Purpose: To investigate the topographic changes of the dark-adapted multifocal electroretinogram (mfERG) across adulthood in the central retina and compare the topography between macular versus extramacular, nasal versus temporal, and inferior versus superior retinal areas.
Methods: Sixty-five subjects (18-88 years) received a comprehensive dilated eye examination to ensure the health of their retina and were tested with a dark-adapted mfERG protocol using a 61-hexagon pattern. The lens absorption of each subject was also estimated using a heterochromatic flicker photometry (HFP) paradigm.
Results: The response amplitude and latency of the dark-adapted mfERG showed a significant change with age, which was best described with a linear model. All the retinal areas examined demonstrated similar aging effects. The extramacular and temporal retina showed higher response amplitude and faster response latency when compared with the macular and nasal retinae, respectively. No difference was found in response amplitude and latency between the inferior and superior retina. The HFP results also showed a significant correlation with age, consistent with senescent increases in short wavelength absorption by the crystalline lens. However, the change in lens absorption did not exceed the magnitude of the change in response amplitude and latency.
Discussion: Our results indicate that there is a decline in dark-adapted retinal activity as measured with the mfERG. These aging processes affect rods and rod-bipolar cells. Their decrease in response can be attributed to both optical and neural factors.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5341623 | PMC |
| http://dx.doi.org/10.1167/iovs.16-20953 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Optimizing transcutaneous spinal stimulation: excitability of evoked spinal reflexes is dependent on electrode montage.
J Neuroeng Rehabil
January 2025
Hulse Spinal Cord Injury Research Lab, Shepherd Center, 2020 Peachtree Road NW, Atlanta, GA, USA.
Background: There is growing interest in use of transcutaneous spinal stimulation (TSS) for people with neurologic conditions both to augment volitional control (by facilitating motoneuron excitability), and to decrease spasticity (by activating inhibitory networks). Various electrode montages are used during TSS, with little understanding of how electrode position influences spinal circuit activation. We sought to identify the thoracolumbar electrode montage associated with the most robust activation of spinal circuits by comparing posterior root-muscle reflexes (PRM reflexes) elicited by 6 montages.
View Article and Find Full Text PDFResearch on the acoustic emission characteristics and instability correlation effect of the dynamic response of waste dump slopes.
Sci Rep
January 2025
Yunnan Phosphating Group Co., Ltd, Kunming, 650600, China.
Due to the fluidity of the loose medium inside the waste dump slope, the traditional monitoring system cannot fully reflect the misalignment and slip between particles inside the medium, and it is also difficult to capture the precursor information of the slip of the loose accumulation body. To reveal the dynamic evolution process of the slope instability of the waste dump slope, the coupling test system of the slope instability of the waste dump slope was used to carry out the study of the acoustic emission characteristics of the slope instability dynamic response of the dump slope under the action of vibration, and to quantitatively analyse the staged characteristics of the acoustic emission parameter evolution of the dump slope under the action of different vibration frequencies and its instability initiation node. The results show that with the increase of vibration frequency, the damage mode of the slope model gradually changes from sliding of small particles to large-scale landslides, and presents the stage process of "vibration compaction → vibration equilibrium → dynamic instability"; Under the action of low-frequency and high-amplitude, the slope model mainly shows that the tiny particles and the basement gravel slip, which is difficult to capture with the naked eye, while under the action of high-frequency and low-amplitude, the slope surface is damaged in a large area, and the overall model is unstable; The dynamic instability of the waste dump slope is accompanied by obvious acoustic emission activities, and the changes of the characteristic parameters of acoustic emission reveal, to a certain extent, the evolution of the internal state of the slope in the process of dynamic instability of the waste dump slope and its stage characteristics; The amplitude and energy efficiency of acoustic emission in the time domain show obvious fractal characteristics in the dynamic instability of the waste dump slope.
View Article and Find Full Text PDFCollective modes in terahertz field response of disordered superconductors.
J Phys Condens Matter
January 2025
Department of Physics, Kent State University, 008 Smith Hall, Kent, Ohio, 44240, UNITED STATES.
We consider a problem of nonlinear response to an external electromagnetic radiation in conventional disordered superconductors which contain a small amount of weak magnetic impurities. We focus on the diffusive limit and use Usadel equation to analyze the excitation energy and dispersion relation of the collective modes. We determine the resonant frequency and dispersion of both amplitude (Schmidt-Higgs) and phase (Carlson-Goldman) modes for moderate strength of magnetic scattering.
View Article and Find Full Text PDFMotor skill experience modulates attentional processing regardless of open- or closed-skill types: an ERP study.
Front Psychol
December 2024
Department of Educational Sciences and Sports Psychology, Faculty of Physical Education, Assiut University, Assiut, Egypt.
Background: Attentional engagement, the ability to maintain focus on relevant tasks, plays a crucial role in optimizing human performance. Studies have shown that athletes exhibit superior attentional engagement compared to non-athletes; however, it remains unclear if these benefits persist in non-sport-related tasks or differ across types of sports expertise, such as open-skill versus closed-skill sports.
Methods: Ninety-three young adults, divided into open-skill athletes ( = 31), closed-skill athletes ( = 31), and a control group ( = 31), completed an auditory oddball task while the P3 component of event-related potentials was measured to assess attentional processing.
Optical Recognition of the English Alphabet Using Proteinoids.
ACS Omega
December 2024
Unconventional Computing Laboratory, University of the West of England, Bristol BS16 1QY, U.K.
We introduce a new abiotic-protein-based substrate for identifying English alphabet characters optically using proteinoids. Proteinoids, which are amino acid polymers produced under thermal stress conditions, have demonstrated promise as materials that are compatible with living organisms and can be used in a wide range of applications. We explore the potential of using proteinoids for the optical stimulation and detection of English alphabet characters.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!