scholarly journals Behavioral and Neural Aspects of the Spatial Processing of Conspecifics in the Electrosensory System

2019 ◽  
Author(s):  
Oak Milam ◽  
Keshav L. Ramachandra ◽  
Gary Marsat
Keyword(s):  
Spatial Information ◽  
Sensory Systems ◽  
Model Systems ◽  
Current Understanding ◽  
Spatial Processing ◽  
Electrosensory System ◽  
Noisy Signals ◽  
Auditory Systems

Localizing the source of a signal is often as important as deciphering the signal’s message. Localization mechanisms must cope with the challenges of representing the spatial information of weak, noisy signals. Comparing these strategies across modalities and model systems allows a broader understanding of the general principles shaping spatial processing. In this review we focus on the electrosensory system of knifefish and provide an overview of our current understanding of spatial processing in this system, in particular, localization of conspecific signals. We argue that many mechanisms observed in other sensory systems, such as the visual or auditory systems, have comparable implementations in the electrosensory system. Our review therefore describes a field of research with unique opportunities to provide new insights into the principles underlying spatial processing.

scholarly journals Behavioral and Neural Aspects of the Spatial Processing of Conspecifics in the Electrosensory System

2018 ◽  
Author(s):  
Oak Milam ◽  
Keshav L. Ramachandra ◽  
Gary Marsat
Keyword(s):  
Spatial Information ◽  
Sensory Systems ◽  
Model Systems ◽  
Current Understanding ◽  
Spatial Processing ◽  
Electrosensory System ◽  
Noisy Signals ◽  
Auditory Systems

Localizing the source of a signal is often as important as deciphering the signal’s message. Localization mechanisms must cope with the challenges of representing the spatial information of weak, noisy signals. Comparing these strategies across modalities and model systems allows a broader understanding of the general principles shaping spatial processing. In this review we focus on the electrosensory system of knifefish and provide an overview of our current understanding of spatial processing in this system, in particular, localization of conspecific signals. We argue that many mechanisms observed in other sensory systems, such as the visual or auditory systems, have comparable implementations in the electrosensory system. Our review therefore describes a field of research with unique opportunities to provide new insights into the principles underlying spatial processing.

Auditory Systems of Drosophila and Other Invertebrates

2017 ◽  
pp. 302-318
Author(s):  
Yun Doo Chung ◽  
Jeongmi Lee
Keyword(s):  
Pattern Recognition ◽  
Sound Localization ◽  
Current Understanding ◽  
Auditory Information ◽  
Neural Processing ◽  
Recent Event ◽  
Auditory Systems ◽  
Intraspecific Communication ◽  
Basic Features ◽  
Electric Signals

Hearing in invertebrates has evolved independently as an adaptation to avoid predators or to mediate intraspecific communication. Although many invertebrate groups are able to respond to sound stimuli, insects are the only group in which hearing is widely used. Therefore, we will focus here on the auditory systems of some well-known insect models. Appearance of the ability to perceive sound in insects is presumably a quite recent event in evolution. As a result of independent evolution, diverse types of hearing organs are evolved in insects. Here we will introduce basic features of insect ears and the mechanisms through which sound stimuli are converted into neuronal electric signals. We will also summarize our current understanding of neural processing of auditory information, including tonotopy, sound localization, and pattern recognition.

scholarly journals Decoding Spatial Versus Non-spatial Processing in Auditory Working Memory

2021 ◽  
Vol 15 ◽  
Author(s):  
Mira Erhart ◽  
Stefan Czoschke ◽  
Cora Fischer ◽  
Christoph Bledowski ◽  
Jochen Kaiser
Keyword(s):  
Working Memory ◽  
Multivariate Analysis ◽  
Spatial Information ◽  
Temporal Cortex ◽  
Spatial Processing ◽  
Whole Brain ◽  
Activation Patterns ◽  
Spatial Sound ◽  
Stimulus Features ◽  
Sound Features

ObjectiveResearch on visual working memory has shown that individual stimulus features are processed in both specialized sensory regions and higher cortical areas. Much less evidence exists for auditory working memory. Here, a main distinction has been proposed between the processing of spatial and non-spatial sound features. Our aim was to examine feature-specific activation patterns in auditory working memory.MethodsWe collected fMRI data while 28 healthy adults performed an auditory delayed match-to-sample task. Stimuli were abstract sounds characterized by both spatial and non-spatial information, i.e., interaural time delay and central frequency, respectively. In separate recording blocks, subjects had to memorize either the spatial or non-spatial feature, which had to be compared with a probe sound presented after a short delay. We performed both univariate and multivariate comparisons between spatial and non-spatial task blocks.ResultsProcessing of spatial sound features elicited a higher activity in a small cluster in the superior parietal lobe than did sound pattern processing, whereas there was no significant activation difference for the opposite contrast. The multivariate analysis was applied using a whole-brain searchlight approach to identify feature-selective processing. The task-relevant auditory feature could be decoded from multiple brain regions including the auditory cortex, posterior temporal cortex, middle occipital gyrus, and extended parietal and frontal regions.ConclusionIn summary, the lack of large univariate activation differences between spatial and non-spatial processing could be attributable to the identical stimulation in both tasks. In contrast, the whole-brain multivariate analysis identified feature-specific activation patterns in widespread cortical regions. This suggests that areas beyond the auditory dorsal and ventral streams contribute to working memory processing of auditory stimulus features.

