scholarly journals Visual Awareness Is Essential for Grouping Based on Mirror Symmetry

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1872
Author(s):  
Dina Devyatko ◽  
Ruth Kimchi
Keyword(s):  
Mirror Symmetry ◽  
Discrimination Task ◽  
Visual Awareness ◽  
Significant Response ◽  
Point Scale ◽  
Response Priming ◽  
Target Task ◽  
Priming Paradigm ◽  
Per Se ◽  
Rule Out

We examined whether symmetry-based grouping can take place in the absence of visual awareness. To this end, we used a priming paradigm, sandwich masking as an invisibility-inducing method, and primes and targets composed of two vertical symmetric or asymmetric lines. The target could be congruent or incongruent with the prime in symmetry. In Experiment 1, participants were presented with masked primes and clearly visible targets. In each trial, the participants performed a two-alternative discrimination task on the target, and then rated the visibility of the prime on a subjective visibility four-point scale (used to assess prime awareness). Subjectively invisible primes failed to produce response priming, suggesting that symmetry processing might depend on visual awareness. However, participants barely saw the prime, and the results for the visible primes were inconclusive, even when we used a conservative criterion for awareness. To rule out the possibility that our prime stimuli could not produce priming per se, we conducted a control visibility experiment (Experiment 2), in which participants were presented with unmasked, clearly visible primes and performed a target task. The results showed that our primes could elicit significant response priming when visible. Taken together, our findings indicate that symmetry-based grouping requires visual awareness.

scholarly journals Effects of Moderate-to-Vigorous Acute Exercise on Visual Consciousness

2021 ◽  
Author(s):  
Binn Zhang ◽  
Xiaoxu Meng ◽  
Yanglan Yu ◽  
Yaogang Han ◽  
Ying LIU
Keyword(s):  
Information Processing ◽  
Discrimination Task ◽  
Acute Exercise ◽  
Visual Awareness ◽  
Hit Rate ◽  
Level Of Consciousness ◽  
Speed Change ◽  
Visual Consciousness ◽  
Almost All ◽  
Subjective Reports

Abstract Background the effect of acute exercise on cognition covers almost all stages of information processing, but few studies have focused on visual awareness. Subjective reports on the appearance of faint speed-changes in the perception of stimuli were used as an index for visual consciousness. Visual consciousness was assessed after exercise or rest. Aside from subjective index, objective speed-change discrimination was added as an index for the level of consciousness. Results: the results showed that subjective reports on the appearance of faint speed-changes in the perception of stimuli were affected by acute aerobic exercise. The hit rate for speed-change detection was marginally significantly higher after exercise than sedentary condition. Furthermore, the d’ index was higher after exercise. Analysis of the results obtained for the objective discrimination task showed that discrimination speed was boosted only when subjects were aware of the speed-change. Conclusions: these results suggest that acute exercise enhances visual consciousness.

scholarly journals Serum silicon concentrations in pregnant women and newborn babies

2013 ◽  
Vol 110 (11) ◽  
pp. 2004-2010 ◽  
Author(s):  
Ravin Jugdaohsingh ◽  
Simon H. C. Anderson ◽  
Lorin Lakasing ◽  
Supannee Sripanyakorn ◽  
Sarah Ratcliffe ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Umbilical Cord ◽  
Essential Role ◽  
Full Term ◽  
Older Children ◽  
Fasting Serum ◽  
Connective Tissues ◽  
Per Se ◽  
Forearm Vein ◽  
Rule Out

Earlier studies in animals have suggested an essential role for Si in connective tissues, but such works have not been replicated per se. Nonetheless, a study conducted in 2000 has reported that Si may be essential during pregnancy for the growing fetus, since serum Si concentrations in infants were approximately 300 % higher than those in older children and adults and serum Si concentrations in pregnant women were approximately 300 % lower than those in age-matched non-pregnant controls. To reproduce these potentially important findings, in the present study, serum Si concentrations were measured in fourteen pregnant women (15–24 weeks of gestation) and compared with those of seventeen non-pregnant, non-lactating female controls. Serum Si concentrations were also measured in fourteen full-term mothers at the time of delivery and in the umbilical cord (UC) vein and artery where possible. Fasting serum Si concentrations in pregnant women were not significantly different from those of the female controls and showed little change with advancing gestation (r 0·2). Mean serum Si concentrations in the UC vein samples were 52 % higher, while those in the UC artery samples were 235 % higher than those in the maternal forearm vein samples, although data were widely spread and differences were not significant. Mean maternal forearm vein Si concentrations at delivery were 50 % lower than those of pregnant women and female controls, but, again, these were not significant. Overall, we note that there are significant analytical challenges in comparing baseline Si levels between different groups; notwithstanding, our findings cannot confirm a reduction in fasting serum Si levels during pregnancy, but, equally, we cannot rule out higher serum Si levels in newborns than in their mothers, and further work is required.

