Temporal Processing of Saccade Targets in Parietal Cortex Area LIP During Visual Search

2007 ◽  
Vol 97 (1) ◽  
pp. 942-947 ◽  
Author(s):  
Neil W. D. Thomas ◽  
Martin Paré
Keyword(s):  
Visual Search ◽  
Parietal Cortex ◽  
Activity Patterns ◽  
Reaction Times ◽  
Stimulus Presentation ◽  
Ideal Observer ◽  
Cortex Area ◽  
The Individual ◽  
Visual Cortical ◽  
Selection Of

We studied whether the lateral intraparietal (LIP) area—a subdivision of parietal cortex anatomically interposed between visual cortical areas and saccade executive centers—contains neurons with activity patterns sufficient to contribute to the active process of selecting saccade targets in visual search. Visually responsive neurons were recorded while monkeys searched for a color-different target presented concurrently with seven distractors evenly distributed in a circular search array. We found that LIP neurons initially responded indiscriminately to the presentation of a visual stimulus in their response fields, regardless of its feature and identity. Their activation nevertheless evolved to signal the search target before saccade initiation: an ideal observer could reliably discriminate the target from the individual activation of 60% of neurons, on average, 138 ms after stimulus presentation and 26 ms before saccade initiation. Importantly, the timing of LIP neuronal discrimination varied proportionally with reaction times. These findings suggest that LIP activity reflects the selection of both the search target and the targeting saccade during active visual search.

Searching for threat

2002 ◽  
Vol 55 (3) ◽  
pp. 1007-1026 ◽  
Author(s):  
Jason Tipples ◽  
Andrew W. Young ◽  
Philip Quinlan ◽  
Paul Broks ◽  
Andrew W. Ellis
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Reaction Times ◽  
Search Rate ◽  
Threat Detection ◽  
Biologically Relevant ◽  
Initial Fixation ◽  
Series Of Experiments ◽  
Selection Of ◽  
Threatening Stimuli

In a series of experiments, a visual search task was used to test the idea that biologically relevant threatening stimuli might be recognized very quickly or capture visuo-spatial attention. In Experiment 1, there was evidence for both faster detection and faster search rates for threatening animals than for plants. However, examination of the basis of this effect in Experiment 2 showed that it was not due to threat per se, as detection and search rate advantages were found for pleasant rather than threatening animals compared to plants. In Experiment 3, participants searched for the plants and pleasant and threatening animals used in Experiments 1 and 2, among a fixed heterogeneous selection of non-target items. There was no search rate or detection advantage for threatening animals compared to pleasant animals or plants. The same targets and non-targets as those used in Experiment 3 were also used in Experiment 4. In Experiment 4, participants searched for targets that were presented either close to or distant from an initial fixation point. There was no evidence for a “threat” detection advantage either close to or distant from the cross. Finally, an experiment was conducted in which target categories (fruit, flowers, and animals) were not pre-specified prior to each trial block. There were no differences in reaction times to detect pleasant animals, threatening animals, or fruit. We conclude that the visual search paradigm does not readily reveal any biases that might exist for threatening stimuli in the general population.

How Serial is Serial Processing in Vision?

Perception ◽  
1989 ◽  
Vol 18 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Ehud Zohary ◽  
Shaul Hochstein
Keyword(s):  
Visual Search ◽  
Parallel Processing ◽  
Processing Speed ◽  
Processing Time ◽  
Reaction Times ◽  
Stimulus Presentation ◽  
Serial Search ◽  
Serial Processing ◽  
Processing Task ◽  
Serial Scanning

Visual search for an element defined by the conjunction of its colour and orientation has previously been shown to be a serial processing task since reaction times increase linearly with the number of distractor elements used in the display. Evidence is presented that there are parallel processing constituents to this serial search. Processing time depended on the ratio of the number of the two distractor types used, suggesting that only one type was scanned. Which type was scanned also depended on the distractor ratio, indicating that this decision was made after stimulus presentation and was based on a parallel figure—ground separation of the stimulus elements. Furthermore, in accordance with this serial scanning model, there was an increase in processing speed (elements scanned per second) with increase in number of elements to be scanned. This increased efficiency suggests that clumps of elements were processed synchronously. Under the stimulation conditions used, clumps contained six to sixteen elements and each clump was processed in 50–150 ms.

