scholarly journals Fluctuations of fMRI activation patterns reveal theta-band dynamics of visual object priming

2017 ◽  
Author(s):  
Bingbing Guo ◽  
Zhengang Lu ◽  
Jessica E. Goold ◽  
Huan Luo ◽  
Ming Meng
Keyword(s):  
Activity Patterns ◽  
Critical Role ◽  
Neural Mechanism ◽  
Occipital Cortex ◽  
Visual Object ◽  
Theta Band ◽  
Activation Patterns ◽  
Temporal Fluctuations ◽  
Face Area ◽  
Object Priming

ABSTRACTThe brain dynamically creates predictions about upcoming stimuli to guide perception efficiently. Recent behavioral results suggest theta-band oscillations contribute to this prediction process, however litter is known about the underlying neural mechanism. Here, we combine fMRI and a time-resolved psychophysical paradigm to access fine temporal-scale profiles of the fluctuations of brain activation patterns corresponding to visual object priming. Specifically, multi-voxel activity patterns in the fusiform face area (FFA) and the parahippocampal place area (PPA) show temporal fluctuations at a theta-band (~5 Hz) rhythm. Importantly, the theta-band power in the FFA negatively correlates with reaction time, further indicating the critical role of the observed cortical theta oscillations. Moreover, alpha-band (~10 Hz) shows a dissociated spatial distribution, mainly linked to the occipital cortex. These findings, to our knowledge, are the first fMRI study that indicates temporal fluctuations of multi-voxel activity patterns and that demonstrates theta and alpha rhythms in relevant brain areas.

scholarly journals Fluctuations of fMRI activation patterns in visual object priming

2020 ◽  
pp. 78-84
Author(s):  
Bingbing Guo ◽  
◽  
Zhengang Lu ◽  
Jessica E. Goold ◽  
Huan Luo ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Activity Patterns ◽  
Critical Role ◽  
Brain Activation ◽  
Neural Mechanism ◽  
Visual Object ◽  
High Temporal Resolution ◽  
Theta Band ◽  
Face Area ◽  
Object Priming

Prior information shapes how the brain processes sensory inputs (e.g., priming effects). Recent studies of "behavioral oscillation” have demonstrated that the effects of visual object primes are temporally coordinated in the theta band to guide perception efficiently. However, the neural mechanism underlying this dynamic processing remains unclear. Here, we combine functional magnetic resonance imaging (fMRI) and a time-resolved paradigm to access high-temporal-resolution profiles of brain activation fluctuations corresponding to "behavioral oscillation" in visual object priming. Specifically, multivoxel activity patterns in the fusiform face area (FFA) and the parahippocampal place area (PPA) show temporal fluctuations in the theta band (~ 5 Hz). Importantly, the theta-band power in the FFA negatively correlates with reaction time, further indicating the critical role of the observed fluctuations in brain activation. By finely mapping the temporal dynamics of cortical responses, our fMRI results demonstrate that category-selective brain areas underlie the rhythmic coordination of visual object processing.

Minimal Recognizable Configurations Elicit Category-selective Responses in Higher Order Visual Cortex

2019 ◽  
Vol 31 (9) ◽  
pp. 1354-1367
Author(s):  
Yael Holzinger ◽  
Shimon Ullman ◽  
Daniel Harari ◽  
Marlene Behrmann ◽  
Galia Avidan
Keyword(s):  
Visual Cortex ◽  
Object Recognition ◽  
Visual Recognition ◽  
Recognition Performance ◽  
Occipital Cortex ◽  
Building Blocks ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Face Area ◽  
Early Visual Cortex

Visual object recognition is performed effortlessly by humans notwithstanding the fact that it requires a series of complex computations, which are, as yet, not well understood. Here, we tested a novel account of the representations used for visual recognition and their neural correlates using fMRI. The rationale is based on previous research showing that a set of representations, termed “minimal recognizable configurations” (MIRCs), which are computationally derived and have unique psychophysical characteristics, serve as the building blocks of object recognition. We contrasted the BOLD responses elicited by MIRC images, derived from different categories (faces, objects, and places), sub-MIRCs, which are visually similar to MIRCs, but, instead, result in poor recognition and scrambled, unrecognizable images. Stimuli were presented in blocks, and participants indicated yes/no recognition for each image. We confirmed that MIRCs elicited higher recognition performance compared to sub-MIRCs for all three categories. Whereas fMRI activation in early visual cortex for both MIRCs and sub-MIRCs of each category did not differ from that elicited by scrambled images, high-level visual regions exhibited overall greater activation for MIRCs compared to sub-MIRCs or scrambled images. Moreover, MIRCs and sub-MIRCs from each category elicited enhanced activation in corresponding category-selective regions including fusiform face area and occipital face area (faces), lateral occipital cortex (objects), and parahippocampal place area and transverse occipital sulcus (places). These findings reveal the psychological and neural relevance of MIRCs and enable us to make progress in developing a more complete account of object recognition.