Tonal Priming Beyond Tonics

2009 ◽  
Vol 26 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Fréédééric Marmel ◽  
Barbara Tillmann
Keyword(s):  
Reference Point ◽  
Discrimination Task ◽  
Implicit Knowledge ◽  
Priming Effects ◽  
The Third ◽  
Priming Paradigm ◽  
Timbre Discrimination

THE MUSICAL PRIMING PARADIGM ALLOWS FOR INVESTIGATION of listeners' expectations based on their implicit knowledge of tonal stability. To date, priming data are limited to reports of facilitated processing for tonic over nontonic events. The special status of the tonic as a cognitive reference point brings into question the subtlety of listeners' tonal knowledge: Is the facilitated processing observed in priming studies limited to tonic events, or is tone processing influenced by subtler tonal contrasts? The present study investigated tonal priming for mediants (the third scale degree) over leading tones (the seventh scale degree) presented in melodic contexts. Experiment 1 used a timbre discrimination task and Experiment 2 an intonation task. Facilitated processing was observed for the more tonally stable mediants over the less stable leading tones, thus showing that priming effects are not limited to pairs of tonal degrees including the tonic. This finding emphasizes the subtlety of nonexpert listeners' tonal knowledge.

EFFECTS OF AMIODARONE ON THYROID IODINE METABOLISM IN VITRO1)

1977 ◽  
Vol 85 (4) ◽  
pp. 781-790 ◽  
Author(s):  
Bernardo E. Gluzman ◽  
Aldo H. Coleoni ◽  
Héctor M. Targovnik ◽  
Hugo Niepomniszcze
Keyword(s):  
Thyroid Gland ◽  
Direct Action ◽  
The Other ◽  
Human Thyroid ◽  
Thyroid Peroxidase ◽  
Iodide Transport ◽  
Iodine Metabolism ◽  
Per Se ◽  
Rule Out

ABSTRACT Since alterations of thyroid function have been reported in patients treated with amiodarone, 2-butyl,3-(4-diethylaminoethoxy-3,5- diiodo, benzoyl) benzofuran, the effects of this drug on the active iodide transport, organic iodine formation, thyroid peroxidase and the enzymatic iodotyrosine deiodination, were studied. In pig thyroid slices the iodide transport was affected by amiodarone at concentrations of 10−4 m and 10−5 M, showing a decrease of T/M (tissue/medium) ratios of 20% and 23%, respectively. Lower concentrations produced no significant differences from the controls. Iodotyrosine synthesis was only, but poorly, affected by 10−4 m and 10−5 m amiodarone. Inhibition of the DIT formation was greater than that produced for MIT. Thyroid peroxidase activity, as measured by the tyrosine-iodinase assay, showed a 20% decrease at 10−3 m amiodarone. None of the other concentrations have affected the activity of the enzyme, except for 7% at a concentration of 10−4 m. The iodotyrosine deiodination was affected by amiodarone only at a concentration of 10−3 m and 10−4 m. The inhibitions were of 22.5% and 16.8%, respectively. We have concluded that, under the conditions of our study, amiodarone per se does not affect the intrathyroidal iodine metabolism in concentrations which are usually present in the sera of patients treated with this drug. However, it is not possible to rule out an in vivo direct action, if amiodarone is substantially concentrated in the human thyroid gland.

Some Phenomena Affecting Handwriting Analysis

1965 ◽  
Vol 20 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Calvin J. Frederick
Keyword(s):  
Present State ◽  
Present Status ◽  
Clinical Skill ◽  
Handwriting Analysis ◽  
Projective Techniques ◽  
Per Se ◽  
Rule Out

In this investigation designed to explore some of the phenomenological aspects of the present status of handwriting analysis, as an expressive technique largely, the results indicate that the technique is of value although it needs considerable refinement. The significant clues which one uses at this stage in analyzing the handwriting are apt to be something in the content, rather than the actual handwriting itself. Many handwriting specialists may be laboring under a false impression that they are picking up cues from the handwriting which really stem from other sources, principally the content of the material. The most significant results thus far seem to depend on clinical skill stemming from assaying content of the writing productions, more than the handwriting itself. The results cannot be said to rule out the value of cues from the handwriting per se, but at the present state of refinement, handwriting is largely still in the realm of many projective techniques in that objective and measurable clues currently employed for handwriting analysis do not seem reliable.

