Week 8 Flashcards
Opponent Process
The representation of colours by the rate of firing of two types of neurones: red/green and yellow/blue
Opponent Process Theory
The theory that the perception of colour is the result of the activity of three opponent-process channels. (Red/Green, Blue/Yellow, Black/White)
Photoreceptor
A receptive cell for vision in the retina; a rod or a cone
Cone
A photoreceptor that is responsible for acute daytime vision and for colour perception
Rod
A photoreceptor that is very sensitive to light but cannot detect changes in hue
Perception
The detection of the more complex properties of a stimulus, including its location and nature
Transduction
The conversion of physical stimuli into changes in the activity of receptor cells of sensory organs
Receptor Cell
A neuron that directly responds to a physical stimulus, such as light, vibrations, or aromatic molecules
Anatomical Coding
A means by which the nervous system represents information; different features are coded by the activity of different neurons
Temporal Coding
A means by which the nervous system represents information; different features are coded by the pattern of activity in neurons
Psychophysics
A branch of psychology that measures the quantitative relation between physical stimuli and perceptual experience
Just-Noticeable Difference (JND)
The smallest difference between two similar stimuli that can be distinguished; also known as difference threshold
Weber Fraction
The ratio between a JND and the magnitude of a stimulus; reasonably constant over the middle range of most stimulus intensities
Threshold
The point at which a stimulus, or a change in the value of a stimulus, can just be detected
Difference Threshold
The smallest difference between two similar stimuli that can be distinguished; also known as JND
Signal Detection Theory
A mathematical theory of the detection of stimuli, which involves discriminating a signal from the noise in which is it embedded and which takes into account participants’ willingness to report detecting the signal
Receiver Operating Characteristic Curve (ROC Curve)
A graph of hits and false alarms of participants under different motivational conditions; indicates people’s ability to detect a particular stimulus
Wavelength
The distance between adjacent waves of radiant energy; in vision, most closely associated with the perceptual dimension of hue
Cornea
The transparent tissue covering the front of the eye
Sclera
The tough outer layer of the eye; the “white” of the eye
Iris
The pigmented muscle of the eye that controls the size of the pupil
Lens
The transparent organ situated behind the iris of the eye; helps focus an image on the retina
Accommodation
Changes in thickness of the lens of the eye that focus images of near or distant objects on the retina
Retina
The tissue at the back inside surface of the eye that contains the photoreceptors and associated neurons
Optic Disc
A circular structure located at the exit point from the retina of the axons of the ganglion cells that form the optic nerve
Ganglion Cell
A neuron in the retina that receives information from photoreceptors by means of bipolar cells and from which axons proceed through the optic nerves to the brain
Bipolar Cell
A neuron in the retina that receives information form photoreceptors and passes it on to the ganglion cells, from which axons proceed through the optic nerves to the rain
Fovea
A small pit near the centre of the retina containing densely packed cones; responsible for the most acute and detailed vision
Photopigment
A complex molecule found in photoreceptors; when struck by light, it splits and stimulates the membrane of the photoreceptor in which it resides
Rhodopsin
The photopigment contained by rods
Dark Adaptation
The process by which the eye becomes capable of distinguishing dimly illuminated objects after going from a bright area to a dark one
Vergence Movement
The co-operative movement of the eyes, which ensures that the image of an object fals on identical portions of both retinas
Saccadic Movement
The rapid movement of the eyes that is used in scanning a visual scene, as opposed to the smooth pursuit movements used to follow a moving object
Pursuit Movement
The movement that the eyes make to maintain an image of a moving image upon the fovea
Hue
A perceptual dimension of colour, most closely related to the wavelength of a pure light
Brightness
A perceptual dimension of colour, most closely related to the intensity or degree of radiant energy emitted by a visual stimulus
Saturation
A perceptual dimension of colour, most closely associated with purity of a colour
Colour Mixing
