Name: measuring visual attention lapses
Uploaded: 2023-04-30T06:46:22.000Z
Duration: 8 min 52 s
Channel: JoVE

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Physical Science

HS. Waves and Electromagnetic Radiation

HS-PS4-5.

The Attentional Blink

1. Equipment
<ol>
	<li>The experiment requires a computer and experiment implementation software such as E-Prime, or a programming environment such as MATLAB or PsychoPy.</li>
</ol>
2. Stimulus and experiment design
<ol>
	<li>This experiment relies on a general experimental procedure called Rapid Serial Visual Presentation, RSVP for short.
	<ol>
		<li>The basics of RSVP involve experimental trials in which a series of images is shown rapidly, one after the other. Images usually remain in a display for less than 200 ms, before being replaced by another image, making extensive processing of the images difficult.</li>
	</ol>
	</li>
	<li>Start by making a basic RSVP program. Set it to present streams of large black lowercase letters (Helvetica font) in the center of the display, each one lasting only 50 ms. The letters should take up about 2.5 in. vertically and 1.5 in. horizontally. Figure 1 schematizes an RSVP sequence.</li>
</ol>
<img alt="Reaction time test diagram with visual sequence S, V, J, F, D for cognitive speed assessment." src="/files/ftp_upload/10211/10211fig1.jpg" data-altupdatedat="1761830439000" data-alt="Figure 1"> 
Figure 1: The basics of rapid serial visual presentation (RSVP). A series of images is shown in rapid succession, in this case, lowercase letters each remaining for only 50 ms before becoming replaced by the subsequent letter.
<ol start="3">
	<li>Now, to make this an attentional blink program, do as follows:
	<ol>
		<li>Make trials that are 30 images long-i.e. there will be 30 characters displayed, each for 50 ms, making each trial 1.5 s total.</li>
		<li>28 of the characters in each trial are lowercase letters as just described, but two are numbers.</li>
		<li>In each trial, randomly select the two numbers between 1 and 9 to show, but also ensure that the two numbers in a trial are always different.</li>
		<li>Randomly select the place in which the first number appears within the boundary of the 8th item presented and the 20th item presented. In other words, in each trial, place one number somewhere between the 8th and 20th RSVP position.</li>
		<li>The second number appears anywhere between immediately after the first and six positions after it. Since the position of the second number is defined relative to the first, these are called lag positions. The second number can have a lag position ranging between 1 and 6. In fact, over the course of the whole experiment there will be an equal number of each of the lag positions between 1 and 6. Figure 2 schematizes the concept of a lag position.</li>
		<li>Program the experiment to include 180 trials total, 30 each for each lag position, 1-6.</li>
		<li>At the end of each trial, the screen should read "First? Second?", as shown in Figure 2, to prompt the observer to report the numbers they saw during the trial.</li>
		<li>Finally, set up the program to produce an output spreadsheet that reports all the relevant data. Each row in the file corresponds to the contents of a single trial, and should include the following information, as shown in Figure 3: the trial number, the position of the first number in the RSVP stream, the lag position of the second number, the true identity of the first number, the true identity of the second number, and the key press made by the participant to identify the first number, and the same for the second.</li>
	</ol>
	</li>
</ol>
<img alt="Reaction time experiment diagram, showing sequence and lag between numbers and decision points." src="/files/ftp_upload/10211/10211fig2.jpg" data-altupdatedat="1761830439000" data-alt="Figure 2"> 
Figure 2: Methods for the attentional blink. A ready screen is followed by an RSVP stream consisting mainly of letters, 30 images in total. Embedded among the letters are two numbers. The first number appears anywhere between the 8th and the 20th positions in the stream. The position of the second number is called a lag and defined relative to the appearance of the first number such that following the first immediately is called lag 1, the next position lag 2, and so on. The experiment consists of 30 trials at each of lags 1-6. 
<img alt="Attention blink experiment spreadsheet; data entry fields include trial number, ID, response data." src="/files/ftp_upload/10211/10211fig3.jpg" data-altupdatedat="1761830439000" data-alt="Figure 3"> 
Figure 3: Organization of a data output table for an attentional blink experiment. Each row corresponds to a trial of the experiment. The important parameters to record are the position of the first number in the stream (a value between 8 and 20), the lag until the second number (a value between 1 and 6), the identity of the two numbers shown, and the responses given by the participant at the end of the trial.
3. Running the experiment
<ol>
	<li>For a complete experiment, it is ideal to test between 10-20 participants, but the result of this experiment should be apparent in the data of most individual participants.</li>
	<li>To test a participant, seat them in front of the computer monitor so that the back of their chair is about 60 cm away.</li>
	<li>Explain the instructions to them as follows:
	<ol>
		<li>"This experiment is designed to investigate the speed of human attention. Each trial will be more or less the same. You will see a screen with the word 'Ready?' on it. The screen will remain so until you press the spacebar to initiate a trial. Once a trial is initiated, you will see a series of lowercase letters appear rapidly in the center of the screen over the course of 1.5 seconds. Two numbers will appear embedded between the letters. They will appear in random positions, and not necessarily immediately after one another. Your task is to pay close attention to the sequence of letters, and to try to recognize the two letters that appear. At the end of a trial, you will be prompted to input the numbers that you think appeared, and in the order that you think you saw them, the first one first, followed by the second. There will be 180 trials total, so the experiment should only last 5-10 minutes. It is very important, however, that you do your best. If you are uncertain about the identity of a number in any trial, just guess. Any questions?"</li>
	</ol>
	</li>
	<li>After answering any questions, start the experiment for the participant, watching as they completes a few trials in case any further questions arise. Then leave the participant to complete the experiment.</li>
</ol>
4. Analyzing Results
<ol>
	<li>The first thing to do in order to analyze the results is to add two columns to the now populated data spreadsheet, a column called Accuracy 1, and one called Accuracy 2, meant to indicate whether the participant correctly identified the number in each position in that trial. Compare the actual number that appeared in each trial with the response given, filling the column with a 1 for a correct response, and a 0 for an incorrect response. Figure 4 shows how the table should look at this point.</li>
</ol>
<img alt="Attention blink data table; trial numbers, responses, accuracy metrics in spreadsheet format." src="/files/ftp_upload/10211/10211fig4.jpg" data-altupdatedat="1761830439000" data-alt="Figure 4"> 
Figure 4: Populated data output for an attentional blink experiment. The columns Accuracy 1 and Accuracy 2 report whether the response entered by a participant matched the actual identities of the number presented during each trial. 1 indicates a correct response, and 0 indicates an incorrect response.
<ol start="2">
	<li>Now compute the overall response accuracy for the participant for the first number. Do this by averaging the numbers in the Accuracy 1 column of the spreadsheet. This should be very high, between 0.90 and 1.</li>
	<li>Finally compute the average response accuracy for each of the six lag positions for the second number.</li>
</ol>

