The relationship between motion sensitivity and fixation variability in eccentric gaze

The development of spatial vision is relatively well documented in human and nonhuman primates. However, little is known about the development of sensitivity to motion. We measured the development of sensitivity to direction of motion, and the relationship between motion and contrast sensitivity in macaque monkeys as a function of age. Monkeys (Macaca nemestrina, aged between 10 days and 3 years) discriminated direction of motion in random-dot kinematograms. The youngest monkeys showed directionally selective orienting and the ability to integrate motion signals at large dot displacements and fast speeds. With age, coherence sensitivity improved for all spatial and temporal dot displacements tested. The temporal interval between the dots was far less important than the spatial offset in determining the animals' performance at all but the youngest ages. Motion sensitivity improved well beyond the end of the first postnatal year, when mid-spatial-frequency contrast sensitivity reached asymptote, and continued for at least 3 years. Sensitivity to contrast at high spatial frequencies also continued to develop beyond the end of the first year. We conclude that the development of motion sensitivity depends on mechanisms beyond the low-level filters presumed to limit acuity and contrast sensitivity, and most likely reflects the function of extrastriate visual areas.

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A relationship between behavioral choice and the visual responses of neurons in macaque MT

Visual Neuroscience ◽

10.1017/s095252380000715x ◽

1996 ◽

Vol 13 (1) ◽

pp. 87-100 ◽

Cited By ~ 605

Author(s):

K. H. Britten ◽

W. T. Newsome ◽

M. N. Shadlen ◽

S. Celebrini ◽

J. A. Movshon

Keyword(s):

Visual Motion ◽

Visual Stimulation ◽

Visual Responses ◽

Stimulus Motion ◽

Area Mt ◽

Motion Sensitivity ◽

Behavioral Choice ◽

Mt Neurons ◽

Preferred Direction ◽

The Relationship

AbstractWe have previously documented the exquisite motion sensitivity of neurons in extrastriate area MT by studying the relationship between their responses and the direction and strength of visual motion signals delivered to their receptive fields. These results suggested that MT neurons might provide the signals supporting behavioral choice in visual discrimination tasks. To approach this question from another direction, we have now studied the relationship between the discharge of MT neurons and behavioral choice, independently of the effects of visual stimulation. We found that trial-to-trial variability in neuronal signals was correlated with the choices the monkey made. Therefore, when a directionally selective neuron in area MT fires more vigorously, the monkey is more likely to make a decision in favor of the preferred direction of the cell. The magnitude of the relationship was modest, on average, but was highly significant across a sample of 299 cells from four monkeys. The relationship was present for all stimuli (including those without a net motion signal), and for all but the weakest responses. The relationship was reduced or eliminated when the demands of the task were changed so that the directional signal carried by the cell was less informative. The relationship was evident within 50 ms of response onset, and persisted throughout the stimulus presentation. On average, neurons that were more sensitive to weak motion signals had a stronger relationship to behavior than those that were less sensitive. These observations are consistent with the idea that neuronal signals in MT are used by the monkey to determine the direction of stimulus motion. The modest relationship between behavioral choice and the discharge of any one neuron, and the prevalence of the relationship across the population, make it likely that signals from many neurons are pooled to form the data on which behavioral choices are based.

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A-95 The Relationship between Attention Deficit Hyperactivity Disorder (ADHD) and Vestibular Impairments Following Adolescent Sports-Related Concussion (SRC)

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acab062.113 ◽

2021 ◽

Vol 36 (6) ◽

pp. 1142-1142

Author(s):

Taylor Gilliland ◽

Erin Reynolds ◽

Kayla Covert ◽

Monica Bennett ◽

Simon Driver

Keyword(s):

