Face-sensitive regions in human extrastriate cortex studied by functional MRI

1995 ◽  
Vol 74 (3) ◽  
pp. 1192-1199 ◽  
Author(s):  
A. Puce ◽  
T. Allison ◽  
J. C. Gore ◽  
G. McCarthy
Keyword(s):  
Time Series ◽  
Power Spectra ◽  
Brain Regions ◽  
Extrastriate Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Electrophysiological Recordings ◽  
Left And Right ◽  
Face Stimuli ◽  
Unfamiliar Faces

1. We have previously identified face-selective areas in the mid-fusiform and inferior temporal gyri in electrophysiological recordings made from chronically implanted subdural electrodes in epilepsy patients. In this study, functional magnetic resonance imaging (fMRI) was used to study the anatomic extent of face-sensitive brain regions and to assess hemispheric laterality. 2. A time series of 128 gradient echo echoplanar images was acquired while subjects continuously viewed an alternating series of 10 unfamiliar faces followed by 10 equiluminant scrambled faces. Each cycle of this alternating sequence lasted 12 s and each experimental run consisted of 14 cycles. The time series of each voxel was transformed into the frequency domain using Fourier analysis. Activated voxels were defined by significant peaks in their power spectra at the frequency of stimulus alternation and by a 180 degrees phase shift that followed changes in stimulus alternation order. 3. Activated voxels to faces were obtained in the fusiform and inferior temporal gyri in 9 of 12 subjects and were approximately coextensive with previously identified face-selective regions. Nine subjects also showed activation in the left or right middle occipital gyri, or in the superior temporal or lateral occipital sulci. Cortical volumes activated in the left and right hemispheres were not significantly different. Activated voxels to scrambled faces were observed in six subjects at locations mainly in the lingual gyri and collateral sulci, medial to the regions activated by faces. 4. Face stimuli activated portions of the midfusiform and inferior temporal gyri, including adjacent cortex within occipitotemporal sulci.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Face-Specific Processing in the Human Fusiform Gyrus

1997 ◽  
Vol 9 (5) ◽  
pp. 605-610 ◽  
Author(s):  
Gregory McCarthy ◽  
Aina Puce ◽  
John C. Gore ◽  
Truett Allison
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brain Regions ◽  
Fusiform Gyrus ◽  
Extrastriate Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Right ◽  
Familiar Stimuli ◽  
No Activation

The perception of faces is sometimes regarded as a specialized task involving discrete brain regions. In an attempt to identi$ face-specific cortex, we used functional magnetic resonance imaging (fMRI) to measure activation evoked by faces presented in a continuously changing montage of common objects or in a similar montage of nonobjects. Bilateral regions of the posterior fusiform gyrus were activated by faces viewed among nonobjects, but when viewed among objects, faces activated only a focal right fusiform region. To determine whether this focal activation would occur for another category of familiar stimuli, subjects viewed flowers presented among nonobjects and objects. While flowers among nonobjects evoked bilateral fusiform activation, flowers among objects evoked no activation. These results demonstrate that both faces and flowers activate large and partially overlapping regions of inferior extrastriate cortex. A smaller region, located primarily in the right lateral fusiform gyrus, is activated specifically by faces.

scholarly journals A place for time: the spatiotemporal structure of neural dynamics during natural audition

2013 ◽  
Vol 110 (9) ◽  
pp. 2019-2026 ◽  
Author(s):  
Greg J. Stephens ◽  
Christopher J. Honey ◽  
Uri Hasson
Keyword(s):  
Power Spectra ◽  
Brain Regions ◽  
Neural Dynamics ◽  
Spatial Gradient ◽  
Neural Responses ◽  
Stimulus Information ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Fmri Time Series ◽  
Stimulus Features

We use functional magnetic resonance imaging (fMRI) to analyze neural responses to natural auditory stimuli. We characterize the fMRI time series through the shape of the voxel power spectrum and find that the timescales of neural dynamics vary along a spatial gradient, with faster dynamics in early auditory cortex and slower dynamics in higher order brain regions. The timescale gradient is observed through the unsupervised clustering of the power spectra of individual brains, both in the presence and absence of a stimulus, and is enhanced in the stimulus-locked component that is shared across listeners. Moreover, intrinsically faster dynamics occur in areas that respond preferentially to momentary stimulus features, while the intrinsically slower dynamics occur in areas that integrate stimulus information over longer timescales. These observations connect the timescales of intrinsic neural dynamics to the timescales of information processing, suggesting a temporal organizing principle for neural computation across the cerebral cortex.

scholarly journals Neural substrates of propranolol-induced impairments in the reconsolidation of nicotine-associated memories in smokers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Lin ◽  
Jiahui Deng ◽  
Kai Yuan ◽  
Qiandong Wang ◽  
Lin Liu ◽  
...  
Keyword(s):  
Neural Activity ◽  
Neural Substrates ◽  
Brain Regions ◽  
Reward Processing ◽  
Memory Reconsolidation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Postcentral Gyrus ◽  
Propranolol Group ◽  
Propranolol Administration

