What Is Signal Detection Theory In Psychology Example?

What Is Signal Detection Theory In Psychology Example
(a) Introduction to signal detection theory. A simple example of using SDT in experimental psychology is when testing the ability of a subject to detect a short tone pip (beep) in a background of white noise (‘ssss’; ). Over repeated trials subjects are required to decide whether there was a tone present or not.

What is a real life example of signal detection theory?

Signal Detection Theory Examples –

Detecting an emergency vehicle’s siren in the background noise of a busy city street. In this case, the signal is the siren, and the noise is the other traffic sounds.

When a customer at an electronics store hears the sound of their phone ringing in their pocket amidst the chatter and beeps from various nearby devices. So, the signal is the phone ringtone, and the noise is everything else in the store.

Parents monitor their children for signs of distress. The signal is the sound or behavior that indicates the child needs help. In contrast, noise is all other sounds and behaviors.

When a person listens to music at a party, they use SDT since they can distinguish the music from all the talking. Here, the signal is the music, and the noise is people’s voices.

During a meeting or lecture, individuals use SDT to decide whether somebody is speaking too loudly. In this case, the signal is the person’s voice, and the noise is all other conversations.

When a person is looking for their car keys, among other objects in a drawer, they are also using SDT. The signal is the clacking of keys as they collide with other surfaces, while the noise is all extraneous sounds that can be heard in your surroundings.

For a hunter tracking their prey, the signal is the sound of movement from the animal, while all other environmental noises are considered noise.

If a child is trying to hear something in the distance, they utilize SDT. In this case, the signal is what they are trying to hear, while the noise is all other background noises.

A consumer that evaluates the quality of a product based on its packaging and marketing claims is a prime example of SDT. Here, the signal is the product’s value, while the noise comes from external factors like advertising.

If a passenger listens to an announcement on a noisy train platform, they use SDT. In this case, the signal is the announcement, while all other environmental noises around them constitute noise.

What does signal detection theory mean AP psychology?

AP Psychology – AP Psychology 119 Which of the following describes the difference between sensation and perception? Possible Answers: Perception is a bottom-up process and sensation is a top-down process Perception requires transduction and sensation does not Sensation requires transduction an perception does not Sensation is a bottom-up process and perception is a top-down process Correct answer: Sensation is a bottom-up process and perception is a top-down process Explanation : Sensation can be described as the process of how our nervous system and sensory receptors receive and translate stimuli from our environment.

Perception is the process by which our brains organize and interpret sensory stimuli, which allows us to recognize significant events and objects. Sensation functions as a bottom-up process because it starts at a smaller level and works its way up (i.e. from sensory receptors to processing centers). Perception functions as a top-down process because it starts at a larger level and gets smaller as it continues (i.e.

from the sensory input down to our expectations and experiences). Which of the following theories predicts when and how we detect a stimulus amid background noise? Possible Answers: Absolute threshold theory Correct answer: Signal detection theory Explanation : The signal detection theory predicts when we will detect weak signals (stimuli).

  • This theory negates the idea of absolute thresholds because the purpose is to ascertain why individuals react to the same stimulus differently.
  • Additionally, it seeks to understand why one individual may perceive a stimulus differently based on circumstances.
  • For instance, an exhausted parent may jump at the slightest whimper of a sleeping baby but fail to recognize a louder noise (i.e.

the dryer buzzer indicating dry clothes). The absolute threshold is defined as the minimum stimulus required for detection 50 percent of the time; therefore, it is an incorrect choice. Conversely, a stimulus may be considered subliminal when it is below one’s conscious awareness: not detected 50 percent of the time.

This is also incorrect. Transduction would be incorrect because it is the process by which stimuli are translated from sensation to perception. Last, priming is also incorrect because it is defined as the process of predisposing one’s memory, perception, or response by making unconscious associations.

This is usually exercised in experiments using flashing images and masking stimuli. Which of the following best defines a difference threshold? Possible Answers: The minimal difference between two stimuli that can be detected 50 percent of the time. The difference between two absolute thresholds.

The difference in absolute threshold and sensory adaptation. The difference between two subliminal thresholds. The difference between an absolute threshold and a subliminal stimulus. Correct answer: The minimal difference between two stimuli that can be detected 50 percent of the time. Explanation : The difference threshold is the noticeable difference a person can detect between any two stimuli 50 percent of the time.

The concept of difference threshold is often associated with Weber’s law. This law states that in order for an individual to perceive a difference between to stimuli then the stimuli must be a certain percent different and not a given amount. This becomes an issue of proportion versus static amount.

