scholarly journals The butterfly effect: amplification of local changes along the temporal processing hierarchy

2017 ◽  
Author(s):  
Y Yeshurun ◽  
M Nguyen ◽  
U. Hasson
Keyword(s):  
Temporal Processing ◽  
Real Life ◽  
Situation Model ◽  
Neural Mechanism ◽  
Neural Responses ◽  
Word Use ◽  
Highly Correlated ◽  
High Level ◽  
Substantial Change ◽  
The Brain

AbstractChanging just a few words in a story can induce a substantial change in the overall narrative. How does the brain accumulate and process local and sparse changes, creating a unique situation model of the story, over the course of a real-life narrative? Recently, we mapped a hierarchy of processing timescales in the brain: from early sensory areas that integrate information over 10s-100s ms, to high-order areas that integrate information over many seconds to minutes. Based on this hierarchy, we hypothesize that early sensory areas would be sensitive to local changes in word use, but that there will be increasingly divergent neural responses along the processing hierarchy as higher-order areas accumulate and amplify these local changes. To test this hypothesis, we created two structurally related but interpretively distinct narratives by changing some individual words. We found that the neural response distance between the stories was amplified as story information is transferred from low-level regions (e.g. early auditory cortex) to high-level regions (e.g precuneus and prefrontal cortex) and that the neural difference between stories is highly correlated with an area’s ability to integrate information over time. Our results suggest a neural mechanism by which two similar situations become easy to distinguish.

Measuring Neural Responses to Apparel Product Attractiveness

2016 ◽  
Vol 35 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Benjamin Touchette ◽  
Seung-Eun Lee
Keyword(s):  
Neural Mechanism ◽  
Neural Responses ◽  
Frontal Asymmetry ◽  
Brain Responses ◽  
Significant Difference ◽  
Left And Right ◽  
Product Attractiveness ◽  
The Brain ◽  
Apparel Product ◽  
Different Levels

The purpose of this study was twofold: (a) to investigate a neural mechanism of apparel product attractiveness and (b) to compare consumers’ brain responses to apparel product attractiveness with their self-reported responses. Based on Davidson’s frontal asymmetry theory, the researchers explored whether hemispheric asymmetry actually exists when consumers view apparel products with different levels of attractiveness. A total of 34 right-handed college students participated in the electroencephalography experiment. Measurements were obtained by recording the electrical activity of the left and right frontal areas of the brain while subjects were viewing apparel products. Supporting Davidson’s theory, the researchers found that a statistically significant difference of frontal asymmetry exists between attractive and unattractive apparel products. The findings of this study suggest that the frontal asymmetry score can be an alternative way to measure consumers’ unconscious responses to apparel product attractiveness.

scholarly journals Hearing through lip-reading: the brain synthesizes features of absent speech

2018 ◽  
Author(s):  
Mathieu Bourguignon ◽  
Martijn Baart ◽  
Efthymia C. Kapnoula ◽  
Nicola Molinaro
Keyword(s):  
Biological Motion ◽  
Real Life ◽  
Low Frequency ◽  
Angular Gyrus ◽  
Synthesis Process ◽  
Lip Reading ◽  
Auditory Cortices ◽  
The Right ◽  
High Level ◽  
The Brain

AbstractLip-reading is crucial to understand speech in challenging conditions. Neuroimaging investigations have revealed that lip-reading activates auditory cortices in individuals covertly repeating absent—but known—speech. However, in real-life, one usually has no detailed information about the content of upcoming speech. Here we show that during silent lip-reading of unknown speech, activity in auditory cortices entrains more to absent speech than to seen lip movements at frequencies below 1 Hz. This entrainment to absent speech was characterized by a speech-to-brain delay of 50–100 ms as when actually listening to speech. We also observed entrainment to lip movements at the same low frequency in the right angular gyrus, an area involved in processing biological motion. These findings demonstrate that the brain can synthesize high-level features of absent unknown speech sounds from lip-reading that can facilitate the processing of the auditory input. Such a synthesis process may help explain well-documented bottom-up perceptual effects.