The perception of two or more lights of different wavelength seen together as light of an intermediate wavelength
The Trichromatic Theory
The theory that colour vision is accomplished by three types of photoreceptors, each of which is maximally sensitive to a different wavelength of light
Negative Afterimage
The image seen after a portion of the retina is exposed to an intense visual stimulus; a negative afterimage consists of colours complementary to those of the physical stimulus
Protanopia
A form of hereditary anomalous colour vision, caused by defective “red” cones in the retina
Deuteranopia
A form of hereditary anomalous colour vision; caused by defective “green” cones in the retina
Tritanopia
A form of hereditary anomalous colour vision; caused by a lack of “blue” cones in the retina
Hertz (Hz)
The primary measure of the frequency of vibration of sound waves; cycles per second
Ossicle
One of the three bones of the middle ear (the hammer, anvil and stirrup) that transmit acoustical vibrations from the eardrum to the membrane behind the oval window of the cochlea
Cochlea
A snail-shaped chamber set in bone in the inner ear, where auditory transduction takes place
Oval Window
An opening in the bone surrounding the cochlea. The stirrup presses against a membrane behind the oval window and transmits sound vibrations into the fluid within the cochlea
Basilar Membrane
One of two membranes that divide the cochlea of the inner ear into three compartments; the receptive organ for audition resides here
Round Window
An opening in the bone surrounding the cochlea. Movements of the membrane behind this opening permit vibrations to be transmitted through the oval window into the cochlea
Auditory Hair Cell
The sensory neuron of the auditory system; located on the basilar membrane
Cilium
A hair-like appendage of a cell; involved in movement or in transducing sensory information. Cilia are found on the receptors in the auditory and vestibular systems
Tectorial Membrane
A membrane located above the basilar membrane; serves as a shelf against which the cilia of the auditory hair cells move
Chemosense
One of the two sense modalities (gustation and olfaction) that detect the presence of particular molecules present in the environment
Gustation
The sense of taste
Papilla
A small bump on the tongue that contains a group of taste buds
Taste bud
A small organ on the tongue that contains a group of gustatory receptor cells
Olfaction
The sense of smell
Pheromones
Chemical signals, usually detected by smell or taste, that regulate reproductive and social behaviours between animals
Olfactory Mucosa
The mucous membrane lining the top of the nasal sinuses; contains the cilia of the olfactory receptors
Olfactory Bulbs
Stalk-like structures located at the base of the brain that contain neural circuits that preform the first analysis of olfactory information
Somatosense
Bodily sensations; sensitivity to such stimuli as touch, pain, and temperature
Free Nerve Ending
A dendrite of somatosensory neurons
Pacinian Corpuscle
A specialized somatosensory nerve ending that detects mechanical stimuli, especially vibrations
Two-Point Discrimination Threshold
The minimum distance between two small points that can be detected as separate stimuli when pressed against a particular region of the skin
Phantom Limb
Sensations that appear to originate in a limb that has been amputated
Muscle Spindle
A muscle fibre that functions as a stretch receptor; arranged parallel to the muscle fibres responsible for contraction of the muscle, it detects muscle length
Vestibular Apparatus
The receptive organs of the inner ear that contribute to balance and perception of head movement
Semicircular Canal
One of a set of three organs in the inner ear that respond to rotational movements of the head
Vestibular Sac
One of a set of two receptor organs in each inner ear that detect changes in the tilt of the head
Adequate stimulus
Type of physical energy to which a sensory receptor is especially tuned
Neuron
An individual neural (or nerve) cell
Nucleus
The nucleus of a cell contains genes (DNA) and makes the proteins that “run” the cell
Afferent Neurons
Afferent Neurons carry impulses towards the brain
Amplitude/Intensity
Amplitude is the heigh of each wave, intensity depends directly on amplitude
Broca’s Aphasia
French physician Paul Broca described the case of patient, Monsieur Leborgne, who could not speak but could only understand language. Leborgne had been ill and died less than a week after Broca met him, after Leborgne’s death Broca removed his brain and examined it, finding a large lesion in the left frontal lobe.
