scholarly journals Investigating the Crucial Role of Optic Flow in Postural Control: Central vs. Peripheral Visual Field

2019 ◽  
Vol 9 (5) ◽  
pp. 934 ◽  
Author(s):  
Milena Raffi ◽  
Alessandro Piras
Keyword(s):  
Visual Field ◽  
Postural Control ◽  
Optic Flow ◽  
Crucial Role ◽  
Visual Fields ◽  
Upright Position ◽  
Peripheral Retina ◽  
Different Parts ◽  
Stimulation Of

Optic flow stimuli are crucial for the control of stance in the upright position. The visual control of posture has recently received a lot of interest from several researchers. One of the most intriguing aspects is the contribution of the different parts of the visual field in the control of stance. Here we reviewed the results of several studies performed with different methodologies that tried to determine the effect of optic flow on postural control, by analyzing the role of the central and peripheral visual fields. Although the results were controversial, the majority of these studies agreed to assign the most important role in postural control to the peripheral retina. However, these studies were performed using different approaches and different definitions of the central and peripheral visual fields. The choice of the exact portion of the retina to be stimulated is crucial given that the stimulation of the central and the peripheral parts of the retina leads to the activation of different geniculo-cortical pathways and results in different cortical processing of information.

Distinguishing Subregions of the Human MT+ Complex Using Visual Fields and Pursuit Eye Movements

2001 ◽  
Vol 86 (4) ◽  
pp. 1991-2000 ◽  
Author(s):  
Sean P. Dukelow ◽  
Joseph F. X. DeSouza ◽  
Jody C. Culham ◽  
Albert V. van den Berg ◽  
Ravi S. Menon ◽  
...  
Keyword(s):  
Visual Field ◽  
Optic Flow ◽  
Visual Fields ◽  
Receptive Fields ◽  
Macaque Monkey ◽  
Peripheral Retina ◽  
Full Field ◽  
Medial Superior Temporal ◽  
Single Target ◽  
To Receive

In humans, functional imaging studies have demonstrated a homologue of the macaque motion complex, MT+ [suggested to contain both middle temporal (MT) and medial superior temporal (MST)], in the ascending limb of the inferior temporal sulcus. In the macaque monkey, motion-sensitive areas MT and MST are adjacent in the superior temporal sulcus. Electrophysiological research has demonstrated that while MT receptive fields primarily encode the contralateral visual field, MST dorsal (MSTd) receptive fields extend well into the ipsilateral visual field. Additionally, macaque MST has been shown to receive extraretinal smooth-pursuit eye-movement signals, whereas MT does not. We used functional magnetic resonance imaging (fMRI) and the neural properties that had been observed in monkeys to distinguish putative human areas MT from MST. Optic flow stimuli placed in the full field, or contralateral field only, produced a large cluster of functional activation in our subjects consistent with previous reports of human area MT+. Ipsilateral optic flow stimuli limited to the peripheral retina produced activation only in an anterior subsection of the MT+ complex, likely corresponding to putative MSTd. During visual pursuit of a single target, a large portion of the MT+ complex was activated. However, during nonvisual pursuit, only the anterolateral portion of the MT+ complex was activated. This subsection of the MT+ cluster could correspond to putative MSTl (lateral). In summary, we observed three distinct subregions of the human MT+ complex that were arranged in a manner similar to that seen in the monkey.

Reactive Oxygen Species-Mediated Homologous Downregulation of Angiotensin II Type 1 Receptor Mrna by Angiotensin II

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 688-688
Author(s):  
Toshihiro Ichiki ◽  
Kotaro Takeda ◽  
Akira Takeshita
Keyword(s):  
Reactive Oxygen Species ◽  
Angiotensin Ii ◽  
Nadph Oxidase ◽  
Mrna Expression ◽  
Crucial Role ◽  
Oxygen Species ◽  
Ang Ii ◽  
Stimulation Of

58 Recent studies suggest a crucial role of reactive oxygen species (ROS) for the signaling of Angiotensin II (Ang II) through type 1 Ang II receptor (AT1-R). However, the role of ROS in the regulation of AT1-R expression has not been explored. In this study, we examined the effect of an antioxidant on the homologous downregulation of AT1-R by Ang II. Ang II (10 -6 mol/L) decreased AT1-R mRNA with a peak suppression at 6 hours of stimulation in rat aortic vascular smooth muscle cells (VSMC). Ang II dose-dependently (10 -8 -10 -6 ) suppressed AT1-R mRNA at 6 hours of stimulation. Preincubation of VSMC with N-acetylcysteine (NAC), a potent antioxidant, almost completely inhibited the Ang II-induced downregulation of AT1-R mRNA. The effect of NAC was due to stabilization of the AT1-R mRNA that was destabilized by Ang II. Ang II did not affect the promoter activity of AT1-R gene. Diphenylene iodonium (DPI), an inhibitor of NADH/NADPH oxidase failed to inhibit the Ang II-induced AT1-R mRNA downregulation. The Ang II-induced AT1-R mRNA downregulation was also blocked by PD98059, an extracellular signal-regulated protein kinase (ERK) kinase inhibitor. Ang II-induced ERK activation was inhibited by NAC as well as PD98059 whereas DPI did not inhibit it. To confirm the role of ROS in the regulation of AT1-R mRNA expression, VSMC were stimulated with H 2 O 2 . H 2 O 2 suppressed the AT1-R mRNA expression and activated ERK. These results suggest that production of ROS and activation of ERK are critical for downregulation of AT1-R mRNA. The differential effect of NAC and DPI on the downregulation of AT1-R mRNA may suggest the presence of other sources than NADH/NADPH oxidase pathway for ROS in Ang II signaling. Generation of ROS through stimulation of AT1-R not only mediates signaling of Ang II but may play a crucial role in the adaptation process of AT1-R to the sustained stimulation of Ang II.

