scholarly journals Entrainment of theta, not alpha, oscillations is predictive of the brightness enhancement of a flickering stimulus

2017 ◽  
Author(s):  
Jennifer K. Bertrand ◽  
Nathan J. Wispinski ◽  
Kyle E. Mathewson ◽  
Craig S. Chapman
Keyword(s):  
Visual Information ◽  
Information Transfer ◽  
Theta Rhythm ◽  
Human Subjects ◽  
Brightness Discrimination ◽  
Perceptual Effect ◽  
Brightness Enhancement ◽  
Discrimination Judgment ◽  
Share Information ◽  
Trial Phase

Frequency-dependent brightness enhancement, where a flickering light can appear twice as bright as an equiluminant constant light, has been reported to exist within the alpha (8 – 12 Hz) band. Could oscillatory neural activity be driving this perceptual effect? Here, in two experiments, human subjects reported which of two flickering stimuli were brighter. Strikingly, 4 Hz stimuli were reported as brighter more than 80% of the time when compared to all other tested frequencies, even though all stimuli were equiluminant and of equal temporal length. Electroencephalography recordings showed that inter-trial phase coherence (ITC) of theta (4 Hz) was: 1) Significantly greater than alpha, contralateral to the flickering stimulus; 2) Enhanced by the presence of a second ipsilateral 4 Hz flickering stimulus; and 3) Uniquely lateralized, unlike the alpha band. Importantly, on trials with two identical stimuli (i.e. 4 Hz vs 4 Hz), the brightness discrimination judgment could be predicted by the hemispheric balance in the amount of 4 Hz ITC. We speculate that the theta rhythm plays a distinct information transfer role, where its ability to share information between hemispheres via entrainment promotes a better processing of visual information to inform a discrimination decision.

scholarly journals Tachyons but Not Photons Might Generate Conscious Dreams

2019 ◽  
Author(s):  
Ahmad Yousef
Keyword(s):  
Eye Movements ◽  
Visual Information ◽  
Human Subjects ◽  
Visual Awareness ◽  
Human Eye ◽  
Rapid Eye Movements ◽  
Cognitive Vision ◽  
Human Awareness

We had learnt from cognitive vision that involuntarily visual awareness should be generated by exogenous stimuli; but not indigenous! Given the complexity of understanding the reasons behind the rapid eye movements during vivid dreams; dreams that carry highly bizarre information; dreams that disallow the human subjects to have control over what they see; these types of dreams should be therefore reside under the umbrella of the “involuntary human awareness”. We therefore suggest possibilities of physical particles that could carry the visual information of these extraordinary exogenous stimuli; particles that should be able to invade the human’s eyes while they are closed; particles that have the ability to move the eye rapidly aiming for perfect transformation of the visual information. The present research aims to talk about these particles, proposes scenarios of how human eye & retina deal with them.

Interhemispheric Transmission of Visuomotor Information in Humans: fMRI Evidence

2002 ◽  
Vol 88 (2) ◽  
pp. 1051-1058 ◽  
Author(s):  
M. Tettamanti ◽  
E. Paulesu ◽  
P. Scifo ◽  
A. Maravita ◽  
F. Fazio ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Visual Information ◽  
Human Subjects ◽  
Conduction Time ◽  
Clear Cut ◽  
Cortical Areas ◽  
Poffenberger Paradigm ◽  
Interhemispheric Transmission ◽  
Hemispheric Activation ◽  
Normal Human

Normal human subjects underwent functional magnetic resonance imaging (fMRI) while performing a simple visual manual reaction-time (RT) task with lateralized brief stimuli, the so-called Poffenberger's paradigm. This paradigm was employed to measure interhemispheric transmission (IT) time by subtracting mean RT for the uncrossed hemifield-hand conditions, that is, those conditions not requiring an IT, from the crossed hemifield-hand conditions, that is, those conditions requiring an IT to relay visual information from the hemisphere of entry to the hemisphere subserving the response. The obtained difference is widely believed to reflect callosal conduction time, but so far there is no direct physiological evidence in humans. The aim of our experiment was twofold: first, to test the hypothesis that IT of visuomotor information requires the corpus callosum and to identify the cortical areas specifically activated during IT. Second, we sought to discover whether IT occurs mainly at premotor or perceptual stages of information processing. We found significant activations in a number of frontal, parietal, and temporal cortical areas and in the genu of the corpus callosum. These activations were present only in the crossed conditions and therefore were specifically related to IT. No selective activation was present in the uncrossed conditions. The location of the activated callosal and cortical areas suggests that IT occurs mainly, but not exclusively, at premotor level. These results provide clear cut evidence in favor of the hypothesis that the crossed-uncrossed difference in the Poffenberger paradigm depends on IT rather than on a differential hemispheric activation.

