Demonstration of an Ebbinghaus Illusion at a Memory Level

2014 ◽  
Vol 61 (5) ◽  
pp. 378-384 ◽  
Author(s):  
Amandine Eve Rey ◽  
Benoit Riou ◽  
Rémy Versace
Keyword(s):  
Present Experiment ◽  
Perceptual Processing ◽  
Size Difference ◽  
Sensorimotor System ◽  
Ebbinghaus Illusion ◽  
Memory Processing ◽  
Neuroimaging Data ◽  
The Difference

Based on recent behavioral and neuroimaging data suggesting that memory and perception are partially based on the same sensorimotor system, the theoretical aim of the present study was to show that it is difficult to dissociate memory mechanisms from perceptual mechanisms other than on the basis of the presence (perceptual processing) or absence (memory processing) of the characteristics of the objects involved in the processing. In line with this assumption, two experiments using an adaptation of the Ebbinghaus illusion paradigm revealed similar effects irrespective of whether the size difference between the inner circles and the surrounding circles was manipulated perceptually (the size difference was perceptually present, Experiment 1) or merely reactivated in memory (the difference was perceptually absent, Experiment 2).

scholarly journals Morphological consistency of bilateral hip joints in adults based on the X-ray and CT data

2021 ◽  
Author(s):  
Ran Zhao ◽  
Hong Cai ◽  
Hua Tian ◽  
Ke Zhang
Keyword(s):  
Hip Joint ◽  
Morphological Difference ◽  
Medullary Cavity ◽  
Size Difference ◽  
Single Plane ◽  
X Ray ◽  
Stem Size ◽  
The Difference ◽  
Ct Data ◽  
Anatomical Parameters

Abstract Purpose The application of the anatomical parameters of the contralateral hip joint to guide the preoperative template of the affected side relies on the bilateral hip symmetry. We investigated the bilateral hip symmetry and range of anatomical variations by measurement and comparison of bilateral hip anatomical parameters. Methods This study included 224 patients (448 hips) who were diagnosed with osteoarthritis (OA) and avascular necrosis (AVN) of the femur head, and underwent bilateral primary total hip arthroplasty (THA) in our hospital from January 2012 to August 2020. Imaging data included 224 patients X-ray and 30 CT data at the end of the cohort. Anatomical parameters, including the acetabular abduction angle and trochanteric height, were measured using the Noble method. Postoperative measurements included stem size, difference of leg length and offset. Results Except for the isthmus width, there were no significant differences in the anatomical morphology of the hip joint. Among the demographic factors, there was a correlation between body weight and NSA. Among various anatomical parameters, a correlation was present between medullary cavity widths of T + 20, T, and T − 20. The difference in the use of stem size is not due to the morphological difference of bilateral medullary cavity, but due to the different of 1- or 2-stage surgery. Conclusion Bilateral symmetry was present among the patients with normal morphology of the hip medullary cavity, theoretically confirming the feasibility of structural reconstruction of the hip joint using the hip joint on the uninjured side. Additionally, the difference in the morphology of the hip medullary cavity is not present in a single plane but is synergistically affected by multiple adjacent planes.

Individual vs Group Learning: Note on Two Task Variables

1968 ◽  
Vol 23 (3) ◽  
pp. 757-758 ◽  
Author(s):  
Herman S. Napier
Keyword(s):  
Present Experiment ◽  
Group Formation ◽  
Group Learning ◽  
Nominal Groups ◽  
Group Members ◽  
Task Variables ◽  
The Difference ◽  
Time Required ◽  
Puzzle Task

The pooling of abilities or nominal groups technique was used in the present experiment to compare individuals with two-person groups on a picture-puzzle task. When size of the task was limited to a part (one-fourth) of the puzzle or the duration of the task was restricted to a few (four) trials, no difference between individuals and groups was evident. However, as task size and number of trials increased, groups performed at a significantly higher level than individuals. The difference was discussed in terms of information available to group members and the time required for group formation.