Sensory evidence integration and action initiation occur in parallel during perceptual decisions

2020 ◽  
Author(s):  
Lluís Hernández-Navarro ◽  
Ainhoa Hermoso-Mendizabal ◽  
Daniel Duque ◽  
Alexandre Hyafil ◽  
Jaime de la Rocha
Keyword(s):  
Time Pressure ◽  
Reaction Times ◽  
Stimulus Presentation ◽  
Perceptual Decision Making ◽  
Evidence Accumulation ◽  
Action Preparation ◽  
Action Model ◽  
The Brain ◽  
Evidence Integration ◽  
Action Initiation

It is commonly assumed that, during perceptual decisions, the brain integrates stimulus evidence until reaching a decision, and then performs the response. There are conditions, however (e.g. time pressure), in which the initiation of the response must be prepared in anticipation of the stimulus presentation. It is therefore not clear when the timing and the choice of perceptual responses depend exclusively on evidence accumulation, or when preparatory motor signals may interfere with this process. Here, we find that, in a free reaction time auditory discrimination task in rats, the timing of fast responses does not depend on the stimulus, although the choices do, suggesting a decoupling of the mechanisms of action initiation and choice selection. This behavior is captured by a novel model, the Parallel Sensory Integration and Action Model (PSIAM), in which response execution is triggered whenever one of two processes, Action Initiation or Evidence Accumulation, reaches a bound, while choice category is always set by the latter. Based on this separation, the model accurately predicts the distribution of reaction times when the stimulus is omitted, advanced or delayed. Furthermore, we show that changes in Action Initiation mediates both post-error slowing and a gradual slowing of the responses within each session. Overall, these results extend the standard models of perceptual decision-making, and shed a new light on the interaction between action preparation and evidence accumulation.

Pengaruh Persepsi Kegunaan, Persepsi Kemudahan, Kecepatan, Keamanan 75 dan Kerahasiaan Serta Kesiapan Teknologi Informasi Wajib Pajak terhadap Penggunaan e-Filing Bagi Wajib Pajak Orang Pribadi Di Kota Tangerang, Kecamatan Karawaci

2016 ◽  
Vol 8 (1) ◽  
pp. 75-91 ◽  
Author(s):  
Shelby Devina ◽  
Waluyo Waluyo
Keyword(s):  
Ease Of Use ◽  
Perceived Usefulness ◽  
Security And Privacy ◽  
Primary Data ◽  
Perceived Ease Of Use ◽  
Analysis Technique ◽  
Convenience Sampling ◽  
The Individual ◽  
Tax Payers ◽  
Selection Of

The objective of this research was to examine the effect of perceived usefulness, perceived ease of use, speed, security and privacy and readiness technology tax payers information to e-Filing usage. The object of this study is the individual tax payers in Tangerang City, Karawaci District. The selection of the sample is determined based on convenience sampling method. Data used in this study was primary data, id est: questionnaires. The respondent in this study were 110. Data analysis technique in this study using multiple linear regression. The result of this study were (1) perceived usefulness have a significant impact towards e-Filing usage; (2) perceived ease of use have a significant impact towards e-Filing usage; (3) speed does not have a significant impact towards e-Filing usage; (4) security and privacy does not have a significant impact towards e-Filing usage; (5) readiness technology tax payers information does not have a significant impact towards e-Filing usage; (6) perceived usefulness, perceived ease of use, speed, security and privacy and readiness technology tax payers information all simultaneously, have a significant impact towards e-Filing usage. Keywords: e-Filing usage, perceived usefulness, perceived ease of use, readiness technology tax payers information, security and privacy.

PROBLEM ASPECTS OF THE IMPLEMENTATION OF CRIMINAL PROCEDURAL NORMS OF PROTECTION OF THE VICTIMS FROM CRIME

2020 ◽  
pp. 72-76
Author(s):  
Яна Валерьевна Самиулина
Keyword(s):  
Preventive Measure ◽  
Criminal Procedure ◽  
Legal Rights ◽  
Criminal Proceedings ◽  
Effective Mechanism ◽  
The Russian Federation ◽  
The Individual ◽  
The Right ◽  
To Receive ◽  
Selection Of

В настоящей статье предпринята попытка исследовать отдельные проблемные аспекты института потерпевшего в российском уголовном процессе. В этих целях подвергнуты анализу правовые нормы, регламентирующие его процессуальный статус. Раскрываются отдельные пробелы уголовно-процессуального законодательства в сфере защиты законных прав и интересов потерпевшего. Автор акцентирует внимание на том, что совершенствование уголовно-процессуального законодательства в части расширения правомочий потерпевшего по отстаиванию своих нарушенных преступлением прав следует продолжить. На основании проведенного исследования действующего законодательства в части регламентации прав потерпевшего от преступления предлагается расширить перечень получаемых им копий постановлений, указанных в п. 13 ч. 2 ст. 42 УПК РФ. Автор предлагает включить в перечень указанной законодательной нормы право получения потерпевшим копии постановления об избрании конкретного вида меры пресечения, избранного в отношении подозреваемого (обвиняемого). Для создания действенного механизма защиты интересов потерпевших от преступления юридических лиц предлагаем ч. 9 ст. 42 УПК РФ изложить в следующей редакции: «в случае признания потерпевшим юридического лица его процессуальное право в уголовном процессе осуществляет представляющий его профессиональный адвокат». This article attempts to investigate certain problematic aspects of the institution of the victim in the Russian criminal process. For this purpose, analyzed the individual norms governing his procedural status. Separate gaps of the criminal procedure legislation in the sphere of protection of the legal rights and interests of the victim are disclosed. The author emphasizes that the improvement of the criminal procedure legislation in terms of the extension of the victim’s authority to defend his rights violated by the crime should be continued. On the basis of the study of the current legislation regarding the regulation of the rights of the victim of a crime, it is proposed to expand the list of decisions received by him, referred to in paragraph 13, part 2 of article 42 Code of Criminal Procedure. The author proposes to include in the list of the indicated legislative norm the right to receive the victim a copy of the decision on the selection of a specific type of preventive measure, selected in relation to the suspect (accused). To create an effective mechanism for protecting the interests of legal entities victims of a crime, we offer part 9 of art. 42 of the Code of Criminal Procedure of the Russian Federation shall be reworded as follows: «if a legal entity is recognized as a victim, his procedural right in criminal proceedings is exercised by the professional lawyer representing him».