scholarly journals Neural timing signal for precise tactile timing judgments

2016 ◽  
Vol 115 (3) ◽  
pp. 1620-1629 ◽  
Author(s):  
Scinob Kuroki ◽  
Junji Watanabe ◽  
Shin'ya Nishida
Keyword(s):  
Information Source ◽  
Low Frequency ◽  
Neural Mechanism ◽  
Sine Wave ◽  
Judgment Task ◽  
The Other ◽  
Neural Responses ◽  
Synchrony Judgment ◽  
The Brain ◽  
Temporal Judgments

The brain can precisely encode the temporal relationship between tactile inputs. While behavioural studies have demonstrated precise interfinger temporal judgments, the underlying neural mechanism remains unknown. Computationally, two kinds of neural responses can act as the information source. One is the phase-locked response to the phase of relatively slow inputs, and the other is the response to the amplitude change of relatively fast inputs. To isolate the contributions of these components, we measured performance of a synchrony judgment task for sine wave and amplitude-modulation (AM) wave stimuli. The sine wave stimulus was a low-frequency sinusoid, with the phase shifted in the asynchronous stimulus. The AM wave stimulus was a low-frequency sinusoidal AM of a 250-Hz carrier, with only the envelope shifted in the asynchronous stimulus. In the experiment, three stimulus pairs, two synchronous ones and one asynchronous one, were sequentially presented to neighboring fingers, and participants were asked to report which one was the asynchronous pair. We found that the asynchrony of AM waves could be detected as precisely as single impulse pair, with the threshold asynchrony being ∼20 ms. On the other hand, the asynchrony of sine waves could not be detected at all in the range from 5 to 30 Hz. Our results suggest that the timing signal for tactile judgments is provided not by the stimulus phase information but by the envelope of the response of the high-frequency-sensitive Pacini channel (PC), although they do not exclude a possible contribution of the envelope of non-PCs.

scholarly journals Visual category-driven differences in memory

2021 ◽  
Author(s):  
Adam Steel ◽  
Edward Silson
Keyword(s):  
Visual Cortex ◽  
Human Memory ◽  
Memory Systems ◽  
Neural Mechanisms ◽  
Neural Responses ◽  
Cortical Areas ◽  
Visual Areas ◽  
High Level ◽  
Human Categorization ◽  
The Brain

Categorizing classes of stimuli in the real-world is thought to underlie features of general intelligence, including our ability to infer identities of new objects, environments, and people never encountered before. Our understanding of human categorization, and the neural mechanisms that underlie this ability, was initially described in the context of visual perception. It is now broadly accepted that a network of high-level visual areas on the ventral and lateral surfaces of the brain exhibit some level of ‘domain (or category)-selective’ activity: preferential neural responses to visual stimuli of one category more than another (e.g., larger responses to faces compared to scenes or manipulable objects). Inspired by this robust and intuitive organization, recent studies have begun investigating the extent to which human memory systems also exhibit a category-selective organization. Surprisingly, this work has revealed strong evidence for the existence of category-selective areas in swaths of cortex previously considered to be domain-general. These results suggest that category-selectivity is a general organizing principle not only of visual cortex, but also for higher-level cortical areas involved in memory. In this chapter we review the evidence for the manifestation of visual category preferences in memory systems, and how this relates to the well-established category-selectivity exhibited within visual cortex.

scholarly journals A precise and adaptive neural mechanism for predictive temporal processing in the frontal cortex

2021 ◽  
Author(s):  
Nicolas Meirhaeghe ◽  
Hansem Sohn ◽  
Mehrdad Jazayeri
Keyword(s):  
Frontal Cortex ◽  
Neural Activity ◽  
Temporal Processing ◽  
Temporal Distribution ◽  
Neural Mechanism ◽  
Predictive Processing ◽  
Neural Responses ◽  
Mathematical Relationship ◽  
Temporal Statistics ◽  
Temporal Events

