Perception - Motion, Audition, Touch, Taste, Smell, and Color Vision
What is the frequency range, beyond which additional noise will not change sensitivity to a faint sound, called?
Critical bands
After tasting one chemical that stimulates one of the primary tastes repeatedly, we also become temporarily less sensitive to other chemicals that stimulate the same primary taste (i.e., saccharine after tasting sugar). This phenomenon is called what?
Cross-adaptation
Touch is the perception of what physical event? What kind of energy is being transduced?
Displacement of skin and Mechanical energy
Sensitivity depends on many factors, including the temperature of the tastant. Generally, we are most sensitive to chemicals at (low, moderate, high) temperatures, and least sensitive to chemicals at (low, moderate, high) temperatures.
Most sensitive to moderate temperatures Low sensitivity at low and high temperatures
For the most part, particular sensations (pressure, heat, pain) do not appear to be the result of specific types of receptors, but rather the ______________ of receptors that is activated by a stimulus.
Particular combination
Relative pitch refers to what ability?
Relative pitch - is the ability to recognize differences in pitch
Pacinian corpuscles respond to what kind of stimulation?
Respond to onset and offsets of pressure NOT continuous Found in hairless skin like soles of feet, palms of hand, lips etc
Which of these two motion perception systems is the basis for apparent motion?
Retinal motion detection
Motion can be detected in 2 ways. What are they?
Retinal motion detection - eyes are fixed relative to the moving object, when this happens light sweeps across retina and stimulates adjacent cells. Smooth pursuit motion detection - looking at an object in motion and moving head
Define similarity (gestalt principle)
Similar features more likely to belong to the same object rather than dissimilar
Define good form (gestalt principle)
Simple objects more likely than complex ones
What is the other main theory of color vision?
The opponent process theory proposes that one member of the color pair suppresses the other color. For example, we do see yellowish-greens and reddish-yellows, but we never see reddish-green or yellowish-blue color hues. proposed by Ewald Herring
Our perception of heat and cold are the result of transduction of what kind of energy? What determines whether something will feel hot or cold to us?
Thermal energy Temperatures above 113 degrees F is hot Temperatures below 86 degrees F is cold
What type of photoreceptor cell mediates color vision?
cones
In general, as we get older, does sensitivity to taste increase or decline?
decline
What happens to olfactory sensitivity as we age?
decline
The condition of insensitivity to the color green is
deuteranomaly shortage of M cones
The condition of blindness to the color green is
deuteranopia
Mach bands are thought to aid what visual process?
edge detection
The cultural influence on taste perception is so strong that some cultures abhor sweet and crave mainly bitter foods. True or false?
false
The quality of a taste depends in a simple way on the molecular structure of a tasted chemical. True or False?
false
Which gender is more sensitive to odors?
female
The representation of the body in sensory cortex is called the
homunculus
What phenomenon does the term color constancy refer to?
illuminance Color constancy refers to our ability to perceive colors as relatively constant over varying illuminations (i.e. light sources). For example, a red apple will still look red on a sunny day or cloudy day - or in a grocery store or a home
What causes perceptions of pain?
A mix of mechanical energy and thermal energy (the extremes)
How can people who work in strongly odorous places stand to do their jobs?
Adaptation Can take many hours or days in strongly odorous places
After tasting one chemical repeatedly (i.e., sugar), sensitivity to that chemical declines temporarily. What is this phenomenon called?
Adaptation? Or afterimage-type phenomenon?
The perception of loudness corresponds mainly to what physical property of sound medium oscillations?
Amplitude of the sound wave
In apparent motion, what happens to the illusion of motion as the stimuli get further apart in space?
Apparent motion becomes less likely the further things are apart. See two images not one
What are the Gestalt principles? I mean as a whole, conceptually, not just the name and description of each.
Assumptions the brain/mind makes
According to the frequency matching theory of frequency coding what aspect of basilar membrane vibration is responsible for our perception of pitch?
Basilar membrane acts like a microphone membrane simply vibrating in synchrony with the stimulus
The smooth pursuit motion perception system relies on a corrective signal to detect motion. Why not just use the retinal motion signal, like the retinal motion system.
Because if used in retinal motion system it will make the static objects (like the background) appear to be in motion and the object in motion will appear still
Non-tasters (i.e., people who are insensitive to the primary taste that most of us are most sensitive to) tend to consume more of what popular bitter beverage?
Black coffee and alcohol
How do we actually code pitch: place coding or frequency matching?
Both place coding and frequency matching Frequency > 1000 Hz is place coding Frequency < 1000 Hz is frequency matching
Although there are exceptions, carbon+water (carbohydrate) compounds usually taste __________, acidic foods generally taste __________, while basic compounds taste _______________, and alkaloid compounds taste _____________.
