scholarly journals The Effects of Audiovisual Inputs on Solving the Cocktail Party Problem in the Human Brain: An fMRI Study

2017 ◽  
Vol 28 (10) ◽  
pp. 3623-3637 ◽  
Author(s):  
Yuanqing Li ◽  
Fangyi Wang ◽  
Yongbin Chen ◽  
Andrzej Cichocki ◽  
Terrence Sejnowski
Keyword(s):  
Auditory Information ◽  
Cocktail Party ◽  
Cocktail Party Problem ◽  
Audiovisual Stimulus ◽  
Neural Representations ◽  
Fmri Study ◽  
Brain Pattern ◽  
Audiovisual Stimuli ◽  
Decoding Accuracy ◽  
The Brain

Abstract At cocktail parties, our brains often simultaneously receive visual and auditory information. Although the cocktail party problem has been widely investigated under auditory-only settings, the effects of audiovisual inputs have not. This study explored the effects of audiovisual inputs in a simulated cocktail party. In our fMRI experiment, each congruent audiovisual stimulus was a synthesis of 2 facial movie clips, each of which could be classified into 1 of 2 emotion categories (crying and laughing). Visual-only (faces) and auditory-only stimuli (voices) were created by extracting the visual and auditory contents from the synthesized audiovisual stimuli. Subjects were instructed to selectively attend to 1 of the 2 objects contained in each stimulus and to judge its emotion category in the visual-only, auditory-only, and audiovisual conditions. The neural representations of the emotion features were assessed by calculating decoding accuracy and brain pattern-related reproducibility index based on the fMRI data. We compared the audiovisual condition with the visual-only and auditory-only conditions and found that audiovisual inputs enhanced the neural representations of emotion features of the attended objects instead of the unattended objects. This enhancement might partially explain the benefits of audiovisual inputs for the brain to solve the cocktail party problem.

Neural Representation of Reward Probability: Evidence from the Illusion of Control

2013 ◽  
Vol 25 (6) ◽  
pp. 852-861 ◽  
Author(s):  
Wouter Kool ◽  
Sarah J. Getz ◽  
Matthew M. Botvinick
Keyword(s):  
Preliminary Evidence ◽  
Neural Representation ◽  
Behavioral Experiment ◽  
Illusion Of Control ◽  
Control Effect ◽  
Incentive Value ◽  
Neural Representations ◽  
Fmri Study ◽  
Reward Probability ◽  
The Brain

To support reward-based decision-making, the brain must encode potential outcomes both in terms of their incentive value and their probability of occurrence. Recent research has made it clear that the brain bears multiple representations of reward magnitude, meaning that a single choice option may be represented differently—and even inconsistently—in different brain areas. There are some hints that the same may be true for reward probability. Preliminary evidence hints that, even as systematic distortions of probability are expressed in behavior, these may not always be uniformly reflected at the neural level: Some neural representations of probability may be immune from such distortions. This study provides new evidence consistent with this possibility. Participants in a behavioral experiment displayed a classic “illusion of control,” providing higher estimates of reward probability for gambles they had chosen than for identical gambles that were imposed on them. However, an fMRI study of the same task revealed that neural prediction error signals, arising when gamble outcomes were revealed, were unaffected by the illusion of control. The resulting behavioral–neural dissociation reinforces the case for multiple, inconsistent internal representations of reward probability, while also prompting a reinterpretation of the illusion of control effect itself.

scholarly journals Prediction errors during naturalistic events modulate hippocampal representations and drive episodic memory updating

2020 ◽  
Author(s):  
Alyssa H. Sinclair ◽  
Grace M. Manalili ◽  
Iva K. Brunec ◽  
R. Alison Adcock ◽  
Morgan D. Barense
Keyword(s):  
Prediction Error ◽  
Link Prediction ◽  
False Memories ◽  
Prediction Errors ◽  
Memory Updating ◽  
Learning From Errors ◽  
Neural Representations ◽  
Fmri Study ◽  
Temporal Continuity ◽  
The Brain

