scholarly journals Pupil constriction via the parasympathetic pathway precedes perceptual switch of ambiguous stimuli

2021 ◽  
Author(s):  
Tamami Nakano ◽  
Arata Ichiki ◽  
Takashi Fujikado
Keyword(s):  
Pupil Constriction ◽  
Ambiguous Stimuli ◽  
Parasympathetic Pathway

Direct Realism and Illusion

2018 ◽  
Author(s):  
J. Christopher Maloney
Keyword(s):  
Perceptual Experience ◽  
Direct Realism ◽  
Perceptual Representation ◽  
Perceptual Error ◽  
Standard Response ◽  
Perceptual Representations ◽  
Ambiguous Stimuli ◽  
Physical Objects ◽  
Apparent Problem

The supposed problem of perceptual error, including illusion and hallucination, has led most theories of perception to deny formulations of direct realism. The standard response to this apparent problem adopts the mistaken presupposition that perception is indeed liable to error. However, the prevailing conditions of observation are themselves elements of perceptual representation, functioning in the manner of predicate modifiers. They ensure that the predicates applied in perceptual representations do indeed correctly attribute properties that perceived physical objects actually instantiate. Thus, perceptual representations are immune to misrepresentation of the sort misguidedly supposed by the spurious problem of perceptual misrepresentation. Granted the possibility that perceptual attribution admits of predicate modification, it is quite possible that perceptual experience permits both rudimentary and sophisticated conceptualization. Moreover, such treatment of perceptual predication rewards by providing an account of aspect alteration exemplified by perception of ambiguous stimuli.

Processing of emotionally ambiguous stimuli in eating disorders: an fMRI pilot study

2021 ◽  
Author(s):  
Petra Holštajn Zemánková ◽  
Martin Gajdoš ◽  
Miroslav Světlák ◽  
Martin Bareš ◽  
Jan Širůček ◽  
...  
Keyword(s):  
Eating Disorders ◽  
Pilot Study ◽  
Ambiguous Stimuli

scholarly journals Human and Human-Interfaced AI Interactions: Modulation of Human Male Autonomic Nervous System via Pupil Mimicry

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1028
Author(s):  
Catherine Spicer ◽  
Prashanna Khwaounjoo ◽  
Yusuf Ozgur Cakmak
Keyword(s):  
Heart Rate ◽  
Nervous System ◽  
Parasympathetic Nervous System ◽  
Pupil Dilation ◽  
Physical Parameters ◽  
Emotional States ◽  
Virtual Humans ◽  
Autonomic Functioning ◽  
Technological Advances ◽  
Pupil Constriction

Pupillary alterations in virtual humans induce neurophysiological responses within an observer. Technological advances have enabled rapid developments in artificial intelligence (AI), from verbal systems, to visual AI interfaces with the ability to express, and respond to emotional states of a user. Visual AI interfaces are able to change their physical parameters, such as pupil diameter. Pupillary changes can alter heart rate, however, effects on heart rate variability (HRV) are unknown. HRV, is an autonomic, non-conscious parameter which monitors sympathetic and parasympathetic nervous system (PNS) activity. N = 34 male participants aged between 19–33 were subjected to a number of conditions such as pupil dilation, constriction and blushing. The present research is the first to investigate the effects of virtual human interactions on human HRV. Outcomes of this study were obtained using eye tracking and HRV measurements. Pupil dilation relative to constriction presented in the female virtual partner induced a significant right pupillary diameter increase (p = 0.041) in human observers. Additionally, female virtual partner pupil constriction relative to dilation induced a significant increase in participants’ PNS HRV response (p = 0.036). These findings indicate the ability of a female virtual interaction partner to modulate parasympathetic autonomic functioning in young healthy male humans. This allows first insights into the effects of interacting with virtual AI interaction partners, on human autonomic functioning, and may aid development of future virtual humans, and their implementation into relevant clinical settings.

A Novel Measure of Real-Time Perseverative Thought

2021 ◽  
pp. 216770262110380
Author(s):  
Elizabeth C. Wade ◽  
Rivka T. Cohen ◽  
Paddy Loftus ◽  
Ayelet Meron Ruscio
Keyword(s):  
Clinical Status ◽  
Self Report ◽  
Repetitive Negative Thinking ◽  
Negative Thinking ◽  
New Methods ◽  
Temporal Process ◽  
Stimulus Valence ◽  
Ambiguous Stimuli ◽  
Perseverative Thinking ◽  
Positive Stimuli