Spatial Processing and Perceptual Sequence Learning in SRT Tasks

2006 ◽  
Vol 53 (1) ◽  
pp. 16-30 ◽  
Author(s):  
Natacha Deroost ◽  
Eric Soetens
Keyword(s):  
Perceptual Learning ◽  
Sequence Learning ◽  
Crucial Role ◽  
Spatial Information ◽  
Relevant Information ◽  
The Other ◽  
Spatial Processing ◽  
Target Pair ◽  
Endogenous Attention ◽  
Different Order

We investigated the influence of processing relevant spatial information on learning a probabilistic sequence of irrelevant locations. Using the SRT design of Remillard (2003 ), we found that spatial perceptual learning occurs with paired but not with single targets. The pairs of targets consisted of the same stimuli, but in a different order, so that responses could have been based on the left-right location of an element, relative to the other element of the pair. The prerequisite of spatial pairs of targets suggests that spatial processing of relevant information plays a crucial role in perceptual location learning. In addition, spatial perceptual learning only took place when the target pair was presented together with other stimuli, but was absent when the target pair was presented in a blank field. Since in the latter case attention is automatically captured, this suggests that sequence learning requires endogenous attention.

scholarly journals Task-specific sensory coding strategies matched to detection and discrimination behaviors in Apteronotus leptorhynchus

2017 ◽  
Author(s):  
K.M. Allen ◽  
G. Marsat
Keyword(s):  
General Principle ◽  
Neural Coding ◽  
Sensory Systems ◽  
Model Systems ◽  
Behavioral Performance ◽  
Sensory Coding ◽  
Apteronotus Leptorhynchus ◽  
Neural Codes ◽  
Coding Strategies ◽  
Behavioral Tasks

ABSTRACTAll sensory systems must reliably translate information about the environment into a neural code, mediating perception. The most relevant aspects of stimuli may change as behavioral context changes, making efficient encoding of information more challenging. Sensory systems must balance rapid detection of a stimulus with perception of fine details that enable discrimination between similar stimuli. We show that in a species of weakly electric fish, Apteronotus leptorhynchus, two coding strategies are employed for these separate behavioral tasks. Using communication signals produced in different contexts, we demonstrate a strong correlation between neural coding strategies and behavioral performance on a discrimination task. Extracellular recordings of pyramidal cells within the electrosensory lateral line lobe of alert fish show two distinct response patterns, either burst discharges with little variation between different signals of the same category, or a graded, heterogeneous response that contains enough information to discriminate between signals with slight variations. When faced with a discrimination-based task, the behavioral performance of the fish closely matches predictions based on coding strategy. Comparisons of these results with neural and behavioral responses observed in other model systems suggest that our study highlights a general principle in the way different neural codes are utilized in the sensory system.SIGNIFICANCE STATEMENTResearch relating the structure of stimuli to the response of sensory neurons has left us with a detailed understanding of how different neural codes can represent information. Although various aspects of neural responses have been related to perceptual abilities, general principles relating behavioral tasks to sensory coding strategies are lacking. A major distinction can be made between signals that must simply be detected versus stimuli that must also be finely discriminated and evaluated. We show that these two different perceptual tasks are systematically matched by distinct neural coding strategies and we argue that our study identifies a general principle that is observed in various sensory systems.Conflict of interest statementThe authors declare no competing financial interests.

scholarly journals Emergent phenomena at multiferroic heterointerfaces

2012 ◽  
Vol 370 (1977) ◽  
pp. 4856-4871 ◽  
Author(s):  
P. Yu ◽  
Y. H. Chu ◽  
R. Ramesh
Keyword(s):  
Degrees Of Freedom ◽  
Magnetic State ◽  
Model Systems ◽  
Current Understanding ◽  
Interesting Phenomenon ◽  
Future Studies ◽  
Exotic States ◽  
Emergent Phenomena ◽  
Open Questions ◽  
Multiferroic Bifeo

The coupling and reconstruction of electronic degrees of freedom (such as charge, spin and orbital) at a heterointerface can lead to unexpected and exotic states of matter. In this study, using model systems consisting of multiferroic BiFeO 3 and ferromagnetic La 0.7 Sr 0.3 MnO 3 , we review the current understanding of a novel interfacial magnetic state formed at the interface, and highlight some possible mechanisms responsible for this interesting phenomenon and identify open questions for future studies.

scholarly journals Anticancer Properties of Graviola (Annona muricata): A Comprehensive Mechanistic Review