AbstractThe brain supports adaptive behavior by generating predictions, learning from errors, and updating memories. Prediction error, or surprise, is a known trigger for memory updating; however, the mechanisms that link prediction error, neural representations, and naturalistic memory updating remain unknown. In an fMRI study, we elicited prediction errors by interrupting familiar narrative videos immediately before an expected conclusion. We found that prediction errors reversed the effect of post-video univariate hippocampal activation on subsequent memory: hippocampal activation predicted false memories after prediction errors, but protected memories from distortion after expected events. Tracking second-by-second neural patterns revealed that prediction errors disrupted the temporal continuity of hippocampal representations. This disruption of signal history led to memory updating after prediction error. We conclude that prediction errors during memory reactivation prompt the hippocampus to abandon ongoing predictions and neural representations. Following prediction error, the hippocampus switches to an externally-oriented processing mode that supports memory updating.

The Auditory Brainstem Implant

2019 ◽  
pp. 758-770
Author(s):  
Robert V. Shannon
Keyword(s):  
Surgical Technique ◽  
Cochlear Nucleus ◽  
Meta Analysis ◽  
Auditory Brainstem ◽  
Auditory Information ◽  
Speech Understanding ◽  
Auditory Neurons ◽  
Auditory Brainstem Implant ◽  
The Brain ◽  
Implanted Device

The auditory brainstem implant (ABI) is a surgically implanted device to electrically stimulate auditory neurons in the cochlear nucleus complex of the brainstem in humans to restore hearing sensations. The ABI is similar in function to a cochlear implant, but overall outcomes are poorer. However, recent applications of the ABI to new patient populations and improvements in surgical technique have led to significant improvements in outcomes. While the ABI provides hearing benefits to patients, the outcomes challenge our understanding of how the brain processes neural patterns of auditory information. The neural pattern of activation produced by an ABI is highly unnatural, yet some patients achieve high levels of speech understanding. Based on a meta-analysis of ABI surgeries and outcomes, a theory is proposed of a specialized sub-system of the cochlear nucleus that is critical for speech understanding.

scholarly journals Acute alcohol intoxication and the cocktail party problem: do “mocktails” help or hinder?

2021 ◽  
Author(s):  
Alistair J. Harvey ◽  
C. Philip Beaman
Keyword(s):  
Working Memory ◽  
Memory Span ◽  
Alcohol Intoxication ◽  
Alcoholic Beverage ◽  
Cognitive Capacity ◽  
Cocktail Party ◽  
Primary Input ◽  
Cocktail Party Problem ◽  
Null Effect ◽  
Cocktail Party Effect

Abstract Rationale To test the notion that alcohol impairs auditory attentional control by reducing the listener’s cognitive capacity. Objectives We examined the effect of alcohol consumption and working memory span on dichotic speech shadowing and the cocktail party effect—the ability to focus on one of many simultaneous speakers yet still detect mention of one’s name amidst the background speech. Alcohol was expected either to increase name detection, by weakening the inhibition of irrelevant speech, or reduce name detection, by restricting auditory attention on to the primary input channel. Low-span participants were expected to show larger drug impairments than high-span counterparts. Methods On completion of the working memory span task, participants (n = 81) were randomly assigned to an alcohol or placebo beverage treatment. After alcohol absorption, they shadowed speech presented to one ear while ignoring the synchronised speech of a different speaker presented to the other. Each participant’s first name was covertly embedded in to-be-ignored speech. Results The “cocktail party effect” was not affected by alcohol or working memory span, though low-span participants made more shadowing errors and recalled fewer words from the primary channel than high-span counterparts. Bayes factors support a null effect of alcohol on the cocktail party phenomenon, on shadowing errors and on memory for either shadowed or ignored speech. Conclusion Findings suggest that an alcoholic beverage producing a moderate level of intoxication (M BAC ≈ 0.08%) neither enhances nor impairs the cocktail party effect.

