeling task. Adolescents rated their subjective social status in US society, while their parents responded to questions about their educational background, occupation, and economic strain (objective SES). Results demonstrated a negative association between subjective social status and neural responses in the amygdala, fusiform face area, and medial prefrontal cortex when adolescents viewed Black (relative to White) faces. In other words, adolescents with lower subjective social status showed greater activity in neural regions involved in processing salience, perceptual expertise, and thinking about the minds of others when they viewed images of Black faces, suggesting enhanced salience of race for these youth. There was no relationship between objective SES and neural responses to the faces. Moreover, instructing participants to focus on the gender or emotion expression on the face attenuated the relationship between subjective social status and neural processing of race. Together, these results demonstrate that subjective social status shapes the way the brain responds to race, which may have implications for psychopathology.

Utilizing the Cortico-Striatal Projectome to Advance the Study of Timing and Time Perception

2016 ◽  
Vol 4 (4) ◽  
pp. 411-422 ◽  
Author(s):  
Nicholas A. Lusk ◽  
Dean V. Buonomano
Keyword(s):  
Time Perception ◽  
Temporal Processing ◽  
Large Scale ◽  
Imaging Techniques ◽  
Brain Connectivity ◽  
Beat Frequency ◽  
Dorsal Striatum ◽  
Frequency Model ◽  
Timing And Time Perception

Over the past decade advances in tracing and imaging techniques have spurred the development of increasingly detailed maps of brain connectivity. Broadly termed ‘connectomes’, these maps provide a powerful tool for systems neuroscience. As with most ‘maps’, connectomes offer a static spatial description of the brain’s circuits, whereas timing and temporal processing are inherently dynamic processes; nevertheless, the timing field stands to be a major beneficiary of these large-scale mapping projects. The recently reported ‘projectome’ of mouse cortico-striatal sub-networks is of particular interest because theoretical developments such as the striatal beat-frequency model emphasize the role of the striatum in temporal processing. The cortico-striatal projectome confirms that the dorsal striatum is ideally situated to sample patterns of activity throughout most of the cortex, but that it also contains a level of modularity previously not considered by integrative models of interval timing. Furthermore, the striatal projectome will allow for targeted studies of whether specific subdivisions of the dorsal striatum are differentially involved in timing and time perception as a function of task, stimulus modality, intensity, and valence.

Movement-related neural processing in people with congenital mirror movements beyond the (cortical) surface

2018 ◽  
Vol 129 (3) ◽  
pp. 707-708 ◽  
Author(s):  
Renzo Manara ◽  
Alessandro Salvalaggio ◽  
Angela Favaro ◽  
Fabrizio Esposito
Keyword(s):  
Cortical Surface ◽  
Neural Processing ◽  
Mirror Movements

Neural Processing of Amplitude-Modulated Sounds

2004 ◽  
Vol 84 (2) ◽  
pp. 541-577 ◽  
Author(s):  
P. X. JORIS ◽  
C. E. SCHREINER ◽  
A. REES
Keyword(s):  
Modulation Depth ◽  
Average Rate ◽  
Modulation Frequency ◽  
Limited Range ◽  
Neural Processing ◽  
Neural Responses ◽  
Critical Stimulus ◽  
Stimulus Attribute ◽  
Neural Architecture ◽  
Physiological Properties

Joris, P. X., C. E. Schreiner, and A. Rees. Neural Processing of Amplitude-Modulated Sounds. Physiol Rev 84: 541–577, 2004; 10.1152/physrev.00029.2003.—Amplitude modulation (AM) is a temporal feature of most natural acoustic signals. A long psychophysical tradition has shown that AM is important in a variety of perceptual tasks, over a range of time scales. Technical possibilities in stimulus synthesis have reinvigorated this field and brought the modulation dimension back into focus. We address the question whether specialized neural mechanisms exist to extract AM information, and thus whether consideration of the modulation domain is essential in understanding the neural architecture of the auditory system. The available evidence suggests that this is the case. Peripheral neural structures not only transmit envelope information in the form of neural activity synchronized to the modulation waveform but are often tuned so that they only respond over a limited range of modulation frequencies. Ascendingthe auditory neuraxis, AM tuning persists but increasingly takes the form of tuning in average firing rate, rather than synchronization, to modulation frequency. There is a decrease in the highest modulation frequencies that influence the neural response, either in average rate or synchronization, as one records at higher and higher levels along the neuraxis. In parallel, there is an increasing tolerance of modulation tuning for other stimulus parameters such as sound pressure level, modulation depth, and type of carrier. At several anatomical levels, consideration of modulation response properties assists the prediction of neural responses to complex natural stimuli. Finally, some evidence exists for a topographic ordering of neurons according to modulation tuning. The picture that emerges is that temporal modulations are a critical stimulus attribute that assists us in the detection, discrimination, identification, parsing, and localization of acoustic sources and that this wide-ranging role is reflected in dedicated physiological properties at different anatomical levels.

scholarly journals A reduced somatosensory gating response in individuals with multiple sclerosis is related to walking impairment

2017 ◽  
Vol 118 (4) ◽  
pp. 2052-2058 ◽  
Author(s):  
David J. Arpin ◽  
James E. Gehringer ◽  
Tony W. Wilson ◽  
Max J. Kurz
Keyword(s):  
Multiple Sclerosis ◽  
Sensory Gating ◽  
Healthy Controls ◽  
Neural Responses ◽  
Neural Basis ◽  
Tactile Discrimination ◽  
Mobility Impairments ◽  
Gait Kinematics ◽  
Walking Performance ◽  
Somatosensory Gating

When identical stimuli are presented in rapid temporal succession, neural responses to the second stimulation are often weaker than those observed for the first. This phenomenon is termed sensory gating and is believed to be an adaptive feature that helps prevent higher-order cortical centers from being flooded with unnecessary information. Recently, sensory gating in the somatosensory system has been linked to deficits in tactile discrimination. Additionally, studies have linked poor tactile discrimination with impaired walking and balance in individuals with multiple sclerosis (MS). In this study, we examine the neural basis of somatosensory gating in patients with MS and healthy controls and assess the relationship between somatosensory gating and walking performance. We used magnetoencephalography to record neural responses to paired-pulse electrical stimulation applied to the right posterior tibial nerve. All participants also walked across a digital mat, which recorded their spatiotemporal gait kinematics. Our results showed the amplitude of the response to the second stimulation was sharply reduced only in controls, resulting in a significantly reduced somatosensory gating in the patients with MS. No group differences were observed in the amplitude of the response to the first stimulation nor the latency of the neural response to either the first or second stimulation. Interestingly, the altered somatosensory gating responses were correlated with aberrant spatiotemporal gait kinematics in the patients with MS. These results suggest that inhibitory GABA circuits may be altered in patients with MS, which impacts somatosensory gating and contributes to the motor performance deficits seen in these patients. NEW & NOTEWORTHY We aimed to determine whether somatosensory gating in patients with multiple sclerosis (MS) differed compared with healthy controls and whether a relationship exists between somatosensory gating and walking performance. We found reduced somatosensory gating responses in patients with MS, and these altered somatosensory gating responses were correlated with the mobility impairments. These novel findings show that somatosensory gating is impaired in patients with MS and is related to the mobility impairments seen in these patients.

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