Which of the following statements associated with Hering’s opponent-process theory are true? Possible Answers: There are three sets of retinal processes: red, blue, green There are six sets of retinal processes: red, blue, green, yellow, black, and white There are two sets of opponent retinal processes: red-green-blue and black-white There are three sets of opponent retinal processes: red-blue, green-yellow, and white-black There are three sets of opponent retinal processes: red-green, blue-yellow, and white-black Correct answer: There are three sets of opponent retinal processes: red-green, blue-yellow, and white-black Explanation : Ewald Hering created the opponent-process theory.

While he saw truth in the Young-Helmholtz trichromatic theory, he felt that it left many questions of color vision unanswered. For example, how is it that people that cannot see red or green see yellow? Hering came to an understanding using ” afterimages,” For instance, if you stare at a green square for long enough and then stare at a white sheet of paper, you will see a red square.

Red in this case is green’s opponent color. The same works for yellow and blue and black and white. You may be familiar with figures in text books having an image of a flag that’s normally red, blue, and white be colored in green, yellow and black. with a blank white space next to it. This is an example of the afterimage effect, staring at the discolored flag for an ample period of time and then immediately staring at a blank white space will yield the creation of an image of the flag in its normal colors.

A century later, researchers supported Hering’s theory. There are three sets of opponent retinal receptors: green-red, blue-yellow, and black-white. This theory complements the Young-Helmholtz theory. Humans can easily detect movement of an object in your peripheral vision, but have trouble identifying the exact shape or color of the object.

Which of the following is the most probable cause of this phenomenon? Possible Answers: The individual is nearsighted There are more rods than cones in the periphery of the retina There are more cones than rods in the periphery of the retina The object is in your blind spot Correct answer: There are more rods than cones in the periphery of the retina Explanation : The periphery of the retina contains many more rods than cones.

Rods allow people to easily detect changes in light, and cones allow us to see in color and are located in the center—fovea—of the retina where visual acuity is best. Rods might not help us with seeing things super accurately, but they do help us with detecting motion because of the changes in light.

  1. The blind spot is where the bundle of nerves at the rear of the eye chamber block incoming light to hit the retina; thus, creating a “hole” in our vision.
  2. Nearsightedness has to do with visual acuity based on distance from the object, not peripheral vision.
  3. A single drop of chocolate pudding is placed on your tongue.

You are told not to move it around on your tongue, and you begin to notice that the original chocolaty flavor begins to fade until there is no taste at all. This scenario is indicative of which of the following principles? Possible Answers: Correct answer: Sensory adaptation Explanation : Sensory adaptation is a gradual decline in sensitivity to prolonged stimulation.

Senses—in this case taste—will automatically adapt to decline their sensitivity to stimulation over time. Habituation is a closely related concept that involves less sensitivity over time; however, habituation has to do more with physiological, cognitive, and perceptual processes rather than basic sensory processes.

Taste bud cell death does not occur after prolonged stimulation. When do action potentials occur? Possible Answers: When sodium ions exit the neuron to make the membrane potential more positive When sodium ions enter the neuron to make the membrane potential more positive When sodium ions exit the neuron to make the membrane potential more negative When potassium ions exit the neuron to make the membrane potential more positive When sodium ions enter the neuron to make the membrane potential more negative Correct answer: When sodium ions enter the neuron to make the membrane potential more positive Explanation : Action potentials are caused when different ions cross the neuron’s membrane. ) to the threshold level of about, which triggers the action potential and raises the membrane potential to roughly Following the action potential, potassium exits the neuron to reduce the membrane potential before the sodium-potassium pump restores the resting potential. Although you wear glasses throughout the day, you don’t contantly notice them on your face, on the bridge of your nose, or on the tops of your ears.

Why is this? Possible Answers: Your memory has a way to process unpleasant stimuli and repress them If you had to notice all the time, it would be impossible to wear glasses Correct answer: Sensory adaptation Explanation : Over time, a constant stimulus in the environment evokes less and less of a response from one’s sensory system.

You might be interested:  How To Study For The Ap Psychology Exam?

Sensory neurons respond at first to these stimuli, but over time they stop responding in order to focus attention on other stimuli in the environment. What types of retinal cells allow us to perceive color? Possible Answers: Explanation : The human retina has two types of cells that respond to light: cones and rods.

  1. Rods are more numerous, but can only detect light and dark shades.
  2. Cones respond to different wavelenghts of light, and can thus transmit color information.
  3. They are highly concentrated in the fovea of the retina.
  4. Which term refers to the part of a visual field that has no photoreceptors, and thus cannot detect images? Possible Answers: Correct answer: Optic disk Explanation : Every visual field has a blind spot, where there are no rods and cones (known as photoreceptors) to detect external images.