Dissociating early and late visual processing via the Ebbinghaus illusion

2016 ◽  
Vol 33 ◽  
Author(s):  
FILIPP SCHMIDT ◽  
ANDREAS WEBER ◽  
ANKE HABERKAMP
Keyword(s):  
Visual Processing ◽  
High Frequency ◽  
Time Course ◽  
Temporal Dynamics ◽  
Low Frequency ◽  
Response Speed ◽  
Ebbinghaus Illusion ◽  
Priming Effects ◽  
Parvocellular Pathway ◽  
The Difference

AbstractVisual perception is not instantaneous; the perceptual representation of our environment builds up over time. This can strongly affect our responses to visual stimuli. Here, we study the temporal dynamics of visual processing by analyzing the time course of priming effects induced by the well-known Ebbinghaus illusion. In slower responses, Ebbinghaus primes produce effects in accordance with their perceptual appearance. However, in fast responses, these effects are reversed. We argue that this dissociation originates from the difference between early feedforward-mediated gist of the scene processing and later feedback-mediated more elaborate processing. Indeed, our findings are well explained by the differences between low-frequency representations mediated by the fast magnocellular pathway and high-frequency representations mediated by the slower parvocellular pathway. Our results demonstrate the potentially dramatic effect of response speed on the perception of visual illusions specifically and on our actions in response to objects in our visual environment generally.

Aging and Time Perception for Short and Long Durations: A Question of Attention?

2017 ◽  
Vol 5 (2) ◽  
pp. 149-167 ◽  
Author(s):  
M. Lamotte ◽  
S. Droit-Volet
Keyword(s):  
Short Term Memory ◽  
Lower Sensitivity ◽  
General Effect ◽  
Younger Adults ◽  
Memory Processing ◽  
Time Sensitivity ◽  
The Difference ◽  
Perception Of Time ◽  
The Individual ◽  
Temporal Bisection Task

This study examined the difference in the perception of time between young and older adults in a temporal bisection task with four different duration ranges from a few milliseconds (500 ms) to several seconds (30 s). In addition, individual cognitive capacities (short-term memory, working memory, processing speed, attention) were assessed with different neuropsychological tests. The results showed a general effect of age on the variability of time judgment, indicating a lower sensitivity to time in the old than in the younger adults, regardless of the duration range tested. In addition, the results showed that the individual differences in time sensitivity were explained by attention capacities, which decline with aging.

The Prediction and Predictability of Speech in Schizophrenic Patients

1975 ◽  
Vol 126 (6) ◽  
pp. 571-576 ◽  
Author(s):  
D. R. Rutter ◽  
J. Wishner ◽  
B. A. Callaghan
Keyword(s):  
Present Experiment ◽  
Future Research ◽  
Orthopaedic Patients ◽  
Cloze Procedure ◽  
Limited Support ◽  
Schizophrenic Patients ◽  
The Difference ◽  
Normal Speech

SummaryPrevious research suggests, though by no means consistently, that schizophrenic patients may be less able than normals to predict the speech of other people, and that schizophrenic speech is less predictable than normal speech. The present experiment tests these two suggestions and also a third possibility, that the difference between schizophrenic and normal speech is less marked for schizophrenics asked to make the predictions than for normals. Twelve schizophrenic patients recently admitted to hospital, and twelve comparable, psychiatrically normal, orthopaedic patients, were asked to predict both schizophrenic and normal speech, using Cloze Procedure, under both fourth-word and fifth-word deletion. The first hypothesis was upheld, but the second and third received only very limited support. The findings are discussed in the light of previous work, and suggestions are made for future research.

scholarly journals Quantitative Volumetric Analysis Post Transsphenoidal Pituitary Adenoma Surgery

2012 ◽  
Vol 39 (5) ◽  
pp. 600-604 ◽  
Author(s):  
Alireza Mansouri ◽  
Sean Symons ◽  
Michael Schwartz ◽  
Joseph Chen ◽  
Farhad Pirouzmand
Keyword(s):  
Pituitary Adenoma ◽  
Volumetric Analysis ◽  
Point Of View ◽  
Size Difference ◽  
Resonance Imaging ◽  
Residual Mass ◽  
Postoperative Assessment ◽  
The Difference ◽  
Magnetic Resonance Imaging Mri

