scholarly journals Ongoing electroencephalographic rhythms related to exploratory movements in transgenic TASTPM mice

2020 ◽  
Vol 16 (S4) ◽  
Author(s):  
Federico Tucci ◽  
Claudio Del Percio ◽  
Wilhelmus (Pim) Drinkenburg ◽  
Susanna Lopez ◽  
Maria Teresa Pascarelli ◽  
...  
Keyword(s):  
Exploratory Movements

scholarly journals Green morays (Gymnothorax funebris) have sedentary ways in mangrove bays, but also ontogenetic forays to reef enclaves

2021 ◽  
Author(s):  
Matthew S. Kendall ◽  
Laughlin Siceloff ◽  
Ashley Ruffo ◽  
Arliss Winship ◽  
Mark E. Monaco
Keyword(s):  
Home Range ◽  
Site Fidelity ◽  
Home Range Size ◽  
Range Size ◽  
Caribbean Region ◽  
History Of ◽  
High Site ◽  
Single Night ◽  
Exploratory Movements ◽  
Moray Eel

AbstractSurprisingly, little is known about basic life history of the largest moray eel species in the Caribbean region, the green moray eel (Gymnothorax funebris). Sixteen eels were captured from the mangrove fringe in multiple bays on St. Croix, USVI, implanted with coded acoustic transmitters, and their movements were tracked for up to 11 months using an array of 37 stationary acoustic receivers. They exhibited high site fidelity in the bays during their residence, using the same general parts of individual bays and did not switch bays except for one individual. There was no relationship between eel size (mean TL = 83 cm, range = 54–126 cm) and home range size (mean area of 95% KUD = 5.8 ha ± 0.7 SE). Most individuals were more frequently detected at night than during the day suggesting greater nocturnal activity. Several of the larger eels (mean TL = 93 cm ± 5.9 SE) showed clear and permanent emigration tracks out of the mangrove estuary to coral reef habitats offshore. For some individuals, these habitat shifts were preceded by exploratory movements away from the eel’s typical home range the night before emigration. All final emigration events took place nocturnally, happened during a single night, and occurred during months from December to May. Mean emigration speed was 3.4 km/h. This study is the first documentation of an ontogenetic habitat shift in moray eels, as well as the first determination of home range size for this species and their site fidelity in mangrove habitats.

The supine position of postnatal human infants

2009 ◽  
Vol 10 (2) ◽  
pp. 252-269 ◽  
Author(s):  
Hideko Takeshita ◽  
Masako Myowa-Yamakoshi ◽  
Satoshi Hirata
Keyword(s):  
Supine Position ◽  
Postnatal Period ◽  
The Body ◽  
Body Parts ◽  
Human Infants ◽  
Face To Face ◽  
Developmental Continuity ◽  
Exploratory Movements ◽  
Locomotor Ability ◽  
Development And Evolution

In this review, we discuss the implications of placing an infant in the supine position with respect to human cognitive development and evolution. When human infants are born, they are relatively large and immature in terms of postural and locomotor ability as compared with their closest relatives, the great apes. Hence, human mothers seemingly adopt a novel pattern of caring for their large and heavy infants, i.e., placing their infants in the supine position; this promotes face-to-face communication with their infants. Moreover, infants in the supine position can interact with other nearby individuals in the same manner from an early age. In addition, the infants can also explore their own body parts and/or objects with their hands since the hands are not required to support the body and are therefore, free to move. These activities are considered to be fundamental to the early development of human social and nonsocial cognition, including knowledge of self, in the first six months after birth. Further, developmental continuity in the voluntary exploratory movements in the prenatal period (in utero) to the early postnatal period is also discussed.

