Chapter 2: Sensation and Perception Flashcards
____________ more appropriately aligns with transduction, which means taking the physical, electromagnetic, auditory, and other information from our internal and external environment and converting this information into electrical signals in the nervous system.
Sensation
_____________ is performed by receptors in the peripheral nervous system, which forward the stimuli to the central nervous system in the form of action potentials and neurotransmitters.
Sensation
_____________ refers to processing this information within the central nervous system in order to make sense of the information’s significance.
Perception
________________ are neurons that respond to stimuli by triggering electrical signals that carry information to the central nervous system.
Sensory receptors
Physical objects outside of the body are referred to as ______________.
Distal stimuli
Distal stimuli often produce photons, sound waves, heat, pressure, or other stimuli that directly interact with sensory receptors; these sensory-stimulating byproducts are called __________________.
Proximal stimuli
The relationship between the physical nature of stimuli and the sensations and perceptions the stimuli evoke is studied in the field of ______________.
Psychophysics
____________ are collections of neuron cell bodies found outside the central nervous system.
Ganglia
_________________: respond to electromagnetic waves in the visible spectrum (sight)
Photoreceptors
________________: respond to pressure or movement. Hair cells, for example, respond to movement of fluid in the inner ear structures (movement, vibration, hearing, rotational and linear acceleration)
Mechanoreceptors
_______________: respond to painful or noxious stimuli (somatosensation)
Nocireceptors
________________: respond to changes in temperature (thermosensation)
Thermoreceptors
_______________: respond to the osmolarity of the blood (water homeostasis)
Osmoreceptors
_______________: respond to volatile compounds (smell)
Olfactory receptors
_______________: respond to dissolved compounds (taste)
Taste receptors
A good example of the psychological element of perception is a ______________ - the minimum amount of a stimulus that renders a difference in perception.
Threshold
There are three main types of threshold: the _____________ threshold, the threshold ___________________, and the _______________ threshold.
- The absolute threshold
- The threshold of conscious perception
- the difference threshold
The ________________ is the minimum of stimulus energy that is needed to activate a sensory system.
Absolute threshold
When we are talking about an ______________, we are talking about how bright, loud, or intense a stimulus must be before it is sensed.
Absolute threshold
The ______________ is the minimum intensity at which a stimulus will be transducer (converted into action potential).
Absolute threshold
The level of intensity that a stimulus must pass in order to be consciously received by the brain is the ____________________.
Threshold of conscious perception.
Information that is received by the central nervous system but that does not cross the threshold of conscious perception is called ________________.
Subliminal perception
A stimulus below the threshold of conscious perception arrives at the ________________, but does not reach the higher-order brain regions that control attention and consciousness.
Central nervous system
The _________________, sometimes called the __________________(______) between two stimuli, refers two the minimum change in magnitude required for an observer to perceive that two different stimuli are, in fact, different.
- Difference threshold
- Just-noticeable difference (jnd)
One common experimental technique researchers use to explore the difference threshold. This technique is called psychophysical discrimination testing, or sometimes just ___________________.
Discrimination testing
This idea of _____________ is that the difference thresholds are proportional and must be computed as percentages.
Weber’s law
______________ theory studies how internal (psychological) and external (environmental) factors influence threshold of sensation and perception.
Signal detection theory
Basic signal detection experimental trials in which the signal is presented are called _____________, whereas those in which the signal is not presented are called ____________.
- Noise trials
- Catch trials
A ________ is a basic signal detection experimental trial in which the signal is presented and the subject correctly perceives the signal.
Hit
A ________ is a basic signal detection experimental trial in which the subject fails to perceive the presented signal.
Miss
A _______________ is a basic signal detection experimental trial in which the subject indicates perceiving the signal, even though the signal was not presented.
False alarm
A _______________ is a basic signal detection experimental trial in which the subject correctly identifies that no signal was presented.
Correct negative
Our ability to detect a stimulus can change over time through ____________.
Adaptation
Most of the exposed portion of the eye is covered by a thick structural layer known as the ___________, or the white of the eye.