scholarly journals Replay of innate vocal patterns during night sleep in suboscines

2021 ◽  
Vol 288 (1953) ◽  
pp. 20210610
Author(s):  
Juan F. Döppler ◽  
Manon Peltier ◽  
Ana Amador ◽  
Franz Goller ◽  
Gabriel B. Mindlin
Keyword(s):  
Activity Patterns ◽  
Vocal Learning ◽  
Neural Mechanism ◽  
Visual Display ◽  
Song Learning ◽  
Activation Patterns ◽  
Evolutionary Origins ◽  
Song Production ◽  
Vocal Activity ◽  
Motor Programme

Activation of forebrain circuitry during sleep has been variably characterized as ‘pre- or replay’ and has been linked to memory consolidation. The evolutionary origins of this mechanism, however, are unknown. Sleep activation of the sensorimotor pathways of learned birdsong is a particularly useful model system because the muscles controlling the vocal organ are activated, revealing syringeal activity patterns for direct comparison with those of daytime vocal activity. Here, we show that suboscine birds, which develop their species-typical songs innately without the elaborate forebrain–thalamic circuitry of the vocal learning taxa, also engage in replay during sleep. In two tyrannid species, the characteristic syringeal activation patterns of the song could also be identified during sleep. Similar to song-learning oscines, the burst structure was more variable during sleep than daytime song production. In kiskadees ( Pitangus sulphuratus ), a second vocalization, which is part of a multi-modal display, was also replayed during sleep along with one component of the visual display. These data show unambiguously that variable ‘replay’ of stereotyped vocal motor programmes is not restricted to programmes confined within forebrain circuitry. The proposed effects on vocal motor programme maintenance are, therefore, building on a pre-existing neural mechanism that predates the evolution of learned vocal motor behaviour.

scholarly journals Individuation of parts of a single object and multiple distinct objects relies on a common neural mechanism in inferior intraparietal sulcus

2019 ◽  
Author(s):  
Moritz F. Wurm ◽  
Katharine B. Porter ◽  
Alfonso Caramazza
Keyword(s):  
Activity Patterns ◽  
Neural Mechanism ◽  
Occipital Cortex ◽  
General Information ◽  
Object Identification ◽  
Single Object ◽  
Object Individuation ◽  
Perceptual Object ◽  
Object Parts ◽  
Multivariate Pattern

AbstractObject identification and enumeration rely on the ability to distinguish, or individuate, objects from the background. Does multiple object individuation operate only over bounded, separable objects or does it operate equally over connected features within a single object? While previous fMRI experiments suggest that connectedness affects the processing and enumeration of objects, recent behavioral and EEG studies demonstrated that parallel individuation occurs over both object parts and distinct objects. However, it is unclear whether individuation of object parts and distinct objects relies on a common or independent neural mechanisms. Using fMRI-based multivariate pattern analyses, we here demonstrate that activity patterns in inferior and superior intraparietal sulci (IPS) encode numerosity independently of whether the individuated items are connected parts of a single object or distinct objects. Lateral occipital cortex is more sensitive to perceptual aspects of the two stimulus types and the targets of the stimuli, suggesting a dissociation between ventral and dorsal areas in representing perceptual object properties and more general information about numerosity, respectively. Our results suggest that objecthood is not a necessary prerequisite for parallel individuation in IPS. Rather, our results point toward a common individuation mechanism that selects targets over a flexible object hierarchy, independently of whether the targets are distinct separable objects or parts of a single object.

scholarly journals How attention extracts objects from noise

2013 ◽  
Vol 110 (6) ◽  
pp. 1346-1356 ◽  
Author(s):  
Michael S. Pratte ◽  
Sam Ling ◽  
Jascha D. Swisher ◽  
Frank Tong
Keyword(s):  
Visual Processing ◽  
Activity Patterns ◽  
Occipital Cortex ◽  
Relevant Information ◽  
Visual Input ◽  
Visual Noise ◽  
Noise Filtering ◽  
Area V4 ◽  
Face Area ◽  
Visual Areas