2018 ◽  
Vol 2018 ◽  
pp. 1-39 ◽  
Author(s):  
Islam Rady ◽  
Melissa B. Bloch ◽  
Roxane-Cherille N. Chamcheu ◽  
Sergette Banang Mbeumi ◽  
Md Rafi Anwar ◽  
...  
Keyword(s):  
Model Systems ◽  
Current Understanding ◽  
Annona Muricata ◽  
Bioactive Constituents ◽  
Annonaceous Acetogenins ◽  
Plant Parts ◽  
Anticancer Properties ◽  
Disease States ◽  
Therapeutic Benefits

Graviola (Annona muricata) is a small deciduous tropical evergreen fruit tree, belonging to the Annonaceae family, and is widely grown and distributed in tropical and subtropical regions around the world. The aerial parts of graviola have several functions: the fruits have been widely used as food confectionaries, while several preparations, especially decoctions of the bark, fruits, leaves, pericarp, seeds, and roots, have been extensively used in traditional medicine to treat multiple ailments including cancers by local communities in tropical Africa and South America. The reported therapeutic benefits of graviola against various human tumors and disease agents in in vitro culture and preclinical animal model systems are typically tested for their ability to specifically target the disease, while exerting little or no effect on normal cell viability. Over 212 phytochemical ingredients have been reported in graviola extracts prepared from different plant parts. The specific bioactive constituents responsible for the major anticancer, antioxidant, anti-inflammatory, antimicrobial, and other health benefits of graviola include different classes of annonaceous acetogenins (metabolites and products of the polyketide pathway), alkaloids, flavonoids, sterols, and others. This review summarizes the current understanding of the anticancer effects of A. muricata and its constituents on diverse cancer types and disease states, as well as efficacy and safety concerns. It also includes discussion of our current understanding of possible mechanisms of action, with the hope of further stimulating the development of improved and affordable therapies for a variety of ailments.

scholarly journals Object size determines the spatial spread of visual time

2016 ◽  
Vol 283 (1835) ◽  
pp. 20161024 ◽  
Author(s):  
Corinne Fulcher ◽  
Paul V. McGraw ◽  
Neil W. Roach ◽  
David Whitaker ◽  
James Heron
Keyword(s):  
Visual Processing ◽  
Spatial Information ◽  
Spatial Processing ◽  
Event Duration ◽  
Spatial Spread ◽  
After Effects ◽  
Neuronal Populations ◽  
After Effect ◽  
Orderly Arrangement ◽  
Perceived Duration

A key question for temporal processing research is how the nervous system extracts event duration, despite a notable lack of neural structures dedicated to duration encoding. This is in stark contrast with the orderly arrangement of neurons tasked with spatial processing. In this study, we examine the linkage between the spatial and temporal domains. We use sensory adaptation techniques to generate after-effects where perceived duration is either compressed or expanded in the opposite direction to the adapting stimulus' duration. Our results indicate that these after-effects are broadly tuned, extending over an area approximately five times the size of the stimulus. This region is directly related to the size of the adapting stimulus—the larger the adapting stimulus the greater the spatial spread of the after-effect. We construct a simple model to test predictions based on overlapping adapted versus non-adapted neuronal populations and show that our effects cannot be explained by any single, fixed-scale neural filtering. Rather, our effects are best explained by a self-scaled mechanism underpinned by duration selective neurons that also pool spatial information across earlier stages of visual processing.

Personal View: The barn owl — a specialist for studying sensory systems

Neuroforum ◽  
2019 ◽  
Vol 25 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Hermann Wagner
Keyword(s):  
Auditory Processing ◽  
Fruit Fly ◽  
Barn Owl ◽  
Sensory Systems ◽  
Model Systems ◽  
Ecological Niches ◽  
Personal View ◽  
California Institute Of Technology ◽  
Institute Of Technology ◽  
The Impact

Abstract In this personal view article, the impact of an auditory specialist, the barn owl, to our understanding of sensory processing, especially auditory processing, is discussed from the perspective of a long-lasting career. In times when research on model systems such as the mouse or the fruit fly, both generalists for most of the behaviors examined, celebrates big successes, one may ask what the work on animals occupying specialized niches, “specialists”, can contribute to advance our knowledge about sensory systems. A specialist in this context is an animal that occupies a certain ecological niche and shows corresponding adaptations in anatomy and physiology. This article presents a personal view on the impact of the work on such a specialist. In my article I shall focus on audition in the barn owl, a specialist for hunting by listening. I started my scientific career in 1979, working with houseflies, and have worked with barn owls since my time as a postdoc at the California Institute of Technology (“Caltech”, Pasadena, CA, USA) in 1985. My interest in specialists derived from my work as an ornithologist when I realized that adaptations like the long and curved bill of the curlew help animals to occupy certain ecological niches. I wanted to understand in a formal sense, and in comparison to engineering, how evolution shapes such specializations.

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