Fusion of Visual and Proprioceptive Information about Hand Position Prior to Movement

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 127-127
Author(s):  
M Desmurget ◽  
Y Rossetti ◽  
C Prablanc
Keyword(s):  
Visual Information ◽  
Human Subjects ◽  
Visual Presentation ◽  
Accurate Estimate ◽  
Open Loop ◽  
The Body ◽  
Hand Position ◽  
Proprioceptive Information ◽  
Movement Onset ◽  
Loop Condition

The problem whether movement accuracy is better in the full open-loop condition (FOL, hand never visible) than in the static closed-loop condition (SCL, hand only visible prior to movement onset) remains widely debated. To investigate this controversial question, we studied conditions for which visual information available to the subject prior to movement onset was strictly controlled. The results of our investigation showed that the accuracy improvement observed when human subjects were allowed to see their hand, in the peripheral visual field, prior to movement: (1) concerned only the variable errors; (2) did not depend on the simultaneous vision of the hand and target (hand and target viewed simultaneously vs sequentially); (3) remained significant when pointing to proprioceptive targets; and (4) was not suppressed when the visual information was temporally (visual presentation for less than 300 ms) or spatially (vision of only the index fingertip) restricted. In addition, dissociating vision and proprioception with wedge prisms showed that a weighed hand position was used to program hand trajectory. When considered together, these results suggest that: (i) knowledge of the initial upper limb configuration or position is necessary to plan accurately goal-directed movements; (ii) static proprioceptive receptors are partially ineffective in providing an accurate estimate of the limb posture, and/or hand location relative to the body, and (iii) visual and proprioceptive information is not used in an exclusive way, but combined to furnish an accurate representation of the state of the effector prior to movement.

Novel Visual Illusions Related to Vasarely's ‘Nested Squares’ Show That Corner Salience Varies with Corner Angle

Perception ◽  
10.1068/p5383 ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 409-420 ◽  
Author(s):  
Xoana G Troncoso ◽  
Stephen L Macknik ◽  
Susana Martinez-Conde
Keyword(s):  
Discrimination Task ◽  
Computational Models ◽  
Visual Illusion ◽  
Human Subjects ◽  
Brightness Discrimination ◽  
Receptive Fields ◽  
Visual Illusions ◽  
Corner Angle ◽  
Brightness Discrimination Task ◽  
Sharp Corners

Vasarely's ‘nested-squares’ illusion shows that 90° corners can be more salient perceptually than straight edges. On the basis of this illusion we have developed a novel visual illusion, the ‘Alternating Brightness Star’, which shows that sharp corners are more salient than shallow corners (an effect we call ‘corner angle salience variation’) and that the same corner can be perceived as either bright or dark depending on the polarity of the angle (ie whether concave or convex: ‘corner angle brightness reversal’). Here we quantify the perception of corner angle salience variation and corner angle brightness reversal effects in twelve naive human subjects, in a two-alternative forced-choice brightness discrimination task. The results show that sharp corners generate stronger percepts than shallow corners, and that corner gradients appear bright or dark depending on whether the corner is concave or convex. Basic computational models of center – surround receptive fields predict the results to some degree, but not fully.

scholarly journals Visual information transfer across eye movements in the monkey

2004 ◽  
Vol 44 (25) ◽  
pp. 2901-2917 ◽  
Author(s):  
Paul S. Khayat ◽  
Henk Spekreijse ◽  
Pieter R. Roelfsema
Keyword(s):  
Eye Movements ◽  
Visual Information ◽  
Information Transfer

Re-Tweet Count Matters: Social Influences on Sharing of Disaster-Related Tweets

2015 ◽  
Vol 12 (3) ◽  
Author(s):  
Huaye Li ◽  
Yasuaki Sakamoto
Keyword(s):  
Social Media ◽  
Disaster Management ◽  
Social Influences ◽  
Human Subjects ◽  
Great East Japan Earthquake ◽  
Current Paper ◽  
Media Technologies ◽  
Emergency Responders ◽  
Related Information ◽  
Share Information

AbstractCommunication during and after disasters increasingly relies on social media technologies. For example, victims, emergency responders, and others took to Twitter to share information about conditions, aid, resources and the like in the aftermath of the 2011 Great East Japan Earthquake. The current paper concerns how a re-tweet count, or the number of others who have already forwarded a message, influences people’s spreading of disaster-related tweets. The results of a human-subjects experiment revealed that, when the re-tweet count of a tweet increased, the likelihood that people would share the tweet increased when it came from an individual’s account, but the likelihood decreased when it came from a news agency’s account. These social influences disappeared when the re-tweet counts were over 1000 people. These findings extend the understanding of how disaster-related information spreads on social media, which is essential for improving social media during disaster management.

Visual Information Transfer using Mobile IT Solutions

2009 ◽  
Author(s):  
O.O. Koseoglu ◽  
B. Erdogan ◽  
Y. Nielsen ◽  
C.J. Anumba ◽  
N.M. Bouchlaghem
Keyword(s):  
Visual Information ◽  
Information Transfer

Effects of Multiplicative Power Law Neural Noise in Visual Information Processing

2011 ◽  
Vol 23 (4) ◽  
pp. 1015-1046 ◽  
Author(s):  
José M. Medina
Keyword(s):  
Power Law ◽  
Visual Information ◽  
Information Transfer ◽  
Channel Model ◽  
Internal Noise ◽  
Minimum Information ◽  
Information Theoretic ◽  
Neural Noise ◽  
Weakly Coupled ◽  
Transfer Of Information

The human visual system is intrinsically noisy. The benefits of internal noise as part of visual code are controversial. Here the information-theoretic properties of multiplicative (i.e. signal-dependent) neural noise are investigated. A quasi-linear communication channel model is presented. The model shows that multiplicative power law neural noise promotes the minimum information transfer after efficient coding. It is demonstrated that Weber's law and the human contrast sensitivity function arise on the basis of minimum transfer of information and power law neural noise. The implications of minimum information transfer in self-organized neural networks and weakly coupled neurons are discussed.

