scholarly journals Prepulse inhibition vs cognitive modulation of the hand-blink reflex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Viviana Versace ◽  
Stefania Campostrini ◽  
Luca Sebastianelli ◽  
Leopold Saltuari ◽  
Josep Valls-Solé ◽  
...  
Keyword(s):  
Prepulse Inhibition ◽  
Visual Processing ◽  
Blink Reflex ◽  
Experimental Conditions ◽  
Median Nerve Stimulation ◽  
Contralateral Hand ◽  
The Face ◽  
Cognitive Modulation ◽  
Self Protection ◽  
Self Stimulation

AbstractThe excitability of brainstem circuitries mediating defensive blinking in response to abrupt sensory inputs is continuously modulated by cortical areas, e.g., the hand-blink reflex (HBR), elicited by intense electrical median nerve stimulation, is enhanced when the stimulated hand is close to the face, with the behavioural purpose to optimize self-protection from increased threat. Here we investigated whether such cortically mediated HBR facilitation can be influenced by prepulse inhibition (PPI), which is known to occur entirely at the subcortical level. Twenty healthy volunteers underwent HBR recordings in five experimental conditions. In conditions 1 and 2, the stimulated hand was held either near (1) or far (2) from the face, respectively. In conditions 3 and 4, stimulation of the hand near the face was preceded by a peri-liminal prepulse to the index finger of the contralateral hand held either near (3) or far from the face (4). In condition 5, participants self-triggered the stimulus eliciting the HBR. We observed a reproducible HBR in 14 out of 20 participants and measured onset latency and area of the HBR in orbicularis oculi muscles bilaterally. HBR area decreased and latency increased in condition 2 relative to condition 1; HBR area decreased and latency increased markedly in condition 3, and somewhat less in condition 4, relative to conditions 1 and 2; self-stimulation (condition 5) also suppressed HBRs, but less than prepulses. These findings indicate that PPI of the HBR is more robust than the cognitive modulation exerted by top-down cortical projections. Possibly, an attentional shift to a prepulse may serve to reduce blinking in response to perturbation when it is convenient, in a given situation, not to interrupt ongoing visual processing.

scholarly journals Transcutaneous trigeminal nerve stimulation modulates the hand blink reflex

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Beniamina Mercante ◽  
Nicola Loi ◽  
Francesca Ginatempo ◽  
Monica Biggio ◽  
Andrea Manca ◽  
...  
Keyword(s):  
Median Nerve ◽  
Trigeminal Nerve ◽  
Nerve Stimulation ◽  
Blink Reflex ◽  
Infraorbital Nerve ◽  
Hand Position ◽  
Median Nerve Stimulation ◽  
Trigeminal Nerve Stimulation ◽  
Before And After ◽  
The Face

AbstractThe hand-blink reflex (HBR) is a subcortical response, elicited by the electrical stimulation of the median nerve, whose magnitude is specifically modulated according to the spatial properties of the defensive peripersonal space (DPPS) of the face. For these reasons, the HBR is commonly used as a model to assess the DPPS of the face. Little is known on the effects induced by the activation of cutaneous afferents from the face on the DPPS of the face. Therefore, we tested the effect of non-painful transcutaneous trigeminal nerve stimulation (TNS) on the amplitude of the HBR. Fifteen healthy participants underwent HBR recording before and after 20 min of sham- and real-TNS delivered bilaterally to the infraorbital nerve in two separate sessions. The HBR was recorded bilaterally from the orbicularis oculi muscles, following non-painful median nerve stimulation at the wrist. The HBR amplitude was assessed in the “hand‐far” and “hand‐near” conditions, relative to the hand position in respect to the face. The amplitudes of the hand-far and hand-near HBR were measured bilaterally before and after sham- and real-TNS. Real-TNS significantly reduced the magnitude of the HBR, while sham-TNS had no significant effect. The inhibitory effect of TNS was of similar extent on both the hand-far and hand-near components of the HBR, which suggests an action exerted mainly at brainstem level.

