Chapter 4 Flashcards
Sensation
simple stimulation of a sense organ; the basic registration of light, sound, pressure, odor, or taste as parts of your body interact with the physical world
Perception
the organization, identification, and interpretation of a sensation in order to form a mental representation
Transduction
what takes place when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the CNS
Psychophysics
methods that measure the strength of a stimulus and the observer’s sensitivity to that stimulus
Absolute threshold
the minimal intensity needed to just barely detect a stimulus in 50% of the trials
just noticeable difference (JND)
the minimal change in a stimulus that can just barely be detected; not a fixed quantity
Weber’s law
the just noticeable difference of a stimulus is a constant proportion despite variations in intensity
Signal detection theory
the response to a stimulus depends both on a person’s sensitivity to the stimulus in the presence of noise and on a person’s response criterion
Perceptual sensitivity
how effectively the perceptual system represents sensory events
Sensory adaptation
sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions
Visual activity
the ability to see fine detail
Visible light
the portion of the electromagnetic spectrum that we can see
3 properties of light waves
- length of a light wave determines its hue, or what humans perceive as color
- intensity/amplitude of light wave determines what we perceive as the brightness of light
- purity is the number of distinct wavelengths that make up the light; corresponds to what humans perceive as saturation or richness of colors
Retina
light-sensitive tissue lining the back of the eyeball
Cornea
clear, smooth outer tissue of eye where light passes first , bending the light wave and sending it through the pupil
Pupil
hold in the colored part of the eye
Iris
colored part of the eye which is a translucent muscle that controls the size of the pupil and the amount of light that can enter the eye
Accommodation
the process by which the eye maintains a clear image of the retina
Cones
photoreceptors that detect color, operate under normal daylight conditions, and allow us to focus on fine detail
Rods
photoreceptors that become active under low-light conditions for night vision; more sensitive than cones; provide no info about color and sense only shades of gray
Fovea
an area of the retina where vision is the clearest and there are no rods at all; absence of rods decreases the sharpness of vision in reduced light
Blind spot
a location in the visual field that produces no sensation on the retina
Color-opponent system
pairs of visual neurons that work in opposition
area V1
the part of the occipital lobe that contains the primary visual cortex
What are the 2 functionally distinct pathways that project from the occipital cortex to visual areas in other parts of the brain?
- the ventral stream: travels across occipital lobe into lower levels of the temporal lobes and includes brain areas that represent an object’s shape and identity
- the dorsal stream: travels up from the occipital lobe to the parietal lobes, connecting with brain areas that identify the location and motion of an object
Visual form agnosia
the inability to recognize objects by sight; can guide actions by sight
Binding problem
how features are linked together so that we see unified objects in our visual world rather than free-floating or miscombined features
Illusory conjunction
a perceptual mistake where features from multiple objects are incorrectly combined
Feature-integration theory
the idea that focused attention is not required to detect the individual features that comprise a stimulus, but is required to bind those individual features together
Perceptual constancy
a perceptual principle stating that even as aspects of sensory signals change, perception remains consistent; perceptual grouping (simplicity, closure, continuity, similarity, proximity, common fate) govern how the features and regions of things fit together
Template
a mental representation that can be directly compared to a viewed shape in the retinal image (image-based object recognition)
Parts-based object recognition
theories that propose instead that the brain deconstructs viewed objects into a collection of parts
Monocular depth cues
aspects of a scene that yield information about depth when viewed with only 1 eye
Binocular disparity
the difference in the retinal images of the two eyes that provides info about depth
Apparent motion
the perception of movement as a result of alternating signals appearing in rapid succession in different locations
Change blindness
when people fail to detect changes to the visual details of a scene
Inattentional blindness
a failure to perceive objects that are not the focus of attention
Pitch
how high or low a sound is
Loudness
a sound’s intensity
Timbre
a listener’s experience of sound quality or resonance
Frequency corresponds to our perception of _____.
pitch
Amplitude corresponds to our perception of _______.
loudness
Complexity corresponds to our perception of ______.
timbre
Cochlea
a fluid-filled tube that is the organ of auditory transduction
Basilar membrane
a structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid
Hair cells
specialized auditory receptor neurons embedded in the basilar membrane; release neurotransmitter molecules, initiating a neural signal in the auditory nerve that travels to the brain
area A1
a portion of the temporal lobe that contains the primary auditory cortex; for most of us, auditory areas in L hemisphere analyze sounds related to language and those in R hemisphere specialize in rhythmic sounds and music
Place code
the process by which different frequencies stimulate neural signals at specific places along the basilar membrane, from which the brain determines pitch; used for high frequencies
Temporal code
the cochlea registers low frequencies via the firing rate of action potentials entering the auditory nerve
How does conductive hearing loss arise?
