The Effect of Set on the Two-Point Tactual Threshold

1966 ◽  
Vol 18 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Anima Sen
Keyword(s):  
University Students ◽  
Test Stimulus ◽  
Opposite Direction ◽  
Adaptation Level ◽  
Critical Stimulus ◽  
Positive Direction ◽  
Control Series ◽  
Longitudinal Line ◽  
Adaptation Level Theory ◽  
The Right

This experiment studies the influence of set on the two-point tactual threshold. The two-point limen (critical stimulus) was determined along the mid-longitudinal line of both volar and dorsal surfaces of the right forearms of seven university students. Test-stimuli were selected at 3 mm. steps both up and down from each of the critical stimuli. Each of these test-stimuli was presented separately, the critical stimulus being interpolated 30 times in each test of the series. The proportions of two-point and one-point responses to the critical stimulus were then determined again in a control series. It was found that, as the test-stimulus deviated in the positive direction from the critical stimulus, the proportion of two-point responses to the critical stimulus increased, reached a maximum and then began to decline. A similar rise and fall in one-point responses were found in the opposite direction. The results were explained by Adaptation Level Theory.

Binocular Adaptation That Cannot Be Measured Monocularly

Perception ◽  
1982 ◽  
Vol 11 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Jeremy M Wolfe ◽  
Richard Held
Keyword(s):  
Test Stimulus ◽  
Opposite Direction ◽  
Human Vision ◽  
Tilt Aftereffect ◽  
Monocular Stimulation ◽  
Random Dot Stereogram ◽  
The Right

The tilt aftereffect (TAE) is used to demonstrate the existence of a purely binocular process in human vision. A purely binocular process is a process that can be activated only by matched inputs to the two eyes. It is insensitive to monocular stimulation. The TAE can be produced by exposure to a bipartite field with the top tilted to the left of vertical, the bottom to the right. After such adaptation a pair of colinear lines appears bent in the opposite direction. A cyclopean random-dot stereogram can be used as an adapting stimulus. It produces a 2° TAE when a cyclopean test stimulus is used and a 1° TAE when a binocular but noncyclopean test stimulus is used. If the same noncyclopean pattern is viewed monocularly, no TAE is measurable. The TAE does not transfer from cyclopean adaptation to monocular testing. Apparently, cyclopean stimuli activate a ‘purely binocular process’ that cannot be activated by either eye alone.

Adaptation-Level Theory

1974 ◽  
Vol 19 (11) ◽  
pp. 773-774
Author(s):  
JACOB BECK
Keyword(s):  
Adaptation Level ◽  
Adaptation Level Theory

scholarly journals Optimal Installation Location of Escape Route Signs at T-Type Intersections

2021 ◽  
Vol 13 (14) ◽  
pp. 7903
Author(s):  
Young-Hoon Bae ◽  
Jong-Yeong Son ◽  
Ryun-Seok Oh ◽  
Hye-Kyoung Lee ◽  
Yoon-Ha Lee ◽  
...  
Keyword(s):  
Decision Making ◽  
University Students ◽  
Simon Effect ◽  
Visual Stimuli ◽  
Escape Route ◽  
Emergency Evacuations ◽  
The Right

This study analyzed the decision-making times (DMTs) of participants at T-type indoor intersections according to the horizontal/vertical installation locations and the arrow directions of escape route signs. A total of 120 university students participated in the study. We analyzed the DMTs and following rates (FRs) required for the participants to observe the visual stimuli of the signs installed in front of the T-type indoor intersections and then properly select a path according to the arrow direction of the signs. The results are as follows: (1) the participants exhibited shorter DMTs for the right arrow direction of the signs, (2) the Simon effect occurred when the horizontal installation location of the signs was more than 60 cm away from the center of the T-type indoor intersection on both sides, (3) the DMTs of participants increased when the vertical installation location of the signs was low. Finally, we proposed an optimal installation location of the signs to support the shortest DMTs at T-type indoor intersections. It is expected that the results of this study will provide a database of DMTs, based on the locations of the signs during emergency evacuations, and will be utilized to improve the installation guidelines and regulations of signs.

scholarly journals From Which Direction Does the Empire Strike (Back)?

