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.

Cross-modal repetition priming with homophones provides clues about representation in the word recognition system

2007 ◽  
Vol 2 (2) ◽  
pp. 183-214 ◽  
Author(s):  
Penny M. Pexman ◽  
Stephen J. Lupker ◽  
Yasushi Hino
Keyword(s):  
Word Recognition ◽  
High Frequency ◽  
Repetition Priming ◽  
Time Course ◽  
Low Frequency ◽  
Recognition System ◽  
Priming Effects ◽  
Distributed Models ◽  
Activation Level ◽  
The Impact

In three experiments, we assessed the impact of auditory homophone primes (/swi:t/) on lexical decisions to visually presented low-frequency (suite) and high-frequency (sweet) homophone spellings. In Experiment 1 we investigated the time course of these cross-modal repetition priming effects. Results suggested that low-frequency homophone spellings do not reach the same activation level as nonhomophones, even at long SOAs. There were no differences in priming between high-frequency homophones and nonhomophones. In Experiments 2 and 3 we attempted to eliminate the impact of strategies with lower proportions of repetition primes. Results showed smaller priming effects for both low- and high-frequency homophones than for nonhomophones, suggesting that neither homophone spelling is fully activated. Implications for local and distributed models of word recognition are discussed.

High-frequency seismic noise as a function of depth

1991 ◽  
Vol 81 (4) ◽  
pp. 1101-1114
Author(s):  
Jerry A. Carter ◽  
Noel Barstow ◽  
Paul W. Pomeroy ◽  
Eric P. Chael ◽  
Patrick J. Leahy
Keyword(s):  
New York ◽  
High Frequency ◽  
Seismic Noise ◽  
Low Frequency ◽  
Time Variability ◽  
Orthogonal Components ◽  
The Difference ◽  
Frequency Coherence ◽  
Cultural Noise ◽  
Natural Wind

Abstract Evidence is presented supporting the view that high-frequency seismic noise decreases with increased depth. Noise amplitudes are higher near the free surface where surface-wave noise, cultural noise, and natural (wind-induced) noise predominate. Data were gathered at a hard-rock site in the northwestern Adirondack lowlands of northern New York. Between 15- and 40-Hz noise levels at this site are more than 10 dB less at 945-m depth than they are at the surface, and from 40 to 100 Hz the difference is more than 20 dB. In addition, time variability of the spectra is shown to be greater at the surface than at either 335- or 945-m depths. Part of the difference between the surface and subsurface noise variability may be related to wind-induced noise. Coherency measurements between orthogonal components of motion show high-frequency seismic noise is more highly organized at the surface than it is at depth. Coherency measurements between the same component of motion at different vertical offsets show a strong low-frequency coherence at least up to 945-m vertical offsets. As the vertical offset decreases, the frequency band of high coherence increases.

Nonword repetition and levels of abstraction in phonological knowledge

2006 ◽  
Vol 27 (4) ◽  
pp. 577-581 ◽  
Author(s):  
Benjamin Munson
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Nonword Repetition ◽  
Chronological Age ◽  
Frequency Effect ◽  
Vocabulary Size ◽  
Levels Of Abstraction ◽  
Opposite Pattern ◽  
The Difference ◽  
Restriction Of Range

Susan Gathercole's Keynote Article (2006) is an impressive summary of the literature on nonword repetition and its relationship to word learning and vocabulary size. When considering research by Mary Beckman, Jan Edwards, and myself, Gathercole speculates that our finding of a stronger relationship between vocabulary measures and repetition accuracy for low-frequency sequences than for high-frequency sequences is due to differences in the range of the two measures. In our work on diphone repetition (e.g., Edwards, Beckman, & Munson, 2004; Munson, Edwards, & Beckman, 2005) we tried to increase the range in our dependent measures by coding errors on a finer grained scale than simple correct/incorrect scoring would allow. Moreover, restriction of range does not appear to be the driving factor in the relationship between vocabulary size and the difference between high- and low-frequency sequence repetition accuracy (what we call the frequency effect) in at least one of our studies (Munson et al., 2005). When the children with the 50 lowest mean accuracy scores for high-frequency sequences were examined, vocabulary size accounted for 10.5% of the variance in the frequency effect beyond what was accounted for by chronological age. When the 50 children with the highest mean accuracy scores for high-frequency sequences were examined (a group in which the range of high-frequency accuracy scores was more compressed, arguably reflecting ceiling effects), an estimate of vocabulary size accounted for only 6.9% of the frequency effect beyond chronological age. The associated β coefficient was significant only at the α<0.08 level. This is the opposite pattern than Gathercole's argument would predict.