scholarly journals Alzheimer’s Disease Progressively Reduces Visual Functional Network Connectivity

2021 ◽  
pp. 1-14
Author(s):  
Jie Huang ◽  
Paul Beach ◽  
Andrea Bozoki ◽  
David C. Zhu
Keyword(s):  
Visual Cortex ◽  
Lower Order ◽  
Resting State ◽  
Visual Processing ◽  
Network Connectivity ◽  
Higher Order ◽  
Functional Network ◽  
Functional Networks ◽  
The Face ◽  
Processing Network

Background: Postmortem studies of brains with Alzheimer’s disease (AD) not only find amyloid-beta (Aβ) and neurofibrillary tangles (NFT) in the visual cortex, but also reveal temporally sequential changes in AD pathology from higher-order association areas to lower-order areas and then primary visual area (V1) with disease progression. Objective: This study investigated the effect of AD severity on visual functional network. Methods: Eight severe AD (SAD) patients, 11 mild/moderate AD (MAD), and 26 healthy senior (HS) controls undertook a resting-state fMRI (rs-fMRI) and a task fMRI of viewing face photos. A resting-state visual functional connectivity (FC) network and a face-evoked visual-processing network were identified for each group. Results: For the HS, the identified group-mean face-evoked visual-processing network in the ventral pathway started from V1 and ended within the fusiform gyrus. In contrast, the resting-state visual FC network was mainly confined within the visual cortex. AD disrupted these two functional networks in a similar severity dependent manner: the more severe the cognitive impairment, the greater reduction in network connectivity. For the face-evoked visual-processing network, MAD disrupted and reduced activation mainly in the higher-order visual association areas, with SAD further disrupting and reducing activation in the lower-order areas. Conclusion: These findings provide a functional corollary to the canonical view of the temporally sequential advancement of AD pathology through visual cortical areas. The association of the disruption of functional networks, especially the face-evoked visual-processing network, with AD severity suggests a potential predictor or biomarker of AD progression.

Visual Processing without Awareness: Evidence from Unilateral Neglect

1992 ◽  
Vol 4 (4) ◽  
pp. 345-351 ◽  
Author(s):  
Anna Berti ◽  
Giacomo Rizzolatti
Keyword(s):  
Visual Processing ◽  
Visual Awareness ◽  
Visual Cognition ◽  
Congruent Condition ◽  
Experimental Conditions ◽  
Unilateral Neglect ◽  
Normal Field ◽  
The Third ◽  
Physically Identical ◽  
Physiological Theory

Can visual processing be carried out without visual awareness of the presented objects? In the present study we addressed this problem in patients with severe unilateral neglect. The patients were required to respond as fast as possible to target stimuli (pictures of animals and fruits) presented to the normal field by pressing one of the two keys according to the category of the targets. We then studied the influence of priming stimuli, again pictures of animals or fruits, presented to the neglected field on the responses to targets. By combining different pairs of primes and targets, three different experimental conditions were obtained. In the first condition, "Highly congruent," the target and prime stimuli belonged to the same category and were physically identical; in the second condition, "Congruent," the stimuli represented two elements of the same category but were physically dissimilar; in the third condition, "Noncongruent," the stimuli represented one exemplar from each of the two categories of stimuli. The results showed that the responses were facilitated not only in the Highly congruent condition, but also in the Congruent one. This finding suggests that patients with neglect are able to process stimuli presented to the neglected field to a categorical level of representation even when they deny the stimulus presence in the affected field. The implications of this finding for psychological and physiological theory of neglect and visual cognition are discussed.

