Behavioral and neural decomposition of skull-induced death awareness

AbstractDeath awareness influences multiple aspects of human lives, but its psychological constructs and underlying brain mechanisms remain unclear. We address these by measuring behavioral and brain responses to images of human skulls. We show that skulls relative to control stimuli delay responses to life-related words but speed responses to death-related words. Skulls compared to the control stimuli induce early deactivations in the posterior ventral temporal cortex followed by activations in the posterior and anterior ventral temporal cortices. The early and late neural modulations by perceived skulls respectively predict skull-induced changes of behavioral responses to life- and death-related words and the early neural modulation further predicts death anxiety. Our findings decompose skull-induced death awareness into two-stage neural processes of a lifeless state of a former life.One sentence summaryBehavioral and brain imaging findings decompose skull-induced death awareness into two-stage neural processes of a lifeless state of a former life.

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Multivoxel Neural Reinforcement Changes Resting-State Functional Connectivity Within the Threat Regulation Network

10.1101/2020.04.03.021956 ◽

2020 ◽

Cited By ~ 1

Author(s):

Vincent Taschereau-Dumouchel ◽

Toshinori Chiba ◽

Ai Koizumi ◽

Mitsuo Kawato ◽

Hakwan Lau

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Temporal Cortex ◽

Physiological Reactivity ◽

Resting State Functional Connectivity ◽

Double Blind ◽

Brain Responses ◽

Regulation Network ◽

Before And After ◽

Ventral Temporal Cortex

AbstractUsing neural reinforcement, participants can be trained to pair a reward with the activation of specific multivoxel patterns in their brains. In a double-blind placebo-controlled experiment, we previously showed that this intervention can decrease the physiological reactivity associated with naturally feared animals. However, the mechanisms behind the effect remain incompletely understood and its usefulness for treatment remains unclear. If the intervention fundamentally changed the brain responses, we might expect to observe relatively stable changes in the functional connectivity within the threat regulation network. To evaluate this possibility, we conducted functional magnetic resonance imaging (fMRI) sessions while subjects were at rest, before and after neural reinforcement, and quantified the changes in resting-state functional connectivity accordingly. Our results indicate that neural reinforcement increased the connectivity of prefrontal regulatory regions with the amygdala and the ventral temporal cortex (where the visual representations of phobic targets are). Surprisingly, we found no evidence of Hebbian-like learning during neural reinforcement, contrary to what one may expect based on previous neurofeedback studies. These results suggest that multivoxel neural reinforcement, also known as decoded neurofeedback (DecNef), may operate via unique mechanisms, distinct from those involved in conventional neurofeedback.

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Extended categorization of conjunction object stimuli decreases the latency of attentional feature selection and recruits orthography-linked ERPs

10.1101/605360 ◽

2019 ◽

Author(s):

Jonathan R. Folstein ◽

Shamsi S. Monfared

Keyword(s):

Feature Selection ◽

Temporal Cortex ◽

Detection Task ◽

Perceptual Expertise ◽

Scalp Distribution ◽

Selection Negativity ◽

Neural Processes ◽

Ventral Temporal Cortex ◽

Target Detection Task

AbstractThe role of attention in driving perceptual expertise effects is controversial. The current study addressed the effect of training on ERP components related to and independent of attentional feature selection. Participants learned to categorize cartoon animals over six training sessions (8,800 trials) after which ERPs were recorded during a target detection task performed on trained and untrained stimulus sets. The onset of the selection negativity, an ERP component indexing attentional modulation, was about 60 ms earlier for trained than untrained stimuli. Trained stimuli also elicited centro-parietal N200 and N320 components that were insensitive to attentional feature selection. The scalp distribution and timecourse of these components were better matched by studies of orthography than object expertise. Source localization using eLORETA suggested that the strongest neural sources of the selection negativity were in right ventral temporal cortex whereas the strongest sources of the N200/N320 components were in left ventral temporal cortex, again consistent with the hypothesis that training recruited orthography related areas. Overall, training altered neural processes related to attentional selection, but also affected neural processes that were independent of feature selection.