scholarly journals Bayesian Comparison of Explicit and Implicit Causal Inference Strategies in Multisensory Heading Perception

2017 ◽  
Author(s):  
Luigi Acerbi ◽  
Kalpana Dokka ◽  
Dora E. Angelaki ◽  
Wei Ji Ma
Keyword(s):  
Causal Inference ◽  
Discrimination Task ◽  
Model Comparison ◽  
Inference Process ◽  
Computational Framework ◽  
Bayesian Model Comparison ◽  
Vestibular Cues ◽  
Multisensory Cues ◽  
The Brain ◽  
Rule Out

AbstractThe precision of multisensory heading perception improves when visual and vestibular cues arising from the same cause, namely motion of the observer through a stationary environment, are integrated. Thus, in order to determine how the cues should be processed, the brain must infer the causal relationship underlying the multisensory cues. In heading perception, however, it is unclear whether observers follow the Bayesian strategy, a simpler non-Bayesian heuristic, or even perform causal inference at all. We developed an efficient and robust computational framework to perform Bayesian model comparison of causal inference strategies, which incorporates a number of alternative assumptions about the observers. With this framework, we investigated whether human observers’ performance in an explicit cause attribution and an implicit heading discrimination task can be modeled as a causal inference process. In the explicit inference task, all subjects accounted for cue disparity when reporting judgments of common cause, although not necessarily all in a Bayesian fashion. By contrast, but in agreement with previous findings, data from the heading discrimination task only could not rule out that several of the same observers were adopting a forced-fusion strategy, whereby cues are integrated regardless of disparity. Only when we combined evidence from both tasks we were able to rule out forced-fusion in the heading discrimination task. Crucially, findings were robust across a number of variants of models and analyses. Our results demonstrate that our proposed computational framework allows researchers to ask complex questions within a rigorous Bayesian framework that accounts for parameter and model uncertainty.

scholarly journals Ecology-driven stereotypes override race stereotypes

2015 ◽  
Vol 113 (2) ◽  
pp. 310-315 ◽  
Author(s):  
Keelah E. G. Williams ◽  
Oliver Sng ◽  
Steven L. Neuberg
Keyword(s):  
United States ◽  
Life History ◽  
Life History Theory ◽  
The United States ◽  
Life History Strategies ◽  
Racial Groups ◽  
Black And White ◽  
Lay Understanding ◽  
Per Se ◽  
Rule Out

Why do race stereotypes take the forms they do? Life history theory posits that features of the ecology shape individuals’ behavior. Harsh and unpredictable (“desperate”) ecologies induce fast strategy behaviors such as impulsivity, whereas resource-sufficient and predictable (“hopeful”) ecologies induce slow strategy behaviors such as future focus. We suggest that individuals possess a lay understanding of ecology’s influence on behavior, resulting in ecology-driven stereotypes. Importantly, because race is confounded with ecology in the United States, we propose that Americans’ stereotypes about racial groups actually reflect stereotypes about these groups’ presumed home ecologies. Study 1 demonstrates that individuals hold ecology stereotypes, stereotyping people from desperate ecologies as possessing faster life history strategies than people from hopeful ecologies. Studies 2–4 rule out alternative explanations for those findings. Study 5, which independently manipulates race and ecology information, demonstrates that when provided with information about a person’s race (but not ecology), individuals’ inferences about blacks track stereotypes of people from desperate ecologies, and individuals’ inferences about whites track stereotypes of people from hopeful ecologies. However, when provided with information about both the race and ecology of others, individuals’ inferences reflect the targets’ ecology rather than their race: black and white targets from desperate ecologies are stereotyped as equally fast life history strategists, whereas black and white targets from hopeful ecologies are stereotyped as equally slow life history strategists. These findings suggest that the content of several predominant race stereotypes may not reflect race, per se, but rather inferences about how one’s ecology influences behavior.

scholarly journals Regulating the Access to Awareness: Brain Activity Related to Probe-related and Spontaneous Reversals in Binocular Rivalry

2017 ◽  
Vol 29 (6) ◽  
pp. 1089-1102 ◽  
Author(s):  
Brian A. Metzger ◽  
Kyle E. Mathewson ◽  
Evelina Tapia ◽  
Monica Fabiani ◽  
Gabriele Gratton ◽  
...  
Keyword(s):  
Binocular Rivalry ◽  
Stimulus Change ◽  
Brain Activity ◽  
Visual Awareness ◽  
Intermediate Stage ◽  
Neural Correlates ◽  
Brain Regions ◽  
Conscious Awareness ◽  
Network Properties ◽  
Per Se