2021 ◽  
Vol 12 ◽  
Author(s):  
Katharina Theresa Halicki ◽  
Moritz Ingendahl ◽  
Maren Mayer ◽  
Melvin John ◽  
Marcel Raphael Schreiner ◽  
...  
Keyword(s):  
Opposite Direction ◽  
Spatial Representation ◽  
Future Research ◽  
Spatial Representations ◽  
The Right ◽  
Attack And Defense

In cultures with left-right-script, agentic behavior is mentally represented as following a left-to-right trajectory, an effect referred to as the Spatial Agency Bias (SAB, Suitner and Maass, 2016). In this research, we investigated whether spatial representations of activities are universal across activities by analyzing the opposite concepts of “attack” and “defense”. Both behaviors involve similar actions (e.g., fighting) but may differ in perceived agency. Moreover “defense” is necessarily always a response to an attack and may therefore be represented by a trajectory in the opposite direction. Two studies found the classic SAB for activities representing attacking but a reduction (Study 1) and reversal (Study 2) for activities involving defense. Although the spatial representation of defense on the right was much weaker and less unequivocal than that of attack on the left, the results suggest that the spatial representations of defense and attack are located in different positions. Apparently not all actors and all activities are spatially represented on the left with a left-to-right trajectory but position and direction depend on the perceived agency. Directions for future research and applications of our findings are discussed.

Dissociative-Traumatic Dimension and Triple Network: An EEG Functional Connectivity Study in a Sample of University Students

2021 ◽  
pp. 1-9
Author(s):  
Giuseppe Alessio Carbone ◽  
Claudio Imperatori ◽  
Francesco Saverio Bersani ◽  
Chiara Massullo ◽  
Egle Maria Orlando ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
University Students ◽  
Posterior Parietal Cortex ◽  
Self Report ◽  
Connectivity Pattern ◽  
Eyes Closed ◽  
Dissociative Symptoms ◽  
Trauma Ct ◽  
Eeg Functional Connectivity ◽  
The Right

<b><i>Aims:</i></b> We investigated the association among triple network electroencephalographic (EEG) functional connectivity, dissociative symptoms, and childhood trauma (CT) in a sample of university students. <b><i>Sampling and Methods:</i></b> Seventy-six participants (30 males and 46 females; mean age 22.12 ± 2.35) completed self-report measures investigating dissociative symptoms, CT, and depressive symptoms. Participants also performed an eyes-closed resting-state EEG recording. EEG analyses were conducted through the exact low-resolution electromagnetic tomography (eLORETA) software. <b><i>Results:</i></b> A 2-step cluster analysis revealed 2 groups: participants (<i>N</i> = 23) with high dissociative-traumatic dimension symptoms (DTD+) and participants (<i>N</i> = 53) with low DTD symptoms (DTD−). Compared to DTD− subjects, DTD+ participants showed decreased theta connectivity between the salience network (SN) and central executive network (CEN), specifically between the right anterior insula and the left posterior parietal cortex. No significant correlation was detected between EEG data and clinical variables. <b><i>Conclusion:</i></b> Our results raise the possibility of a dysfunctional connectivity pattern occurring between the SN and CEN in individuals with high DTD symptoms. Such connectivity pattern might reflect the neuropsychophysiological disintegration related to pathological dissociation.

Visual Gap Perception: Judgment Performance at Different Times and the Evaluation of Psychophysical Methods

1978 ◽  
Vol 22 (1) ◽  
pp. 115-115
Author(s):  
Helmut T. Zwahlen
Keyword(s):  
Test Stimulus ◽  
Classical Method ◽  
Standard Stimulus ◽  
Estimation Procedure ◽  
Psychophysical Method ◽  
Computer Simulation Model ◽  
Step Size ◽  
Starting Point ◽  
Stimulus Distance ◽  
The Right

The first part of this study investigated the visual gap judgment performance of twenty-four subjects (21–37 years old) in the laboratory. A scaled down (1:12) two-dimensional gap display (black on yellow background) representing the front silhouette of a car and a post placed on the right side of the car was viewed by the subjects from a distance of 46 inches (total viewing angle of display 17 degrees). The width of the car represented the standard stimulus and the horizontal adjustable distance between the car and the post (gap) represented the test stimulus. The subjects were required to make a forced choice judgment with respect to whether the test stimulus distance (gap) was larger or smaller than the standard stimulus distance (car width). The subjects were tested twice on the same day, once using the randomized classical psychophysical method and once using the Up and Down Transformed Response (U.D.T.R.) rule. The data from the randomized classical psychophysical method was analyzed using the probit and the Kärber method of analysis. The data from the U.D.T.R. method was analyzed using a modified Wetherill estimation procedure. The second part of this study investigated the visual gap judgment performance and eye scanning behavior of two subjects over two days (seven experiments per day). Horizontal eye movements were recorded with a Biometrics Eye Movement Monitor system. The third part of this study investigated the efficacies of two psychophysical methods: The randomized classical method and the sequential U.D.T.R. rule. The results from part one of this study were used to determine a psychometric perception curve of an “average” human being. A digital computer simulation model was built to represent a human being's gap judgment responses and the experimental gap judgment situation. Each method was simulated for the following parameters: the step size between the stimulus levels, the bias of the starting point, and the selected number of trials in an experiment.

