The Possible Role of Eye-Muscle Potentiation in Several Forms of Prism Adaptation

It is possible to explain a number of observations of visual adaptation to optical rearrangement and other visual effects as examples of the ‘Kohnstamm phenomenon’. This is the tendency for a stressed muscle to remain innervated for a period of time after cessation of the voluntary signal to relax. When this phenomenon operates with respect to eye muscles, it may be referred to as ‘eye-muscle potentiation’. Several studies and their results are presented that demonstrate eye-muscle potentiation effects on apparent visual distance. The implications of these studies for prism adaptation are discussed.

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Deepfaking Keanu: YouTube deepfakes, platform visual effects, and the complexity of reception

Convergence The International Journal of Research into New Media Technologies ◽

10.1177/13548565211030454 ◽

2021 ◽

pp. 135485652110304

Author(s):

Lisa Bode

Keyword(s):

Film Studies ◽

Media Theory ◽

Digital Rhetoric ◽

Visual Effects ◽

After Effects ◽

Starting Point ◽

Media Creation ◽

Media Practices

On July 14, 2019, a 3-minute 36-second video titled “Keanu Reeves Stops A ROBBERY!” was released on YouTube visual effects (VFX) channel, Corridor. The video’s click-bait title ensured it was quickly shared by users across platforms such as Facebook, Twitter, and Reddit. Comments on the video suggest that the vast majority of viewers categorised it as fiction. What seemed less universally recognised, though, was that the performer in the clip was not Keanu Reeves himself. It was voice actor and stuntman Reuben Langdon, and his face was digitally replaced with that of Reeves, through the use of an AI generated deepfake, an open access application, Faceswap, and compositing in Adobe After Effects. This article uses Corridor’s deepfake Keanu video (hereafter shorted to CDFK) as a case study which allows the fleshing out of an, as yet, under-researched area of deepfakes: the role of framing contexts in shaping how viewers evaluate, categorise, make sense of and discuss these images. This research draws on visual effects scholarship, celebrity studies, cognitive film studies, social media theory, digital rhetoric, and discourse analysis. It is intended to serve as a starting point of a larger study that will eventually map types of online manipulated media creation on a continuum from the professional to the vernacular, across different platforms, and attending to their aesthetic, ethical, cultural and reception dimensions. The focus on context (platform, creator channel, and comments) also reveals the emergence of an industrial and aesthetic category of visual effects, which I call here “platform VFX,” a key term that provides us with more nuanced frames for illuminating and analysing a range of manipulated media practices as VFX software becomes ever more accessible and lends itself to more vernacular uses, such as we see with various face swap apps

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Réponses évoquées par les mouvements oculaires d'exploration (réponse lambda): Rôle des afférences intervenant à divers moments du processus oculo-moteur

Perception ◽

10.1068/p010167 ◽

1972 ◽

Vol 1 (2) ◽

pp. 167-175 ◽

Cited By ~ 4

Author(s):

Nicole Lesèvre ◽

A Rémond

Keyword(s):

Eye Movements ◽

Eye Movement ◽

Visual Effects ◽

Experimental Conditions ◽

Initial Portion ◽

Vertical Movements ◽

Black Field ◽

Fixation Points ◽

Lambda Response

Experiments are reported the aim of which was to elucidate the cause of each of the components of the lambda response, and particularly to evaluate the role of ‘on’ and ‘off’ visual effects which appear at various times during the oculomotor process and also the possible influence of non-visual mechanisms. Eight subjects with normal sight were studied under the following conditions: (i) horizontal eye movements of 12° were guided by fixation points placed on a dimly-lit uniform black field of 20°; a checkerboard of 6° aperture was placed in this field so as to be integrated into the oculomotor process at different times—at the beginning, during and at the end of the eye movement; (ii) successive horizontal eye movements of 3°, 7° and 11° scanned a checkerboard of 20°, each square of which had a 40′ aperture; (iii) the checkerboard was moved with an amplitude and period similar to those of the eye movements in (ii), but this time with gaze fixed. Horizontal and vertical movements of both eyes were recorded with an EOG. An EEG of the parieto-occipital regions was obtained using eight linked bipolar derivations in line on two montages, median longitudinal and right-left transverse. The EEG and EOG data were digitalized and a numerical programme of waveform recognition was used to identify the beginning of the saccade which triggers the averaging out of the EEG before (100 ms) and after (500 ms) the eye movement. A discussion of the results, taking into account the latency of the different components and their reinforcements or inhibition depending on experimental conditions, suggests that the two initial components of lambda response (including the initial portion of the classical lambda wave) might be due to visual effects (‘off effect’) that arise at the start of the movement or slightly before it at the time that the saccadic suppression begins. The later components could be attributed to visual effects brought into play towards the end of the movement (‘on effect’), when perception becomes normal again. It is, however, difficult to explain some of the results related to the amplitude of lambda components without bringing in a mechanism of non-visual origin (corollary discharge).