AbstractThe majority of smokers relapse even after successfully quitting because of the craving to smoking after unexpectedly re-exposed to smoking-related cues. This conditioned craving is mediated by reward memories that are frequently experienced and stubbornly resistant to treatment. Reconsolidation theory posits that well-consolidated memories are destabilized after retrieval, and this process renders memories labile and vulnerable to amnestic intervention. This study tests the retrieval reconsolidation procedure to decrease nicotine craving among people who smoke. In this study, 52 male smokers received a single dose of propranolol (n = 27) or placebo (n = 25) before the reactivation of nicotine-associated memories to impair the reconsolidation process. Craving for smoking and neural activity in response to smoking-related cues served as primary outcomes. Functional magnetic resonance imaging was performed during the memory reconsolidation process. The disruption of reconsolidation by propranolol decreased craving for smoking. Reactivity of the postcentral gyrus in response to smoking-related cues also decreased in the propranolol group after the reconsolidation manipulation. Functional connectivity between the hippocampus and striatum was higher during memory reconsolidation in the propranolol group. Furthermore, the increase in coupling between the hippocampus and striatum positively correlated with the decrease in craving after the reconsolidation manipulation in the propranolol group. Propranolol administration before memory reactivation disrupted the reconsolidation of smoking-related memories in smokers by mediating brain regions that are involved in memory and reward processing. These findings demonstrate the noradrenergic regulation of memory reconsolidation in humans and suggest that adjunct propranolol administration can facilitate the treatment of nicotine dependence. The present study was pre-registered at ClinicalTrials.gov (registration no. ChiCTR1900024412).

scholarly journals Event-Related Functional Magnetic Resonance Imaging Study of the Extrastriate Cortex Response to a Categorically Ambiguous Stimulus Primed by Letters and Familiar Geometric Figures

2001 ◽  
Vol 21 (11) ◽  
pp. 1330-1341 ◽  
Author(s):  
Hélène Gros ◽  
Kader Boulanouar ◽  
Gérard Viallard ◽  
Emmanuelle Cassol ◽  
Pierre Celsis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Right Hemisphere ◽  
Extrastriate Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Ambiguous Stimulus ◽  
Form Processing ◽  
Geometric Figures

Functional neuroimaging studies have suggested a specific role of the extrastriate cortex in letter string and visual word form processing. However, this region has been shown to be involved in object recognition and its specificity for the processing of linguistic stimuli may be questioned. The authors used an event-related functional magnetic resonance imaging design with category priming to record the response elicited by the passive viewing of single letters, geometric figures, and of the categorically ambiguous stimulus “O” that pertains to both sets of familiar symbols. Bilateral activations in the extrastriate cortex were found, with a left predominance particularly pronounced for the ambiguous stimulus. Individual analysis of spatial extent and signal intensity showed a priming × stimulus × hemisphere interaction. When primed by the congruous categoric set, a bilateral decrease in activation was observed for letters and geometric figures. The ambiguous stimulus behaved as a letter for the left hemisphere, with decreased activation when primed by letters, whereas in the right hemisphere, an adaptation effect occurred when primed by geometric figures. These priming effects suggest that, for the ambiguous stimulus, letter processing was systematically involved in the left extrastriate cortex. The current results support the existence of a neural substrate for the abstract category of letters.

scholarly journals Globally conditioned Granger causality in brain–brain and brain–heart interactions: a combined heart rate variability/ultra-high-field (7 T) functional magnetic resonance imaging study

2016 ◽  
Vol 374 (2067) ◽  
pp. 20150185 ◽  
Author(s):  
Andrea Duggento ◽  
Marta Bianciardi ◽  
Luca Passamonti ◽  
Lawrence L. Wald ◽  
Maria Guerrisi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Resting State ◽  
High Field ◽  
Brain Activity ◽  
Brain Regions ◽  
Sympathovagal Balance ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Ultra High Field ◽  
Conditioned Approach

