scholarly journals General neural mechanisms can account for rising slope preference in localization of ambiguous sounds

2019 ◽  
Author(s):  
Jean-Hugues Lestang ◽  
Dan F. M. Goodman
Keyword(s):  
Sound Localization ◽  
Neural Circuits ◽  
Dominant Frequency ◽  
Neural Mechanisms ◽  
Auditory Cues ◽  
Sound Localisation ◽  
Wide Range ◽  
Reverberant Environments ◽  
The Brain ◽  
Localization Information

Sound localization in reverberant environments is a difficult task that human listeners perform effortlessly. Many neural mechanisms have been proposed to account for this behavior. Generally they rely on emphasizing localization information at the onset of the incoming sound while discarding localization cues that arrive later. We modelled several of these mechanisms using neural circuits commonly found in the brain and tested their performance in the context of experiments showing that, in the dominant frequency region for sound localisation, we have a preference for auditory cues arriving during the rising slope of the sound energy (Dietz et al., 2013). We found that both single cell mechanisms (onset and adaptation) and population mechanisms (lateral inhibition) were easily able to reproduce the results across a very wide range of parameter settings. This suggests that sound localization in reverberant environments may not require specialised mechanisms specific to perform that task, but could instead rely on common neural circuits in the brain. This would allow for the possibility of individual differences in learnt strategies or neuronal parameters. This research is fully reproducible, and we made our code available to edit and run online via interactive live notebooks.

scholarly journals A Diverse Range of Factors Affect the Nature of Neural Representations Underlying Short-Term Memory

2018 ◽  
Author(s):  
A. Emin Orhan ◽  
Wei Ji Ma
Keyword(s):  
Neural Circuits ◽  
Short Term Memory ◽  
Persistent Activity ◽  
Short Term ◽  
Diverse Range ◽  
Term Memory ◽  
Temporal Complexity ◽  
Wide Range ◽  
Activity Models ◽  
The Brain

AbstractSequential and persistent activity models are two prominent models of short-term memory in neural circuits. In persistent activity models, memories are represented in persistent or nearly persistent activity patterns across a population of neurons, whereas in sequential models, memories are represented dynamically by a sequential pattern of activity across the population. Experimental evidence for both types of model in the brain has been reported previously. However, it has been unclear under what conditions these two qualitatively different types of solutions emerge in neural circuits. Here, we address this question by training recurrent neural networks on several short-term memory tasks under a wide range of circuit and task manipulations. We show that sequential and nearly persistent solutions are both part of a spectrum that emerges naturally in trained networks under different conditions. Fixed delay durations, tasks with higher temporal complexity, strong network coupling, motion-related dynamic inputs and prior training in a different task favor more sequential solutions, whereas variable delay durations, tasks with low temporal complexity, weak network coupling and symmetric Hebbian short-term synaptic plasticity favor more persistent solutions. Our results help clarify some seemingly contradictory experimental results on the existence of sequential vs. persistent activity based memory mechanisms in the brain.

scholarly journals Reward enhances memory via age-varying online and offline neural mechanisms across development

2021 ◽  
Author(s):  
Alexandra O Cohen ◽  
Morgan M Glover ◽  
Xinxu Shen ◽  
Camille V Phaneuf ◽  
Kristen N Avallone ◽  
...  
Keyword(s):  
Associative Memory ◽  
Neural Circuits ◽  
Neural Mechanisms ◽  
Age Related ◽  
High Reward ◽  
Memory Representations ◽  
Dopamine Signaling ◽  
Reward Motivation ◽  
The Brain

Reward motivation enhances memory through interactions between mesolimbic, hippocampal, and cortical systems - both during and after encoding. Developmental changes in these distributed neural circuits may lead to age-related differences in reward-motivated memory and the underlying neural mechanisms. Converging evidence from cross-species studies suggests that subcortical dopamine signaling is increased during adolescence, which may lead to stronger memory representations of rewarding, relative to mundane, events and changes in the contributions of underlying subcortical and cortical brain mechanisms across age. Here, we used fMRI to examine how reward motivation influences the "online" encoding and "offline" post-encoding brain mechanisms that support long-term associative memory from childhood to adulthood. We found that reward motivation led to both age-invariant as well as adolescent-specific enhancements in associative memory after 24 hours. Furthermore, reward-related memory benefits were linked to age-varying neural mechanisms. During encoding, interactions between the prefrontal cortex and ventral tegmental area (VTA) were associated with better high-reward memory to a greater degree with increasing age. Pre- to post-encoding changes in functional connectivity between the anterior hippocampus and VTA were also associated with better high-reward memory, but more so at younger ages. Our findings suggest that there may be developmental shifts - from offline subcortical to online cortical processes - in the brain mechanisms supporting reward-motivated memory.

scholarly journals Nanowire transistor arrays for mapping neural circuits in acute brain slices