Like many other laboratory tasks for studying attention, the attentional blink has become a common tool in studies of brain damage, as well as in studies that use neuroimaging techniques to investigate the brain areas involved in controlling and coordinating attention.
The attentional blink paradigm has also been used to investigate the kinds of things that may capture attention automatically, and even how anxiety and other mental health problems may cause diverted attention. These studies use...

the attentional blink

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
In order for recognition of a certain stimulus to take place, visual attention needs to be directed towards said stimulus. To the earliest parts of the visual system, objects are not objects, they are collections of visual features-lines, corners, changes in texture, color, and light. Attention is the resource that is necessary for later processing in order to recognize what a given bundle of features adds up to. This makes attention a central focus of research. One especially important set of questions concerns how people sustain attention, that is, the extent to which they can continuously maintain a focus of attention from moment-to-moment. It is now known that sustained attention takes great effort. When attention needs to be focused very rapidly on something that is moving or changing very quickly, the effort involved causes a momentary lapse in attention once it is disengaged. This kind of lapse in attention is called an attentional blink. It is like the brain blinks for a moment, shutting down attention for a rest. Stimuli that appear during an attentional blink will not be perceived. 
In 1992, a group of researchers devised a paradigm to study the attentional blink, and the paradigm has come to be known by the same name.1 It demonstrates some of the challenges to maintaining focused attention. This video demonstrates how to implement the attentional blink paradigm in order to study sustained visual attention.

