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 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 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 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.

Developmental regulation of plasticity in cat somatosensory cortex

1994 ◽  
Vol 72 (4) ◽  
pp. 1706-1716 ◽  
Author(s):  
S. L. Juliano ◽  
D. E. Eslin ◽  
M. Tommerdahl
Keyword(s):  
Somatosensory Cortex ◽  
Sensory Input ◽  
Developmental Regulation ◽  
Normal Pattern ◽  
Metabolic Pattern ◽  
Somatosensory Cortices ◽  
Experimental Side ◽  
Adult Cats ◽  
Evoked Activity ◽  
The Individual

1. The neocortical response to deprivation of somatic sensory input in young animals of different ages was compared with the same manipulation in adults. The response was measured through the use of 2-deoxyglucose (2DG) mapping. Although several features of the cortical response were similar in animals of all ages, the metabolic patterns evoked by somatic stimulation differed substantially from each other at all ages. 2. When adult cats receive a digit amputation and survive from 2 to 8 wk, the pattern of stimulus-evoked metabolic uptake expands dramatically in the somatosensory cortex contralateral to the deprived forepaw. Comparisons between the normal and experimental somatosensory cortices reveal that the distribution of activity on the experimental side was roughly an expanded version of the normal pattern. 3. Unilateral digit amputations of digit 2 were conducted on kittens 2, 4, or 6 wk old. They survived until 3–4 mo and then received a 2DG experiment, during which digit 3 was stimulated bilaterally. Evaluation of the evoked metabolic pattern indicated substantial differences from the activity elicited in adults undergoing identical manipulations. 4. The individual patches of activity that made up the metabolic pattern were similar in intensity in both hemispheres when the digit amputation was conducted at either 2, 4, or 6 wk. After a digit amputation at 2 wk, the patches were significantly narrower in the experimental hemisphere; after a digit amputation at 6 wk, the patches were significantly wider in the hemisphere receiving from the deprived forepaw. 5. Two-dimensional maps of 2DG uptake in areas 3b and 1 of the somatosensory cortex reveal that after a digit amputation at 2, 4, or 6 wk, the distribution of activity in the hemisphere receiving from the digit amputation was more dispersed and widespread than in the normal hemisphere. The dispersed pattern of uptake was not an expanded version of the normal pattern, but scattered over a wider region of somatosensory cortex. This observation is similar to the normal pattern of evoked activity seen in developing animals. 6. The total area of 2DG uptake in the somatosensory cortex contralateral to a digit amputation conducted at 2 or 4 wk was not greater than that in the normal hemisphere, even though it was more widespread. After a digit amputation at 6 wk, however, the area of evoked activity was greater in the experimental hemisphere but not of the magnitude as the same manipulation in an adult.(ABSTRACT TRUNCATED AT 400 WORDS)

Development of metabolic activity patterns in the somatosensory cortex of cats

1993 ◽  
Vol 70 (5) ◽  
pp. 2117-2127 ◽  
Author(s):  
S. L. Juliano ◽  
R. A. Code ◽  
M. Tommerdahl ◽  
D. E. Eslin
Keyword(s):  
Somatosensory Cortex ◽  
Metabolic Activity ◽  
Activity Patterns ◽  
Vertical Displacement ◽  
Two Dimensional ◽  
Small Spot ◽  
Cortical Responses ◽  
Different Ages ◽  
Evoked Activity ◽  
The Individual

1. The development of cortical responses to somatic stimulation was studied in kittens 2-5 wk of age using the 2-deoxyglucose (2DG) technique. During the 2DG experiment each kitten received an innocuous intermittent vertical displacement stimulus to the forepaw. 2. The pattern of metabolic activity was substantially different in young animals compared with adults. In the individual autoradiographs of the 2-wk-old kittens stimulus-evoked 2DG uptake in primary somatosensory cortex was localized to a small spot in the upper portion of the cortex, whereas in the adult the label extended vertically through the cortical layers and appeared more column-like. Individual patches of label were substantially smaller and less dense in young animals. Over a period of several weeks the evoked activity evolved to the more extensive adult pattern. The 2DG uptake displayed a mature distribution by approximately 4-5 wk of age. During this period, the cortical architecture also evolved from an immature to a mature arrangement. 3. The evoked activity was reconstructed into two-dimensional maps; the distribution of label > or = 1.5 SD above background was considered to be stimulus related. In the adult, the pattern appeared as a strip or strips of increased metabolic activity that extended in the rostrocaudal direction for approximately 1 mm. In contrast, the activity pattern in animals 2-4 wk old was less discretely organized into "strips" and was more diffusely spread over several mms of somatosensory cortex. The two-dimensional pattern gradually coalesced into a more localized strip by approximately 4-5 wk of age. Although the pattern of label was more widespread in the young animals, the absolute distance of the spread of activity did not vary substantially, regardless of the age of the animal. 4. Other measurements regarding the distribution of activity at different ages indicate that the amount of cortex activated increases in absolute terms, although the percent of cortex activated by the stimulus decreases. The overall intensity of the 2DG uptake as measured on the two-dimensional maps increases with age, as does the variability of the 2DG uptake; a wider range of intensity values is seen in the adult. Plots created from the individual two-dimensional reconstructions allowed a measure of "patch strength" at different ages. These histograms relate the most intense region of uptake in a given map to the spatial distribution of activity spreading in the medial and lateral directions.(ABSTRACT TRUNCATED AT 400 WORDS)

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