Our brain uses context clues from the environment to help fill in this blind spot to make a complete picture. The blind spot is located on the optic disk, which is the location where the optic nerve exits the back of the eye. Due to the nerve tissue in this spot, there are no photoreceptors to detect input. Sara Certified Tutor University of Houston, Bachelor of Science, Psychology. Kiki Certified Tutor Frederick Community College, Associate in Science, Psychology. University of Maryland Global Campus, Bachelor of Science, Psy. Bianca Certified Tutor Washington University in St Louis, Bachelor of Science, Anthropology. If you’ve found an issue with this question, please let us know. With the help of the community we can continue to improve our educational resources. If you believe that content available by means of the Website (as defined in our Terms of Service) infringes one or more of your copyrights, please notify us by providing a written notice (“Infringement Notice”) containing the information described below to the designated agent listed below.

  • If Varsity Tutors takes action in response to an Infringement Notice, it will make a good faith attempt to contact the party that made such content available by means of the most recent email address, if any, provided by such party to Varsity Tutors.
  • Your Infringement Notice may be forwarded to the party that made the content available or to third parties such as ChillingEffects.org.

Please be advised that you will be liable for damages (including costs and attorneys’ fees) if you materially misrepresent that a product or activity is infringing your copyrights. Thus, if you are not sure content located on or linked-to by the Website infringes your copyright, you should consider first contacting an attorney.

Please follow these steps to file a notice: You must include the following: A physical or electronic signature of the copyright owner or a person authorized to act on their behalf; An identification of the copyright claimed to have been infringed; A description of the nature and exact location of the content that you claim to infringe your copyright, in \ sufficient detail to permit Varsity Tutors to find and positively identify that content; for example we require a link to the specific question (not just the name of the question) that contains the content and a description of which specific portion of the question – an image, a link, the text, etc – your complaint refers to; Your name, address, telephone number and email address; and A statement by you: (a) that you believe in good faith that the use of the content that you claim to infringe your copyright is not authorized by law, or by the copyright owner or such owner’s agent; (b) that all of the information contained in your Infringement Notice is accurate, and (c) under penalty of perjury, that you are either the copyright owner or a person authorized to act on their behalf. Send your complaint to our designated agent at:

Charles Cohn Varsity Tutors LLC 101 S. Hanley Rd, Suite 300 St. Louis, MO 63105 Or fill out the form below: : AP Psychology – AP Psychology

What is an example of correct rejection signal detection theory?

Information and Criterion – I begin here with a medical scenario. Imagine that a radiologist is examining a CT scan, looking for evidence of a tumor. Interpreting CT images is hard and it takes a lot of training. Because the task is so hard, there is always some uncertainty as to what is there or not.

Either there is a tumor (signal present) or there is not (signal absent). Either the doctor sees a tumor (they respond “yes”) or does not (they respond “no”). There are four possible outcomes: hit (tumor present and doctor says “yes”), miss (tumor present and doctor says “no”), false alarm (tumor absent and doctor says “yes”), and correct rejection (tumor absent and doctor says “no”).

Hits and correct rejections are good. False alarms and misses are bad. What Is Signal Detection Theory In Psychology Example There are two main components to the decision-making process: information acquisition and criterion. Information acquisition: First, there is information in the CT scan. For example, healthy lungs have a characteristic shape. The presence of a tumor might distort that shape.

Tumors may have different image characteristics: brighter or darker, different texture, etc. With proper training a doctor learns what kinds of things to look for, so with more practice/training they will be able to acquire more (and more reliable) information. Running another test (e.g., MRI) can also be used to acquire more information.

Regardless, acquiring more information is good. The effect of information is to increase the likelihood of getting either a hit or a correct rejection, while reducing the likelihood of of the two possible mistaken outcomes (false alarms and misses). What Is Signal Detection Theory In Psychology Example Criterion: The second component of the decision process is quite different. For, in addition to relying on technology/testing to provide information, the medical profession allows doctors to use their own judgement. Different doctors may feel that the different types of errors are not equal.

For example, some doctors may feel that missing an opportunity for early diagnosis may mean the difference between life and death. A false alarm, on the other hand, may result only in a routine biopsy operation. They may choose to err toward “yes” (tumor present) decisions. Other doctors, however, may feel that unnecessary surgeries (even routine ones) are very bad (expensive, stress, etc.).

They may choose to be more conservative and say “no” (no tumor) more often. They will miss more tumors, but they will be doing their part to reduce unnecessary surgeries. And they may feel that a tumor, if there really is one, will be picked up at the next check-up. What Is Signal Detection Theory In Psychology Example

What is signal detection theory briefly describe?

Overview – Signal detection theory (often abridged as SDT) is used to analyze data coming from experiments where the task is to categorize ambiguous inputs which can be generated either by a known process (called the signal) or be obtained by chance (called the noise in the SDT framework).

  1. For example, a radar operator must decide if what she sees on the radar screen indicates the presence of a plane (the signal) or the presence of parasites (the noise).
  2. This type of applications was the original framework of SDT (see the founding work of Green and Swets, 1966 ).
  3. But the notion of signal and noise can be somewhat metaphorical is some experimental contexts.