Background:Computed tomogram (CT) imaging is often used for immediate postoperative assessment of transsphenoidal pituitary adenoma resection while magnetic resonance imaging (MRI) is used for follow-up. The residual mass is known to decrease in size over time but the difference between the two imaging modalities has not been quantified. Our objective was to quantify the size difference of the residual mass on immediate postoperative CT compared with delayed MRI.Methods:Retrospective analysis of 69 patients who had undergone pituitary adenoma resection at our institution between 2004-2010. Sellar and suprasellar diameter, along with the overall volume of the residual mass were measured on both the immediate postoperative CT and delayed MRI.Results:Average preoperative sellar and suprasellar diameter was 22.2 ± 4.6mm and 20.9 ± 5.9mm, respectively. Average sellar residual diameter on immediate postoperative CT (16.5 ± 5.4 mm, 25% reduction) was significantly larger than delayed MRI (10.6 ± 6.2mm, 52% reduction). The average suprasellar component on CT (15.5±6.5mm, 26% reduction) was also significantly larger than that on MRI (3.3 ± 5.4 mm, 84% reduction). The postoperative CT showed a 46% reduction in volume while a 71% reduction was noted on the delayed MRI.Conclusion:A significant reduction in residual mass is noted on delayed MR imaging compared with immediate postoperative CT. Therefore, from a resource management and prognostication point of view, CT should be used for immediate postoperative assessment while delayed MRI should be used to assess operative success and for communication with patients.

scholarly journals Is there a problem with methods skills in cognitive neuroscience? Evidence from an online survey

2018 ◽  
Author(s):  
Olaf Hauk
Keyword(s):  
Data Analysis ◽  
Linear Algebra ◽  
Cognitive Neuroscience ◽  
Signal Analysis ◽  
Online Survey ◽  
Complex Data ◽  
Multiple Choice Questions ◽  
Neuroimaging Data ◽  
The Difference ◽  
Training Programmes

AbstractCognitive neuroscience increasingly relies on complex data analysis methods. Researchers in this field come from highly diverse scientific backgrounds, such as psychology, engineering and medicine. This poses challenges with respect to acquisition of appropriate scientific computing and data analysis skills, as well as communication among researchers with different knowledge and skills sets. Are researchers in cognitive neuroscience adequately equipped to address these challenges? Here, we present evidence from an online survey of methods skills. Respondents (n=305) mainly comprised students and post-doctoral researchers working in the cognitive neurosciences. Multiple choice questions addressed a variety of basic and fundamental aspects of neuroimaging data analysis, such as signal analysis, linear algebra, and statistics. We analysed performance with respect to the following factors: undergraduate degree (grouped into Psychology, Methods, Biology), current researcher status (undergraduate student, PhD student, post-doctoral researcher), gender, and self-rated expertise levels. Overall accuracy was 72%. Not surprisingly, the Methods group performed best (87%), followed by Biology (73%) and Psychology (66%). Accuracy increased from undergraduate (59%) to PhD (74%) level, but not from PhD to post-doctoral (74%) level. The difference in performance for the Methods versus non-methods (Psychology/Biology) groups was particularly striking for questions related to signal analysis and linear algebra, two areas especially relevant to neuroimaging research. Self-rated methods expertise was not strongly predictive of performance. The majority of respondents (93%) indicated they would like to receive at least some additional training on the topics covered in this survey. In conclusion, methods skills among junior researchers in cognitive neuroscience can be improved, researchers are aware of this, and there is strong demand for more skills-oriented training opportunities. We hope that this survey will provide an empirical basis for the development of bespoke skills-oriented training programmes in cognitive neuroscience institutions.

scholarly journals Motor expertise facilitates the precision of state extrapolation in perception

2017 ◽  
Author(s):  
Nicolas Ludolph ◽  
Jannis Plöger ◽  
Martin A. Giese ◽  
Winfried Ilg
Keyword(s):  
Individual Differences ◽  
Motor Learning ◽  
Motor Behavior ◽  
Motor Training ◽  
Second Phase ◽  
Sensorimotor System ◽  
Action Perception ◽  
Forward Models ◽  
The Difference ◽  
Pole System

AbstractPredicting the behavior of objects in the environment is an important requirement to overcome latencies in the sensorimotor system and realize precise actions in rapid situations. Internal forward models that were acquired during motor training might not only be used for efficiently controlling fast motor behavior but also to facilitate extrapolation performance in purely perceptual tasks. In this study, we investigated whether preceding virtual cart-pole balancing training facilitates the ability to extrapolate the pole motion. We compared a group of 10 subjects, proficient in performing the cart-pole balancing task, to 10 naïve subjects. Our results demonstrate that preceding motor training increases the precision of pole movement extrapolation, although extrapolation is not trained explicitly. Additionally, we modelled subjects’ behaviors and show that the difference in extrapolation performance can be explained by individual differences in the accuracy of internal forward models. When subjects are provided with feedback about the true pole movement in a second phase, both groups improve rapidly. The results indicate that the perceptual capability to extrapolate the state of the cart-pole system accurately is implicitly trained during motor learning. We discuss these results in the context of shared representations and action-perception transfer.