Sclera
The sclera does not cover the frontmost portion of the eye, the ___________.
Cornea
The eye is supplied with nutrients by two sets of blood vessels: the _____________ vessels, a complex intermingling of blood vessels between the sclera and the retina, and the _______________ vessels.
- Choroidal vessels
- Retinal vessels
The innermost layer of the eye is the ___________, which contains the actual photoreceptors that transduce light into electrical information the brain can process.
Retina
When entering the eye, light passes first through the ____________, a clear domelike window in the front of the eye, which gathers and focuses the incoming light.
Cornea
The front of the eye is divided into the _____________ chamber, which lies in front of the iris, and the ____________ chamber between the iris and the lens.
- Anterior chamber
- Posterior chamber
The _________, which is the coloured part of the eye, is composed of two muscles: the __________________ and the ________________.
- Iris
- Dilator pupillae
- Constrictor pupillae
The ______________ opens the pupil under sympathetic stimulation.
Dilator pupillae
The ______________ constricts the pupil under parasympathetic stimulation.
Constrictor pupillae
The iris is continuous with the ___________, which is a vascular layer of connective tissue that surrounds and provides nourishment to the retina.
Choroid
This iris is continuous with the _______________, which produces the aqueous humour that bathes the front of the eye before draining into the canal of Schlemm.
Ciliary body
The ciliary body produces the ______________ that bathes the eye.
Aqueous humour
The aqueous humour is drained into the __________________.
Canal of Schlemm
The ________ lies right behind the iris and helps control the refraction of the incoming light.
Lens
Contraction of the ______________, a component of the ciliary body, is under parasympathetic control.
Ciliary muscle
As the ciliary muscle contracts, it pulls on the _________________ and changes the shape of the lens to focus on an image as the distance varies.
Suspensory ligaments
As the ciliary muscle contracts, it pulls on the suspensory ligaments, and changes the shape of the lens to focus on an image as the distance varies, a phenomenon known as _______________.
Accommodation
Behind the lens lies the ______________, a transparent gel that supports the retina.
Vitreous humour
The ____________ is in the back of the eye and is like a screen consisting of neural elements and blood vessels.
Retina
____________’s function is to convert incoming photons of light to electrical signals.
Retina
The _______________ or _________________ states that the retina contains two kinds of photoreceptors: those specialized for light-and-dark detection and those specialized for colour detection.
- Duplexity
- Duplicity theory of vision
__________ are used for colour vision and to sense fine details. They are most effective in bright light and comes in three forms, which are named for the wavelengths of light they best absorb.
Cones
In reduced illumination, ___________ are more functional than cones because each rod cell is highly sensitive to photons and is somewhat easier to stimulate than a cone cell.
Rods
The sensitivity of rods has to do with the fact that all rods contain only a single pigment type called ________________.
Rhodopsin
While there are many more rods than cones in the human eye, the central section of the retina, called the ____________, has a high concentration of cones.
Macula
The center most region of the macula, called the _____________, contains only rods.
Fovea
As one moves further away from the fovea, the concentration of ______ increases while the concentration of ______ decreases.
- Rods
- Cones
The region of the retina, which is devoid of photoreceptors, is called the __________.
Optic disk
The optic disk gives rise to a ___________.
Blind spot
Rods and cones synapse directly with ___________ cells, which highlight gradients between adjacent rods or cones.
Bipolar cells
Bipolar cells synapse with ___________ cells, the axons of which group together to form the optic nerve.
Ganglion cells
The axons of ganglion cells group together to form ____________.
Optic nerve
As the number of receptors that converge through the bipolar neurons onto one ganglion cell increases, the resolution (increases?/decreases?)_____________.
Increases
__________ cells and ____________ cells receive input from multiple retinal cells in the same area before the information is passed on to ganglion cells.
- Amacrine cells
- Horizontal cells
____________ refer to both the anatomical connections between the eyes and brain and to the flow of visual information along these connections.
Visual pathways
Visual information from objects to your left is processed by the _________ side of your brain.
Right side
As the retinal fibers from each eye travel through the optic nerves toward the brain, a significant event occurs at the ____________.