Graph average response accuracy for the first number, along with response accuracy for the second number as a function of lag position. Figure 5 shows an example.
<img alt="Attentional blink chart shows accuracy vs. Lag, highlighting Lag 1 sparing and blink effect." src="/files/ftp_upload/10211/10211fig5.jpg" data-altupdatedat="1761830439000" data-alt="Figure 5"> 
Figure 5: Results of...

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
In order for recognition of a certain stimulus to take place, visual attention ...

Processing information in a rapidly changing environment is demanding, and visual attention is necessary for object recognition to occur.For example, to recognize how a group of features comprises an object, like this football, visual attention is required, and sustaining it takes considerable effort.In dynamic situations where items move rapidly?like a football and players on the field during a game?the attentional effort involved causes a momentary lapse in attention once it is disengaged, such as when the quarterback is looking for a receiver. This lapse is referred to as an attentional blink?as if the brain blinks for a moment, shutting down attention for a rest?in which stimuli, such as an opponent, are not perceived.Based on the methods pioneered by Raymond, Shapiro and Arnell in 1992, this video demonstrates how to implement the phenomenon of Attentional Blink by discussing the steps required to design the stimuli and execute the paradigm, as well as how to analyze the data and interpret the results describing the accuracy of responses across trials with varying levels of attentional engagement. In this experiment, a series of images, such as large black lower case letters and numbers in Helvetica font, are presented for 50 ms one after the other?an experimental procedure called Rapid Serial Visual Presentation, RSVP for short. Each trial is programmed to display 30 characters in total, whereby two of the images are different numbers between 1 and 9.The first is randomly placed somewhere between the eighth and twentieth RSVP position, while the second digit is randomly inserted in a spot immediately after the first number, to six places after it. This spacing is called the lag position, which can range from 1 to 6. Over the course of the experiment, there are 180 trials, 30 at each of the 6 lag positions.After each trial, participants are asked to report the numbers, in the order that they appeared, during the RSVP. The dependent variable is recorded as the number of correct responses across lag positions. The logic behind the paradigm is that the first number will grab the participant?s attention, leading to a very high accuracy in naming the first ones. However, depending on the lag position, performance is expected to vary when reporting the second number. If it appears immediately after the first, performance should still be very high?a concept called lag 1 sparing.Accuracy should be affected most dramatically when the second number is in the second and third lag positions?because of the attentional blink phenomenon?and accuracy will be less affected at the later lag positions, those that occur after the short attentional blink window. Before the experiment, set up the program to generate an output spreadsheet that reports all of the relevant data for subsequent analysis, including the trial number, the position of the first digit in the RSVP stream and the lag, the true identity of the first and second numbers, and the responses given.To begin, greet the participant in the lab and guide them into the experimental room. Have them sit comfortably in front of the computer, with their chair back approximately 60 cm away.Now, explain the task instructions: The screen will display the word "Ready?"until the space bar is pressed, after which a series of letters and numbers will immediately and rapidly appear. Direct the participant to indicate what numbers they saw by pressing the corresponding keys in the same order they saw them. Remind them that if they are not sure what numbers they saw, to just guess. After answering any questions, leave the room and allow them to complete the 30 trials at all lag positions, for a total of 180. When they are finished, thank them for taking part in the experiment. To begin data analysis, open the spreadsheet with the data output from the experiment. Add two columns, named 'Accuracy 1' and 'Accuracy 2', to indicate whether the participant correctly identified the number in each position. For each trial, in the column labeled 'Accuracy 1', indicate whether or not they identified the first number correctly by placing a 1 or incorrectly by assigning a 0. Duplicate this for the column labeled 'Accuracy 2'. Next graph the mean accuracy across all trials for the first, along with the averages for the second numbers reported?'Accuracy 2'?by lag positions.Notice that the response for the first number?'Accuracy 1'?was very high, which demonstrates that even though the number appears very briefly, in an unpredictable location and embedded between letters, focused attention can support detailed processing and recognition.As predicted, when the second number immediately followed the first, accuracy remained high due to lag 1 sparing. Thus, focused attention triggered by the first number remains engaged, allowing for the capture of the second number. However, for lag positions 2 and 3, mean accuracy values decreased dramatically, reflecting the phenomenon of attentional blink. That is, after processing the first number, attention becomes temporarily disengaged, thereby reducing processing and recognition.Though, the attentional blink did not last long, as shown by the improved performance for lag positions 4, 5, and 6.Now that you are familiar with the phenomenon, let?s look at how the paradigm is used to investigate the basic limitations of visual attention in more detail, including the kinds of things that may capture it automatically, and even how anxiety and other mental health problems may divert it.In a similar RSVP task using photographs, participants were asked to identify a target image?one that was rotated in an unusual position. For example, an upside-down room was included as the target, and participants reported if it was an indoor or an outdoor scene. In some trials, researchers added a picture of a spider to the stream in a position preceding the target. They hypothesized that this might automatically capture attention because of the fear it induces. In this case, they reasoned that it should produce an attentional blink?leading the rotated target to be missed. Indeed, participants responded inaccurately when a spider preceded the target, demonstrating that fear-inducing objects can automatically capture attention and produce attentional blinks.Researchers have also used the same paradigm to investigate differences between people with severe phobias and those with just a typical dislike of spiders. In this instance, the task is reversed: the rotated room is shown beforehand, presenting the spider in the lag 2 position. For most participants then, the perception of the spider is blocked by the attentional blink. Interestingly, individuals with severe arachnophobia did not show an attentional blink, as they reported seeing the spider?suggesting that at times, emotional stimuli have a very strong pull on attention, when it would otherwise be disengaged.You?ve just watched JoVE?s introduction to the attentional blink. Now you should have a good understanding of how to design and execute an attention-engagement task, as well as analyze and assess the results. Thanks for watching!