because the eardrum or ossicles are damaged to the point that they cannot conduct sound waves effectively to the cochlea
Sensorineural hearing loss
caused by damage to the cochlea, hair cells, or the auditory nerve (happens to almost all of us as we age)
Haptic perception
active exploration of the environment by touching and grasping object with our hands
Referred pain
feeling of pain when sensory info form internal and external areas converges on the same nerve cells in the spinal cord
Gate-control theory of pain
a theory of pain perception based on the idea that signals arriving from pain receptors in the body can be stopped, or gated, by interneurons in the spinal cord via feedback from two directions; bottoms-up control is when senses feed information, top-down control explains how brain influences the experience of touch and pain
Experience of pain depends on 2 distinct pathways. What are they?
- Sends signals to the somatosensory cortex to indicate the location/type of pain.
- Sends signals to the emotional centers of the brain that result in unpleasant feelings
What are balance and acceleration influenced by?
Depend primarily on the vestibular system but are influenced by vision
Vestibular system
the 3 fluid-filled semicircular canals and adjacent organs located next to the cochlea in each inner ear; influences maintaining balance
Smell is directly connected to what part of the brain?
Forebrain
Olfactory receptor neurons (ORNs)
Receptor cells that initiate the sense of smell; when odorant molecules bind to these cells, they send action potentials to the olfactory nerve
Olfactory bulb
a brain structure located above the nasal cavity beneath the frontal lobes; ORNs converge at the glomerulus within the olfactory bulb
Why can smell have immediate and powerful effects on us?
the olfactory bulb sends signals to parts of the brain that control drives, emotions, and memories
How is smell involved in social behavior?
pheromones
Pheromones
biochemical odorants emitted by other members of its species that can affect an animal’s behavior or physiology
taste buds
the organ of taste transduction
What do sensations of taste depend on?
taste buds
Taste experiences depend on _____.
cognitive influences
Sensation involves ________, whereas perception involves _______.
a. organization, coordination
b. stimulation, interpretation
c. identification, translation
d. comprehension, information
b. stimulation, interpretation
What process converts physical signals form the environment into neural signals by sensory neurons into the CNS?
a. representation
b. identification
c. propagation
d. transduction
d. transduction
The smallest intensity needed to just barely detect a stimulus is called
a. proportional magnitude
b. absolute threshold
c. just notable difference
d. Weber’s law
b. absolute threshold
The world of light outside the body is linked tot he world of vision inside the CNS by the
a. cornea
b. lens
c. retina
d. optic nerve
c. retina
Light striking the retina, causing a specific pattern of response in the 3 cone types, leads to our ability to see
a. motion
b. colors
c. depth
d. shadows
b. colors
In which part of the brain is the primary visual cortex, where encoded info is systematically mapped into a representation of the visual scene?
a. the thalamus
b. the lateral geniculate nucleus
c. the fovea
d. area V1
d. area V1
Our ability to visually combine details so that we perceive unified objects is explained by
a. feature-integration theory
b. illusory conjunction
c. synesthesia
d. ventral and dorsal streaming
a. feature-integration theory
The idea that specialized brain areas represent particular classes of objects is
a. the modular view
b. attentional processing
c. distributed representation
d. neuron response
a. the modular view
The principle of _____ holds that even as sensory signals change, perception remains consistent.
a. apparent motion
b. signal detection
c. perceptual constancy
d. closure
c. perceptual constancy
Image-based and parts-based theories both involve the problem of
a. motion detection
b. object identification
c. separating figure from ground
d. judging proximity
b. object identification
What kind of cues are relative size and linear perspective?
a. motion-based
b. binocular
c. monocular
d. template
c. monocular
What does the frequency of a sound wave determine?
a. pitch
b. loudness
c. sound quality
d. timbre
a. pitch
The placement of our ears on opposite sides of the head is crucial to our ability to
a. localize sound sources
b. determine pitch
c. judge intensity
d. recognize complexity
a. localize sound sources
The location and type of pain we experience is indicated by signals sent to
a. the amygdala
b. the spinal cord
c. pain receptors
d. the somatosensory cortex
d. the somatosensory cortex
What best explains why smells can have immediate and powerful effects?
a. the involvement in smell of brain centers for emotions and memories
b. the vast number of olfactory receptor neurons we have
c. our ability to detect odors from pheromones
d. the fact that different odorant molecules produce varied patterns of activity
a. the involvement in smell of brain centers for emotions and memories