For example, in a memory recognition experiment, participants have to decide if the input they currently see was presented before. Here the signal corresponds to a familiarity feeling generated by a memorized input, whereas the noise corresponds to a familiarity feeling generated by a new stimulus.

  • The goal of signal detection theory is to estimate two main parameters from the experimental data.
  • The first parameter, called d ′, indicates the strength of the signal (relative to the noise).
  • The second parameter called C (a variant of it is called β ) reflects the strategy of response of the participant of being more willing to say, for example, yes rather than no.

SDT is used in very different domains from psychology (psychophysics, perception, memory), medical diagnostics (do the symptoms match a known diagnostic or can they be dismissed are irrelevant), to statistical decision (do the data indicate that the experiment has an effect or not).

The classic work on SDT is Green and Swets (1995), a basic introduction is McNicol (1972), two recent comprehensive references are Macmillan and Creelman (2005) and Wickens (2002), A few examples of SDT to education can be found in McDermott et al, (1992), more recent examples can be found in McFall and Treat (1999), DeCarlo (2005), and DeCarlo and Luthar (2000),

Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780080448947013646

What is a signal give an example and explain how it is useful?

Example: Signals and Classification of Signals Example: Signals and Classification of Signals A signal is a function or a data set representing a physical quantity or variable. Usually, the signal encapsulates information about the behavior of a physical phenomenon, for example, electrical current flowing through a resistor, sonar sound waves propagating under water, or earthquakes.

Mathematically, a signal is represented as a function of an independent variable t, typically representing time. Thus, a signal is denoted x(t). Continuous-Time and Discrete-Time Signals A signal x(t) is a continuous-time signal if t is a continuous variable. If t is a discrete variable, that is, x(t) is defined at discrete times, then x(t) is a discrete-time signal – often denoted as x(n), where n is an integer.

A discrete-time signal x(n) may represent a phenomenon for which the independent variable is inherently discrete, such as the daily closing value of a stock price, or it may be obtained by sampling a continuous-time signal x(t) at t = nT, where T is the sampling period. n -10 20 U n 10 Φ n The Heaviside Step function states that f(0)=0.5 2. Define the range and plot the unit step function. n_range n 10 n The Unit Impulse Signal 1. Define the unit impulse function. δ1 n 10 if n 0 1 0 2. Plot the unit impulse function. 3. Set a value of k to shift the impulse by k samples to the right. k 3 δ2 n 10 if n k 0 1 0 Sinusoidal Signal 1. Set the frequency. ω 0.6 2. Define the sinusoidal function. x n 10 sin ω n 3. Plot the sinusoidal function. Exponential Signal 1. Set the alpha factor. α 0.95 2. Define the exponential function. y n 10 α n 3. Plot the exponential function. Exponentially Decaying Sinusoid Plot the function resulting from the product of the sinusoidal function and the exponential function.

  1. Z n 10 x n 10 y n 10 The result is an exponentially decaying sinusoid function.
  2. Analog and Digital Signals If a continuous-time signal x(t) can take on any value within a continuous time interval, then x(t) is called an analog signal.
  3. If a discrete-time signal x(n) can take on only a finite number of distinct values, then it is called a digital signal.

To convert an analog signal into a digital signal, the analog signal needs to be sampled and quantized. Real and Complex Signals A signal x(t) is a real signal if its values are real numbers. Similarly, a signal x(t) is a complex signal if its values are complex numbers.

Use functions and to manipulate complex signals. Deterministic and Random Signals Deterministic signals are those whose values are completely specified for any given time. Thus, a deterministic signal can be modeled by a known function of time x(t). Random signals, on the other hand, are those signals that can take random values at any given time.

Random signals can only be characterized statistically. The noise-generator functions, and are designed to produce pseudo-random signals characterized by user-defined statistical parameters. : Example: Signals and Classification of Signals

What are the different types of signal detection in psychology?

The four possibilities in signal detection theory are hit, miss, false alarm, and correct rejections.

You might be interested:  Why Am I So Hard On Myself Psychology?

What are the 4 possible responses in signal detection theory?

Internal response probability density functions. There are four possible outcomes: hit (signal present and subject says ‘yes’), miss (signal present and subject says ‘no’), false alarm (signal absent and subject says ‘yes’), and correct rejection (signal absent and subject says ‘no’).

What are the advantages of signal detection theory in psychology?

Summary of Benefits of Signal Detection Theory – If one is going to keep score of prediction performance, signal detection theory provides an ideal framework. Its fundamental value is separating the effects of base rates, detector accuracy, and cut-point biases motivated by avoiding either false alarms or misses.