scholarly journals A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP-KLH Immunized Mice

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Sun Kwang Kim ◽  
Youngseop Lee ◽  
Hyunjoo Cho ◽  
Sungtae Koo ◽  
Sun Mi Choi ◽  
...  
Keyword(s):  
Parametric Study ◽  
High Frequency ◽  
Low Frequency ◽  
Specific Ige ◽  
Th2 Cytokines ◽  
Immunomodulatory Effects ◽  
Frequency Dependent ◽  
Total Ige ◽  
The Difference

This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non-acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36-PA (IM + plain acupuncture at ST36), ST36-LEA (IM + low frequency (1 Hz) EA at ST36), ST36-HEA (IM + high frequency (120 Hz) EA at ST36), NA-LEA (IM + low frequency (1 Hz) EA at non-acupoint) and NA-HEA (IM + high frequency (120 Hz) EA at non-acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP-KLH specific IgE, IL-4 and IFN-γlevels were measured at the end of the experiment. The results of this study showed that the IgE and IL-4 levels were significantly suppressed in the ST36-LEA and ST36-HEA groups, but not in the NA-LEA and NA-HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36-LEA and ST36-HEA groups. Taken together, these results suggest that EA stimulation-induced immunomodulation is not frequency dependent, but that it is acupoint specific.

scholarly journals Different Coupling Modes Mediate Cortical Cross-Frequency Interactions

2015 ◽  
Author(s):  
Randolph F Helfrich ◽  
Christoph S Herrmann ◽  
Andreas K Engel ◽  
Till R Schneider
Keyword(s):  
Information Integration ◽  
Visual Processing ◽  
High Frequency ◽  
Low Frequency ◽  
Gamma Oscillations ◽  
Frequency Component ◽  
High Frequency Component ◽  
Alpha Power ◽  
Alpha Oscillation ◽  
Transcranial Alternating Current Stimulation

Cross-frequency coupling (CFC) has been suggested to constitute a highly flexible mechanism for cortical information gating and processing, giving rise to conscious perception and various higher cognitive functions in humans. In particular, it might provide an elegant tool for information integration across several spatiotemporal scales within nested or coupled neuronal networks. However, it is currently unknown whether low frequency (theta/alpha) or high frequency gamma oscillations orchestrate cross-frequency interactions, raising the question of who is master and who is slave. While correlative evidence suggested that at least two distinct CFC modes exist, namely phase-amplitude-coupling (PAC) and amplitude-envelope-correlations (AEC), it is currently unknown whether they subserve distinct cortical functions. Novel non-invasive brain stimulation tools, such as transcranial alternating current stimulation (tACS), now provide the unique opportunity to selectively entrain the low or high frequency component and study subsequent effects on CFC. Here, we demonstrate the differential modulation of CFC during selective entrainment of alpha or gamma oscillations. Our results reveal that entrainment of the low frequency component increased PAC, where gamma power became preferentially locked to the trough of the alpha oscillation, while gamma-band entrainment reduced alpha power through enhanced AECs. These results provide causal evidence for the functional role of coupled alpha and gamma oscillations for visual processing.

scholarly journals Effect of Losartan, an Angiotensin II Type 1 Receptor Antagonist on Cardiac Autonomic Functions of Rats During Acute and Chronic Inhibition of Nitric Oxide Synthesis

2012 ◽  
pp. 135-144
Author(s):  
M. CHASWAL ◽  
S. DAS ◽  
J. PRASAD ◽  
A. KATYAL ◽  
A. K. MISHRA ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Rate ◽  
High Frequency ◽  
Spectral Power ◽  
Pressor Response ◽  
Low Frequency ◽  
Renin Angiotensin System ◽  
Nitric Oxide Synthesis ◽  
Total Spectral Power ◽  
The Difference