Visual Field Sensitivity on a Two-Choice Discrimination Task

1981 ◽  
Vol 53 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Paul Salmon ◽  
Albert Rodwan
Keyword(s):  
Visual Field ◽  
Signal Detection ◽  
Left Visual Field ◽  
Discrimination Task ◽  
Visual Fields ◽  
Detection Analysis ◽  
Field Sensitivity ◽  
Signal Detection Analysis ◽  
The Right ◽  
Stimulation Of

A signal-detection analysis was used to evaluate visual-field sensitivity on a two-choice (same/different) discrimination task. Pairs of unfamiliar geometrical forms were presented tachistoscopically to the right or left visual fields of 12 subjects. Of 12 subjects 11 obtained left visual-field values which exceeded those of the right. The data suggested that the superiority of stimulation of the left visual field resulted from greater sensitivity to “same” figure pairs.

Binocular neurons in the nucleus of the basal optic root (nBOR) of the pigeon are selective for either translational or rotational visual flow

1990 ◽  
Vol 5 (5) ◽  
pp. 489-495 ◽  
Author(s):  
Douglas R. Wylie ◽  
Barrie J. Frost
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Visual Motion ◽  
Visual Fields ◽  
Receptive Fields ◽  
Locomotor Behavior ◽  
Visual Flow ◽  
Electrophysiological Studies ◽  
Crucial Part ◽  
Stimulation Of

AbstractPrevious electrophysiological studies have shown that neurons in the nucleus of the basal optic root (nBOR) of the pigeon respond best to wholefield stimuli moving slowly in a particular direction in the contralateral visual field. In this study, we have found that some nBOR neurons respond to wholefield stimulation of both eyes. These binocular neurons have spatially separate receptive fields in both visual fields. Some binocular neurons prefer the same direction of wholefield motion in both eyes, and thus respond best to wholefield visual motion which would result from translation movements of the bird, either ascent, descent, or forward and backward motion. Other neurons prefer opposite directions of wholefield motion in each eye and therefore respond optimally to wholefield visual motion simulating rotational movements of the bird, either roll or yaw. These binocular neurons may play a crucial part in the locomotor behavior of the pigeon by providing visual information distinguishing translational and rotational movements.

scholarly journals Ventral motion parallax enhances fruit fly steering to visual sideslip

2020 ◽  
Vol 16 (5) ◽  
pp. 20200046
Author(s):  
Carlos Ruiz ◽  
Jamie C. Theobald
Keyword(s):  
Visual Field ◽  
Optic Flow ◽  
Motion Parallax ◽  
Visual Fields ◽  
Fruit Fly ◽  
Depth Information ◽  
Experimental Proof ◽  
Important Region

Flies and other insects use incoherent motion (parallax) to the front and sides to measure distances and identify obstacles during translation. Although additional depth information could be drawn from below, there is no experimental proof that they use it. The finding that blowflies encode motion disparities in their ventral visual fields suggests this may be an important region for depth information. We used a virtual flight arena to measure fruit fly responses to optic flow. The stimuli appeared below ( n = 51) or above the fly ( n = 44), at different speeds, with or without parallax cues. Dorsal parallax does not affect responses, and similar motion disparities in rotation have no effect anywhere in the visual field. But responses to strong ventral sideslip (206° s −1 ) change drastically depending on the presence or absence of parallax. Ventral parallax could help resolve ambiguities in cluttered motion fields, and enhance corrective responses to nearby objects.

scholarly journals Influence of central and peripheral visual field on the postural control when viewing an optic flow stimulus

2010 ◽  
Vol 8 (6) ◽  
pp. 858-858 ◽  
Author(s):  
J. M. Hanssens ◽  
J. C. Piponnier ◽  
J. Faubert
Keyword(s):  
Visual Field ◽  
Postural Control ◽  
Optic Flow ◽  
Peripheral Visual Field

scholarly journals The Internal Senses in Nemesius, Plotinus and Galen: the Beginning of an Idea