Education

JoVE Science Education

Psychology

Sensation and Perception

measuring visual attention lapses

Visual attention is needed to recognize a stimulus. Early in vision, objects are not seen as whole objects. They are processed as features such as lines, corners, texture changes, color, and light. Attention helps later processing combine those features into something the brain can identify.

This makes attention a major topic in vision research. A key question is how people sustain attention over time. Sustained attention means keeping focus from moment to moment. It takes effort, especially when attention must shift very quickly to something that is moving or changing rapidly.

That effort can cause a brief lapse after attention is disengaged. This lapse is called an attentional blink. During that short pause, stimuli that appear are not perceived. Researchers use the attentional blink paradigm, named for this effect, to study how well people maintain focused visual attention.

The paradigm was first devised in 1992. It shows some of the challenges of keeping attention steady under fast-changing conditions. The method in this video demonstrates how to implement the attentional blink paradigm for studying sustained visual attention.

Measuring Visual Attention Lapses

color afterimages

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How the Brain Fills In the Blind Spot

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Visual Awareness Through Motion Illusion

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The Rubber Hand Illusion shows how the brain builds a map of the body in space. This body map helps people reach for objects, walk without hitting obstacles, and sit down without missing a chair. It depends on proprioception, which is the brain's sense of where the limbs are based on control and feedback signals. The brain does not rely on proprioception alone. It also uses vision, touch, and even sound to represent body parts in space. The classic illusion, first described by Botvinick and...