We studied the effect of losartan on baroreflex sensitivity (BRS) and heart rate variability (HRV) of adult Wistar rats during acute and chronic inhibition of nitric oxide synthesis by NG-nitro-L-arginine methyl ester (L-NAME). Chronic L-NAME administration (50 mg/kg per day for 7 days, orally through gavage) increased mean arterial pressure (MAP), heart rate but significantly decreased BRS. In addition, a significant fall of standard deviation of normal RR intervals, total spectral power, high frequency spectral power and a rise of low frequency to high frequency (LF: HF) ratio was seen. Acute L-NAME administration (30 mg/kg, i.v. bolus dose) also raised MAP and impaired HRV but it was associated with augmented BRS for bradycardia reflex. Losartan treatment (10 mg/kg, i.v.) in both acute and chronic L-NAME treated rats, decreased MAP but the difference was not significant. On the other hand, losartan administration normalized depressed BRS for bradycardia reflex and significantly reduced LF to HF ratio in chronic L-NAME treated rats. But this improvement was not observed in acute L-NAME group. These results indicate importance of mechanisms other than renin-angiotensin system in the pressor response of both acute as well as chronic L-NAME. However, autonomic dysregulation especially following chronic L-NAME appears to be partly angiotensin dependent.

scholarly journals Altered Temporal Dynamic Intrinsic Brain Activity in Late Blindness

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Huang ◽  
Zhi Wen ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
Han-Dong Dan ◽  
...  
Keyword(s):  
Visual Processing ◽  
Brain Activity ◽  
Gaussian Random Field ◽  
Low Frequency ◽  
Sliding Window ◽  
Crossmodal Plasticity ◽  
The Difference ◽  
Structural Architecture ◽  
The Right ◽  
Intrinsic Brain Activity

Previous neuroimaging studies demonstrated that visual deprivation triggers significant crossmodal plasticity in the functional and structural architecture of the brain. However, prior neuroimaging studies focused on the static brain activity in blindness. It remains unknown whether alterations of dynamic intrinsic brain activity occur in late blindness (LB). This study investigated dynamic intrinsic brain activity changes in individuals with late blindness by assessing the dynamic amplitude of low-frequency fluctuations (dALFFs) using sliding-window analyses. Forty-one cases of late blindness (LB) (29 males and 12 females, mean age: 39.70±12.66 years) and 48 sighted controls (SCs) (17 males and 31 females, mean age: 43.23±13.40 years) closely matched in age, sex, and education level were enrolled in this study. The dALFF with sliding-window analyses was used to compare the difference in dynamic intrinsic brain activity between the two groups. Compared with SCs, individuals with LB exhibited significantly lower dALFF values in the bilateral lingual gyrus (LING)/calcarine (CAL) and left thalamus (THA). LB cases also showed considerably decreased dFC values between the bilateral LING/CAL and the left middle frontal gyrus (MFG) and between the left THA and the right LING/cerebelum_6 (CER) (two-tailed, voxel-level P<0.01, Gaussian random field (GRF) correction, cluster-level P<0.05). Our study demonstrated that LB individuals showed lower-temporal variability of dALFF in the visual cortices and thalamus, suggesting lower flexibility of visual thalamocortical activity, which might reflect impaired visual processing in LB individuals. These findings indicate that abnormal dynamic intrinsic brain activity might be involved in the neurophysiological mechanisms of LB.

Can masked synonym priming replicate masked translation priming?