Carbon and water taste sweet Acidic food taste like sour Basic compounds taste like salty Alkaloid compounds taste like bitterness
The range of frequencies that will cause a change in the firing rate of an auditory receptor cell is called what?
Characteristic frequency
Olfaction involves the transduction of what kind of energy?
Chemical energy
Taste involves the transduction of what kind of energy?
Chemical energy
What is the relationship between odorant concentration and perception of smell intensity?
Follows stevens power law
Define Proximity (gestalt principle)
Elements closely together are more likely to be a part of the same object
Define connectedness (gestalt principle)
Elements connected by continuous boundary likely to belong to the same element
Define good continuation/continuum (gestalt principle)
Elements following simple lines likely to belong to same object rather than complex lines
People with amusia also tend to have difficulties comprehending speech. True or False.
False
The auditory detection threshold is independent of sound frequency. True or False?
False
Sensitivity to the primary tastes is evenly distributed across the tongue. True or false?
False Certain tastes are more sensitive to different parts of the tongue
There are how many so-called primary tastes? What are they?
Five Sweet, sour, salty, bitter, umami
What do we call the phenomenon that moving objects are seen slightly ahead of a static flash when they are both at the same location?
Flash-lag phenomenon
The process of estimating the frequencies and relative amplitudes that comprise a wave is called what?
Fourier analysis
The most common type of receptor cell in the skin is called what? What kind of sensation is this cell type associated with?
Free nerve endings - found throughout skin, primarily produce pain sensations
The perception of pitch corresponds to what physical property of sound medium oscillations?
Frequency of sound wave
What are the 3 components of color?
Hue - is what we commonly perceive as colors and corresponds to the physical property of wavelengths (frequency) Brightness - corresponds to the physical property of flux (energy/time measured in lumens) Saturation - is the degree of color mixing
The experiment by Dowling & Fujitani (1971) discussed in class indicates that what aspect of melody is most important in determining recognition?
Melodic contour
Describe the three binaural cues to spatial location discussed in class.
Interaural time difference (ITD) - the difference between when a sound wave reaches one ear and then the other Phase difference - if the wavelength of the sound is large enough (low frequencies), then the ears will receive the sound on a common cycle but different phases, and the degree of this phase shift provides a clue to direction. Intensity - the amplitude of sound waves decreases with distance, and when sound waves curve around an obstacle. This can cause slight loudness differences between the two ears that again indicate direction. loudness difference tells us direction
What is perceptual delay? About how long is it in the visual modality?
It is a lag between the retinal transduction and V1 (about 30 - 50 milliseconds) and V1 does not peak until about 130 milliseconds. 100 milliseconds or 1/10th of a second
What is the effect of adding bandpass noise to a faint signal on sensitivity to that signal?
It will raise the threshold to detect the tone
According to the place theory of frequency coding by the inner ear, our perception of different pitches depends on what aspect of basilar membrane vibration?
Location of hair cells along the basilar membrane
Describe the two monaural cues to spatial location discussed in class.
Loudness - all other things being equal, less intense sounds are further away, louder sounds are closer Doppler shift - the pitch of an objects changes as it approaches and the recedes
We are able to discriminate a given taste from pure (tasteless) water at a (higher OR lower) threshold than we are able to identify the taste.
Lower We can tell something is in the pure water before we can tell what it is
The term 'mechanoreceptor' refers to a cell that responds to what type of stimulation?
Mechanoreceptor - transduce mechanical displacements of skin, some found in joints Respond to onset and offsets of pressure NOT continuous
What is the name of the most common scale for pitch perception? How is this scale measured?
Mel Scale measured in mel
The general term for receptors that produce pain signals is
Nociceptors
The specific receptor that appears to be most closely associated with pain is the
Nociceptors
The primary olfactory cortex is called what?
Olfactory bulb
Taste preference is the result of both biological and cultural influences. In general, pleasant tastes signal what kind of substance? Unpleasant tastes signal what kind of substance?
Pleasant - sweet and salty Unpleasant - bitter and sour
Sensitivity to touch is most commonly measured with what two techniques?
Point localization - refers to our ability to locate the source of stimulation on the skin. Touch on body ask where did I touch you. Can't see them touch you. Two-point detection - refers to the smallest distance between two points of stimulation that can be discriminated from stimulation at a single point
Melody perception is thought to reflect Gestalt organizing principles similar to those used in vision to group objects. What are they?