Leborgne had a type of Aphasia - a language disorder resulting from brain damage, we now call such a disorder in which the primary difficulty is with producing language, rather than understanding language
Audition
Sensing with the ears; hearing
Autonomic Nervous System
Receives information from and sends commands to the heart and other organs
Axon
Nerve fibre that carries messages away from the cell body towards the cells with which the neuron communicates
Axon Terminal
Sends information across a synapse
Basal Ganglia
Group of subcortical structures that exchange information with different parts of the cerebral cortex and play a role in voluntary movement, learning and remembering how to do something
Brainstem
The lower part of the brain that connects it with the spinal cord; important for consciousness, sleep, and life-maintaining functions like breathing and heartbeat
Brightness
Perceptual property related to intensity of a light
Aphasia
A language disorder resulting from brain damage to the brain
Cell Body
The cell body contains structures that maintain cell health and metabolism
Central Nervous System (CNS)
The CNS includes the brain and spinal cord. The spinal cord communicates with all the sensory organs and muscles, except those of the head
Cerebellum
Pair of hemispheres resembling the cerebral hemispheres that are involved in motor control - the cerebellum ensures that movements are coordinated, well timed, and precise
Cerebral Cortex
Outer layer of the cerebral hemispheres of the brain consisting of a “rind” of grey matter - the neuron cell bodies. Underneath the grey matter, there is white matter - the myelinated long axons of some of those cells, communicating with cells in other brain regions
Chemical Senses
The senses of taste and smell together
Cilia
Hair-like appendages of a receptor cell involved in movement or transducing mechanical vibration into neural activity
Cochlear Implant
Electronic device that can provide a sense of sound to someone who is profoundly hearing impaired
Complexity
The number of different frequencies present in a sound
Compressed
Regions of high air pressure
Convergence
Meeting, Uniting, coming together
Cranial Nerves
Twelve pairs of nerve fibres that travel into and out of the skull and carry all sensory information (except for somatosenses) from parts of the body below the neck to the brain
Dendrite
Tree-Shaped structures branching from the body of a nerve cell that take input from other neurons
Efferent Neurons
Efferent neurons carry impulses away from the brain to the body
Eye movements
Humans make two to four eye movements every second, or more than 100,000 every day. These eye movements are necessary because of the design of the human eye - the eye’s acuity varies across the visual field
Neural Fatigue
Neurons that are subjected to steady, continuous stimulation become unable to send signals, probably because of a temporary depletion in the neurotransmitter that send signals across synapses
Frequency
The number of peaks per second (inverse of wavelength)
Frequency Resolution
Ability to hear two frequencies that are very close to each other as different sounds
Glia
The glia, neuroglia or glial cells are supporting cells. There are different kinds of glia (beyond the scope of this course) and they serve supportive and protective functions - helping the neurons to do their work
Graded Potentials
Graded potentials are small voltages generated at the postsynaptic membrane by the action of neurotransmitters that make the postsynaptic neuron either more likely to generate an action potential at the cell body (if they are excitatory) or less likely (if they are inhibitory). Graded potentials from all the dendrites of a neuron are summed in the cell body; if the summed potential is excitatory enough, an action potential is generated
Habituation
A decrease, in perception or behaviour in response to a stimulus when an organism has learned that that stimulus is irrelevant (neither good nor bad)
Homeostasis
The tendency of an animal to regulate its internal conditions (e.g., temperature, glucose levels, osmotic pressure of cells), by a system of feedback controls (hunger and eating; thirst and drinking; shivering and putting on a sweater), so as to optimize health and function
Hypothalamus
Area of the brain that controls the hormonal system and drives like hunger, thirst and body temperature (where the behaviours are responses to these drives)
Homunculus
Latin for ‘little man’, now used to refer to the somatotopic map of the body in the brain
Interneurons
Any neuron that is not a sensory or motor neuron. They link sensory/motor neurons and work to integrate and communicate information, rather than to transmit information from the body to the brain or from the brain to the body
Kinaesthetic Senses
Sensory endings located in our internal organs, bones, joints, and muscles that convey position of muscles, limbs, and painful, neutral and pleasurable sensory information.