Learning and exploration: Lessons from infants

2001 ◽  
Vol 24 (2) ◽  
pp. 213-214 ◽  
Author(s):  
Karen E. Adolph ◽  
Ludovic M. Marin ◽  
Frederic F. Fraisse
Keyword(s):  
Exploratory Movements

Based on studies with infants, we expand on Stoffregen & Bardy's explanation of perceptual motor errors, given the global array. Information pick-up from the global array is not sufficient without adequate exploratory movements and learning to support perceptually guided activity.

scholarly journals Emergence of an invariant representation of texture in primate somatosensory cortex

2019 ◽  
Author(s):  
Justin D. Lieber ◽  
Sliman J. Bensmaia
Keyword(s):  
Cortical Neurons ◽  
Rhesus Macaques ◽  
Scanning Speed ◽  
Nerve Fibers ◽  
Invariant Representation ◽  
Major Function ◽  
Neural Representations ◽  
Wide Range ◽  
Sensory Modalities ◽  
Exploratory Movements

ABSTRACTA major function of sensory processing is to achieve neural representations of objects that are stable across changes in context and perspective. Small changes in exploratory behavior can lead to large changes in signals at the sensory periphery, thus resulting in ambiguous neural representations of objects. Overcoming this ambiguity is a hallmark of human object recognition across sensory modalities. Here, we investigate how the perception of tactile texture remains stable across exploratory movements of the hand, including changes in scanning speed, despite the concomitant changes in afferent responses. To this end, we scanned a wide range of everyday textures across the fingertips of Rhesus macaques at multiple speeds and recorded the responses evoked in tactile nerve fibers and somatosensory cortical neurons. We found that individual cortical neurons exhibit a wider range of speed-sensitivities than do nerve fibers. The resulting representations of speed and texture in cortex are more independent than are their counterparts in the nerve and account for speed-invariant perception of texture. We demonstrate that this separation of speed and texture information is a natural consequence of previously described cortical computations.

How Prior Reward Experience Biases Exploratory Movements: A Probabilistic Model

2007 ◽  
Vol 97 (3) ◽  
pp. 2083-2093 ◽  
Author(s):  
Paul W. German ◽  
Howard L. Fields
Keyword(s):  
Probability Distribution ◽  
Computer Simulations ◽  
Probabilistic Model ◽  
Probabilistic Models ◽  
Neural Mechanisms ◽  
Behavioral Strategy ◽  
Line Configuration ◽  
Before And After ◽  
Exit Probabilities ◽  
Exploratory Movements

Animals return to rewarded locations. An example of this is conditioned place preference (CPP), which is widely used in studies of drug reward. Although CPP is expressed as increased time spent in a previously rewarded location, the behavioral strategy underlying this change is unknown. We continuously monitored rats ( n = 22) in a three-room in-line configuration, before and after morphine conditioning in one end room. Although sequential room visit durations were variable, their probability distribution was exponential, indicating that the processes controlling visit durations can be modeled by instantaneous room exit probabilities. Further analysis of room transitions and computer simulations of probabilistic models revealed that the exploratory bias toward the morphine room is best explained by an increase in the probability of a subset of rapid, direct transitions from the saline- to the morphine-paired room by the central room. This finding sharply delineates and constrains possible neural mechanisms for a class of self-initiated, goal-directed behaviors toward previously rewarded locations.

scholarly journals Kinematics of unconstrained tactile texture exploration

2015 ◽  
Vol 113 (7) ◽  
pp. 3013-3020 ◽  
Author(s):  
Thierri Callier ◽  
Hannes P. Saal ◽  
Elizabeth C. Davis-Berg ◽  
Sliman J. Bensmaia
Keyword(s):  
Neural Coding ◽  
Scanning Speed ◽  
Perceptual Task ◽  
Textured Surfaces ◽  
Cutaneous Mechanoreceptors ◽  
Texture Information ◽  
Different Types ◽  
Exploratory Movements

A hallmark of tactile texture exploration is that it involves movement between skin and surface. When we scan a surface, small texture-specific vibrations are produced in the skin, and specialized cutaneous mechanoreceptors convert these vibrations into highly repeatable, precise, and informative temporal spiking patterns in tactile afferents. Both texture-elicited vibrations and afferent responses are highly dependent on exploratory kinematics, however; indeed, these dilate or contract systematically with decreases or increases in scanning speed, respectively. These profound changes in the peripheral response that accompany changes in scanning speed and other parameters of texture scanning raise the question as to whether exploratory behaviors change depending on what surface is explored or what information is sought about that surface. To address this question, we measure and analyze the kinematics as subjects explore textured surfaces to evaluate different types of texture information, namely the textures' roughness, hardness, and slipperiness. We find that the exploratory movements are dependent both on the perceptual task, as has been previously shown, but also on the texture that is scanned. We discuss the implications of our findings regarding the neural coding and perception of texture.

