scholarly journals Neural excitability and sensory input determine intensity perception with opposing directions in initial cortical responses

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Tilman Stephani ◽  
Alice Hodapp ◽  
Mina Jamshidi Idaji ◽  
Arno Villringer ◽  
Vadim V Nikulin
Keyword(s):  
Stimulus Intensity ◽  
Sensory Input ◽  
Sensory Information ◽  
Single Trial ◽  
Brain Potentials ◽  
Neural Excitability ◽  
Intensity Perception ◽  
Cortical Responses ◽  
Common Framework ◽  
Stimulus Features

Perception of sensory information is determined by stimulus features (e.g., intensity) and instantaneous neural states (e.g., excitability). Commonly, it is assumed that both are reflected similarly in evoked brain potentials, that is, larger amplitudes are associated with a stronger percept of a stimulus. We tested this assumption in a somatosensory discrimination task in humans, simultaneously assessing (i) single-trial excitatory post-synaptic currents inferred from short-latency somatosensory evoked potentials (SEPs), (ii) pre-stimulus alpha oscillations (8–13 Hz), and (iii) peripheral nerve measures. Fluctuations of neural excitability shaped the perceived stimulus intensity already during the very first cortical response (at ~20 ms) yet demonstrating opposite neural signatures as compared to the effect of presented stimulus intensity. We reconcile this discrepancy via a common framework based on the modulation of electro-chemical membrane gradients linking neural states and responses, which calls for reconsidering conventional interpretations of brain potential magnitudes in stimulus intensity encoding.

scholarly journals Opposing signatures of neural excitability and sensory input in initial cortical responses differentially predict intensity perception

2020 ◽  
Author(s):  
T. Stephani ◽  
A. Hodapp ◽  
M. Jamshidi Idaji ◽  
A. Villringer ◽  
V. V. Nikulin
Keyword(s):  
Stimulus Intensity ◽  
Sensory Input ◽  
Sensory Information ◽  
Brain Potentials ◽  
Neural Excitability ◽  
Intensity Perception ◽  
Cortical Responses ◽  
Common Framework ◽  
Evoked Activity ◽  
Stimulus Features

AbstractPerception of sensory information is determined by stimulus features (e.g., intensity) and instantaneous neural states (e.g., excitability). Commonly, it is assumed that both are reflected similarly in evoked brain potentials, that is, higher evoked activity leads to a stronger percept of a stimulus. We tested this assumption in a somatosensory discrimination task in humans, simultaneously assessing (i) single-trial excitatory post-synaptic currents inferred from short-latency somatosensory evoked potentials (SEP), (ii) pre-stimulus alpha oscillations (8-13 Hz), and (iii) peripheral nerve measures. Fluctuations of neural excitability shaped the perceived stimulus intensity already during the very first cortical response (at ∼20 ms) yet demonstrating opposite neural signatures as compared to the effect of presented stimulus intensity. We reconcile this discrepancy via a common framework based on modulations of electro-chemical membrane gradients linking neural states and responses, which calls for reconsidering conventional interpretations of brain potential magnitudes in stimulus intensity encoding.

scholarly journals The brain detects stimulus features, but not stimulus conflict in task-irrelevant sensory input

2019 ◽  
Author(s):  
Stijn A. Nuiten ◽  
Andrés Canales-Johnson ◽  
Lola Beerendonk ◽  
Nutsa Nanuashvili ◽  
Johannes J. Fahrenfort ◽  
...  
Keyword(s):  
Sensory Input ◽  
Sensory Information ◽  
Past Research ◽  
Conflict Detection ◽  
Information Analysis ◽  
Task Relevance ◽  
Human Participants ◽  
Stimulus Features ◽  
Task Irrelevant ◽  
The Brain

AbstractCognitive control over conflicting sensory input is central to adaptive human behavior. It might therefore not come as a surprise that past research has shown conflict detection in the absence of conscious awareness. This would suggest that the brain may detect conflict fully automatically, and that it can even occur without paying attention. Contrary to this intuition, we show that task-relevance is crucial for conflict detection. Univariate and multivariate analyses on electroencephalographic data from human participants revealed that when auditory stimuli are fully task-irrelevant, the brain disregards conflicting input entirely, whereas the same input elicits strong neural conflict signals when task-relevant. In sharp contrast, stimulus features were still processed, irrespective of task-relevance. These results show that stimulus properties are only integrated to allow conflict to be detected by prefrontal regions when sensory information is task-relevant and therefore suggests an attentional bottleneck at high levels of information analysis.

scholarly journals Modeling the effect of locus coeruleus firing on cortical state dynamics and single-trial sensory processing

2015 ◽  
Vol 112 (41) ◽  
pp. 12834-12839 ◽  
Author(s):  
Houman Safaai ◽  
Ricardo Neves ◽  
Oxana Eschenko ◽  
Nikos K. Logothetis ◽  
Stefano Panzeri
Keyword(s):  
Locus Coeruleus ◽  
Cortical Excitability ◽  
Temporal Structure ◽  
Sensory Information ◽  
Evoked Responses ◽  
Single Trial ◽  
Dynamical Interaction ◽  
Sensory Stimuli ◽  
Cortical Dynamics ◽  
Cortical Responses