Visual Motion ◽

Treatment Strategies ◽

Categorical Variables ◽

Continuous Variables ◽

Adolescent Athletes ◽

Chi Square ◽

Motion Sensitivity ◽

Vestibulo Ocular Reflex ◽

History Of ◽

The Relationship

Abstract Objective Athletes with ADHD may experience longer and/or more complicated recoveries following SRC; however, previous research has focused on neurocognitive outcomes. The objective of this study was to investigate the relationship between a history of ADHD among adolescent athletes and vestibular impairments following SRC. Method Participants included 166 athletes aged 15.9 +/− 1.5 who sustained an SRC, including 25 with a documented history of ADHD. Appropriate summary statistics were used to describe the data. ADHD and non-ADHD groups were compared using t-tests and Mann–Whitney U tests for continuous variables and Chi-square tests for categorical variables. A linear regression model analyzed the relationship between a history of ADHD and vestibular outcomes including horizontal and vertical vestibulo-ocular reflex (hVOR; vVOR), visual motion sensitivity (VMS), and Dizziness Handicap Index (DHI), while referral to vestibular therapy (VT) was analyzed using logistic regression. Results Athletes with ADHD experienced significantly higher rates of on-field dizziness, (p = 0.039) and dizziness following vVOR testing on the Vestibular/Ocular Motor Screening (VOMS; p = 0.041). Athletes with ADHD were more likely to be referred to vestibular therapy (VT) (p = 0.033) and displayed abnormal vVOR test during the initial VT visit (p = 0.040). Conclusions Adolescent athletes with a history of ADHD are more likely to report on-field dizziness following SRC and increased dizziness with vVOR testing on VOMS, thus resulting in more frequent referrals to VT, where they also display abnormal vVOR results. Additional research is needed to improve treatment strategies and recovery outcomes in athletes after SRC.

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Interstellar gas in the central region of the Galaxy

Symposium - International Astronomical Union ◽

10.1017/s0074180900101032 ◽

1967 ◽

Vol 31 ◽

pp. 239-251 ◽

Cited By ~ 3

Author(s):

F. J. Kerr

Keyword(s):

Central Region ◽

Galactic Plane ◽

Neutral Hydrogen ◽

Continuum Emission ◽

Galactic Centre ◽

Interstellar Gas ◽

Hydrogen Recombination ◽

The Galaxy ◽

Centre Region ◽

The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

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The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽

10.1017/s0094837300025707 ◽

1980 ◽

Vol 6 (02) ◽

pp. 146-160 ◽

Cited By ~ 29

Author(s):

William A. Oliver

Keyword(s):

Critical Points ◽

Scleractinian Corals ◽

Convincing Evidence ◽

Early Triassic ◽

Rugose Corals ◽

History Of ◽

The Subject ◽

Relationship Of ◽

The Relationship ◽

Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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Choosing a Markov blanket

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002632 ◽

2020 ◽

Vol 43 ◽

Author(s):

Thomas Parr

Keyword(s):

Markov Blanket ◽

Target Article ◽

The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

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Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

Behavioral and Brain Sciences ◽

10.1017/s0140525x19001018 ◽

2019 ◽

Vol 42 ◽

Author(s):

Paul Benjamin Badcock ◽

Axel Constant ◽

Maxwell James Désormeau Ramstead

Keyword(s):

Evolutionary Psychology ◽

Research Program ◽

Active Inference ◽

Innovative Research ◽

Cognitive Faculties ◽

Cultural Evolutionary ◽

The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

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Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068291 ◽

1970 ◽

Vol 28 ◽

pp. 260-261

Author(s):

Robert M. Glaeser

Keyword(s):

High Resolution ◽

Particle Flux ◽

Unit Area ◽

Signal To Noise ◽

Resolution Image ◽

High Resolution Image ◽

Pass Through ◽

Counting Statistics ◽

The Relationship ◽

Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

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Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074768 ◽

1983 ◽

Vol 41 ◽

pp. 194-195

Author(s):

D. F. Blake ◽

L. F. Allard ◽

D. R. Peacor

Keyword(s):

High Resolution ◽

Marine Invertebrates ◽

Sea Urchins ◽

Structural Features ◽

Sea Stars ◽

High Resolution Tem ◽

Relationship Of ◽

The Relationship ◽

Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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