Notes on age at dispersal of beaver (Castor fiber) in an expanding population

1997 ◽  
Vol 75 (6) ◽  
pp. 959-962 ◽  
Author(s):  
Göran Hartman
Keyword(s):  
Castor Fiber ◽  
Rate Of Increase ◽  
Expanding Population ◽  
Exploratory Movements

Movements of nine young beavers (Castor fiber) that were trapped at the front of an expanding population were monitored using radiotelemetry. Two years is generally considered the normal age at dispersal in beavers, but in this study the ages at dispersal were evenly distributed between 11 and 23 months. At least one of the females in the study gave birth at 2 years of age. Exploratory movements of three individuals outside the natal terrritory before the time of dispersal were observed. The observed plasticity in age at dispersal and parturition indicates that the rate of increase may be greater than expected at the front of expanding beaver populations.

Individual variation in migratory and exploratory movements and habitat use by adult red deer (Cervus elaphus L.) in a mountainous temperate forest

2008 ◽  
Vol 23 (6) ◽  
pp. 1005-1013 ◽  
Author(s):  
Dominique Pépin ◽  
Christophe Adrados ◽  
Georges Janeau ◽  
Jean Joachim ◽  
Carole Mann
Keyword(s):  
Habitat Use ◽  
Cervus Elaphus ◽  
Individual Variation ◽  
Temperate Forest ◽  
Red Deer ◽  
Exploratory Movements

Tactile Discrimination of Direction of Lines in Relation to Hemispheric Specialization

1982 ◽  
Vol 54 (2) ◽  
pp. 655-660 ◽  
Author(s):  
Daniela Brizzolara ◽  
Gianni L. De Nobili ◽  
Giovanni Ferretti
Keyword(s):  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Line Orientation ◽  
Contralateral Hemisphere ◽  
Tactile Discrimination ◽  
Experimental Procedure ◽  
Left Hand ◽  
The Right ◽  
Exploratory Movements

The role of the right hemisphere in a task of haptic discrimination of line orientation was studied in 16 children aged 7–6 and 16 adults aged 25 yr. The exploratory movements were limited to hand and wrist, since it has been shown that distal movements are mediated by the contralateral hemisphere. A comparison of the performance of the two hands shows a clear superiority of the left hand and inferred right hemisphere in both children and adults. An especial emphasis in the discussion is given to the role of the experimental procedure in enhancing the effect of the hemispheric functional asymmetries.

scholarly journals Modeling Basal Ganglia for Understanding Parkinsonian Reaching Movements

2011 ◽  
Vol 23 (2) ◽  
pp. 477-516 ◽  
Author(s):  
K. N. Magdoom ◽  
D. Subramanian ◽  
V. S. Chakravarthy ◽  
B. Ravindran ◽  
Shun-ichi Amari ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Reaching Movements ◽  
Substantia Nigra Pars Compacta ◽  
Temporal Difference ◽  
Indirect Pathway ◽  
Dynamical Disease ◽  
Exploratory Movements ◽  
Dopamine Signal

We present a computational model that highlights the role of basal ganglia (BG) in generating simple reaching movements. The model is cast within the reinforcement learning (RL) framework with correspondence between RL components and neuroanatomy as follows: dopamine signal of substantia nigra pars compacta as the temporal difference error, striatum as the substrate for the critic, and the motor cortex as the actor. A key feature of this neurobiological interpretation is our hypothesis that the indirect pathway is the explorer. Chaotic activity, originating from the indirect pathway part of the model, drives the wandering, exploratory movements of the arm. Thus, the direct pathway subserves exploitation, while the indirect pathway subserves exploration. The motor cortex becomes more and more independent of the corrective influence of BG as training progresses. Reaching trajectories show diminishing variability with training. Reaching movements associated with Parkinson's disease (PD) are simulated by reducing dopamine and degrading the complexity of indirect pathway dynamics by switching it from chaotic to periodic behavior. Under the simulated PD conditions, the arm exhibits PD motor symptoms like tremor, bradykinesia and undershooting. The model echoes the notion that PD is a dynamical disease.

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