In their abstract for a review chapter on clinical assessment, McFall and Treat (1999, p.215) provide an excellent summary of the benefits of signal detection theory. One can read the following and substitute “intelligence assessment” for “clinical assessment.” Suggested Citation: “4 Use of Signal Detection Theory as a Tool for Enhancing Performance and Evaluating Tradecraft in Intelligence Analysis-Gary H.

McClelland.” National Research Council.2011. Intelligence Analysis: Behavioral and Social Scientific Foundations, Washington, DC: The National Academies Press. doi: 10.17226/13062. × A rephrasing of the two last sentences appropriate for intelligence analysis might be: An important benefit of using signal detection theory to evaluate and compare performance of individuals, teams, systems, procedures, and other factors is that it would require only a minimal, almost trivial, addition to the daily activities of the typical analyst.

The only additional workload for the analyst would be to produce a probabilistic or categorical prediction of the future events being analyzed. Other researchers—not working analysts—could then subsequently assess the accuracy of those predictions in a signal detection analysis. That is, signal detection methods would not involve any immediate change in how the analysts did their work.

Instead, SDT would be used by researchers to sift the wheat from the chaff among the methods and procedures analysts are already using or new ones that might be proposed.

What is the problem with signal detection theory?

A key difficulty with signal detection theory is that the expected reproductive success (the reproductive values in the payoff matrix) should depend on the reserve state of the individual. For instance, the cost of fleeing may be very high if the individual is near starvation.

What is an example of signal detection in sport?

5.2 Information Processing – 5.2.1 Describe a simple model of information processing

In response to input stimuli, the performer perceives the stimulus, and recounts by executing an appropriate output, after their brain goes through the decision making process. Feedback is then often given, so that the response can be altered to be made better if necessary. Example: A penalty kick is about to take place, the goalie observes the angle of the kicker (input), makes a decision on where to dive (decision making) and follows with a diving movement (output). Terminal feedback on the movement is applied for the next shot.

5.2.2 Describe Welford’s model of information processing

sense organs perception short-term memory longterm memory decision making effector control feedback

5.2.3 Outline the components associated with sensory output

The information is taken in through the senses prior to a decision being made in three main ways. These are:

  • what we see (vision)
  • what we hear (auditory)
  • what we sense (proprioception)

Vision:

seeing the ball or the opponent; for eg, picking up the flight of the shuttle cock coming over the net in badminton

Audition

hearing the call of a team-mate or the sound of the ball on the racket

Proprioception:

Proprioceptors are located on the nerves, muscles, tendons, joints and inner ear, which provide intrinsic (internal) information about the movement and balance of the body during the performance. The three components of proprioception are : (1) touch, (2) equilibrium (balance) and (3) Kinaesthesis

Touch – is our tactile sense, it detects pressure, pain, temperature. It’s used in many sports. Eg The feel of the ball in the hands or the tense feel of the tennis racket in the hand as you hit a return

Exteroceptors : Exteroceptors provide information about the external environment, like touch, pressure, temperature, light, sound, taste, smell etc. Sometimes receptors sensing light, sound and smell, which provide information about the distant environment, have been called telereceptors. Introceptors: Pass information from within the body’s internal organs such as the heart and lungs to the brain via the nervous system. This helps to regulate the various functions of the body and cater for the changing demands placed upon it. Kinaesthetic information or Proprioception (body awareness) – the inner sense within the muscles, tendons and joints, which gives automatic internal information about the position of joints and the tension in the muscles. Proprioceptors : Proprioceptors provide information about the position and posture of our body in space. They sense stimuli from the muscles, tendons and the joints as well from the vestibular apparatus. Equilibrium – the balance needed before hitting a serve or the balance used in the skillful performance of a gymnast on the balance beam. Kinaesthesis – the inner sense within the muscles, tendons and joints, which gives automatic internal information about the position of joints and the tension in the muscles. A javelin thrower would know, without looking, that the arm is fully extended and that the elbow is ‘locked’ before he throws.

5.2.4 Explain the signal-detection process Brain identifies that a stimulus is present. It often detects more stimuli than we are aware of. If we attend to that information even briefly, then it is passed further through the process Perception is the process by which the brain interprets and makes sense of the information it is receiving from the sensory organs

  • Detection: identification of the stimulus
  • Comparison: gathered stimuli compared to memory stores
  • Recognition: the stimuli is matched to one stored in the memory

Sporting example: Returning a tennis serve Detection: the ball is tossed above the head rather than slightly in front, stimulus ranges from spin and flight path of the ball. These important stimuli stand out from background noise of irrelevant detail through selective attention Comparison: the stimulus is passed through the memory and compared with similar codes stored in the memory such as a previous serve from the same opponent in the match Recognition: occurs when the code of incoming information matches a code stored in the long term memory.

What is an example of internal noise in signal detection theory?