How does the brain process time? insights from an event-related fMRI study

NeuroImage ◽  
2000 ◽  
Vol 11 (5) ◽  
pp. S49
Author(s):  
D.L. Harrington ◽  
L.A. Mead ◽  
A.R. Mayer ◽  
K.Y. Haaland ◽  
S.M. Rao
Keyword(s):  
Process Time ◽  
Brain Process ◽  
Fmri Study ◽  
The Brain

scholarly journals Neurodegeneration in friedreich's ataxia is associated with a mixed activation pattern of the brain. A fMRI study

2011 ◽  
Vol 33 (8) ◽  
pp. 1780-1791 ◽  
Author(s):  
Andrea Ginestroni ◽  
Stefano Diciotti ◽  
Paolo Cecchi ◽  
Ilaria Pesaresi ◽  
Carlo Tessa ◽  
...  
Keyword(s):  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Activation Pattern ◽  
Fmri Study ◽  
The Brain

scholarly journals Neural Representations of Death in the Cortical Midline Structures Promote Temporal Discounting

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Kuniaki Yanagisawa ◽  
Emiko S Kashima ◽  
Yayoi Shigemune ◽  
Ryusuke Nakai ◽  
Nobuhito Abe
Keyword(s):  
Temporal Discounting ◽  
Future Thinking ◽  
Multivoxel Pattern Analysis ◽  
Default Mode ◽  
Neural Representations ◽  
Economic Decision Making ◽  
Imaging Experiment ◽  
Behavioral Evidence ◽  
Decoding Accuracy ◽  
Magnetic Resonance Imaging Experiment

Abstract Death is an important reminder that our lives are finite. Although some studies have shown that thinking about one’s own death increases temporal discounting (i.e., the devaluing of future rewards), the underlying neural mechanisms are still unknown. In a functional magnetic resonance imaging experiment, we compared the neural and behavioral processes of temporal discounting across four conditions involving distinct types of future thinking (death related, negative, neutral, and positive). Replicating prior research, the behavioral evidence showed that temporal discounting increased when thinking about one’s own future death. Multivoxel pattern analysis showed that death-related future thinking was decoded in default mode regions, including the inferior parietal lobule, precuneus, and medial prefrontal cortex (MPFC). When future thinking was death related (vs. negative), increased temporal discounting was associated with a higher decoding accuracy in the precuneus and MPFC. The present findings suggest that death-related neural representations are distributed across default mode regions, and neural populations in the cortical midline structures play a crucial role in the integration of one's own death into economic decision-making.

scholarly journals Quantitative representations of an exaggerated anxiety response in the brain of female spider phobics-a parametric fMRI study

2017 ◽  
Vol 38 (6) ◽  
pp. 3025-3038 ◽  
Author(s):  
Anna Zilverstand ◽  
Bettina Sorger ◽  
Anita Kaemingk ◽  
Rainer Goebel
Keyword(s):  
Fmri Study ◽  
Anxiety Response ◽  
The Brain

scholarly journals Task dependence of neural representations of global scene properties but not scene categories in the prefrontal cortex

2020 ◽  
Author(s):  
Yaelan Jung ◽  
Dirk B. Walther
Keyword(s):  
Prefrontal Cortex ◽  
Visual Cortex ◽  
Scene Perception ◽  
Sound Level ◽  
Task Context ◽  
Complex Scene ◽  
Neural Representations ◽  
Task Conditions ◽  
Scene Content ◽  
The Brain

AbstractNatural scenes deliver rich sensory information about the world. Decades of research has shown that the scene-selective network in the visual cortex represents various aspects of scenes. It is, however, unknown how such complex scene information is processed beyond the visual cortex, such as in the prefrontal cortex. It is also unknown how task context impacts the process of scene perception, modulating which scene content is represented in the brain. In this study, we investigate these questions using scene images from four natural scene categories, which also depict two types of global scene properties, temperature (warm or cold), and sound-level (noisy or quiet). A group of healthy human subjects from both sexes participated in the present study using fMRI. In the study, participants viewed scene images under two different task conditions; temperature judgment and sound-level judgment. We analyzed how different scene attributes (scene categories, temperature, and sound-level information) are represented across the brain under these task conditions. Our findings show that global scene properties are only represented in the brain, especially in the prefrontal cortex, when they are task-relevant. However, scene categories are represented in the brain, in both the parahippocampal place area and the prefrontal cortex, regardless of task context. These findings suggest that the prefrontal cortex selectively represents scene content according to task demands, but this task selectivity depends on the types of scene content; task modulates neural representations of global scene properties but not of scene categories.

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