Optic chiasm
If photons from an object are captured by the left eye, then this visual information needs to be routed to the opposite side of your brain. This routing is done using the ____________.
Optic chiasm
Only nasal fibers are routed through the optic chiasm. The reorganized pathways are called _____________ after leaving the optic chiasm.
Optic tracts
From the optic chiasm, the information goes to several different places in the brain: some nerve fibers pass to the ___________________ (_____) of the thalamus.
Lateral geniculate nucleus (LGN)
The lateral geniculate nucleus (LGN) is located in the ___________.
Thalamus
Some nerve fibers pass to the lateral geniculate nucleus (LGN) of the thalamus where they synapse with nerves that then pass through radiations in the temporal and parietal lobes to the _____________ in the occipital lobe.
Visual cortex
Other nerve fibers branch off from the optic tracts, skip the thalamus, and head directly to the _______________ in the midbrain, which control some reflexive responses to visual stimuli and reflexive eye movements.
Superior colliculi
When there is a sudden, bright flash of light, the ________________ aligns the eyes with the likely stimulus.
Superior colliculi
The connections between optic tract, LGN, and visual cortex help create a cohesive image of the world through a phenomenon known as _____________.
Parallel processing
Visual ____________ is the brain’s ability to analyze information regarding colour, form, motion, and depth simultaneously, i.e. “in parallel”, using independent pathways in the brain.
Parallel processing
________ refers not only to the shape of an object, but also our ability to discriminate an object of interest from the background by detecting its boundaries.
Form
Neuron carrying information from the focea and surrounding central portion of the retina synapse with ________________ cells in the lateral geniculate nucleus.
Parvocellular cells
Parvocellular cells in the lateral geniculate nucleus have very high colour ______________; that is, these cells permit us to detect very fine detail when thoroughly examining an object.
Spatial resolution
Parvocellular cells can only work with stationary or slow-moving objects because these cells have very low _______________.
Temporal resolution
______________ cells are well-suited for detecting motion because these cells have very high temporal resolution.
Magnocellular cells
Reflecting the fact that form and motion are processed in parallel, magnocellular cells and parvocellular cells are located in distinct layers of the ________________.
Lateral geniculate nucleus
_______________, our ability to discriminate the three-dimensional shape of our environment and judge the distance of objects within it, is largely based on discrepancies between the inputs the brain receives from our two eyes.
Depth perception
Specialized cells in the visual cortex known as _______________ are responsible for comparing the inputs to each hemisphere and detecting these differences.
Binocular neurons
Each _______________ cell type detects a very particular, individual feature of an object in the visual field.
Feature detector
The ear is a couplex organ responsible not only for our sense of hearing, but also for our _________________, which is our ability to both detect rotational and linear acceleration and to use this information to inform our sense of balance and spatial orientation.
Vestibular sense
The ear is divided into three parts: the __________, __________, and __________ ear.
- Outer
- Middle
- Inner
A sound wave first reaches the cartilaginous outside part of the ear, called the ___________ or ____________.
- Pinna
- Auricle
The main function of the pinna is to channel sound waves into the __________________.
External auditory canal
The external auditory canal directs the sound waves to the __________________ (__________).
Tympanic membrane (eardrum)
Louder sounds have greater ____________, which corresponds to an increased amplitude of vibration.
Intensity
The _______________ (_________) divides the outer ear from the middle ear.
Tympanic membrane (eardrum)
The middle ear houses the three smallest bones in the body, called ____________.
Ossicles
The ____________ help transmit and amplify the vibrations from the tympanic membrane to the inner ear.
Ossicles
The ____________ (____________) is affixed to the tympanic membrane.
Malleus (hammer)
The malleus (hammer) acts on the __________ (__________).
Incus (anvil)
The incus (anvil) acts on the __________ (___________).
Stapes (stirrup)
The baseplate of the stapes rests on the oval window of the ___________, which is the entrance to the inner ear.
Cochlea
The middle ear is connected to the nasal cavity via the _______________, which helps equalize pressure between the middle ear and the environment.