2016 ◽  
Vol 10 (2) ◽  
pp. 119 ◽  
Author(s):  
Muhammad Umar Faruque
Keyword(s):  
Crucial Role ◽  
The Body ◽  
Sense Perception ◽  
Sense Organs ◽  
Textual Evidence ◽  
Localization Theory ◽  
The Brain ◽  
Different Parts ◽  
The Way

This study traces the notion of the internal senses in three ancient authors, namely Nemesius, Plotinus and Galen. It begins with Nemesius, and then by going backward ends with Galen. The textual evidence investigated in this study shows clearly that Galen, after acknowledging the Platonic tripartite soul, locates the various dunameis of the soul in the brain. The “localization” theory of Galen plays a crucial role in paving the way for the foundation of the internal senses, which both Plotinus and Nemesius adapted. Just as with the external senses one can locate various sense-organs in different parts of the body, viz., touch, smell, sight etc., so too with the internal senses, thanks to Galen, one is able to locate them in various organs of the body. Thus philosophers are able to explain the role of all these different (internal) senses in their account of sense-perception.

Differential Recognition of Tachistoscopically Presented English and Hebrew Words in Right and Left Visual Fields

1965 ◽  
Vol 21 (2) ◽  
pp. 431-437 ◽  
Author(s):  
Melvin I. Barton ◽  
Harold Goodglass ◽  
Amnon Shai
Keyword(s):  
Visual Field ◽  
Cerebral Hemisphere ◽  
Left Visual Field ◽  
Visual Fields ◽  
Cerebral Dominance ◽  
Consistent Finding ◽  
Differential Recognition ◽  
The Right ◽  
Language Areas

In this study, the role of lateral cerebral dominance in the consistent finding of lower tachistoscopic thresholds in the right than in the left visual field for alphabetic material was tested for readers of Hebrew and English. Twenty Israeli Ss were presented with Hebrew and English three-letter words, printed vertically, through a monocular tachistoscope, displaced to left or right of fixation by 2°21′. Ten American Ss were also tested for three-letter English words, under similar conditions. Significantly lower thresholds in the right field were found for both groups and for both languages, despite the fact that Hebrew, unlike English, is read from right to left. These findings tend to support the hypothesis that alphabetic stimuli arriving in the major cerebral hemisphere are more readily recognized than similar stimuli arriving in the hemisphere contralateral to the language areas.

scholarly journals Larger head displacement to optic flow presented in the lower visual field.

2019 ◽  
Author(s):  
Kanon Fujimoto ◽  
Hiroshi Ashida
Keyword(s):  
Visual Field ◽  
Postural Control ◽  
Field Condition ◽  
Optic Flow ◽  
Postural Adjustment ◽  
Lower Visual Field ◽  
Postural Response ◽  
Head Displacement ◽  
Upper Visual Field ◽  
Self Motion

Optic flow that simulates self-motion often produces postural adjustment. Although literature suggested that human postural control considerably depends on visual inputs from the lower field in the environment, effects of the vertical location of optic flow are not well investigated on postural response. Here, we examined whether optic flow presented in the lower visual field produces a stronger postural response than optic flow in the upper visual field. Either expanding or contracting the optic flow was presented in three visual locations (upper, lower, and full visual fields) on an Oculus Rift head-mounted display. Head displacement and vection strength was measured. Results showed larger head displacement under the optic flow presentation in the lower visual field, than in the upper visual field, but only for the early period of the presentation of the contracting optic flow. Full visual field condition also produced larger head displacement than the upper visual field condition, but for contraction only. Vection was stronger for the lower visual field than the upper visual field, stronger for full visual field than upper and lower visual field. Our findings support the notion that more ecologically relevant information has a more important role in human postural control and self-motion perception.

scholarly journals The role of orthographic neighbourhood effects in lateralized lexical decision: a replication study and meta-analysis

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11266
Author(s):  
Adam J. Parker ◽  
Ciara Egan ◽  
Jack H. Grant ◽  
Sophie Harte ◽  
Brad T. Hudson ◽  
...  
Keyword(s):  
Visual Field ◽  
Lexical Decision ◽  
Meta Analysis ◽  
Visual Fields ◽  
Reaction Times ◽  
Right Visual Field ◽  
Facilitative Role ◽  
The Right ◽  
Future Work

The effect of orthographic neighbourhood size (N) on lexical decision reaction time differs when words are presented in the left or right visual fields. Evidence suggests a facilitatory N effect (i.e., faster reaction times for words with larger neighbourhoods) in the left visual field. However, the N effect in the right visual field remains controversial: it may have a weaker facilitative role or it may even be inhibitory. In a pre-registered online experiment, we replicated the interaction between N and visual field and provided support for an inhibitory N effect in the right visual field. We subsequently conducted a pre-registered systematic review and meta-analysis to synthesise the available evidence and determine the direction of N effects across visual fields. Based on the evidence, it would seem the effect is inhibitory in the right visual field. Furthermore, the size of the N effect is considerably smaller in the right visual field. Both studies revealed considerable heterogeneity between participants and studies, and we consider the implications of this for future work.

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