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Early and late evoked brain responses differentially reflect feature encoding and perception in the flash-lag illusion

10.1101/2021.06.03.446877 ◽

2021 ◽

Author(s):

Julian Keil ◽

Daniel Senkowski ◽

James K Moran

Keyword(s):

Temporal Integration ◽

Temporal Cortex ◽

Stimulus Presentation ◽

Sensory Stimulation ◽

Feedback Processing ◽

Brain Responses ◽

Neural Processes ◽

Feature Encoding ◽

The Right ◽

Reentrant Processing

In the flash-lag illusion (FLI), the position of a flash presented ahead of a moving bar is mislocalized, so the flash appears to lag the bar. Currently it is not clear whether this effect is due to early perceptual-related neural processes such as motion extrapolation or reentrant processing, or due to later feedback processing relating to postdiction, i.e. retroactively altered perception. We presented 17 participants with the FLI paradigm while recording EEG. A central flash occurred either 51ms (early) or 16ms (late) before the bar moving from left to right reached the screen center. Participants judged whether the flash appeared to the right (no flash lag illusion) or to the left (flash-lag illusion) of the bar. Using single-trial linear modelling, we examined the influence of timing (early vs. late) and perception (illusion vs. no illusion) on flash-evoked brain responses, and estimated the cortical sources underlying the FLI. Perception of the FLI was associated with a late window (368-452ms) in the ERP, with larger deflections for illusion than no illusion trials, localized to the left fusiform gyrus. An earlier frontal and occipital component (200-276ms) differentiated time-locked early vs. late stimulus presentation. Our results suggest a postdiction-related reconstruction of ambiguous sensory stimulation involving late processes in the occipito-temporal cortex, previously associated with temporal integration phenomena. This indicates that perception of the FLI relies on an interplay between ongoing stimulus encoding of the moving bar and feedback processing of the flash, which takes place at later integration stages.

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Brain Networks Sensitive to Object Novelty, Value, and Their Combination

Cerebral Cortex Communications ◽

10.1093/texcom/tgaa034 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Ali Ghazizadeh ◽

Mohammad Amin Fakharian ◽

Arash Amini ◽

Whitney Griggs ◽

David A Leopold ◽

...

Keyword(s):

Brain Networks ◽

Temporal Cortex ◽

Common Currency ◽

Brain Responses ◽

Activation Dynamics ◽

Fractal Patterns ◽

The Common ◽

Ventral Temporal Cortex ◽

Value Coding ◽

The Brain

Abstract Novel and valuable objects are motivationally attractive for animals including primates. However, little is known about how novelty and value processing is organized across the brain. We used fMRI in macaques to map brain responses to visual fractal patterns varying in either novelty or value dimensions and compared the results with the structure of functionally connected brain networks determined at rest. The results show that different brain networks possess unique combinations of novelty and value coding. One network identified in the ventral temporal cortex preferentially encoded object novelty, whereas another in the parietal cortex encoded the learned value. A third network, broadly composed of temporal and prefrontal areas (TP network), along with functionally connected portions of the striatum, amygdala, and claustrum, encoded both dimensions with similar activation dynamics. Our results support the emergence of a common currency signal in the TP network that may underlie the common attitudes toward novel and valuable objects.

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Human endogenous oxytocin and its neural correlates show adaptive responses to social touch based on recent social context

10.1101/2021.04.08.438987 ◽

2021 ◽

Author(s):

Linda Handlin ◽

Giovanni Novembre ◽

Helene Lindholm ◽

Robin Kampe ◽

India Morrison

Keyword(s):

Social Context ◽

Functional Neuroimaging ◽

Temporal Cortex ◽

Adaptive Responses ◽

Social Touch ◽

Neural Modulation ◽

Brain Responses ◽

Serial Sampling ◽

Social Encounters ◽

Endogenous Release

Both oxytocin (OT) and touch are key mediators of social attachment. In rodents, tactile stimulation elicits endogenous release of OT, potentially facilitating attachment and other forms of prosocial behavior, yet the relationship between endogenous OT and neural modulation remains unexplored in humans. Using serial sampling of plasma hormone levels during functional neuroimaging, we show that contextual circumstances of social touch facilitate or inhibit not only current hormonal and brain responses, but also calibrate later responses. Namely, touch from a romantic partner enhanced subsequent OT release for touch from an unfamiliar stranger, yet OT responses to partner touch were dampened following stranger touch. Hypothalamus and dorsal raphe activation reflected plasma OT changes during the initial interaction. In the subsequent social interaction, OT modulation depended on the previous interaction, mediated by precuneus and parietal-temporal cortex pathways, including a region of medial prefrontal cortex that also covaried with plasma cortisol. These findings demonstrate that hormonal neuromodulation during successive human social interactions is adaptive to social context, and they point to mechanisms that flexibly calibrate receptivity in social encounters.

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