The person is listening out and begins to ‘hear’ the visitor, and may decide to go open the door, if nobody is there what was it? This is (internal) NOISE. This person is ‘detecting’ a signal that is not there because the decision is that it would be worse to miss than just check see if the individual is there.

What is another name for signal detection theory?

Introduction – “Signal detection theory” has long been used to guide the design and analysis of vestibular studies (e.g., Clark and Stewart 1968 ; Doty 1969 ; Ormsby 1974 ; Benson et al.1986, 1989 ; Mah et al.1989 ; Carpenter-Smith et al.1995 ), but, after nearly a 20-year hiatus, there has been a recent resurgence of interest in the application of signal detection theory to vestibular responses (e.g., Gu et al.2007 ; Sadeghi et al.2007 ; De Vrijer et al.2008 ; Grabherr et al.2008 ; Zupan and Merfeld 2008 ; Barnett-Cowan and Harris 2009 ; MacNeilage et al.2010 ; Mallery et al.2010 ).

In part, this resurgence has occurred because detection theory can help address some unique technical and practical challenges associated with vestibular psychophysics. What is signal detection theory? In brief, detection theory is nothing more than the application of standard statistical hypothesis testing to the detection of a specific event (“signal”) despite the presence of noise.

Therefore, those who understand the theoretical basis underlying Student’s t -test will readily understand the basis of detection theory. In other words, signal detection theory is a general statistical approach that helps make decisions about signals with noise.

It does not address questions of how one might optimally filter a signal or how one might combine two or more noisy signals, both of which are the purview of estimation theory. Signal detection theory is often just called detection theory; other names include “hypothesis testing” and “decision theory”.

Detection theory has been applied to a broad range of physiological responses, with an immense influence on psychophysics. For example, even when not explicitly noted, detection theory is implicitly invoked when thresholds are measured using tasks that require the subject to select one of two alternative answers, and the data are fit with some sort of cumulative distribution (e.g., cumulative Gaussian).

In fact, it will be shown that detection theory directly relates thresholds to the standard deviation of the noise present. What is “discrimination”? And how does discrimination relate to “detection” and “recognition”? According to Macmillan and Creelman (2005) and others (e.g., Treutwein 1995 ), discrimination is the ability to tell two stimuli apart.

There are two types of discrimination. When one of the stimulus classes is a null stimulus, the task is called detection; the standard hearing test where a subject indicates whether they hear or do not hear a tone is a very common detection task. When neither stimulus class is null, the task is called recognition.

For example, a subject discriminating leftward from rightward motion (or leftward from rightward orientation) is a common vestibular direction-recognition task (e.g., Benson et al.1986, 1989 ; Carpenter-Smith et al.1995 ; Gu et al.2007 ; De Vrijer et al.2008 ; Grabherr et al.2008 ; Zupan and Merfeld 2008 ).

Another vestibular recognition paradigm is exemplified by Mallery et al. (2010), where subjects compared two stimuli to determine whether the test stimulus was greater than a non-zero reference. Consistent with historical usage, we will refer to the general theory as detection theory.

  • Otherwise, we will reserve the terms detect and detection to refer to paradigms, where one of the stimulus classes is the null stimulus (i.e., no motion).
  • Detection theory uses signals provided by brain “estimation” processes.
  • Estimation theory, which is not the focus of this paper, describes the application of statistical signal processing to extract information from noisy signals but not decision-making per se.

Specifically, estimation theory helps estimate variables in the presence of noise. Standard approaches include minimum variance unbiased (MVU) estimation, simple linear weighting maximum likelihood (ML) estimation, Wiener filters, Bayesian maxima a posteriori (MAP) estimation, and Kalman filters.

In this paper, we will assume that a noisy signal has been estimated using one of the above optimal techniques, by simple filtering, or by one of a myriad of suboptimal estimation approaches. Given such a noisy signal, detection theory then guides the decision-making process. (For recognition, did I move to the right or left? For detection, did I move or not move?) Obviously, how the signals are estimated and sampled is critical to signal detection, but this is a separate topic that requires separate coverage and cannot be summarized in a few pithy paragraphs.

In a short paper like this, we cannot be comprehensive, so some issues are left partially explored. To maintain focus, this paper concentrates primarily on vestibular psychophysical responses, but much of the information relates to the use of detection theory for other behavioral responses (e.g., VOR thresholds, etc.).

  1. To keep the length reasonable, we assume a rudimentary knowledge of detection theory.
  2. For those interested in pursuing these topics to a deeper understanding, several books and papers are recommended.
  3. The book by Macmillan and Creelman (2005) provides an excellent introduction to the application of signal detection theory to psychophysics, and the book by Green and Swets (1966) is considered a classic.