2010 ◽  
Vol 107 (5) ◽  
pp. 1882-1887 ◽  
Author(s):  
Quan Qing ◽  
Sumon K. Pal ◽  
Bozhi Tian ◽  
Xiaojie Duan ◽  
Brian P. Timko ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Spatial Resolution ◽  
Neural Circuits ◽  
Silicon Nanowire ◽  
Brain Slices ◽  
Active Surface ◽  
Channel Blockers ◽  
Array Measurements ◽  
Wide Range ◽  
The Brain

Revealing the functional connectivity in natural neuronal networks is central to understanding circuits in the brain. Here, we show that silicon nanowire field-effect transistor (Si NWFET) arrays fabricated on transparent substrates can be reliably interfaced to acute brain slices. NWFET arrays were readily designed to record across a wide range of length scales, while the transparent device chips enabled imaging of individual cell bodies and identification of areas of healthy neurons at both upper and lower tissue surfaces. Simultaneous NWFET and patch clamp studies enabled unambiguous identification of action potential signals, with additional features detected at earlier times by the nanodevices. NWFET recording at different positions in the absence and presence of synaptic and ion-channel blockers enabled assignment of these features to presynaptic firing and postsynaptic depolarization from regions either close to somata or abundant in dendritic projections. In all cases, the NWFET signal amplitudes were from 0.3–3 mV. In contrast to conventional multielectrode array measurements, the small active surface of the NWFET devices, ∼0.06 μm2, provides highly localized multiplexed measurements of neuronal activities with demonstrated sub-millisecond temporal resolution and, significantly, better than 30 μm spatial resolution. In addition, multiplexed mapping with 2D NWFET arrays revealed spatially heterogeneous functional connectivity in the olfactory cortex with a resolution surpassing substantially previous electrical recording techniques. Our demonstration of simultaneous high temporal and spatial resolution recording, as well as mapping of functional connectivity, suggest that NWFETs can become a powerful platform for studying neural circuits in the brain.

scholarly journals The many faces of research on face perception

2011 ◽  
Vol 366 (1571) ◽  
pp. 1634-1637 ◽  
Author(s):  
Anthony C. Little ◽  
Benedict C. Jones ◽  
Lisa M. DeBruine
Keyword(s):  
Face Perception ◽  
Neural Mechanisms ◽  
Direct Stimulation ◽  
The Social ◽  
Wide Range ◽  
Different Types ◽  
Cell Recording ◽  
The Many ◽  
The Brain ◽  
Stimulation Of

Face perception is fundamental to human social interaction. Many different types of important information are visible in faces and the processes and mechanisms involved in extracting this information are complex and can be highly specialized. The importance of faces has long been recognized by a wide range of scientists. Importantly, the range of perspectives and techniques that this breadth has brought to face perception research has, in recent years, led to many important advances in our understanding of face processing. The articles in this issue on face perception each review a particular arena of interest in face perception, variously focusing on (i) the social aspects of face perception (attraction, recognition and emotion), (ii) the neural mechanisms underlying face perception (using brain scanning, patient data, direct stimulation of the brain, visual adaptation and single-cell recording), and (iii) comparative aspects of face perception (comparing adult human abilities with those of chimpanzees and children). Here, we introduce the central themes of the issue and present an overview of the articles.

A review on aversive Pavlovian-to-Instrumental transfer in humans

2020 ◽  
Author(s):  
Anna Gerlicher ◽  
Merel Kindt
Keyword(s):  
Avoidance Behavior ◽  
Neural Circuits ◽  
Transfer Effects ◽  
Future Directions ◽  
Transfer Paradigm ◽  
Wide Range ◽  
Threat Cues ◽  
Imminent Threat ◽  
Fear And Anxiety ◽  
Pathological Anxiety

A cue that indicates imminent threat elicits a wide range of physiological, hormonal, autonomic, cognitive, and emotional fear responses in humans and facilitates threat-specific avoidance behavior. The occurrence of a threat cue can, however, also have general motivational effects and affect behavior. That is, the encounter with a threat cue can increase our tendency to engage in general avoidance behavior that does neither terminate nor prevent the threat-cue or the threat itself. Furthermore, the encounter with a threat-cue can substantially reduce our likelihood to engage in behavior that leads to rewarding outcomes. Such general motivational effects of threat-cues on behavior can be informative about the transition from normal to pathological anxiety and could also explain the development of comorbid disorders, such as depression and substance abuse. Despite the unmistakable relevance of the motivational effects of threat for our understanding of anxiety disorders, their investigation is still in its infancy. Pavlovian-to-Instrumental transfer is one paradigm that allows us to investigate such motivational effects of threat cues. Here, we review studies investigating aversive transfer in humans and discuss recent results on the neural circuits mediating Pavlovian-to-Instrumental transfer effects. Finally, we discuss potential limitations of the transfer paradigm and future directions for employing Pavlovian-to-Instrumental transfer for the investigation of motivational effects of fear and anxiety.