The visual system is remarkably proficient at extracting relevant object information from noisy, cluttered environments. Although attention is known to enhance sensory processing, the mechanisms by which attention extracts relevant information from noise are not well understood. According to the perceptual template model, attention may act to amplify responses to all visual input, or it may act as a noise filter, dampening responses to irrelevant visual noise. Amplification allows for improved performance in the absence of visual noise, whereas a noise-filtering mechanism can only improve performance if the target stimulus appears in noise. Here, we used fMRI to investigate how attention modulates cortical responses to objects at multiple levels of the visual pathway. Participants viewed images of faces, houses, chairs, and shoes, presented in various levels of visual noise. We used multivoxel pattern analysis to predict the viewed object category, for attended and unattended stimuli, from cortical activity patterns in individual visual areas. Early visual areas, V1 and V2, exhibited a benefit of attention only at high levels of visual noise, suggesting that attention operates via a noise-filtering mechanism at these early sites. By contrast, attention led to enhanced processing of noise-free images (i.e., amplification) only in higher visual areas, including area V4, fusiform face area, mid-Fusiform area, and the lateral occipital cortex. Together, these results suggest that attention improves people's ability to discriminate objects by de-noising visual input in early visual areas and amplifying this noise-reduced signal at higher stages of visual processing.

scholarly journals Aldehyde-specific responses of olfactory sensory neurons in the praying mantis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kota Ezaki ◽  
Takashi Yamashita ◽  
Thomas Carle ◽  
Hidehiro Watanabe ◽  
Fumio Yokohari ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Activity Patterns ◽  
Critical Role ◽  
Response Spectra ◽  
Olfactory Cues ◽  
Olfactory Sensory Neurons ◽  
Praying Mantis ◽  
Pheromonal Communication ◽  
Class B ◽  
Excitatory Responses

AbstractAlthough praying mantises rely mainly on vision for predatory behaviours, olfaction also plays a critical role in feeding and mating behaviours. However, the receptive processes underlying olfactory signals remain unclear. Here, we identified olfactory sensory neurons (OSNs) that are highly tuned to detect aldehydes in the mantis Tenodera aridifolia. In extracellular recordings from OSNs in basiconic sensilla on the antennae, we observed three different spike shapes, indicating that at least three OSNs are housed in a single basiconic sensillum. Unexpectedly, one of the three OSNs exhibited strong excitatory responses to a set of aldehydes. Based on the similarities of the response spectra to 15 different aldehydes, the aldehyde-specific OSNs were classified into three classes: B, S, and M. Class B broadly responded to most aldehydes used as stimulants; class S responded to short-chain aldehydes (C3–C7); and class M responded to middle-length chain aldehydes (C6–C9). Thus, aldehyde molecules can be finely discriminated based on the activity patterns of a population of OSNs. Because many insects emit aldehydes for pheromonal communication, mantises might use aldehydes as olfactory cues for locating prey habitat.

scholarly journals Shared space, separate processes: Neural activation patterns for auditory description and visual object naming in healthy adults

2013 ◽  
Vol 35 (6) ◽  
pp. 2507-2520 ◽  
Author(s):  
Marla J. Hamberger ◽  
Christian G. Habeck ◽  
Spiro P. Pantazatos ◽  
Alicia C. Williams ◽  
Joy Hirsch
Keyword(s):  
Healthy Adults ◽  
Visual Object ◽  
Object Naming ◽  
Neural Activation ◽  
Activation Patterns ◽  
Shared Space ◽  
Visual Object Naming

scholarly journals In Vivo Characterization of Cortical and White Matter Microstructural Pathology in Growth Hormone-Secreting Pituitary Adenoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Taoyang Yuan ◽  
Jianyou Ying ◽  
Chuzhong Li ◽  
Lu Jin ◽  
Jie Kang ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Adenoma ◽  
White Matter ◽  
Diffusion Tensor ◽  
Critical Role ◽  
Mean Diffusivity ◽  
Occipital Cortex ◽  
Test Surface ◽  
Neuropsychological Dysfunction