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Adaptation to tilt is not produced by eye-muscle potentiation

Vision Research ◽

10.1016/0042-6989(90)90103-r ◽

1990 ◽

Vol 30 (5) ◽

pp. 779-783 ◽

Cited By ~ 1

Author(s):

H.H. Mikaelian ◽

D.M. Mikaelian ◽

E.L. Cameron

Keyword(s):

Eye Muscle ◽

Muscle Potentiation

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A Study on the role of Visual Effects in Virtual Reality Animation

Journal of Digital Contents Society ◽

10.9728/dcs.2021.22.2.223 ◽

2021 ◽

Vol 22 (2) ◽

pp. 223-231

Author(s):

Wook-Sang Chang ◽

Sun-Young Park

Keyword(s):

Virtual Reality ◽

Visual Effects

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Extraocular Muscles Tension, Tonus, and Proprioception in Infantile Strabismus: Role of the Oculomotor System in the Pathogenesis of Infantile Strabismus—Review of the Literature

Scientifica ◽

10.1155/2016/5790981 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Costantino Schiavi

Keyword(s):

Critical Period ◽

Muscle Force ◽

Sensory System ◽

Oculomotor System ◽

Extraocular Muscles ◽

Review Of The Literature ◽

Eye Muscle ◽

System A ◽

Concomitant Strabismus

The role played by the extraocular muscles (EOMs) in the etiology of concomitant infantile strabismus is still debated and it has not yet definitively established if the sensory anomalies in concomitant strabismus are a consequence or a primary cause of the deviation. The commonest theory supposes that most strabismus results from abnormal innervation of the EOMs, but the cause of this dysfunction and its origin, whether central or peripheral, are still unknown. The interaction between sensory factors and innervational factors, that is, esotonus, accommodation, convergence, divergence, and vestibular reflexes in visually immature infants with family predisposition, is suspected to create conditions that prevent binocular alignment from stabilizing and strengthening. Some role in the onset of fixation instability and infantile strabismus could be played by the feedback control of eye movements and by dysfunction of eye muscle proprioception during the critical period of development of the visual sensory system. A possible role in the onset, maintenance, or worsening of the deviation of abnormalities of muscle force which have their clinical equivalent in eye muscle overaction and underaction has been investigated under either isometric or isotonic conditions, and in essence no significant anomalies of muscle force have been found in concomitant strabismus.

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The Role of Movement Synchronization with an Auditory Signal in Producing Prism Adaptation

Perception ◽

10.1068/p7036 ◽

2012 ◽

Vol 41 (8) ◽

pp. 950-962 ◽

Cited By ~ 4

Author(s):

Mona A Bornschlegl ◽

Manfred Fahle ◽

Gordon M Redding

Keyword(s):

Prism Adaptation ◽

Auditory Signal ◽

Movement Synchronization

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Impairment of cross-modality of vision and olfaction in Parkinson disease

Neurology ◽

10.1212/wnl.0000000000005110 ◽

2018 ◽

Vol 90 (11) ◽

pp. e977-e984 ◽

Cited By ~ 3

Author(s):

Motoyasu Honma ◽

Yuri Masaoka ◽

Takeshi Kuroda ◽

Akinori Futamura ◽

Azusa Shiromaru ◽

...

Keyword(s):

Parkinson Disease ◽

Cognitive Functions ◽

Visual Information ◽

Visual Cues ◽

Visual Effects ◽

Behavioral Experiments ◽

Odor Evaluation ◽

Patient Performance ◽

Normal Controls

ObjectiveTo determine whether Parkinson disease (PD) affects cross-modal function of vision and olfaction because it is known that PD impairs various cognitive functions, including olfaction.MethodsWe conducted behavioral experiments to identify the influence of PD on cross-modal function by contrasting patient performance with age-matched normal controls (NCs). We showed visual effects on the strength and preference of odor by manipulating semantic connections between picture/odorant pairs. In addition, we used brain imaging to identify the role of striatal presynaptic dopamine transporter (DaT) deficits.ResultsWe found that odor evaluation in participants with PD was unaffected by visual information, while NCs overestimated smell when sniffing odorless liquid while viewing pleasant/unpleasant visual cues. Furthermore, DaT deficit in striatum, for the posterior putamen in particular, correlated to few visual effects in participants with PD.ConclusionsThese findings suggest that PD impairs cross-modal function of vision/olfaction as a result of posterior putamen deficit. This cross-modal dysfunction may serve as the basis of a novel precursor assessment of PD.

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