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Visual Attention and Missed Objects

Visual attention helps determine which parts of the visual world the brain processes and how well it processes them. Because attention is limited, people cannot take in everything at once, even when an object is right in front of them. Researchers began showing this effect in the 1960s. Ulrich Neisser demonstrated that people can miss visible objects when their attention is distracted. Later, in the 1980s and 1990s, Arien Mack and Irvin Rock built on that work and developed a simple way to...

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Visual attention is the limited ability to focus on some information while ignoring other stimuli in the environment. It is studied in many senses, including vision, hearing, touch, taste, and smell. Researchers most often examine it in vision because it is easy to test with controlled displays. A common method is the spatial cueing paradigm. In this task, a cue appears to guide attention toward one location, and researchers measure what happens when attention is focused there instead of...

Visual attention is needed to recognize a stimulus. Early in vision, objects are not seen as whole objects. They are processed as features such as lines, corners, texture changes, color, and light. Attention helps later processing combine those features into something the brain can identify. This makes attention a major topic in vision research. A key question is how people sustain attention over time. Sustained attention means keeping focus from moment to moment. It takes effort, especially...

crowding

Peripheral Vision and Letter Crowding

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Face Recognition and Upside-Down Faces

Face recognition is a specialized part of human perception. It often feels effortless, but it actually depends on complex and intensive processing. The brain uses dedicated networks to detect faces and tell them apart.

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Visual Masking with Object Substitution

Visual masking describes cases where one image is presented, but an observer does not perceive it because a second image appears. In vision science, this kind of interference helps researchers study how the brain selects and stores visual information. Object substitution masking is a surprising form of visual masking. It became an important topic in vision research after it was discovered relatively recently, around 1997, by Enns and Di Lollo. The effect has been studied because it shows that...

sensation and perception

This collection delves into a variety of procedures to study how the brain processes our complex sensory world and solves problems confronting conscious awareness and visual, tactile, and auditory perception. 

Explore how the attentional blink reveals brief lapses in visual attention and how researchers use the paradigm to study sustained attention in fast-changing scenes.

Measuring Visual Attention Lapses | JoVE K12

Life Science

Structure and Function

HS-LS1-2.

Jonathan Flombaum

Overview

Stimulus and Experimental Design

Running the Experiment

Data Analysis and Representative Results

Applications

Summary

Travelling Waves

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Equations of Wave Motion

Mathematically, the motion of a wave can be studied using a wavefunction. Consider a string oscillating up and down in simple harmonic motion, having a ...

Graphing the Wave Function

Consider the wave equation for a sinusoidal wave moving in the positive x-direction. The wave equation is a function of both position and time. From the ...

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A wave propagates through a medium with a constant speed, known as a wave velocity. It is different from the speed of the particles of the medium, which ...

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The speed of a wave depends on the characteristics of the medium. For example, in the case of a guitar, the strings vibrate to produce the sound. The ...

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Problem-Solving: Tuning of a Guitar String

In the case of stringed instruments like the guitar, the elastic property that determines the speed of the sound produced is its linear mass density or ...

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Kinetic and Potential Energy of a Wave

All forms of waves carry energy; this is directly visualized in nature. For instance, the waves of earthquakes are so intense that they can shake huge ...

Energy and Power of a Wave

The total energy associated with a wavelength is the sum of the potential energy and the kinetic energy. The average rate of energy transfer associated ...

Interference and Superposition of Waves

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Reflection of Waves

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Standing Waves

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Modes of Standing Waves - I

A close look at earthquakes provides evidence for the conditions appropriate for resonance, standing waves, and constructive and destructive interference. ...

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Modes of Standing Waves: II

The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions ...

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Sound Waves

Sound waves can be thought of as fluctuations in the pressure of a medium through which they propagate. Since the pressure also makes the medium&#39;s ...

Sound as Pressure Waves

Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As ...

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Perception of Sound Waves

The human ear is not equally sensitive to all frequencies in the audible range. It may perceive sound waves with the same pressure but different ...

Speed of Sound in Solids and Liquids

Most solids and liquids are incompressible&#8212;their densities remain constant throughout. In the presence of an external force, the molecules tend to ...

