Psychology Signal Detection and Processing

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Questions and Answers

What does the absolute threshold refer to?

The point at which sensory receptors fail to respond to stimuli.

The minimum stimulation needed to detect a particular stimulus 50% of the time. (correct)

The maximum stimulation required to detect a stimulus.

The level of stimulation required for a stimulus to be perceived subliminally.

Which of the following correctly describes Weber's Law?

The absolute threshold varies based on sensory adaptation over time.

The perceived difference between stimuli is a constant percentage rather than a constant amount. (correct)

Larger stimuli require greater differences to be perceived as different.

The perception of differences between stimuli is based on constant amounts.

What is meant by subliminal threshold?

The level at which stimuli are detected with full awareness.

Stimuli that are above the absolute threshold for conscious awareness.

The threshold at which a stimulus begins to lose its perceptual clarity.

Stimuli that are below one's absolute threshold for conscious awareness. (correct)

Which of the following best illustrates the concept of just noticeable difference (JND)?

Feeling a weight difference between 50 pounds and 51 pounds. Signup and view all the answers

Which process is described as the conversion of physical stimuli into changes in receptor cells?

Transduction Signup and view all the answers

What is the first aspect of death that adults typically come to understand?

Nonfunctionality Signup and view all the answers

In the context of successful aging, which factor is least likely to contribute?

High income Signup and view all the answers

How does socioemotional selectivity theory describe changes in social contacts among older adults?

Total number of contacts declines in favor of more emotionally meaningful relationships Signup and view all the answers

Which of the following factors is associated with a higher likelihood of violence in families?

Social isolation and poor communication Signup and view all the answers

What is typically the first stage in Kubler-Ross's stages of dying?

Denial Signup and view all the answers

Which of the following best describes sensation in the context of perception?

The conversion of stimuli into neural signals Signup and view all the answers

Which statement about committed relationships is true?

They can be difficult to maintain. Signup and view all the answers

Which of the following is NOT true regarding attitudes toward death?

Understanding of death does not change throughout adulthood. Signup and view all the answers

What does signal detection theory primarily address?

The ability to detect a stimulus amid background noise Signup and view all the answers

Which type of processing begins with sensory receptors and follows the pathway to the brain for interpretation?

Bottom-up processing Signup and view all the answers

What is the main function of the iris in the eye?

To regulate the amount of light entering the eye Signup and view all the answers

What occurs during sensory adaptation?

Diminished sensitivity due to constant stimulation Signup and view all the answers

Which part of the eye is responsible for focusing light onto the retina?

Lens Signup and view all the answers

How does top-down processing influence perception?

It involves filling in missing information based on prior knowledge Signup and view all the answers

Which type of photoreceptor in the eye is primarily responsible for detecting color?

Cones Signup and view all the answers

What creates the blind spot in the human eye?

Optic nerve entry point Signup and view all the answers

What primarily determines the brightness of a color in the visible spectrum?

Amplitude of the light wave Signup and view all the answers

Which visual condition occurs when the eye is too long and images are focused in front of the fovea?

Myopia Signup and view all the answers

What determines the hue of a color?

Wavelength of light Signup and view all the answers

What is considered an additive process in color perception?

Using a prism to split white light Signup and view all the answers

Which of the following accurately describes trichromatic theory?

Uses red, green, and blue to create all colors Signup and view all the answers

How is sound frequency measured?

Using Hertz (Hz) Signup and view all the answers

What role do cones in the retina play in color perception?

They contain different pigment receptors to perceive colors. Signup and view all the answers

What characteristic defines saturation in color perception?

The purity of the dominant wavelength Signup and view all the answers

What happens to color perception in individuals with color blindness?

They inaccurately perceive certain colors. Signup and view all the answers

Which factors determine the loudness of a sound?

Amplitude and height of the wave Signup and view all the answers

What is the primary function of the outer ear?

To capture sound waves and direct them to the ear canal Signup and view all the answers

What role does the cochlea play in hearing?

It vibrates the fluid in the perilymph, stimulating the organ of Corti Signup and view all the answers

How does the brain determine the location of a sound?

By assessing which ear drum vibrates more intensely Signup and view all the answers

Which factors can decrease taste sensitivity over time?

Aging, smoking, and alcohol consumption Signup and view all the answers

What is the structure that contains taste receptors called?

Papilla Signup and view all the answers

What is the main mechanism of olfactory detection?

Chemicals in the air are transported to receptor cells in the nasal cavity Signup and view all the answers

What do cilia in the auditory system do upon exposure to sound?

Vibrate less after exposure to loud noise Signup and view all the answers

Which of the following senses involves the detection of touch, pressure, and pain?