For those interested in a more general, more theoretical, and more mathematical coverage, two books provide a very good introduction to estimation ( Kay 1993 ) and detection ( Kay 1998 ). Those interested in Kalman filtering—a classic advanced estimation approach—might consider Gelb (1974) and/or Brown and Hwang (1992), a shows objective stimuli having amplitudes of 0 (the null stimulus) and 6. b shows that a vestibular bias of −2 yields the sensed stimuli of −2 and +4. c A probability density function (PDF) represents that the perceived amplitude will have some variation ( σ = 2) due to noise.

  • D A cumulative distribution function (CDF) is calculated as the integral of the PDF.
  • E, f show the PDF and CDF in objective coordinates.
  • The right column ( g through l ) represents the same quantities but normalized by 2—the standard deviation from the left column.
  • In these normalized units, g the objective stimuli are 0 and 3, h the vestibular bias is −0.5 yielding sensed stimuli of −0.5 and 2.5, ( i through l ) the noise has a standard deviation of 1 Before proceeding, it is important to note that no general psychophysical model of perception for any sensory modality has ever been built exclusively on the incremental knowledge gleaned from detection theory.

Therefore, while detection theory is powerful when applied correctly, recall that it only evaluates the ability to tell things apart and does not estimate their magnitude. Hence, the application of detection theory complements—and does not replace—the use of other standard psychophysical techniques (e.g., Guedry 1974 ) like magnitude estimation.

  1. In this paper, we apply detection theory to vestibular responses.
  2. Because vestibular responses have some unique characteristics (e.g., bidirectional, vestibular “bias”, linear, etc.), we do not begin by using earlier psychophysical applications of detection theory (e.g., Green and Swets 1966 ).
  3. Instead, while cognizant of these earlier works, we begin de novo with basic signal detection theory ( Kay 1998 ).

More specifically, we will present a model underlying “one-interval recognition” tasks and then will highlight comparisons to “one-interval detection”, “two-interval detection”, and “two-interval recognition”. Following are some of the specific questions that will be answered.

What are 2 examples of signal words?

When writing relationships are complex, good writers use signal words and phrases to help readers follow without having to stop and puzzle out the relationships. Here are some examples of signal words and phrases: ‘as a result,’ ‘nevertheless,’ ‘at the same time,’ and ‘similarly.’

Which of the following is an example of signals?

Explanation: AM radio signal is an example for y (t) = x1 (t) * x2 (t) where, x1 (t) consists of an audio signal plus a dc component and x2 (t) is a sinusoidal signal called carrier wave.

What are typical signals examples?

Signals and Systems Classification of Signals A signal can be defined in one of the following ways −

Anything that conveys information can be termed as a signal. A signal can also be defined as a single valued function of one or more independent variables which has some information. A signal may also be defined as any physical quantity that varies with time or any other independent variable.

A signal may be represented in time domain or frequency domain. Some common examples of a signal are human speech, electric current, electric voltage, etc. By the definition, a signal can be a function of one or more independent variables such as time, position, pressure, temperature, etc.

What is an example of signal in daily life?

Definition – A signal, formally defined as a function of one or more variables, conveys information about the nature of a physical phenomenon. In simple terms, we can define a signal as any physical quantity that changes with time, distance, speed, position, pressure, temperature, or some other quantity.

What are the examples of data signal processing?

Answer: Digital Signal Processing is used in multiple areas, namely audio signal, speech and voice processing, RADAR, seismology, etc. It is used in mobile phones for speech compression and transmission. Other appliances where it is used are Mp3, CAT scans, computer graphics, MRI, etc.

What is a signal and its importance in real time system?

8.4 Signals – A signal is a software interrupt that is generated when an event has occurred. It diverts the signal receiver from its normal execution path and triggers the associated asynchronous processing. Essentially, signals notify tasks of events that occurred during the execution of other tasks or ISRs.

As with normal interrupts, these events are asynchronous to the notified task and do not occur at any predetermined point in the task’s execution. The difference between a signal and a normal interrupt is that signals are so-called software interrupts, which are generated via the execution of some software within the system.

By contrast, normal interrupts are usually generated by the arrival of an interrupt signal on one of the CPU’s external pins. They are not generated by software within the system but by external devices. Chapter 10 discusses interrupts and exceptions in detail.

  1. The number and type of signals defined is both system-dependent and RTOS-dependent.
  2. An easy way to understand signals is to remember that each signal is associated with an event.
  3. The event can be either unintentional, such as an illegal instruction encountered during program execution, or the event may be intentional, such as a notification to one task from another that it is about to terminate.

While a task can specify the particular actions to undertake when a signal arrives, the task has no control over when it receives signals. Consequently, the signal arrivals often appear quite random, as shown in Figure 8.10, Figure 8.10: Signals. When a signal arrives, the task is diverted from its normal execution path, and the corresponding signal routine is invoked. The terms signal routine, signal handler, asynchronous event handler, and asynchronous signal routine are interchangeable.