AbstractThe theory of predictive processing posits that the nervous system uses expectations to process information predictively. Direct empirical evidence in support of this theory however has been scarce and largely limited to sensory areas. Here, we report a precise and adaptive neural mechanism in the frontal cortex of non-human primates consistent with predictive processing of temporal events. We found that the speed at which neural states evolve over time is inversely proportional to the statistical mean of the temporal distribution of an expected stimulus. This lawful relationship was evident across multiple experiments and held true during learning: when temporal statistics underwent covert changes, neural responses underwent predictable changes that reflected the new mean. Together, these results highlight a precise mathematical relationship between temporal statistics in the environment and neural activity in the frontal cortex that could serve as a mechanistic foundation for predictive temporal processing.

scholarly journals Amplification of local changes along the timescale processing hierarchy

2017 ◽  
Vol 114 (35) ◽  
pp. 9475-9480 ◽  
Author(s):  
Yaara Yeshurun ◽  
Mai Nguyen ◽  
Uri Hasson
Keyword(s):  
Gradual Increase ◽  
Word Choice ◽  
Neural Responses ◽  
Grammatical Structure ◽  
Neural Representations ◽  
Cortical Hierarchy ◽  
Highly Correlated ◽  
Time Amplification ◽  
The Brain ◽  
Over Time

Small changes in word choice can lead to dramatically different interpretations of narratives. How does the brain accumulate and integrate such local changes to construct unique neural representations for different stories? In this study, we created two distinct narratives by changing only a few words in each sentence (e.g., “he” to “she” or “sobbing” to “laughing”) while preserving the grammatical structure across stories. We then measured changes in neural responses between the two stories. We found that differences in neural responses between the two stories gradually increased along the hierarchy of processing timescales. For areas with short integration windows, such as early auditory cortex, the differences in neural responses between the two stories were relatively small. In contrast, in areas with the longest integration windows at the top of the hierarchy, such as the precuneus, temporal parietal junction, and medial frontal cortices, there were large differences in neural responses between stories. Furthermore, this gradual increase in neural differences between the stories was highly correlated with an area’s ability to integrate information over time. Amplification of neural differences did not occur when changes in words did not alter the interpretation of the story (e.g., sobbing to “crying”). Our results demonstrate how subtle differences in words are gradually accumulated and amplified along the cortical hierarchy as the brain constructs a narrative over time.

Methyl mercury in the dutch rhine delta

1994 ◽  
Vol 30 (10) ◽  
pp. 213-219 ◽  
Author(s):  
Hendrik Pieters ◽  
Victor Geuke
Keyword(s):  
Suspended Matter ◽  
Methyl Mercury ◽  
Mercury Contamination ◽  
Benthic Organisms ◽  
Considerable Decrease ◽  
Continuous Sedimentation ◽  
Highly Correlated ◽  
High Level ◽  
Almost All

Samples of yellow eel from various locations in the Dutch Rhine area have been analyzed for trend monitoring of mercury since 1977. In the western Rhine delta mercury levels in eels have hardly changed since the seventies, whereas in the eastern part of the Dutch Rhine area a considerable decrease of mercury concentrations in eel has occurred. Because of continuous sedimentation of contaminated suspended matter transported from upstream regions, accumulation rates and concentrations of mercury in eel in the western Rhine delta remained at a relatively high level. Analyses of methyl mercury in biota have been performed to elucidate the role of methyl mercury in the mercury contamination of the Dutch Rhine ecosystem. Low percentages of methyl mercury were observed in zooplankton (3 to 35%). In benthic organisms (mussels) percentages of methyl mercury ranged from 30 to 57%, while in fish species and liver of aquatic top predator birds almost all the mercury was present in the form of methyl mercury (> 80%). During the period 1970-1990 mercury concentrations of suspended matter in the eastern Rhine delta have drastically decreased. These concentrations seemed to be highly correlated with mercury concentrations of eel (R = 0.84). The consequences of this relation are discussed.

