Neural coding of nociceptive stimuli—from rat spinal neurones to human perception

Pain ◽  
2013 ◽  
Vol 154 (8) ◽  
pp. 1263-1273 ◽  
Author(s):  
Shafaq Sikandar ◽  
Irene Ronga ◽  
Gian Domenico Iannetti ◽  
Anthony H. Dickenson
2013 ◽  
Vol 110 (5) ◽  
pp. 1190-1204 ◽  
Author(s):  
Maria Ter-Mikaelian ◽  
Malcolm N. Semple ◽  
Dan H. Sanes

Animal communication sounds contain spectrotemporal fluctuations that provide powerful cues for detection and discrimination. Human perception of speech is influenced both by spectral and temporal acoustic features but is most critically dependent on envelope information. To investigate the neural coding principles underlying the perception of communication sounds, we explored the effect of disrupting the spectral or temporal content of five different gerbil call types on neural responses in the awake gerbil's primary auditory cortex (AI). The vocalizations were impoverished spectrally by reduction to 4 or 16 channels of band-passed noise. For this acoustic manipulation, an average firing rate of the neuron did not carry sufficient information to distinguish between call types. In contrast, the discharge patterns of individual AI neurons reliably categorized vocalizations composed of only four spectral bands with the appropriate natural token. The pooled responses of small populations of AI cells classified spectrally disrupted and natural calls with an accuracy that paralleled human performance on an analogous speech task. To assess whether discharge pattern was robust to temporal perturbations of an individual call, vocalizations were disrupted by time-reversing segments of variable duration. For this acoustic manipulation, cortical neurons were relatively insensitive to short reversal lengths. Consistent with human perception of speech, these results indicate that the stable representation of communication sounds in AI is more dependent on sensitivity to slow temporal envelopes than on spectral detail.


2016 ◽  
Author(s):  
Paul M Bays

AbstractSimple visual features, such as orientation, are thought to be represented in the spiking of visual neurons using population codes. I show that optimal decoding of such activity predicts characteristic deviations from the normal distribution of errors at low gains. Examining human perception of orientation stimuli, I show that these predicted deviations are present at near-threshold levels of contrast. The findings may provide a neural-level explanation for the appearance of a threshold in perceptual awareness, whereby stimuli are categorized as seen or unseen. As well as varying in error magnitude, perceptual judgments differ in certainty about what was observed. I demonstrate that variations in the total spiking activity of a neural population can account for the empirical relationship between subjective confidence and precision. These results establish population coding and decoding as the neural basis of perception and perceptual confidence.


1996 ◽  
Vol 75 (6) ◽  
pp. 2369-2379 ◽  
Author(s):  
C. R. Plata-Salaman ◽  
V. L. Smith-Swintosky ◽  
T. R. Scott

1. Psychophysicists have shown that the intensity and quality of a taste stimulus, as perceived by humans, is modified by including that stimulus in a mixture. Gustatory neurons in the primary taste cortex (anterior insula and frontal operculum) of the cynomolgus macaque are involved with the coding of stimulus intensity and quality, and so should reflect the impact of these stimulus interactions. 2. We recorded the activity of 48 neurons in primary taste cortex in response to the oral application of each of the four basic stimuli, their six possible dyads, the four triads, and the tetrad of all four. Stimuli were maintained at a constant intensity in all mixtures by increasing their concentrations as the number of components rose. 3. Glucose was the most effective basic stimulus, followed by quinine HCl, NaCl, and HCl. The mean response to dyads was suppressed by 50% from the sum of responses to the two unmixed components. The response to triads was 62% lower than the sum of responses to their three components, and activity evoked by the tetrad was suppressed by 74% from the sum of all four individual responses. Therefore there was nearly total suppression in the sense that the responses to the mixtures were approximately 1/2, 1/3, and 1/4 the sums of responses to two, three, and four components, respectively. 4. Neurons could be divided into four subtypes: those that responded best to each of the basic stimuli. All subtypes except HCl cells were about equally suppressed when their preferred stimulus was included in a mixture. HCl was a particularly ineffective stimulus, such that this subtype responded poorly and so was less susceptible to mixture suppression. 5. Taste quality, as indexed by correlation coefficients among profiles of activity, was quite predictable for dyads. If the mixture included HCl, the profile it generated correlated poorly (about +0.20) with that of HCl and rather well (about +0.60) with that of the other component. If HCl was not included, the mixture's profile correlated about +0.40 with that of each component. 6. The profile generated by the mixture of three stimuli was predictable only if one of the components was HCl. In that case, the triad elicited a profile midway between those of the other two components, i.e., the contribution of HCl was largely ignored. When HCl was not involved, or when all four basic stimuli were combined, the resulting profiles were poorly correlated with those of all basic stimuli. 7. The contribution made by each basic taste to human perception and to the macaque's neurophysiological response was compared for all mixtures. The contribution was often quite similar for human and macaque, but when differences occurred, they were typically due to lower activity from HCl cells in the macaque, a loss that was replaced mainly by larger responses from glucose neurons. 8. The magnitude of responses to mixtures in the macaque taste cortex matches well with expectations from human psychophysical studies. The presumed quality of the response to mixtures is also similar, except that HCl is less effective in monkeys and sugars more so.


2019 ◽  
Vol 42 ◽  
Author(s):  
Giulia Frezza ◽  
Pierluigi Zoccolotti

Abstract The convincing argument that Brette makes for the neural coding metaphor as imposing one view of brain behavior can be further explained through discourse analysis. Instead of a unified view, we argue, the coding metaphor's plasticity, versatility, and robustness throughout time explain its success and conventionalization to the point that its rhetoric became overlooked.


2018 ◽  
Vol 3 (6) ◽  
pp. 61-76
Author(s):  
Leslie D. Grush ◽  
Frederick J. Gallun ◽  
Curtis J. Billings
Keyword(s):  

2017 ◽  
Vol 131 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Marianne T. E. Heberlein ◽  
Dennis C. Turner ◽  
Marta B. Manser

2012 ◽  
Author(s):  
R. A. Grier ◽  
H. Thiruvengada ◽  
S. R. Ellis ◽  
P. Havig ◽  
K. S. Hale ◽  
...  

Author(s):  
Rajesh Kumar Gupta ◽  
L. N. Padhy ◽  
Sanjay Kumar Padhi

Traffic congestion on road networks is one of the most significant problems that is faced in almost all urban areas. Driving under traffic congestion compels frequent idling, acceleration, and braking, which increase energy consumption and wear and tear on vehicles. By efficiently maneuvering vehicles, traffic flow can be improved. An Adaptive Cruise Control (ACC) system in a car automatically detects its leading vehicle and adjusts the headway by using both the throttle and the brake. Conventional ACC systems are not suitable in congested traffic conditions due to their response delay.  For this purpose, development of smart technologies that contribute to improved traffic flow, throughput and safety is needed. In today’s traffic, to achieve the safe inter-vehicle distance, improve safety, avoid congestion and the limited human perception of traffic conditions and human reaction characteristics constrains should be analyzed. In addition, erroneous human driving conditions may generate shockwaves in addition which causes traffic flow instabilities. In this paper to achieve inter-vehicle distance and improved throughput, we consider Cooperative Adaptive Cruise Control (CACC) system. CACC is then implemented in Smart Driving System. For better Performance, wireless communication is used to exchange Information of individual vehicle. By introducing vehicle to vehicle (V2V) communication and vehicle to roadside infrastructure (V2R) communications, the vehicle gets information not only from its previous and following vehicle but also from the vehicles in front of the previous Vehicle and following vehicle. This enables a vehicle to follow its predecessor at a closer distance under tighter control.


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