directed information
Recently Published Documents


TOTAL DOCUMENTS

183
(FIVE YEARS 34)

H-INDEX

20
(FIVE YEARS 2)

2021 ◽  
Author(s):  
Douglas D Gaffin ◽  
Maria G Muñoz ◽  
Mariëlle H Hoefnagels

The Navigation by Chemotextural Familiarity Hypothesis (NCFH) suggests that scorpions use their midventral pectines to gather chemical and textural information near their burrows and use this information as they subsequently return home. For NCFH to be viable, animals must somehow acquire home-directed ″tastes″ of the substrate, such as through path integration (PI) and/or learning walks. We conducted laboratory behavioral trials using desert grassland scorpions (Paruroctonus utahensis). Animals reliably formed burrows in small mounds of sand we provided in the middle of circular, sand lined behavioral arenas. We processed overnight infrared video recordings with a MATLAB script that tracked animal movements at 1-2 s intervals. In all, we analyzed the movements of 23 animals, representing nearly 1500 hours of video recording. We found that once animals established their home burrows, they immediately made one to several short, looping excursions away from and back to their burrows before walking greater distances. We also observed similar excursions when animals made burrows in level sand in the middle of the arena (i.e., no mound provided). These putative learning walks, together with recently reported PI in scorpions, may provide the crucial home-directed information requisite for NCFH.


2021 ◽  
Vol 15 ◽  
Author(s):  
Tie Liang ◽  
Qingyu Zhang ◽  
Lei Hong ◽  
Xiaoguang Liu ◽  
Bin Dong ◽  
...  

As a common neurophysiological phenomenon, voluntary muscle fatigue is accompanied by changes in both the central nervous system and peripheral muscles. Considering the effectiveness of the muscle network and the functional corticomuscular coupling (FCMC) in analyzing motor function, muscle fatigue can be analyzed by quantitating the intermuscular coupling and corticomuscular coupling. However, existing coherence-based research on muscle fatigue are limited by the inability of the coherence algorithm to identify the coupling direction, which cannot further reveal the underlying neural mechanism of muscle fatigue. To address this problem, we applied the time-delayed maximal information coefficient (TDMIC) method to quantitate the directional informational interaction in the muscle network and FCMC during a right-hand stabilized grip task. Eight healthy subjects were recruited to the present study. For the muscle networks, the beta-band information flow increased significantly due to muscle fatigue, and the information flow between the synergist muscles were stronger than that between the synergist and antagonist muscles. The information flow in the muscle network mainly flows to flexor digitorum superficialis (FDS), flexor carpi ulnar (FCU), and brachioradialis (BR). For the FCMC, muscle fatigue caused a significant decrease in the beta- and gamma-band bidirectional information flow. Further analysis revealed that the beta-band information flow was significantly stronger in the descending direction [electroencephalogram (EEG) to surface electromyography (sEMG)] than that in the ascending direction (sEMG to EEG) during pre-fatigue tasks. After muscle fatigue, the beta-band information flow in the ascending direction was significantly stronger than that in the descending direction. The present study demonstrates the influence of muscle fatigue on information flow in muscle networks and FCMC. We proposes that beta-band intermuscular and corticomuscular informational interaction plays an adjusting role in autonomous movement completion under muscle fatigue. Directed information flow analysis can be used as an effective method to explore the neural mechanism of muscle fatigue on the macroscopic scale.


2021 ◽  
Author(s):  
Francisco García-Rosales ◽  
Luciana López-Jury ◽  
Eugenia González-Palomarez ◽  
Johannes Wetekam ◽  
Yuranny Cabral-Calderin ◽  
...  

Abstract The mammalian frontal and auditory cortices are fundamental structures supporting vocal behaviour, yet the patterns of information exchange between these regions during vocalization remain unknown. Here, we address this issue by means of electrophysiological recordings in the fronto-auditory network of freely-vocalizing Carollia perspicillata bats. We show that oscillations in frontal and auditory cortices predict vocalization type with complementary patterns across structures. Transfer entropy analyses of oscillatory activity revealed directed information exchange in the circuit, predominantly of top-down nature (frontal to auditory). The dynamics of information flow depended on vocalization type and on the timing relative to vocal onset. Remarkably, we observed the emergence of predominant bottom-up information transfer, only when animals produced calls with imminent post-vocal consequences (echolocation signals). These results unveil changes of information flow in a large-scale sensory and association network associated to the behavioural consequences of vocalization in a highly vocal mammalian model.  


Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 533
Author(s):  
Milan S. Derpich ◽  
Jan Østergaard

We present novel data-processing inequalities relating the mutual information and the directed information in systems with feedback. The internal deterministic blocks within such systems are restricted only to be causal mappings, but are allowed to be non-linear and time varying, and randomized by their own external random input, can yield any stochastic mapping. These randomized blocks can for example represent source encoders, decoders, or even communication channels. Moreover, the involved signals can be arbitrarily distributed. Our first main result relates mutual and directed information and can be interpreted as a law of conservation of information flow. Our second main result is a pair of data-processing inequalities (one the conditional version of the other) between nested pairs of random sequences entirely within the closed loop. Our third main result introduces and characterizes the notion of in-the-loop (ITL) transmission rate for channel coding scenarios in which the messages are internal to the loop. Interestingly, in this case the conventional notions of transmission rate associated with the entropy of the messages and of channel capacity based on maximizing the mutual information between the messages and the output turn out to be inadequate. Instead, as we show, the ITL transmission rate is the unique notion of rate for which a channel code attains zero error probability if and only if such an ITL rate does not exceed the corresponding directed information rate from messages to decoded messages. We apply our data-processing inequalities to show that the supremum of achievable (in the usual channel coding sense) ITL transmission rates is upper bounded by the supremum of the directed information rate across the communication channel. Moreover, we present an example in which this upper bound is attained. Finally, we further illustrate the applicability of our results by discussing how they make possible the generalization of two fundamental inequalities known in networked control literature.


2021 ◽  
Author(s):  
Francisco García-Rosales ◽  
Luciana López-Jury ◽  
Eugenia Gonzalez-Palomares ◽  
Johannes Wetekam ◽  
Yuranny Cabral-Calderín ◽  
...  

AbstractThe mammalian frontal and auditory cortices are fundamental structures supporting vocal production, yet the dynamics of information exchange between these regions during vocalization are unknown. Here, we tackle this issue by means of electrophysiological recordings in the fronto-auditory network of freely-vocalizing Carollia perspicillata bats. We find that oscillations in frontal and auditory cortices provide correlates of vocal production with complementary patterns across structures. Causality analyses of oscillatory activity revealed directed information exchange in the network, predominantly of top-down nature (frontal to auditory). Such directed connectivity was dynamic, as it depended on the type of vocalization produced, and on the timing relative to vocal onset. Remarkably, we observed the emergence of bottom-up information transfer only when bats produced calls with evident post-vocal consequences (echolocation pulses). Our results link vocal production to dynamic information transfer between sensory (auditory) and association areas in a highly vocal mammalian animal model.


Author(s):  
Joseph Young ◽  
Curtis L Neveu ◽  
John H Byrne ◽  
Behnaam Aazhang

Sign in / Sign up

Export Citation Format

Share Document