Perseverative thinking (PT), or repetitive negative thinking, has historically been measured using global self-report scales. New methods of assessment are needed to advance understanding of this inherently temporal process. We developed an intensive longitudinal method for assessing PT. A mixed sample of 77 individuals ranging widely in trait PT, including persons with PT-related disorders (generalized anxiety disorder, major depression) and persons without psychopathology, used a joystick to provide continuous ratings of thought valence and intensity following exposure to scenarios of differing valence. Joystick responses were robustly predicted by trait PT, clinical status, and stimulus valence. Higher trait perseverators exhibited more extreme joystick values overall, greater stability in values following threatening and ambiguous stimuli, weaker stability in values following positive stimuli, and greater inertia in values following ambiguous stimuli. The joystick method is a promising measure with the potential to shed new light on the dynamics and precipitants of perseverative thinking.

scholarly journals Phaco-nucleotomy techniques in management of pseudoexfoliation syndrome

2017 ◽  
Vol 8 (2) ◽  
pp. 144-150 ◽  
Author(s):  
Amol Bansal ◽  
K. P.S. Malik ◽  
V. K. Malik ◽  
Kirti Jain
Keyword(s):  
Intraoperative Complications ◽  
Divide And Conquer ◽  
Pseudoexfoliation Syndrome ◽  
Extracellular Material ◽  
Ocular Tissues ◽  
Operative Complications ◽  
Pupil Constriction ◽  
The Mean ◽  
Almost All ◽  
Systemic Condition

Introduction: Pseudoexfoliation syndrome is a common clinically important systemic condition characterized by the pathological production and accumulation of an abnormal fibrillar extracellular material in many intraocular and extra ocular tissues. Many studies have shown that pseudoexfoliation syndrome patients have higher rates of intraoperative complications during cataract surgery compared to the patients without it. Objectives: To compare Phaco-chop and Divide and Conquer techniques of phacoemulsification, in the management of pseudoexfoliation syndrome in terms of intraoperative complications. Materials and methods: It is a hospital based prospective study of 90 patients with cataract and pseudoexfoliation syndrome attending ophthalmology outpatient department in our hospital. Results: The mean age of patients in the study was 61.7 years with equal number of unilateral and bilateral cases. Intra operative complications noted in vertical chopping technique was only pupil constriction in 6.7%, no other complications were seen in this technique, whereas in horizontal chopping, 13.3% had pupil constriction, 6.7% had difficulty in chopping, 3.3% had zonular dehiscence and 3.3% had posterior capsular rent . In divide and conquer technique 16.7% had pupil constriction, 10% had difficulty in trenching, 3.3% had posterior capsular rent. Almost all the patients (97.8%) were implanted with intraocular lens after employment of various surgical modifications. Conclusion: Vertical chopping techniques scores over horizontal chopping and divide and conquer technique of phacoemulsification with good surgical outcome because of less complications. 

scholarly journals A visual circuit uses complementary mechanisms to support transient and sustained pupil constriction

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
William Thomas Keenan ◽  
Alan C Rupp ◽  
Rachel A Ross ◽  
Preethi Somasundaram ◽  
Suja Hiriyanna ◽  
...  
Keyword(s):  
Neural Coding ◽  
Pupil Size ◽  
Neural Circuit ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Neural Basis ◽  
Behavioral Dynamics ◽  
Pupil Constriction ◽  
Sustained Responses ◽  
Stable Control

Rapid and stable control of pupil size in response to light is critical for vision, but the neural coding mechanisms remain unclear. Here, we investigated the neural basis of pupil control by monitoring pupil size across time while manipulating each photoreceptor input or neurotransmitter output of intrinsically photosensitive retinal ganglion cells (ipRGCs), a critical relay in the control of pupil size. We show that transient and sustained pupil responses are mediated by distinct photoreceptors and neurotransmitters. Transient responses utilize input from rod photoreceptors and output by the classical neurotransmitter glutamate, but adapt within minutes. In contrast, sustained responses are dominated by non-conventional signaling mechanisms: melanopsin phototransduction in ipRGCs and output by the neuropeptide PACAP, which provide stable pupil maintenance across the day. These results highlight a temporal switch in the coding mechanisms of a neural circuit to support proper behavioral dynamics.

scholarly journals Linking Dynamics Between Pupil and Lens

2019 ◽  
Author(s):  
Ahmad Yousef
Keyword(s):  
Real World ◽  
Pupil Dilation ◽  
Pupil Constriction ◽  
Physical Stimuli

This article aims to measure pupil variations through real physical stimuli in a real world; and to link them with lens accommodation theories. It is concluded that pupil dilation is linked to rounded lens, and pupil constriction is linked to faltered lens.

Sign in / Sign up

Export Citation Format

Share Document