Somatosenses Signup and view all the answers

Study Notes

Signal Detection Theory

Describes how and when humans are able to detect a stimulus among background noise
How we react to stimuli may vary based on experience, expectations, motivation, and level of fatigue

Bottom Up Processing

Begins with analysis of the stimulus starting from the sensory receptors
Vision begins with the eyes and processed in the brain
Helps to quickly and efficiently identify sensory inputs

Top Down Processing

Info processing guided by higher-level mental processes
Used when information is missing
Allows us to fill in information based on expectations, prior experiences, and context

Sensing the World

Sensory capabilities are tailored to the needs of the organism
Human ears are more sensitive to human voices
Sensory Adaptation: We become less sensitive to constant stimulation
Examples:
- Bandid on skin, sensation fades after time
- Airplane noise, we adapt and no longer notice
- Uncomfortable airplane seats, we get used to it
This adaptation helps us sense the world not as it is, but in a way that is useful

Wavelength

The distance from the peak of a wave to the next peak
Describes the hue or color
Short wavelength = High frequency sound waves & Blue color
Long wavelength = Low frequency sound waves & Red color

Intensity

Determined by the amplitude (height) of the wave
Large (high) amplitude = bright colors & loud sound
Short (low) amplitude = dull colors & quiet sounds

The Eye and its Functions

Key parts of the eye:
- Cornea: Protects the eye and bends light
- Pupil: Light enters the eye through this small opening
- Iris: The colored part of the eye, regulates pupil size by contracting and expanding to adjust for light intensity, also affected by emotions
- Lens: Located behind the pupil, focuses light onto the retina
- Sclera: White outer surface of the eye
- Aqueous humour: Fluid within the eye that helps regulate pressure
How the lens works:
- Changes shape to focus images
- Images are projected upside down and reversed on the retina
- The brain interprets these images correctly

Visual Acuity

Fovea: Small "divot" at the back of the eye that is responsible for sharp central vision (visual activity)
Normal Sight: Image is focused directly on the fovea
Nearsightedness: Eyeball is too long, image focuses in front of the fovea, blurry vision for distant objects
Farsightedness: Eyeball is too short, image focuses behind the fovea, blurry vision for close objects

Photoreceptors

Located in the retina, rods and cones are responsible for converting light into electrical signals that the brain can interpret
Rods: Sensitive to light but not color, responsible for vision in low light conditions
Cones: Perceive color, function when there is enough light for clear vision, responsible for detail (central vision)
There are approximately 130 million rods and cones in each eye

Neural Pathway

Light travels through the eye to the photoreceptors (rods and cones)
Signal is passed on to bipolar cells
Signal is sent to ganglion cells
Ganglion cells form the optic nerve
Optic nerve carries the signal to the brain
Important to understand this pathway, it will be tested

Fovea

The fovea contains only cone photoreceptors, this is important and will be a test question

Blind Spot

Located where the optic nerve leaves the eye
No receptor cells in this area
Can demonstrate this by closing one eye and focusing on a dot, then looking at a star 4 inches away
The star will disappear when it is lined up with the blind spot

Transduction

Conversion of physical stimuli to electrical signals that neurons can transmit
Receptors on sensory organs detect stimuli and change it into electrical signals that can be processed by the brain

Anatomical Coding

Brain uses the location of active nerve fibers to determine the type of sensory stimuli
Example: Rubbing your eye stimulates nerve fibers in the eye, the brain interprets the signal but doesn't know if it's light or pressure

Psychophysics

The systematic study of the relationship between physical characteristics of stimuli and how our senses perceive them
Focuses on how stimuli are detected, interpreted, and perceived

Just Noticeable Difference (JND)

Also known as the difference threshold
Smallest difference between two similar stimuli that can be distinguished
Ex: Volume of sound on a television, minimum change needed to hear a difference
The amount of difference required to detect 50% of the time

Absolute Threshold

Minimum stimulation needed to detect a particular stimulus 50% of the time
Also, a test question

Weber's Law

Two stimuli must differ by a constant percentage rather than a constant amount to be perceived as different
Ex: 40 lbs vs 41 lbs weight difference is difficult to detect, 80lbs vs 81lbs is also difficult
Each sense has a different percentage needed for a just noticeable difference
Ex: Light needs 8% difference, weight needs 2% difference, tone needs 3% difference

Subliminal Threshold

Stimuli below the absolute threshold for conscious awareness, below our level of conscious perception
Example, sounds in the background that we might not consciously hear, but are still processing
As we age our acuity for sensation may decrease, hearing, taste, light, pressure
The stimuli is still being processed but we may not be consciously aware

Developmental Challenges in Adulthood

Maintaining committed relationships is an important part of adulthood
Half of marriages in North America end in divorce
Realistic expectations are vital in relationships, to prevent conflicts and unmet needs
Violence in families can be an issue, related to:
- Marital difficulties
- Economic stress
- Poor communication
- Impulsivity
- Social isolation
- Mental health disorders (depression, substance abuse

Can affect mental health
Can be an issue for older adults who may be alone due to loss of friends or children moving away