What is signal detection theory and how is it applied in the real world?

Signal detection theory is based on the decision-making process as one has to decide if they will act on the signal or not. The decision-making process is applied to the signal detection theory by one’s response or sensitivity to stimuli (a signal). The brain responds to a signal that may or may not be present.

What is an example of signal detection in sport?

5.2 Information Processing – 5.2.1 Describe a simple model of information processing

In response to input stimuli, the performer perceives the stimulus, and recounts by executing an appropriate output, after their brain goes through the decision making process. Feedback is then often given, so that the response can be altered to be made better if necessary. Example: A penalty kick is about to take place, the goalie observes the angle of the kicker (input), makes a decision on where to dive (decision making) and follows with a diving movement (output). Terminal feedback on the movement is applied for the next shot.

5.2.2 Describe Welford’s model of information processing

sense organs perception short-term memory longterm memory decision making effector control feedback

5.2.3 Outline the components associated with sensory output

The information is taken in through the senses prior to a decision being made in three main ways. These are:

  • what we see (vision)
  • what we hear (auditory)
  • what we sense (proprioception)

Vision:

seeing the ball or the opponent; for eg, picking up the flight of the shuttle cock coming over the net in badminton

Audition

hearing the call of a team-mate or the sound of the ball on the racket

Proprioception:

Proprioceptors are located on the nerves, muscles, tendons, joints and inner ear, which provide intrinsic (internal) information about the movement and balance of the body during the performance. The three components of proprioception are : (1) touch, (2) equilibrium (balance) and (3) Kinaesthesis

Touch – is our tactile sense, it detects pressure, pain, temperature. It’s used in many sports. Eg The feel of the ball in the hands or the tense feel of the tennis racket in the hand as you hit a return

Exteroceptors : Exteroceptors provide information about the external environment, like touch, pressure, temperature, light, sound, taste, smell etc. Sometimes receptors sensing light, sound and smell, which provide information about the distant environment, have been called telereceptors. Introceptors: Pass information from within the body’s internal organs such as the heart and lungs to the brain via the nervous system. This helps to regulate the various functions of the body and cater for the changing demands placed upon it. Kinaesthetic information or Proprioception (body awareness) – the inner sense within the muscles, tendons and joints, which gives automatic internal information about the position of joints and the tension in the muscles. Proprioceptors : Proprioceptors provide information about the position and posture of our body in space. They sense stimuli from the muscles, tendons and the joints as well from the vestibular apparatus. Equilibrium – the balance needed before hitting a serve or the balance used in the skillful performance of a gymnast on the balance beam. Kinaesthesis – the inner sense within the muscles, tendons and joints, which gives automatic internal information about the position of joints and the tension in the muscles. A javelin thrower would know, without looking, that the arm is fully extended and that the elbow is ‘locked’ before he throws.

5.2.4 Explain the signal-detection process Brain identifies that a stimulus is present. It often detects more stimuli than we are aware of. If we attend to that information even briefly, then it is passed further through the process Perception is the process by which the brain interprets and makes sense of the information it is receiving from the sensory organs

  • Detection: identification of the stimulus
  • Comparison: gathered stimuli compared to memory stores
  • Recognition: the stimuli is matched to one stored in the memory

Sporting example: Returning a tennis serve Detection: the ball is tossed above the head rather than slightly in front, stimulus ranges from spin and flight path of the ball. These important stimuli stand out from background noise of irrelevant detail through selective attention Comparison: the stimulus is passed through the memory and compared with similar codes stored in the memory such as a previous serve from the same opponent in the match Recognition: occurs when the code of incoming information matches a code stored in the long term memory.

What is an example of signal detection and vigilance?

Signal Detection and Vigilance In the case of Vigilance, it can be said that Automatic Vigilance occurs when a target stimulus, irrespective of its positive consequences and negative consequences, is identified very faster and accurately. For example, if a person comes across a Cockroach or a rat that he or she fears the most will catch the person’s attention, and it will last for a longer period as the person is scared of the stimulus.

  • Vigilance is also driven by and depends on an individual’s Reflex Action.
  • It is categorized faster; especially it carries a sense of sacredness or fear or when it carries a threatening prime stimulus than a hedonically neutral prime stimulus.
  • Similarly, in the case of a positive stimulus, suppose when good news comes to the person, he or she gets happy or excited as soon as he/she comes across the incident.

This is the daily life example of Vigilance. While in the case of Signal detection, it can be said that, for example, when testing, the capability of a subject is examined to detect a very short tone or sound in the background of transparent color, for example, say White or Black.

What is the use of signal detection theory in research on human computer interaction?

SDT provides a means for distinguishing between accuracy and criterion setting in decision-making environments. This is useful in evaluating the effectiveness of the decision-making performance of an intelligent machine, a human user, or a human-machine system.