Proximity - notes played close together in time are more likely to belong to the same melody Similarity - notes that are more similar to each other are more likely to belong to the same melody Common fate - notes that rise or fall or stop together are more likely to belong to the same melody Figure-ground organization - the part of a musical passage that requires the least attention to hear is probably the melody. Other parts of the music (i.e., harmony, percussion) may require effortful allocation of attention, but melody usually stands out. Melodic contour - is the shape (in sound space) of the sequence of rising and falling pitches. perceptual constancy; melodies are recognizable in different keys
The region of skin that causes a change in a receptor's firing rate is called what?
Receptive field
Define symmetry (gestalt principle)
Symmetric figures more likely than asymmetric
Supertasters will likely find broccoli (delicious, repugnant), while non-tasters typically find it (delicious, repugnant).
Tasters -Find broccoli repugnant Non-tasters - find broccoli delicious
What do we call the predictive/corrective signal from cerebellum that smoothes eye movement in smooth pursuit?
The corrective signal or layer 1 signal
What is the volley principle?
The frequency code is generated by the mass action of thousands of neurons
The cells that transduce basilar membrane vibrations into neural impulses are called what?
The hair cells of the Organ of Corti
What 3 factors determine the intensity of heat and cold perception?
The rate of energy transfer from skin to object or from object to skin The temperature of skin The extent of skin that is stimulated
What happens as the flashes get further apart in time?
They look like two different images
Define common fate (gestalt principle)
Things that move together are more likely part of the same object than things that don't
What are the three main categories of sensation from the skin?
Touch, hot or cold, pain Mechanical energy - causing displacement results in the perception of what is commonly called touch. Thermal energy - causing molecular motion of the skin to increase or decrease produces the sensation of heat or cold. Mechanical or thermal energy - at extreme intensities, usually associated with tissue damage, cause the sensation of pain.
What theory of color vision does this number provide support for?
Trichromatic theory of color perception (proposed by Thomas Young) The trichromatic theory of color vision says that human eyes only perceive three colors of light: red, blue, and green. The wavelengths of these three colors can be combined to create every color on the visible light spectrum. Young-Helmholz theory
Absolute pitch requires musical training in childhood. True or False?
True
The basis of the distribution of sensitivity to primary tastes across the tongue is not well understood, but does not appear to be the result of specific receptors for each of the primary tastes. True or false?
True Receptors will have a taste they will respond to more than others but will still respond to other tastes
There are believed to be how many different types of these auditory transducers? What are they called? What type of information is each type thought to be responsible for?
Two Inner hair cells - like cones and photopic vision, discriminate a wide range of frequencies, require high amplitude to generate action potential (high acuity) Outer hair cells - like rods and scotopic vision, detect very low amplitude, low frequency vibrations (high sensitivity)
There is another proposed primary taste, termed Umami, which is the taste of what common food additive?
Umami - savory, meat
What phenomenon appears to rule out frequency matching?
Volley principle
What physical property of light is most related to perception of hue?
Wavelength
In vision, there is a tradeoff between spatial acuity and sensitivity. Describe the similar tradeoff in audition.
Yes Just as visual acuity and sensitivity are tradeoffs, temporal acuity (ability to resolve time) and frequency resolution (ability to discriminate nearby frequencies) are tradeoffs
What is an inverse problem?
a problem with multiple solutions
What do we call the reduction in sensitivity to an odor with prolonged exposure?
adaptation
What phenomenon of color vision does trichromatic/Young-Helmholz theory explain
additive color mixing
What phenomenon of color vision was the opponent-process theory of color perception meant to explain?
afterimages
Most people are most sensitive to which of the primary tastes?
bitter
What other physical property of sound medium oscillations has a large effect on loudness perception?
pitch
Sound is transduced by what type of energy
mechanical energy
What popular form of entertainment is based on apparent motion?
movies
The condition of blindness to the color red is
protanopia
The condition of insensitivity to the color red is
protoanomaly shortage of L cones
Olfaction is the only sense that does not pass through what structure before being processed in neocortex?
thalamus
How many types of color-sensitive photoreceptor are there?
three S - short and blue M - medium and green L - large and red
There are how many primary smells?
too many six Putrid fragrant spicy resinous ethereal and burned People cannot consistently classify them into these six categories
Vision processing has early and late stages. The early stages are primarily concerned with extracting features, also called visual ____________, while later stages are concerned with constructing percepts from features, also called visual ___________________
visual analysis visual synthesis
What do inverse problems have to do with vision?
visual perception faces inverse problems in which it must make assumptions about the world
Is there any physiological evidence for the opponent process theory?
yes The main evidence for this theory derived from recordings of retinal and thalamic (LGN) cells, which were excited by one color and suppressed by another. blue yellow red green