Repetition Suppression of Induced Gamma Activity Predicts Enhanced Orienting toward a Novel Stimulus in 6-month-old Infants

2008 ◽  
Vol 20 (12) ◽  
pp. 2137-2152 ◽  
Author(s):  
Kelly A. Snyder ◽  
Andreas Keil
Keyword(s):  
Visual Processing ◽  
Novelty Detection ◽  
Neural Mechanisms ◽  
Human Infant ◽  
Gamma Activity ◽  
Repeated Stimulus ◽  
Repetition Suppression ◽  
The Face ◽  
Over 40 Years

Habituation refers to a decline in orienting or responding to a repeated stimulus, and can be inferred to reflect learning about the properties of the repeated stimulus when followed by increased orienting to a novel stimulus (i.e., novelty detection). Habituation and novelty detection paradigms have been used for over 40 years to study perceptual and mnemonic processes in the human infant, yet important questions remain about the nature of these processes in infants. The aim of the present study was to examine the neural mechanisms underlying habituation and novelty detection in infants. Specifically, we investigated changes in induced alpha, beta, and gamma activity in 6-month-old infants during repeated presentations of either a face or an object, and examined whether these changes predicted behavioral responses to novelty at test. We found that induced gamma activity over occipital scalp regions decreased with stimulus repetition in the face condition but not in the toy condition, and that greater decreases in the gamma band were associated with enhanced orienting to a novel face at test. The pattern and topography of these findings are consistent with observations of repetition suppression in the occipital–temporal visual processing pathway, and suggest that encoding in infant habituation paradigms may reflect a form of perceptual learning. Implications for the role of repetition suppression in infant habituation and novelty detection are discussed with respect to a biased competition model of visual attention.

NEW INSPIRATION FROM CHINA'S PHILOSOPHY OF "UNITY OF MAN AND HEAVEN": CONTEMPORARY INTERNATIONAL RELATIONS UNDER THE COVID-19 PANDEMIC

2021 ◽  
pp. 21-34
Author(s):  
PU JINGXIN
Keyword(s):  
International Relations ◽  
Human Society ◽  
The Novel ◽  
The World ◽  
The Face ◽  
New Type ◽  
Novel Coronavirus ◽  
The Ancient Chinese ◽  
Self Protection ◽  
Harmonious Community

Abstract: The danger of the novel coronavirus has not yet come to an end, and new variants have begun to attack the world. What philosophy should humankind’s strategy be based on when human society as a group is fighting against Covid-19, as the pandemic ravages the world? Unfortunately, political leaders of various countries have failed to achieve the overall awareness of attacking the pandemic for a shared future for mankind so far. In the face of the pandemic, mankind as a whole urgently needs to break through the narrow nation-oriented ideology of seeking only self-protection. The International Community should establish a new type of international cooperation featuring the concept of harmony of "all things under heaven as a unity". The international relations system dominated by the power ofwestern discourse is now in a bottleneck. The main aim of this article is to study the ancient Chinese wisdom of "the Unity of Man and Heaven" philosophy and build a global harmonious community. The author argues that the “export” of the aforementioned wisdom must be a priority for Chinese scholars. Keywords: Tao; Unity of Man and Heaven; Novel Coronavirus; Anthropocentrism; Harmony.

Reliability of the conditioned pain modulation paradigm across three anatomical sites

2020 ◽  
Vol 20 (2) ◽  
pp. 283-296
Author(s):  
Rania Nuwailati ◽  
Michele Curatolo ◽  
Linda LeResche ◽  
Douglas S. Ramsay ◽  
Charles Spiekerman ◽  
...  
Keyword(s):  
Cold Pressor Test ◽  
Pressure Pain Threshold ◽  
Pain Modulation ◽  
Conditioned Pain Modulation ◽  
Dominant Hand ◽  
Pain Mechanisms ◽  
Relative Reliability ◽  
Contralateral Hand ◽  
The Face ◽  
Absolute Reliability