2019 ◽  
Vol 72 (10) ◽  
pp. 2554-2562 ◽  
Author(s):  
Naoko Witzel
Keyword(s):  
High Frequency ◽  
Priming Effect ◽  
Lexical Processing ◽  
Low Frequency ◽  
Masked Priming ◽  
Semantic Interpretation ◽  
Priming Effects ◽  
Translation Priming ◽  
Masked Translation Priming ◽  
Robust Evidence

This study examines whether synonyms are represented similarly to translation equivalents in the bilingual mind. In particular, this study investigated whether there is masked synonym priming such that it will simulate masked translation priming in the L1-L2 direction. Given that masked translation priming studies consistently show priming in the L1-L2 direction, it was predicted that synonyms should show a masked priming effect if the prime was higher in frequency than the target. Contrary to what Bilingual Interactive Activation models would predict, there was no priming for synonyms in the high-to-low frequency (HF-LF) condition or in the low-to-high frequency (LF-HF) condition in Experiment 1. Experiment 2 only tested the HF-LF condition to ensure that previous exposure to LF words within the experiment did not affect the results. Again, no HF-LF synonym priming was observed. The effect sizes of these synonym priming effects were comparable with that of L2-L1 translation priming, all of which were weak. This is not surprising given that semantic interpretation of a given word usually occurs post-lexically and requires partial awareness. What is surprising is that there is robust evidence showing strong L1-L2 masked translation priming effect, which bilingual lexical processing models should attempt to explain, thereby uncovering the relations between L1 words and their L2 translations.

The nonlinear effects of sound in a liquid with relaxation losses

2015 ◽  
Vol 93 (11) ◽  
pp. 1391-1396
Author(s):  
Anna Perelomova
Keyword(s):  
Chemical Reaction ◽  
High Frequency ◽  
Low Frequency ◽  
Nonlinear Effects ◽  
Dynamic Equations ◽  
High Frequency Sound ◽  
Frequency Sound ◽  
Relaxation Modes ◽  
The Difference ◽  
Wave Modes

The nonlinear effects of sound in electrolyte with a chemical reaction are examined. The dynamic equations that govern non-wave modes in the field of intense sound are derived, and acoustic forces of vortex, entropy, and relaxation modes are determined in the cases of low-frequency sound and high-frequency sound. The difference in the nonlinear effects of sound in electrolyte and in a gas with excited vibrational degrees of molecules, are specified and discussed.

Autonomic Dysfunction is Associated with Increased Cardiometabolic Risk in Patients with Childhood-Onset Craniopharyngioma

2020 ◽  
Vol 52 (07) ◽  
pp. 500-508
Author(s):  
Hae Woon Jung ◽  
Hwa Young Kim ◽  
Ji Young Kim ◽  
Jung-Eun Cheon ◽  
In-One Kim ◽  
...  
Keyword(s):  
Autonomic Dysfunction ◽  
High Frequency ◽  
Cardiometabolic Risk ◽  
Low Frequency ◽  
Total Power ◽  
Childhood Onset ◽  
Serum Triglycerides ◽  
Cross Sectional ◽  
The Metabolic Syndrome ◽  
The Difference

AbstractPatients with craniopharyngioma are susceptible to autonomic dysfunction as a result of hypothalamic damage. We evaluated indices of heart rate variability (HRV) in patients with childhood-onset craniopharyngioma to investigate autonomic function and its relationship with components of the metabolic syndrome (MetS). This cross-sectional, case-only study included 53 patients (10–30 years of age). We measured the standard deviation of all normal R-R intervals (SDNN) and total power indicating overall HRV, the root-mean square of the difference of successive R-R intervals (RMSSD) and high frequency indicating parasympathetic modulation, and low frequency. These indices were compared according to the presence of the MetS. During the mean 10.8 years of follow-up, 25% of patients were diagnosed with the MetS. Patients with the MetS showed significantly lower levels of SDNN (29.0 vs. 40.6 ms), total power (416.1 vs. 1129.6 ms2), RMSSD (20.1 vs. 34.5 ms), high frequency (94.7 vs. 338.5 ms2), and low frequency (94.5 vs. 289.4 ms2) than those without (p <0.05, for all). Individual components of the MetS including insulin resistance, serum triglycerides levels, and systolic blood pressure were inversely associated with SDNN, total power, RMSSD and high frequency. Higher overall variability and parasympathetic modulation were related to decreased odds ratios for having the MetS (OR 0.91, p=0.029 for SDNN; OR 0.91, p=0.032 for total power). In conclusion, autonomic dysfunction, as evidenced by reduced HRV indices, is associated with increased cardiometabolic risk in patients with childhood-onset craniopharyngioma.

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