Perspectives

1990 ◽  
Vol 15 (4) ◽  
pp. 3-10
Author(s):  
Jayanth R Varma ◽  
N Venkiteswaran
Keyword(s):  
Capital Market ◽  
Economic Activity ◽  
Critical Role ◽  
Regulatory Agencies ◽  
Recent Past ◽  
Positive Direction ◽  
Emerging Trends ◽  
The Government ◽  
The Right

The Indian capital market has shown signs of buoyancy and dynamism in the recent past. There is a very real need, therefore, to nurture and to give positive direction to the emerging trends in this sphere of economic activity. It is in this context that regulatory agencies have a critical role in providing the right kind of support to avoid bunching of issues as well as in protecting investors against manipulation by unscrupulous investors. Have Indian regulatory agencies risen to the occasion by formulating appropriate and adequate policies to facilitate the development of the capital markets in India? In this article, Varma and Venkiteswaran examine the role of Indian regulatory agencies and evaluate the methodology spelt out in the official guidelines for valuation of equity shares made public by the Government of India.

SOLITON STEERING IN A RAMP WAVEGUIDE WITH NONLOCAL NONLINEARITY

2011 ◽  
Vol 20 (01) ◽  
pp. 33-41
Author(s):  
A. SURYANTO ◽  
I. DARTI
Keyword(s):  
Refractive Index ◽  
Refractive Index Profile ◽  
Initial Position ◽  
Spatial Soliton ◽  
Positive Direction ◽  
Nonlocal Nonlinearity ◽  
Uniform Medium ◽  
Soliton Amplitude ◽  
The Right ◽  
Nicolson Scheme

We present an analytical and numerical investigation of a spatial soliton propagating in a waveguide with ramp linear refractive index profile (ramp waveguide) and nonlocal nonlinearity. It is shown analytically by equivalent particle approach and numerically by implicit Crank-Nicolson scheme that in a ramp waveguide with local nonlinearity, the soliton experiences negative acceleration along the waveguide where its refractive index decreases linearly. On the other hand, if the soliton propagates in a uniform medium with nonlocal nonlinear response then it will experience a self-bending in the positive direction where the bending level depends on the soliton amplitude as well as on the strength of nonlocality. By combining these two effects, rich dynamics of soliton can be achieved. In this case, the soliton may oscillate inside the waveguide, move to the left or to the right part of the waveguide or even be trapped. Such soliton steering can be controlled by the soliton amplitude or by its initial position.

scholarly journals XI. On the causes which influence the direction of the growth of roots. By T. A. Knight, Esq. F. R. S. In a letter to the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S

1811 ◽  
Vol 101 ◽  
pp. 209-219 ◽  
Keyword(s):  
Centrifugal Force ◽  
Opposite Direction ◽  
Animal Life ◽  
The Earth ◽  
The Right ◽  
Fibrous Roots ◽  
Germinating Seeds

I have shewn, in a former communication, the effects of centrifugal force upon germinating seeds; from which I have inferred that the radicles are made to descend towards the earth, and the germs, or elongated plumules, to take the opposite direction, by the influence of gravitation; and I believe the facts I have stated to be sufficient to support the inferences I have drawn. But the fibrous roots of plants, being much less succulent, though not uninfluenced in the directions they take by gravitation, are, to a great extent, obedient to other laws, and are generally found to extend themselves most rapidly, and to the greatest length, in whatever direction the soil is most favourable: whence many naturalists have been disposed to believe that these are guided by some degrees of feeling and perception, analogous to those of animal life. I shall proceed to state some of the facts upon which this hypothesis has been founded, and others which have occurred in the course of my own experience, and which are favourable to it; after which I shall endeavour to trace the effects observed to the operation of different causes.

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