AbstractBackground and aimsConditioned Pain Modulation (CPM) is a measure of pain inhibition-facilitation in humans that may elucidate pain mechanisms and potentially serve as a diagnostic test. In laboratory settings, the difference between two pain measures [painful test stimulus (TS) without and with the conditioning stimulus (CS) application] reflects the CPM magnitude. Before the CPM test can be used as a diagnostic tool, its reliability on the same day (intra-session) and across multiple days (inter-session) needs to be known. Furthermore, it is important to determine the most reliable anatomical sites for both the TS and the CS. This study aimed to measure the intra-session and inter-session reliability of the CPM test paradigm in healthy subjects with the TS (pressure pain threshold-PPT) applied to three test sites: the face, hand, and dorsum of the foot, and the CS (cold pressor test-CPT) applied to the contralateral hand.MethodsSixty healthy participants aged 18–65 were tested by the same examiner on 3 separate days, with an interval of 2–7 days. On each day, testing was comprised of two identical experimental sessions in which the PPT test was performed on each of the three dominant anatomical sites in randomized order followed by the CPM test (repeating the PPT with CPT on the non-dominant hand). CPM magnitude was calculated as the percent change in PPT. The Intraclass Correlation Coefficient (ICC), Coefficient of Variation (CV), and Bland-Altman analyses were used to assess reliability.ResultsPPT relative reliability ranged from good to excellent at all three sites; the hand showed an intra-session ICC of 0.90 (0.84, 0.94) before CPT and ICC of 0.89 (0.83, 0.92) during CPT. The PPT absolute reliability was also high, showing a low bias and small variability when performed on all three sites; for example, CV of the hand intra-session was 8.0 before CPT and 8.1 during CPT. The relative reliability of the CPM test, although only fair, was most reliable when performed during the intra-session visits on the hand; ICC of 0.57 (0.37, 0.71) vs. 0.20 (0.03, 0.39) for the face, and 0.22 (0.01, 0.46) for the foot. The inter-session reliability was lower in all three anatomical sites, with the best reliability on the hand with an ICC of 0.40 (0.23, 0.55). The pattern of absolute reliability of CPM was similar to the relative reliability findings, with the reliability best on the hand, showing lower intra-session and inter-session variability (CV% = 43.5 and 51.5, vs. 70.1 and 73.1 for the face, and 75.9 and 78.9 for the foot). The CPM test was more reliable in women than in men, and in older vs. younger participants.DiscussionThe CPM test was most reliable when the TS was applied to the dominant hand and CS performed on the contralateral hand. These data indicate that using the CS and TS in the same but contralateral dermatome in CPM testing may create the most reliable results.

Fear leads to a deficit of prepulse inhibition of blink reflex in healthy humans

2019 ◽  
Vol 40 (12) ◽  
pp. 2581-2586
Author(s):  
Ayşegül Gündüz ◽  
Selen Koçak ◽  
Sedat Gez ◽  
Meral E. Kızıltan
Keyword(s):  
Prepulse Inhibition ◽  
Blink Reflex ◽  
Healthy Humans

The Postauricular Reflex as a Measure of Attention and Positive Emotion

2018 ◽  
Author(s):  
Stephen D. Benning
Keyword(s):  
Personality Traits ◽  
Prepulse Inhibition ◽  
Opioid Dependence ◽  
Positive Emotion ◽  
Well Being ◽  
Blink Reflex ◽  
Startle Blink ◽  
Startle Blink Reflex

The postauricular reflex is a muscular reaction that occurs behind the ear in response to short, abrupt sounds. Its magnitude increases with louder eliciting sounds, rotating the eyes in the direction of the eliciting sound, and flexing the head forward. The reflex exhibits prepulse inhibition, especially during attention to complex foreground stimuli. Its magnitude is larger (or potentiated) during pleasant than during neutral pictures, sounds, and videos that are highly arousing. This pattern is particularly evident for erotic, food, and nurturant scenes, suggesting it assesses more than just appetitive processing. This reflex’s potentiation varies across development; positively correlates with personality traits associated with well-being; and negatively correlates with such psychopathologies as depression, schizophrenia, and opioid dependence. It appears distinct from and uncorrelated with the startle blink reflex. New data suggest that activity in left frontal areas generates postauricular reflex potentiation during pleasant versus neutral pictures.

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