SAMUEL J. BROADS CONTRIBUTIONS TO THE ACCOUNTING PROFESSION

1996 ◽  
Vol 23 (2) ◽  
pp. 69-85 ◽  
Author(s):  
Gary John Previts ◽  
Thomas R. Robinson
Keyword(s):  
Self Regulation ◽  
Accounting Profession ◽  
General Acceptance ◽  
Accounting Principles ◽  
The Individual ◽  
Securities Laws ◽  
Analogous Reasoning ◽  
Independent Audit ◽  
Selection Of

In the decade following the passage of the Federal Securities Laws of 1933 and 1934, the reform of accounting and auditing practices directed authority for selection of accounting principles and auditing procedures away from the discretion of the individual accountant and auditor. Instead, a self-regulatory peer driven process to establish general acceptance for a more limited set of principles and procedures was being initiated. Two events which occurred in 1938 indelibly affected this process, the SEC's decision to issue Accounting Series Release No. 4, which empowered non-governmental entities as potential sources of authoritative support, and the McKesson & Robbins fraud which called into question the value of the independent audit and the role of external auditing at the very time a momentum had been established for self-regulation by the nascent and recently reunified accounting profession. The contributions of Samuel J. Broad in both the initiatives for self-regulation of accounting principles and of auditing procedures is examined in this paper. Further, several examples of Broad's rhetorical technique of employing analogous reasoning to facilitate dissemination of complex economic and accounting issues are examined.

Application of the turbidity ratio method in the spherical particle size determination in the range m ∈ and α ∈

1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann
Keyword(s):  
Refractive Index ◽  
Spherical Particle ◽  
Ratio Method ◽  
Refractive Indices ◽  
Relative Refractive Index ◽  
Particle Size Determination ◽  
The Individual ◽  
The Given ◽  
Turbidity Ratio ◽  
Selection Of

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.

Revising the Indications of Transtemporal Surgical Approaches in the Modern Endoscopic Era of Skull Base Surgery: A Dying Art

2020 ◽  
Author(s):  
Ravi Sankar Manogaran ◽  
Raj Kumar ◽  
Arulalan Mathialagan ◽  
Anant Mehrotra ◽  
Amit Keshri ◽  
...  
Keyword(s):  
Skull Base ◽  
Surgical Approach ◽  
Nerve Palsy ◽  
Tertiary Care ◽  
Surgical Approaches ◽  
Microsurgical Anatomy ◽  
Complete Excision ◽  
Lateral Skull Base ◽  
The Individual ◽  
Selection Of

Abstract Objectives The aim of the study is to emphasize and explore the possible transtemporal approaches for spectrum of complicated lateral skull base pathologies. Design Retrospective analysis of complicated lateral skull base pathologies was managed in our institute between January 2017 and December 2019. Setting The study was conducted in a tertiary care referral center. Main Outcome Measures The study focused on the selection of approach based on site and extent of the pathology, the surgical nuances for each approach, and the associated complications. Results A total of 10 different pathologies of the lateral skull base were managed by different transtemporal approaches. The most common complication encountered was facial nerve palsy (43%, n = 6). Other complications included cerebrospinal fluid (CSF) collection (15%, n = 2), cosmetic deformity (24%, n = 4), petrous internal carotid artery injury (7%, n = 1), and hypoglossal nerve palsy (7%, n = 1). The cosmetic deformity included flap necrosis (n = 2) and postoperative bony defects leading to contour defects of the scalp (n = 2). Conclusion Surgical approach should be tailored based on the individual basis, to obtain adequate exposure and complete excision. Selection of appropriate surgical approach should also be based on the training and preference of the operating surgeon. Whenever necessary, combined surgical approaches facilitating full tumor exposure are recommended so that complete tumor excision is feasible. This requires a multidisciplinary team comprising neurosurgeons, neuro-otologist, neuroanesthetist, and plastic surgeons. The surgeon must know precise microsurgical anatomy to preserve the adjacent nerves and vessels, which is necessary for better surgical outcomes.

scholarly journals Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Porcine Model ◽  
Animal Experiments ◽  
Radioactive Tracers ◽  
The Individual ◽  
Selection Of

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

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