Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Frequency-dependent Selection01:21

Frequency-dependent Selection

23.1K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
23.1K
Muscle Stimulation Frequency01:22

Muscle Stimulation Frequency

4.3K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
4.3K
Subliminal Perception01:15

Subliminal Perception

770
Subliminal perception refers to the processing of sensory information that occurs below the level of conscious awareness. Researchers study subliminal perception by presenting a stimulus, such as a word or image, very quickly, typically around 50 milliseconds. This rapid presentation is often followed by another stimulus, such as a pattern of dots or lines, which blocks further mental processing of the initial stimulus. As a result, if participants cannot identify the initial stimulus better...
770
Factors Affecting Perception01:25

Factors Affecting Perception

2.7K
Perception is influenced by perceptual set, context, motivation, and emotion. Perceptual set, or perceptual expectancy, refers to the tendency to perceive things in a particular way, influenced by previous experiences and expectations. This phenomenon affects the interpretation of stimuli, creating a set of mental tendencies and assumptions that impact sensory perceptions of sound, taste, touch, and sight.
An illustrative example of a perceptual set is the scenario where an airline pilot told...
2.7K
Perception01:28

Perception

1.0K
Perception is a fundamental psychological process that enables individuals to organize, interpret, and consciously experience sensory information. This process is crucial for understanding and interacting with the world around us. It includes both bottom-up and top-down processing, each playing a distinct role in how we perceive our environment.
Bottom-up processing begins at the sensory level, where receptors detect external environmental stimuli. These could include the tactile sensation of...
1.0K
Gestalt Principles of Perception01:21

Gestalt Principles of Perception

1.1K
Gestalt principles provide a framework for understanding how humans perceive objects as unified wholes within their context. These principles are essential in explaining the cognitive processes that make sense of complex visual stimuli by organizing them into coherent groups. One fundamental principle is proximity, which posits that objects located close to each other are perceived as a collective group. For instance, when dots are positioned near one another, the visual system interprets them...
1.1K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Neuropsychological and metabolic interconnectivity in obesity, anorexia and bulimia nervosa - an integrative literature review.

Metabolic brain disease·2026
Same author

Correction: Loughran et al. Radiofrequency Electromagnetic Field Exposure and the Resting EEG: Exploring the Thermal Mechanism Hypothesis. <i>Int. J. Environ. Res. Public Health</i> 2019, <i>16</i>, 1505.

International journal of environmental research and public health·2026
Same author

Visual Factors in Cybersickness: A Literature Survey and Meta-Analysis.

Multisensory research·2025
Same author

Electroencephalogram Gamma Band Power Correlates with Anhedonia in a Community Sample.

Journal of personalized medicine·2025
Same author

Looking for Biomarkers Which May Explain Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF): Does RF-EMF Exposure Influence Salivary Cortisol Response?

Bioelectromagnetics·2025
Same author

An Exploratory Comparison of Alpha and Beta Network Connectivity Across Four Depression Subtypes.

Journal of clinical medicine·2025

Related Experiment Video

Updated: Jan 21, 2026

Electrode Positioning and Montage in Transcranial Direct Current Stimulation
12:00

Electrode Positioning and Montage in Transcranial Direct Current Stimulation

Published on: May 23, 2011

265.4K

Frequency-dependent and montage-based differences in phosphene perception thresholds via transcranial alternating

Ian D Evans1,2,3,4, Stephen Palmisano1,2, Sarah P Loughran1,2,3,4

  • 1School of Psychology, University of Wollongong, Wollongong, Australia.

Bioelectromagnetics
|July 25, 2019
PubMed
Summary

Transcranial alternating current stimulation (tACS) can cause phosphenes. This study found stimulation location and 16 Hz frequency significantly affect phosphene perception thresholds, crucial for safety standards.

Keywords:
EMF safetyphosphenesretinal activationtranscranial alternating current stimulationvolume conduction

More Related Videos

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation
11:11

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Published on: September 23, 2017

9.6K
The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram
06:14

The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram

Published on: October 10, 2025

507

Related Experiment Videos

Last Updated: Jan 21, 2026

Electrode Positioning and Montage in Transcranial Direct Current Stimulation
12:00

Electrode Positioning and Montage in Transcranial Direct Current Stimulation

Published on: May 23, 2011

265.4K
Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation
11:11

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Published on: September 23, 2017

9.6K
The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram
06:14

The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram

Published on: October 10, 2025

507

Area of Science:

  • Neuroscience
  • Bioelectromagnetics
  • Sensory Perception

Background:

  • Transcranial alternating current stimulation (tACS) can induce phosphenes, visual artifacts perceived as light.
  • Phosphene thresholds are used to estimate safe electrical stimulation limits for human neural functioning.
  • The exact relationship between tACS parameters and phosphene perception thresholds requires further clarification.

Purpose of the Study:

  • To systematically investigate how tACS stimulation location and frequency influence phosphene perception thresholds.
  • To determine the specific tACS parameters that elicit the lowest phosphene perception thresholds.
  • To assess the consistency of phosphene thresholds across participants for potential use in safety standards.

Main Methods:

  • Utilized tACS to deliver electrical stimulation to the scalp in 24 participants.
  • Investigated two stimulation sites: FPz-Cz and Oz-Cz.
  • Tested stimulation frequencies ranging from 2 Hz to 30 Hz in 2 Hz increments.
  • Employed a within-subject design to obtain phosphene perception thresholds.

Main Results:

  • Phosphene perception thresholds were significantly lower with FPz-Cz stimulation compared to Oz-Cz.
  • The lowest phosphene perception thresholds were consistently observed at a stimulation frequency of 16 Hz, irrespective of location.
  • Minimal variation in thresholds was found across participants, indicating high reliability.

Conclusions:

  • The location of tACS application and stimulation frequency critically impact phosphene perception thresholds.
  • A 16 Hz stimulation frequency appears to be most sensitive for eliciting phosphenes.
  • The low inter-subject variability supports the use of phosphene thresholds in establishing robust safety guidelines for tACS.