scholarly journals Cortical response to naturalistic stimuli is largely predictable with deep neural networks

2021 ◽  
Vol 7 (22) ◽  
pp. eabe7547
Author(s):  
Meenakshi Khosla ◽  
Gia H. Ngo ◽  
Keith Jamison ◽  
Amy Kuceyeski ◽  
Mert R. Sabuncu
Keyword(s):  
Brain Function ◽  
Deep Neural Networks ◽  
Neural Responses ◽  
Dynamic Interactions ◽  
Hierarchical Processing ◽  
Human Connectome Project ◽  
Neural Information ◽  
Neural Information Processing ◽  
Visual Interactions ◽  
High Level

Naturalistic stimuli, such as movies, activate a substantial portion of the human brain, invoking a response shared across individuals. Encoding models that predict neural responses to arbitrary stimuli can be very useful for studying brain function. However, existing models focus on limited aspects of naturalistic stimuli, ignoring the dynamic interactions of modalities in this inherently context-rich paradigm. Using movie-watching data from the Human Connectome Project, we build group-level models of neural activity that incorporate several inductive biases about neural information processing, including hierarchical processing, temporal assimilation, and auditory-visual interactions. We demonstrate how incorporating these biases leads to remarkable prediction performance across large areas of the cortex, beyond the sensory-specific cortices into multisensory sites and frontal cortex. Furthermore, we illustrate that encoding models learn high-level concepts that generalize to task-bound paradigms. Together, our findings underscore the potential of encoding models as powerful tools for studying brain function in ecologically valid conditions.

scholarly journals Temporal Processing Capacity in High-Level Visual Cortex Is Domain Specific

2015 ◽  
Vol 35 (36) ◽  
pp. 12412-12424 ◽  
Author(s):  
A. Stigliani ◽  
K. S. Weiner ◽  
K. Grill-Spector
Keyword(s):  
Visual Cortex ◽  
Temporal Processing ◽  
Processing Capacity ◽  
Domain Specific ◽  
High Level

scholarly journals Using electrodermal activity to validate multilevel pain stimulation in healthy volunteers evoked by thermal grills

2020 ◽  
Vol 319 (3) ◽  
pp. R366-R375
Author(s):  
Hugo F. Posada-Quintero ◽  
Youngsun Kong ◽  
Kimberly Nguyen ◽  
Cara Tran ◽  
Luke Beardslee ◽  
...  
Keyword(s):  
Tissue Injury ◽  
Electrodermal Activity ◽  
Pain Scale ◽  
Potential Harm ◽  
Electric Pulses ◽  
Stimulation Level ◽  
Highly Correlated ◽  
The Brain ◽  
Different Levels ◽  
Assessment Research

We have tested the feasibility of thermal grills, a harmless method to induce pain. The thermal grills consist of interlaced tubes that are set at cool or warm temperatures, creating a painful “illusion” (no tissue injury is caused) in the brain when the cool and warm stimuli are presented collectively. Advancement in objective pain assessment research is limited because the gold standard, the self-reporting pain scale, is highly subjective and only works for alert and cooperative patients. However, the main difficulty for pain studies is the potential harm caused to participants. We have recruited 23 subjects in whom we induced electric pulses and thermal grill (TG) stimulation. The TG effectively induced three different levels of pain, as evidenced by the visual analog scale (VAS) provided by the subjects after each stimulus. Furthermore, objective physiological measurements based on electrodermal activity showed a significant increase in levels as stimulation level increased. We found that VAS was highly correlated with the TG stimulation level. The TG stimulation safely elicited pain levels up to 9 out of 10. The TG stimulation allows for extending studies of pain to ranges of pain in which other stimuli are harmful.

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