Neuronal responses to sensory stimuli are not only driven by feedforward sensory pathways but also depend upon intrinsic factors (collectively known as the network state) that include ongoing spontaneous activity and neuromodulation. To understand how these factors together regulate cortical dynamics, we recorded simultaneously spontaneous and somatosensory-evoked multiunit activity from primary somatosensory cortex and from the locus coeruleus (LC) (the neuromodulatory nucleus releasing norepinephrine) in urethane-anesthetized rats. We found that bursts of ipsilateral-LC firing preceded by few tens of milliseconds increases of cortical excitability, and that the 1- to 10-Hz rhythmicity of LC discharge appeared to increase the power of delta-band (1–4 Hz) cortical synchronization. To investigate quantitatively how LC firing might causally influence spontaneous and stimulus-driven cortical dynamics, we then constructed and fitted to these data a model describing the dynamical interaction of stimulus drive, ongoing synchronized cortical activity, and noradrenergic neuromodulation. The model proposes a coupling between LC and cortex that can amplify delta-range cortical fluctuations, and shows how suitably timed phasic LC bursts can lead to enhanced cortical responses to weaker stimuli and increased temporal precision of cortical stimulus-evoked responses. Thus, the temporal structure of noradrenergic modulation may selectively and dynamically enhance or attenuate cortical responses to stimuli. Finally, using the model prediction of single-trial cortical stimulus-evoked responses to discount single-trial state-dependent variability increased by ∼70% the sensory information extracted from cortical responses. This suggests that downstream circuits may extract information more effectively after estimating the state of the circuit transmitting the sensory message.

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.

Differential effects of stimulus intensity on peripheral and neuromagnetic cortical responses to median nerve stimulation

NeuroImage ◽  
2003 ◽  
Vol 20 (2) ◽  
pp. 909-917 ◽  
Author(s):  
Yung-Yang Lin ◽  
Yang-Hsin Shih ◽  
Jen-Tse Chen ◽  
Jen-Chuen Hsieh ◽  
Tzu-Chen Yeh ◽  
...  
Keyword(s):  
Median Nerve ◽  
Stimulus Intensity ◽  
Nerve Stimulation ◽  
Differential Effects ◽  
Median Nerve Stimulation ◽  
Cortical Responses

Interactions Between Neurones Mediating Tuft Withdrawal in Tritonia Hombergi

1974 ◽  
Vol 61 (3) ◽  
pp. 655-666
Author(s):  
D. A. DORSETT ◽  
A. O. D. WILLOWS
Keyword(s):  
Motor Activity ◽  
Stimulus Intensity ◽  
Large Amplitude ◽  
Sensory Input ◽  
Behavioural Response ◽  
Spike Pattern ◽  
General Increase ◽  
Repeated Use ◽  
Three Stages ◽  
Central Excitability

The seven neurones that command the three stages of branchial tuft withdrawal interact by electrotonic and chemically mediated polysynaptic pathways. The pleural tuft retractors, L and R Pl 6, make electrotonic synapses with the ipsilateral neuronesPd2, which cause retraction of the tips of the tufts. The chemically transmitting pathways, between these and other retractor neurones, are mostly reciprocal and can be classified as weak or strong. The former are small in amplitude, with long latencies (1-3 sec) and are labile to repeated activation; the latter are of large amplitude and shorter latency (0·5-0·8 sec), but may still show decrement with repeated use. Frequently the p.s.p. shows indications of 1:1 correlation with the spike pattern in the driven neurone, but the long latencies require the presence of at least one interneurone in the pathway. The progressive spread of the behavioural response (withdrawal of the tips, complete unilateral withdrawal, complete bilateral withdrawal of all tufts), which occurs with increasing stimulus intensity, is not dependent on a central hierarchy in the activation of the tuft retractor neurones. Reciprocal feedback leads to a general increase in central excitability, the threshold for more extensive responses being probably determined largely by the sensory input to individual neurones. The unique pleural cell R Pl 5 is exceptional, both in the variety of motor activity it commands and in the absence of reciprocal connexions from other retractor neurones.

scholarly journals Serotonergic modulation across sensory modalities

2020 ◽  
Vol 123 (6) ◽  
pp. 2406-2425
Author(s):  
Tyler R. Sizemore ◽  
Laura M. Hurley ◽  
Andrew M. Dacks
Keyword(s):  
Serotonin Receptor ◽  
Physiological State ◽  
Sensory Information ◽  
Specific Stimulus ◽  
Sensory Organization ◽  
Sensory Modalities ◽  
Multiple Levels ◽  
Stimulus Features ◽  
Ubiquitous Presence ◽  
Serotonergic Modulation

The serotonergic system has been widely studied across animal taxa and different functional networks. This modulatory system is therefore well positioned to compare the consequences of neuromodulation for sensory processing across species and modalities at multiple levels of sensory organization. Serotonergic neurons that innervate sensory networks often bidirectionally exchange information with these networks but also receive input representative of motor events or motivational state. This convergence of information supports serotonin’s capacity for contextualizing sensory information according to the animal’s physiological state and external events. At the level of sensory circuitry, serotonin can have variable effects due to differential projections across specific sensory subregions, as well as differential serotonin receptor type expression within those subregions. Functionally, this infrastructure may gate or filter sensory inputs to emphasize specific stimulus features or select among different streams of information. The near-ubiquitous presence of serotonin and other neuromodulators within sensory regions, coupled with their strong effects on stimulus representation, suggests that these signaling pathways should be considered integral components of sensory systems.

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