Research on the neural correlates of consciousness (NCC) has implicated an assortment of brain regions, ERP components, and network properties associated with visual awareness. Recently, the P3b ERP component has emerged as a leading NCC candidate. However, typical P3b paradigms depend on the detection of some stimulus change, making it difficult to separate brain processes elicited by the stimulus itself from those associated with updates or changes in visual awareness. Here we used binocular rivalry to ask whether the P3b is associated with changes in awareness even in the absence of changes in the object of awareness. We recorded ERPs during a probe-mediated binocular rivalry paradigm in which brief probes were presented over the image in either the suppressed or dominant eye to determine whether the elicited P3b activity is probe or reversal related. We found that the timing of P3b (but not its amplitude) was closely related to the timing of the report of a perceptual change rather than to the onset of the probe. This is consistent with the proposal that P3b indexes updates in conscious awareness, rather than being related to stimulus processing per se. Conversely, the probe-related P1 amplitude (but not its latency) was associated with reversal latency, suggesting that the degree to which the probe is processed increases the likelihood of a fast perceptual reversal. Finally, the response-locked P3b amplitude (but not its latency) was associated with the duration of an intermediate stage between reversals in which parts of both percepts coexist (piecemeal period). Together, the data suggest that the P3b reflects an update in consciousness and that the intensity of that process (as indexed by P3b amplitude) predicts how immediate that update is.

scholarly journals Visual awareness judgments are sensitive to accuracy feedback in stimulus discrimination task

2019 ◽  
Author(s):  
Marta Siedlecka ◽  
Michał Wereszczyński ◽  
Borysław Paulewicz ◽  
Michał Wierzchoń
Keyword(s):  
Discrimination Task ◽  
Performance Monitoring ◽  
Visual Awareness ◽  
Feedback Condition ◽  
Perceptual Discrimination ◽  
Perceptual Awareness ◽  
Discrimination Accuracy ◽  
Stimulus Discrimination ◽  
Correct Discrimination

AbstractIn this study we tested the hypothesis that perceptual awareness judgments are sensitive to the accuracy feedback about previous behaviour. We used a perceptual discrimination task in which participants reported their stimulus awareness. We created two conditions: No-feedback and Feedback (discrimination accuracy feedback was provided at the end of each trial). The results showed that visual awareness judgments are related to the accuracy of current and previous responses. Participants reported lower stimulus awareness for incorrectly versus correctly discriminated stimuli in both conditions; they also reported lower stimulus awareness in trials preceded by incorrect discrimination responses, compared to trials preceded by correct discrimination. This difference was significantly stronger in the Feedback condition. Moreover, in the Feedback condition we also observed larger post-error slowing for PAS ratings. We discuss the relation between the effects of performance monitoring and visual awareness and interpret the results in the context of current theories of consciousness.

scholarly journals Metacognitive awareness of difficulty in action selection: the role of the cingulo-opercular network

2019 ◽  
Author(s):  
Martyn Teuchies ◽  
Kobe Desender ◽  
Wouter de Baene ◽  
Jelle Demanet ◽  
Marcel Brass
Keyword(s):  
Reaction Times ◽  
Action Selection ◽  
Metacognitive Awareness ◽  
Direct Access ◽  
Response Priming ◽  
Cognitive States ◽  
Priming Paradigm ◽  
Metacognitive Experience ◽  
Increased Activity

AbstractThe question whether and how we are able to monitor our own cognitive states (metacognition) has been a matter of debate for decades. Do we have direct access to our cognitive processes or can we only infer them indirectly based on their consequences? In the current study, we wanted to investigate the brain circuits that underlie the metacognitive experience of fluency in action selection. To manipulate action-selection fluency we used a subliminal response priming paradigm. On each trial, participants additionally engaged in the metacognitive process of rating how hard they felt it was to respond to the target stimulus. Despite having no conscious awareness of the prime, results showed that participants rated incompatible trials (during which subliminal primes interfered with the required response) to be more difficult than compatible trials (where primes facilitated the required response) reflecting metacognitive awareness of difficulty. This increased sense of subjective difficulty was mirrored by increased activity in the rostral cingulate zone (RCZ) and the anterior insula, two regions that are functionally closely connected. Importantly, these reflected unique activations and were not explained by reaction times or prime-response compatibility. We interpret these findings in light of a possible grounding of the metacognitive judgement of fluency in action selection in interoceptive signals resulting from increased effort.

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