Proprioceptive coordination of movement sequences: discrimination of joint angle versus angular distance

1994 ◽  
Vol 71 (5) ◽  
pp. 1862-1872 ◽  
Author(s):  
L. Bevan ◽  
P. Cordo ◽  
L. Carlton ◽  
M. Carlton
Keyword(s):  
Visual Information ◽  
Joint Angle ◽  
Human Subjects ◽  
Joint Space ◽  
Angular Distance ◽  
Target Distance ◽  
Central Position ◽  
Starting Position ◽  
Fourth Experiment ◽  
The Right

1. The purpose of these experiments was to determine the accuracy with which human subjects could discriminate proprioceptive (nonretinotopic) targets during movement. The targets were located at either a specified angle in joint space, or a specified angular distance from an initial joint angle. 2. In these experiments the right elbows of normal human subjects were passively extended from either predictable or unpredictable starting angles. The subjects were instructed to open the right hand to indicate that the elbow was passing through a target joint angle or a target angular distance. The subjects were not given visual information about the location of the elbow, so they had to rely on proprioceptive input to perform this task. The target (criterion joint angle or angular distance) was learned by the use of proprioception during 8-15 practice trials. 3. Four experiments were conducted. In three experiments the target was located at a constant joint angle, and in the fourth experiment the target was located at a constant angular distance from the starting angle. The starting angle in all four experiments was pseudorandomly varied from trial to trial. 4. On the basis of an analysis of constant errors, subjects were more accurate at discriminating angular distance than joint angle. The slope of the relationship between the starting position and the constant errors was dictated by the task requirement. 5. In the distance discrimination experiment, when the starting angle was more flexed than the intermediate (i.e., central) position, the subjects slightly overshot the target distance. Conversely, when the starting angle was more extended than the intermediate position, the subjects slightly undershot the target distance. 6. In the joint angle discrimination experiments, the opposite results were obtained. Subjects overshot the target when the starting position of the elbow was more extended than the intermediate starting position, and they undershot the target when the starting position was more flexed than the intermediate starting position. The amplitude of these systematic errors increased when the subjects were unaware that the initial angle of their elbow was variable. 7. It is concluded that, in kinesthetic tasks of this type, the discrimination of angular distance is more accurate than the discrimination of joint angle. We hypothesize that the nervous system extracts kinematic information related to both joint angle and angular distance from proprioceptors, and that the encoding and or decoding of angular distance is more accurate than that of absolute joint angle.(ABSTRACT TRUNCATED AT 400 WORDS)

Excitatory Actions of Dopamine Via D1-Like Receptors in the Rat Lateral Geniculate Nucleus

2005 ◽  
Vol 94 (6) ◽  
pp. 3708-3718 ◽  
Author(s):  
G. Govindaiah ◽  
Charles L. Cox
Keyword(s):  
Visual Information ◽  
Information Transfer ◽  
Neuronal Excitability ◽  
Slow Wave Sleep ◽  
Membrane Depolarization ◽  
Dopamine Receptor Agonist ◽  
Cation Current ◽  
Cell Recording ◽  
Specific Antagonist ◽  
Relay Neurons

The excitability of relay neurons in the dorsal geniculate nucleus (dLGN) can be altered by a variety of neuromodulators. The dLGN receives substantial dopaminergic input from the brain stem, and this innervation may play a crucial role in the gating of visual information from the retina to visual neocortex. In this study, we investigated the action of dopamine on identified dLGN neurons using whole cell recording techniques. Dopamine (2–200 μM) produced a membrane depolarization in >95% of relay neurons tested but did not alter excitability of dLGN interneurons. The D1-like dopamine receptor agonist SKF38393 (2–50 μM) produced a similar depolarization in dLGN relay neurons. However, the D2-like receptor agonists, bromocriptine (25–50 μM) and PPHT (1–50 μM), did not alter the membrane potential of relay neurons. SCH23390 (5–10 μM), a D1-like receptor antagonist, attenuated the depolarizing actions of both dopamine and SKF38393 . Furthermore, the excitatory actions of dopamine and SKF38393 were attenuated by ZD7288, a specific antagonist for the hyperpolarization activated mixed cation current, Ih. Our data suggest that dopamine, acting via D1-like receptors, activates Ih leading to a membrane depolarization. Through the modulation of dLGN neuronal excitability, ascending and descending activating systems may not only control the state of the thalamus such as the transition from slow-wave sleep to waking but also regulate the efficacy of information transfer during waking states.

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