Eustachian tube
The inner ear sits within a _____________, which is a hollow region of the temporal bone containing the cochlea, vestibule, and semicircular canals.
Bony labyrinth
Inside the bony labyrinth rests a continuous collection of tubes and chambers called the _________________.
Membranous labyrinth
The membranous labyrinth is filled by a potassium-rich fluid called ______________, and is suspended within the bony labyrinth by a thin layer of another fluid called perilymph.
Endolymph
_____________ simultaneously transmits vibrations from the outside world and cushions the inner ear structures.
Perilymph
The ___________ is a spiral-shaped organ that contains the receptors for hearing.
Cochlea
The cochlea is divided into three parts called ___________.
Scalae
The middle Scala houses the actual hearing apparatus, called the ________________.
Organ of Corti
The organ of Corti rests on a thin, flexible membrane called the _______________.
Basilar membrane
The organ of Corti is composed of thousands of hair cells, which are bathed in ___________.
Endolymph
On top of the organ of Corti is relatively immobile membrane called the ________________.
Tectorial membrane
Because fluids are essentially incompressible, the _____________, a membrane-covered hole in the cochlea, permits the perilymph to actually move within the cochlea.
Round window
Like the rods and cones of the eye, the hair cells in the organ of Corti transduce the physical stimulus into an electrical signal, which is carried to the central nervous system by the _________________ (________________)__________
Auditory (vestibulocochlear) nerve
The ___________ refers to the portion of the bony labyrinth that contains the utricle and saccule.
Vestibule
____________ and ____________ of the vestibule are sensitive to linear acceleration, so are used as part of the balancing apparatus and to determine one’s orientation in the three-dimensional space.
- Utricle
- Saccule
The utricle and saccule contain modified hair cells covered with ______________.
Otoliths
While the utricle and saccule are sensitive to linear acceleration, the three _______________ are sensitive to rotational acceleration.
Semicircular canals
The semicircular canals are arranged perpendicularly to each other, and each ends in a swelling called an _____________, where hair cells are located.
Ampulla
Most sound information in the auditory pathways passes through the vestibulocochlear nerve to the brainstem, where it ascends to the ____________________ (_______) of the thalamus.
Medial geniculate nucleus (MGN)
Nerve fibers from the medial geniculate nucleus (LGN) project to the _____________ in the temporal lobe for sound processing.
Auditory cortex
Some sound information from the medial geniculate nucleus is sent to the ______________, which localizes the sound, and the ________________, which is involved in the startle reflex and helps keep the eyes fixed on a point while the head is turned (vestibule-ocular reflex).
- Superior olive
- Inferior colliculi
Hair cells are named for the long tufts of ________________ on their top surface.
Stereocilia
The ______________ changes thickness depending on its location in the cochlea.
Basilar membrane
The accepted theory on sound perception is _______________, which states that the location of a hair cell on the basilar membrane determines the perception of pitch when that hair cell is vibrated.
Place theory
Low-frequency pitches cause vibrations at the __________, away from the oval window.
Apex
The cochlea is _________________ organized: which hair cells are vibrating gives the brain an indication of the pitch of the sound.
Tonotopically
_________________ (_______________) are located in olfactory epithelium in the upper part of the nasal cavity.
Olfactory chemoreceptors (olfactory nerves)
Smell can carry interpersonal information through the medium of ______________, which are chemicals secreted by one animal, and which, one bonded with chemoreceptors, compel or urge another animal to behave in a specific way.
Pheromones
Odor molecules are inhaled into the nasal passages and then contact the olfactory nerves in the olfactory epithelium. These receptor cells are activated, sending signals to the _____________.
Olfactory bulb
Signals received by the olfactory bulb are then relayed via the ______________ to higher regions of the brain, including the limbic system.
Olfactory tract
Taste are detected by _______________, which are sensitive to dissolved compounds.
Chemoreceptors
The receptors for taste are group of cells called ______________.
Taste buds
The taste buds are found in little bumps on the bumps on the tongue called _____________.
Papillae
Taste information travels from taste buds to the brainstem, then ascends to the _____________ in the thalamus before travelling to higher-order brain regions.