Undersizing the Exeter stem in hip hemiarthroplasty increases the risk of periprosthetic fracture

2019 ◽  
Vol 30 (4) ◽  
pp. 469-473
Author(s):  
Lars Korsnes ◽  
Andreas Gottvall ◽  
Christian Buttazzoni ◽  
Michael Mints
Keyword(s):  
Femoral Component ◽  
Area Under Curve ◽  
Size Difference ◽  
Optimal Cutoff ◽  
Hip Hemiarthroplasty ◽  
Stem Size ◽  
Median Size ◽  
Optimal Cutoff Point ◽  
The Difference ◽  
Post Hoc

Introduction: Whether under- or oversizing of the femoral component of cemented hip hemiarthroplasties impacts the risk of periprosthetic fractures (PPF) has only been examined experimentally. This study was carried out to add more knowledge about the risks of PPF in cemented polished tapered hemiarthroplasties. Methods: 20 patients with PPF following hip hemiarthroplasty with cemented Exeter V40 stems were compared to 50 controls who never suffered PPF having received the same type of Exeter hemiprosthesis for the same indication. The difference between stem size and post-hoc radiographic ideal templated size was investigated as a predictor of PPF. Results: Cases had a median size difference to post-hoc templating of –2, while controls had a median size difference of –1 ( p = 0.09). An ROC curve constructed to find an optimal cutoff point in size difference between cases and controls arrived at an area under curve of 63%, with –1.5 as the cutoff. Patients with size differences exceeding –1.5 had a statistically significant increased PPF risk (odds ratio = 3.8, 95% confidence interval, 1.1–13.3, p < 0.05). This group covered 55% of all cases. Conclusion: An implanted femoral component that is 2 or more sizes smaller than the template that is shown to be appropriate will increase the risk of PPF in Exeter hip hemiarthroplasties.

Viscosities of mixtures of SnR4 compounds and of some other large globular molecules. Effect of size difference

1977 ◽  
Vol 55 (8) ◽  
pp. 1360-1366 ◽  
Author(s):  
Claude Jambon ◽  
Geneviève Delmas
Keyword(s):  
Large Range ◽  
Size Difference ◽  
The Core ◽  
Large Size ◽  
Heats Of Mixing ◽  
C Value ◽  
Condensation Effect ◽  
The Difference ◽  
Increasing Function ◽  
Core Volume

Solution viscosities have been measured at 25 °C on seven I systems of SnR4 compounds: SnBut4 with SnMe4, SnEt4, SnPr4, SnOct4, SnLaur4 and SnLaur4 with SnEt4 and SnPr4. The effect of shape difference on excess solution viscosities was investigated. The experimental value Δ ln ηexp = ln ηs − x1 ln η1 − x2 ln η2 was compared to Δ ln ηth.Δ ln ηth was obtained using ΔGM(mixing) in place of GM≠(activation) and free volume theories. Experimental heats of mixing have been measured and are used inΔ ln ηth. It was found that with the Van der Waals model for the energy, the difference Δ ln ηexp − Δ ln ηth, indicative of the agreement between the predicted and experimental value, is relatively small for mixtures of molecules not having a large size difference. However, for systems different in size, Δ ln ηexp − Δ ln ηth is positive and large and is shown to be an increasing function of the size difference. Δ ln ηth could be adjusted to Δ ln ηexp by adding a term ln ηΔV* = c(V1*1/2 − V2*1/2)2 where V* is the core volume. To confirm the validity of ln ηΔV*, the seven II systems chosen in order to present a large range (V1*1/2 − V2*1/2) were measured: SnBut4 + squalane, Si(OEt)4 + Si(OOct)4, n-C10 + Si(OOct)4, Si(OEt)4 + squalane, n-C12 + SnOct4, Si(OMe)4 + Si(OOct)4, n-C16 + benzene. A c value of 5.3 × 10−3 cm3 appears to be adequate for all the systems studied in this work. The 'condensation effect' of SnEt4 and SnPr4 observed by calorimetry is possibly seen here in the series SnLaur4 with SnEt4, SnPr4, SnBut4.

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