BackgroundThe growth hormone (GH) and insulin-like-growth factor 1 (IGF-1) axis has long been recognized for its critical role in brain growth, development. This study was designed to investigate microstructural pathology in the cortex and white matter in growth hormone-secreting pituitary adenoma, which characterized by excessive secretion of GH and IGF-1.Methods29 patients with growth hormone-secreting pituitary adenoma (acromegaly) and 31 patients with non-functional pituitary adenoma as controls were recruited and assessed using neuropsychological test, surface-based morphometry, T1/T2-weighted myelin-sensitive magnetic resonance imaging, neurite orientation dispersion and density imaging, and diffusion tensor imaging.ResultsCompared to controls, we found 1) acromegaly had significantly increased cortical thickness throughout the bilateral cortex (pFDR < 0.05). 2) T1/T2-weighted ratio in the cortex were decreased in the bilateral occipital cortex and pre/postcentral central gyri but increased in the bilateral fusiform, insular, and superior temporal gyri in acromegaly (pFDR < 0.05). 3) T1/T2-weighted ratio were decreased in most bundles, and only a few areas showed increases in acromegaly (pFDR < 0.05). 4) Neurite density index (NDI) was significantly lower throughout the cortex and bundles in acromegaly (pTFCE < 0.05). 5) lower fractional anisotropy (FA) and higher mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in extensive bundles in acromegaly (pTFCE < 0.05). 6) microstructural pathology in the cortex and white matter were associated with neuropsychological dysfunction in acromegaly.ConclusionsOur findings suggested that long-term persistent and excess serum GH/IGF-1 levels alter the microstructure in the cortex and white matter in acromegaly, which may be responsible for neuropsychological dysfunction.

scholarly journals Intrinsic functional connectivity resembles cortical architecture at various levels of isoflurane anesthesia

2016 ◽  
Author(s):  
Felix Fischer ◽  
Florian Pieper ◽  
Edgar Galindo-Leon ◽  
Gerhard Engler ◽  
Claus C. Hilgetag ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Activity Patterns ◽  
Structural Connectivity ◽  
Occipital Cortex ◽  
Amplitude Envelope ◽  
Cortical Areas ◽  
Temporal Properties ◽  
Connectivity Patterns ◽  
Different Depths ◽  
Amplitude Correlation

AbstractCortical activity patterns change in different depths of general anesthesia. Here we investigate the associated network level changes of functional connectivity. We recorded ongoing electrocorticographic (ECoG) activity from the ferret temporo-parieto-occipital cortex under various levels of isoflurane and determined the functional connectivity by computing amplitude envelope correlations. Through hierarchical clustering, we derived typical connectivity patterns corresponding to light, intermediate and deep anesthesia. Generally, amplitude correlation strength increased strongly with depth of anesthesia across all cortical areas and frequency bands. This was accompanied by the emergence of burstsuppression activity in the ECoG signal and a change of the spectrum of the amplitude envelope. Normalizing the functional connectivity patterns showed that the topographical structure remained similar across depths of anesthesia, resembling the functional association of the underlying cortical areas. Thus, while strength and temporal properties of amplitude co-modulation vary depending on the activity of local neural circuits, their network-level interaction pattern is presumably most strongly determined by the underlying structural connectivity.

Neuronal Function in the Cortical Face Perception Network

2013 ◽  
pp. 171-182
Author(s):  
Bin Wang ◽  
Tianyi Yan ◽  
Jinglong Wu
Keyword(s):  
Face Perception ◽  
Visual Analysis ◽  
Neural Systems ◽  
Visual Object ◽  
Lateral Side ◽  
Face Area ◽  
Object Categories ◽  
Neural Representations ◽  
Perceptual Skill ◽  
Multiple Regions

Face perception is considered the most developed visual perceptual skill in humans. Functional magnetic resonance imaging (fMRI) studies have graphically illustrated that multiple regions exhibit a stronger neural response to faces than to other visual object categories, which were specialized for face processing. These regions are in the lateral side of the fusiform gyrus, the “fusiform face area” or FFA, in the inferior occipital gyri, the “occipital face area” or OFA, and in the superior temporal sulcus (pSTS). These regions are supposed to perform the visual analysis of faces and appear to participate differentially in different types of face perception. An important question is how faces are represented within these areas. In this chapter, the authors review the function, interaction, and topography of these regions relevant to face perception. They also discuss the human neural systems that mediate face perception and attempt to show some research dictions for face perception and neural representations.

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