The causal, directed interactions between brain regions at rest (brain–brain networks) and between resting-state brain activity and autonomic nervous system (ANS) outflow (brain–heart links) have not been completely elucidated. We collected 7 T resting-state functional magnetic resonance imaging (fMRI) data with simultaneous respiration and heartbeat recordings in nine healthy volunteers to investigate (i) the causal interactions between cortical and subcortical brain regions at rest and (ii) the causal interactions between resting-state brain activity and the ANS as quantified through a probabilistic, point-process-based heartbeat model which generates dynamical estimates for sympathetic and parasympathetic activity as well as sympathovagal balance. Given the high amount of information shared between brain-derived signals, we compared the results of traditional bivariate Granger causality (GC) with a globally conditioned approach which evaluated the additional influence of each brain region on the causal target while factoring out effects concomitantly mediated by other brain regions. The bivariate approach resulted in a large number of possibly spurious causal brain–brain links, while, using the globally conditioned approach, we demonstrated the existence of significant selective causal links between cortical/subcortical brain regions and sympathetic and parasympathetic modulation as well as sympathovagal balance. In particular, we demonstrated a causal role of the amygdala, hypothalamus, brainstem and, among others, medial, middle and superior frontal gyri, superior temporal pole, paracentral lobule and cerebellar regions in modulating the so-called central autonomic network (CAN). In summary, we show that, provided proper conditioning is employed to eliminate spurious causalities, ultra-high-field functional imaging coupled with physiological signal acquisition and GC analysis is able to quantify directed brain–brain and brain–heart interactions reflecting central modulation of ANS outflow.

Hedonic-Specific Activity in Piriform Cortex During Odor Imagery Mimics That During Odor Perception

2007 ◽  
Vol 98 (6) ◽  
pp. 3254-3262 ◽  
Author(s):  
Moustafa Bensafi ◽  
Noam Sobel ◽  
Rehan M. Khan
Keyword(s):  
Specific Activity ◽  
Piriform Cortex ◽  
Brain Regions ◽  
Specific Pattern ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Odor Perception ◽  
Cortical Areas ◽  
Visual Cortical ◽  
Left Insula

Although it is known that visual imagery is accompanied by activity in visual cortical areas, including primary visual cortex, whether olfactory imagery exists remains controversial. Here we asked whether cue-dependent olfactory imagery was similarly accompanied by activity in olfactory cortex, and in particular whether hedonic-specific patterns of activity evident in olfactory perception would also be present during olfactory imagery. We used functional magnetic resonance imaging to measure activity in subjects who alternated between smelling and imagining pleasant and unpleasant odors. Activity induced by imagining odors mimicked that induced by perceiving real odorants, not only in the particular brain regions activated, but also in its hedonic-specific pattern. For both real and imagined odors, unpleasant stimuli induced greater activity than pleasant stimuli in the left frontal portion of piriform cortex and left insula. These findings combine with findings from other modalities to suggest activation of primary sensory cortical structures during mental imagery of sensory events.

scholarly journals Increased sensitivity to strong perturbations in a whole-brain model of LSD

2021 ◽  
Author(s):  
Beatrice M. Jobst ◽  
Selen Atasoy ◽  
Adrián Ponce-Alvarez ◽  
Ana Sanjuán ◽  
Leor Roseman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
External Perturbation ◽  
Brain Regions ◽  
Lysergic Acid ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Whole Brain ◽  
Response Diversity ◽  
Brain States ◽  
The Brain

AbstractLysergic acid diethylamide (LSD) is a potent psychedelic drug, which has seen a revival in clinical and pharmacological research within recent years. Human neuroimaging studies have shown fundamental changes in brain-wide functional connectivity and an expansion of dynamical brain states, thus raising the question about a mechanistic explanation of the dynamics underlying these alterations. Here, we applied a novel perturbational approach based on a whole-brain computational model, which opens up the possibility to externally perturb different brain regions in silico and investigate differences in dynamical stability of different brain states, i.e. the dynamical response of a certain brain region to an external perturbation. After adjusting the whole-brain model parameters to reflect the dynamics of functional magnetic resonance imaging (fMRI) BOLD signals recorded under the influence of LSD or placebo, perturbations of different brain areas were simulated by either promoting or disrupting synchronization in the regarding brain region. After perturbation offset, we quantified the recovery characteristics of the brain area to its basal dynamical state with the Perturbational Integration Latency Index (PILI) and used this measure to distinguish between the two brain states. We found significant changes in dynamical complexity with consistently higher PILI values after LSD intake on a global level, which indicates a shift of the brain’s global working point further away from a stable equilibrium as compared to normal conditions. On a local level, we found that the largest differences were measured within the limbic network, the visual network and the default mode network. Additionally, we found a higher variability of PILI values across different brain regions after LSD intake, indicating higher response diversity under LSD after an external perturbation. Our results provide important new insights into the brain-wide dynamical changes underlying the psychedelic state - here provoked by LSD intake - and underline possible future clinical applications of psychedelic drugs in particular psychiatric disorders.HighlightsNovel offline perturbational method applied on functional magnetic resonance imaging (fMRI) data under the effect of lysergic acid diethylamide (LSD)Shift of brain’s global working point to more complex dynamics after LSD intakeConsistently longer recovery time after model perturbation under LSD influenceStrongest effects in resting state networks relevant for psychedelic experienceHigher response diversity across brain regions under LSD influence after an external in silico perturbation

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