Work and Retirement

Career choices can impact health and relationships
Most students see financial success as a priority
Successful aging is linked to health, social support, and active lifestyle
Disengagement theory has been largely discredited
Most retired individuals are engaged in some way

Socioemotional Selectivity Theory

People tend to prioritize their relationships, preferring close, emotional connections over distant, more casual ones
This can lead to less social interaction overall, but those interactions are usually deeper and emotionally significant
People choose who they want to spend time with
Some experience empty nest syndrome: a period of adjustment after children leave the home
Finding new activities that fill needs and provide purpose is important for a satisfying retirement

Attitudes towards Death and Dying

Thanatology is the study of death and dying
As adults we become aware of:
- Permanence: Once something dies, it can't be brought back to life
- Universality: All things eventually die
- Nonfunctionality: All functions cease at death
Avoidance of discussing death and dying contributes to ageism
MAID (Medical Assistance in Dying): A medical option for individuals with terminal illness, allowing them to choose the time and manner of their death

Kubler-Ross Stages of Grief

Denial, Anger, Bargaining, Depression, Acceptance
These are not necessarily experienced in order or uniformly by everyone

Sensation

Detection of physical energy (stimuli) by our sensory organs, involves converting physical stimuli into neural signals
Sensation: The act of detecting stimuli
Perception: How our brain interprets and makes sense of those signals
Key brain areas:
- Somatosensory cortex: Processes sensations like pain, pressure, warmth
- Diagram of the brain will be included in the test, study it, and understand the functions of each area

Key Concepts to Know

Signal Detection Theory
Bottom Up Processing
Top Down Processing
Sensory Adaptation
Wavelength
Intensity
The Eye and its Functions
Photoreceptors
Transduction
Anatomical Coding
Psychophysics
Just Noticeable Difference (JND)
Absolute Threshold
Weber's Law
Subliminal Threshold
Developmental Challenges in Adulthood
Socioemotional Selectivity Theory
Thanatology
Kubler-Ross Stages of Grief
Sensation
Perception

Color Perception

Color is not inherent to objects, but rather a result of light reflection interpreted by our brains.
We can perceive 7 million color variations, with primates having the largest color perception among mammals.
Fish do not see colors, and bulls do not see red.
Each cone in the eye contains a different pigment receptor (short, medium, and long) allowing us to perceive a range of colors.
Hue is determined by the wavelength of light.
Brightness is the amount of light energy perceived, and black represents minimal brightness.
Saturation is the intensity or purity of the dominant wavelength.
How light hits our cones determines our perception of color.
The additive process demonstrates that white light is a mixture of all colors.
In 1802, it was discovered that the human eye can perceive any color using combinations of red, green, and blue.
The trichromatic theory explains color vision, stating that red, green, and blue cones are responsible for color perception.
Color blindness is a genetic disorder that affects the ability to perceive certain colors, particularly green and red.

Audition

Sound waves, which are expanding and compressing molecules, stimulate the auditory system.
Frequency, or pitch, is determined by the wavelength of sound waves.
Sound is measured in decibels (dB).
Amplitude, or loudness, is determined by the height of the sound wave.
The speech banana represents the range of sounds our auditory system can perceive.
The human ear can hear vibrations between 30 and 2000 Hz.

Auditory System Anatomy

The outer ear includes the pinna, which collects and amplifies sound waves.
The middle ear is composed of the ear drum (tympanic membrane) and ossicles, which transmit vibrations to the inner ear.
The inner ear contains the cochlea, where sound waves are converted into electrical signals that are transmitted to the brain.
The cochlea contains fluid (perilymph) which vibrates the organ of Corti, stimulating cilia.
The Eustachian tube removes debris and waste from the inner ear.

Gustation

The palate (hard at the front and soft at the back) plays a role in taste perception.
Taste buds are located on the tongue and contain taste receptors.
We have around 200 taste buds, which renew every couple of weeks.
Taste sensitivity can decline with age, disease, smoking, and alcohol consumption.
The five basic tastes are bitter, sour, umami, sweet, and salty.

Olfaction

We inhale approximately 20,000 breaths daily, allowing for olfactory stimulation.
The olfactory system detects chemicals in the air and transmits them to about 5 million receptor cells in the nasal cavity.
The olfactory system is protected by bones, located at the base of the brain.
Infants can recognize their mothers through smell, and mothers can identify their babies by scent.
Our olfactory system can detect around 10,000 different odors.

Somatosenses

Somatosenses include touch, pressure, warmth, cold, and pain, and are detected by receptors in the skin and internally.
Premature babies who receive massage therapy may leave the hospital earlier.
Pain serves as a warning system, alerting the body to potential danger.
Chronic pain is persistent and can vary in intensity based on individual thresholds.

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Description

This quiz covers key concepts in Signal Detection Theory and the distinction between bottom-up and top-down processing. Explore how our sensory systems adapt and respond to stimuli, taking into account factors like experience and context. Test your understanding of how we perceive the world around us.