Speed of Sound in Gases

The speed of sound in a gaseous medium depends on various factors. Since gases constitute molecules that are free to move, they are highly compressible. ...

Shock Waves

While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the ...

Echo

The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More ...

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Use mathematical representations to support a claim regarding relationships among the period, frequency, wavelength, and speed of waves traveling and transferring energy (amplitude, frequency) in various media.

HS-PS4-1.

Using GIS to Investigate Urban Forestry

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
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Evaluate questions about the advantages of using a digital transmission and storage of information.

HS-PS4-2.

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Concept of Resonance and its Characteristics

If a driven oscillator needs to resonate at a specific frequency, then very light damping is required. An example of light damping includes playing piano ...

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Sound Waves: Resonance

Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical ...

Sound Waves: Interference

Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure ...

Interference: Path Lengths

Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two ...

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The Wave Nature of Light

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The Electromagnetic Spectrum

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The Quantum-Mechanical Model of an Atom

Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of ...

Quantum Numbers

It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy ...

Interference and Diffraction

Source: Yong P. Chen, PhD, Department of Physics &#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
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Photoelectric Effect

Source: Yong P. Chen, PhD, Department of Physics &#38;&#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
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Reflection and Refraction

Source: Derek Wilson,&#160;Asantha Cooray, PhD, Department of Physics &#38; Astronomy, School of Physical Sciences, University of California, Irvine, CA
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Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model (quantum theory), and that for some situations one model is more useful than the other.

HS-PS4-3.

Electric Charge in a Magnetic Field

Source: Andrew Duffy, PhD, Department of Physics, Boston University, Boston, MA
This experiment duplicates J.J. Thomson's famous experiment at the end of ...

Electromagnetic Fields

Electric fields generated by static charges, often referred to as electrostatic fields, are characteristically different from electric fields created by ...

Electromagnetic Waves

James Clerk Maxwell formulated a single theory combining all the electric and magnetic effects scientists knew during that time, calling the phenomena his ...

Electromagnetic waves are categorized according to their wavelengths and frequencies, giving the electromagnetic spectrum. These waves are classified as ...

Plane Electromagnetic Waves I

The existence of combined electric and magnetic fields that propagate through space as electromagnetic (EM) waves is the most significant prediction of ...

Plane Electromagnetic Waves II

Consider a plane wavefront traveling in position x-direction with a constant speed. This wavefront can be utilized to obtain the relationship between ...

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Electromagnetic waves are consistent with Ampere&#39;s law. Assuming there is no conduction current Ampere&#39;s law is given as:


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Electromagnetic waves can travel in the vacuum as well as in matter. For example light, which is an electromagnetic wave, can travel through air, water, ...

Energy Carried By Electromagnetic Waves

Anyone who has used a microwave oven knows there is energy in electromagnetic waves. Sometimes, this energy is obvious, such as in the summer sun&#39;s ...

Intensity Of Electromagnetic Waves

The energy transport per unit area per unit time, or the Poynting vector, gives the energy flux of an electromagnetic wave at any specific time. For a ...

Momentum And Radiation Pressure

An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because ...

Cardiac Magnetic Resonance Imaging

Source: Frederick W. Damen and Craig J. Goergen, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
In this video, high ...

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An Introduction to Drosophila melanogaster

Drosophila melanogaster, also known as the fruit fly, is a powerful model organism widely used in biological research that has made significant ...

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An Introduction to the Zebrafish: Danio rerio

Zebrafish (Danio rerio) are small freshwater fish that are used as model organisms for biomedical research. The many strengths of these fish include their ...

An Overview of Genetics and Disease

Many human diseases are associated with mutations or variations in genetic sequences. Some of these genetic variants are heritable, passed down from ...

Color Afterimages

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
Human color vision is impressive. People with normal color vision can tell apart ...

Evaluate the validity and reliability of claims in published materials of the effects that different frequencies of electromagnetic radiation have when absorbed by matter.

HS-PS4-4.

Measuring Visual Attention Lapses

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