Taste center
_______________ is often reduced to “touch” when listed as a sense, but is actually quite complex.
Somatosensation
_______________ is usually described as having four modalities: pressure, vibration, pain, and temperature.
Somatosensation
________________: respond to deep pressure and vibration
Pacinian corpuscles
_______________: respond to light touch
Meissner corpuscles
______________ (_______): respond to deep pressure and texture
Merkel cells (discs)
_____________: respond to stretch
Ruffini endings
_________________: respond to pain and temperature
Free nerve endings
Transduction occurs in the receptors, which send the signal to the central nervous system where it eventually travels to the ___________________ in the parietal lobe.
Somatosensory cortex
There are three additional concepts related to touch perception that are important to know: ______________, _______________, and _______________.
- Two-point thresholds
- Physiological zero
- Gate theory of pain
A _______________ refers to the minimum distance necessary between two points of stimulation on the skin such that the points will be felts as two distinct stimuli.
Two-point threshold
Temperature is judged relative to _________________, or the normal temperature of the skin (between 86-97 degrees Fahrenheit).
Physiological zero
Pain perception is part of the somatosensory system and can result from signals sent from a variety of sensory receptors, most commonly ______________.
Nocireceptors
The ________________ proposes that a special “gating” mechanism can turn pain signals on or off, affecting whether or not we perceive pain.
Gate theory of pain
_______________ is also called ______________ and refers to the ability to tell where one’s body is in space. Even with your eyes closed, you could still describe the location and position of your hand.
- Kinesthetic sense
- Proprioception
The receptors for proprioception, called ________________, are found mostly in muscle and joints, and play critical roles in hand-eye coordination, balance and mobility.
Proprioceptors
Modern theories of object recognition assume at least two major types of psychological processing: _________________ and ________________.
- Bottom-up (data-driven) processing
- Top-down (conceptually driven) processing
_______________ (______________) processing refers to object recognition by parallel processing and feature detection. The brain takes the individual sensory stimuli and combines them together to create a cohesive image before determining what the object is.
Bottom-up (data-driven) processing
_______________ (________________) processing is driven by memories and expectations that allow the brain to recognize the whole object and then recognize the components based on these expectations.
Top-down (conceptually driven) processing
_________________ refers to the ability to create a complete picture or idea by combining top-down and bottom-up processing with all of the other sensory clues gathered from an object.
Perceptual organization
________________ only require one eye and include relative size, interposition, linear perspective, motion parallax, and other minor cues.
Monocular cues
_____________ refers to the idea that objects appear larger the closer they are.
Relative size
______________ means that when two objects overlap, the one in front is closer.
Interposition
______________ refers to the convergence of parallel lines at a distance: the greater the convergence, the further the distance.
Linear perspective
______________ is the perception that objects closer to us seem to move faster when we change our field of vision (look at something else).
Motion parallax
______________ primarily involve retinal disparity which refers to the slight difference is images projected on the two retinas.
Retinal disparity
A secondary binocular cue is ______________, in which the brain detects the angle between the two eyes required to bring an object into focus.
Convergence
The form of an object is usually determined through ________________ cells and feature detection, and the motion of an object is perceived through _______________ cells.
- Parvocellular cells
- Magnocellular cells
_____________ refers to our ability to perceive that certain characteristics of objects remain the same, despite changes in the environment.
Constancy
_______________ are a set of general rules that account for the fact that the brain tends to view incomplete stimuli in organized, patterned ways.
Gestalt principles
The _______________ says that elements close to one another tend to be perceived as a unit.
Law of proximity
The ________________ says that objects that are similar tend to be grouped together.
Law of similarity
The _________________ says that elements that appear to follow in the same pathway tend to be grouped together.
Law of good continuation
_______________ have two do with perceiving contours and, therefore, shapes that are not actually present in the stimulus.
Subjective contours
The ________________ says that when a space is enclosed by a contour, the space tends to be perceived as a complete figure.
Law of closure
The Gestalt principles by the _____________________, which says that perceptual organization will always be a regular, simple, and symmetric as possible.
Law of pragnanz