scholarly journals Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Andreas Fink ◽  
Arne Nagels ◽  
Benjamin Straube ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Positive Emotions ◽  
Emotional Memory ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Frontal Brain ◽  
Successful Resolution ◽  
Neural Underpinnings ◽  
The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

scholarly journals Bio-Inspired Modality Fusion for Active Speaker Detection

2021 ◽  
Vol 11 (8) ◽  
pp. 3397
Author(s):  
Gustavo Assunção ◽  
Nuno Gonçalves ◽  
Paulo Menezes
Keyword(s):  
Superior Colliculus ◽  
Visual Information ◽  
Human Beings ◽  
Validation Process ◽  
Detection Approach ◽  
Wide Range ◽  
Speaker Detection ◽  
The One ◽  
The Brain ◽  
Fusion Ability

Human beings have developed fantastic abilities to integrate information from various sensory sources exploring their inherent complementarity. Perceptual capabilities are therefore heightened, enabling, for instance, the well-known "cocktail party" and McGurk effects, i.e., speech disambiguation from a panoply of sound signals. This fusion ability is also key in refining the perception of sound source location, as in distinguishing whose voice is being heard in a group conversation. Furthermore, neuroscience has successfully identified the superior colliculus region in the brain as the one responsible for this modality fusion, with a handful of biological models having been proposed to approach its underlying neurophysiological process. Deriving inspiration from one of these models, this paper presents a methodology for effectively fusing correlated auditory and visual information for active speaker detection. Such an ability can have a wide range of applications, from teleconferencing systems to social robotics. The detection approach initially routes auditory and visual information through two specialized neural network structures. The resulting embeddings are fused via a novel layer based on the superior colliculus, whose topological structure emulates spatial neuron cross-mapping of unimodal perceptual fields. The validation process employed two publicly available datasets, with achieved results confirming and greatly surpassing initial expectations.

scholarly journals The emulation theory of representation: Motor control, imagery, and perception

2004 ◽  
Vol 27 (3) ◽  
pp. 377-396 ◽  
Author(s):  
Rick Grush
Keyword(s):  
Motor Control ◽  
Sensory Feedback ◽  
Sensory Input ◽  
Neural Circuits ◽  
Sensory Information ◽  
The Body ◽  
Feedback Delay ◽  
Run Off ◽  
Effects Of Feedback ◽  
The Brain

The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of an emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language.

Senses of Vibration

2012 ◽  
Author(s):  
Shelly Trower
Keyword(s):  
Sensory Experience ◽  
Cultural Imaginary ◽  
Wide Range ◽  
History Of ◽  
The Senses ◽  
To Come ◽  
The Brain

The study of the senses has become a rich topic in recent years. Senses of Vibration explores a wide range of sensory experience and makes a decisive new contribution to this growing field by focussing not simply on the senses as such, but on the material experience - vibration - that underpins them. This is the first book to take the theme of vibration as central, offering an interdisciplinary history of the phenomenon and its reverberations in the cultural imaginary. It tracks vibration through the work of a wide range of writers, including physiologists (who thought vibrations in the nerves delivered sensations to the brain), physicists (who claimed that light, heat, electricity and other forms of energy were vibratory), spiritualists (who figured that spiritual energies also existed in vibratory form), and poets and novelists from Coleridge to Dickens and Wells. Senses of Vibration is a work of scholarship that cuts through a range of disciplines and will reverberate for many years to come.

The impact of SARS-Cov-2 on the Nervous system and Mental Health

2021 ◽  
Vol 19 ◽  
Author(s):  
Mohamed Said Boulkrane ◽  
Victoria Ilina ◽  
Roman Melchakov ◽  
Mikhail Arisov ◽  
Julia Fedotova ◽  
...  
Keyword(s):  
Mental Health ◽  
Respiratory Illness ◽  
World Health ◽  
Current Review ◽  
Wide Range ◽  
Serious Disease ◽  
Health Organization ◽  
The Impact ◽  
The Brain ◽  
Severe Acute Respiratory Illness

: The World Health Organization declared the pandemic situation caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) in March 2020, but the detailed pathophysiological mechanisms of Coronavirus disease 2019 (COVID-19) are not yet completely understood. Therefore, to date, few therapeutic options are available for patients with mild-moderate or serious disease. In addition to systemic and respiratory symptoms, several reports have documented various neurological symptoms and impairments of mental health. The current review aims to provide the available evidence about the effects of SARS-CoV-2 infection on mental health. The present data suggest that SARS-CoV-2 produces a wide range of impairments and disorders of the brain. However, a limited number of studies investigated the neuroinvasive potential of SARS-CoV-2. Although the main features and outcomes of COVID-19 are linked to severe acute respiratory illness. The possible damages on the brain should be considered, too.

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