Left and Right Hemispheres
Together, the two hemispheres of the brain control much of your behaviour. The left is relatively more specialized for speech and language; the right, for appreciation of 3D space and spatial relationships
Limbic System
Number of interlinked structures that form a border around the brainstem and are important for motivation, emotion, and some types of memory
Motor Neurons
Direct muscles to relax or contract, producing movement. They are efferent neurons, sending information FROM the brain TO the body
Multisensory
Relating to or involving more than one physiological sense
Myelin
A sheath or covering that makes the axon faster and more efficient
Nerve
A bundle of fibres, Each fibre in the bundle is a long conduit (axon) extending from a neuron’s cell body. Nerves transmit information with the PNS and between the PNS (Peripheral Nervous System) and CNS (Central NS)
Peripheral Nervous System (PNS)
The PNS includes cranial nerves and spinal nerves, which transmit sensory information from the body to the CNS and transmit motor and other commands in the other direction, from the CNS to muscles, glands and internal organs
Photons
Particles that transmit light
Pitch
The psychological property corresponding to frequency; the property that allows sound to be ordered on a musical scale
Population Code
Instead of information being conveyed by single nerve cells or a small group of cells, it is conveyed in the activity across a whole population - a lot of cells
Primary Somatosensory Cortex
Region of the somatosensory cortex that receives information directly from the somatosensory system
Pupil
The opening (black circle) in the middle of the iris (coloured part) of the eye; the pupil changes size to increase or decrease the amount of light entering the eye
Purity
The extent to which a light source is composed of a single wavelength
Qualitative
Pertaining to some quality or characteristic other than magnitude (e.g., the wavelength of a sound or light)
Quantitative
Referring to amounts or quantities that can be measured objectively
Rarefied
Regions of low air pressure
Rate of firing
Codes the intensity of a stimulus
Sensation
Physiological process that underlies transformation of the chemical, mechanical, light and sound energy in the world into electrical activity in the brain
Sensory Adaptation
A chance, usually a decrease, in sensitivity that occurs when a sensory system is repeatedly stimulated in exactly the same way
Sensory Neurons
Detect information from the physical world and pass that information to the brain (e.g., light receptor neurons in the eye or touch receptor neurons in the skin). Sensory neurons are often called afferent neurons because they send signals from the body to the brain
Sine Wave
A waveform with a single frequency: a smooth, regular oscillation between peaks and troughs (compressions and rarefactions)
Somatosenses
The bodily senses
Somatotopic Representation
The spatial organization of body parts is maintained in the brain, such that each body part is represented next to adjacent areas
Spontaneous Rate
Rate of neuronal firing when no stimulus is present
Synapse
Junction between the terminal button of one neuron and the membrane of a muscle fibre, a gland, or another neuron
<p>
| Thalamus</p>
<p>
Information from the sensory organs and motor signals from subcortical structures like the basal ganglia are received by thalamic regions and relayed separately to the cortex. The thalamus is also involved in regulating wakefulness and sleep</p>
Timbre
Perceptual dimension of sound determined in part by its complexity
Thermoreceptors
Nerve endings sensitive to stimulation by heat
Tracts
Nerves that are entirely within the brain and spinal cord (i.e., the CNS) are called tracts
Vestibular Sense
Senses involved in balance
Vestibule
Bony chamber attached to the cochlea
Wernicke’s Aphasia
After Broca’s findings, german physician, Carl Wernicke found that not all aphasic pantients behaved the same. Unlike Leborgne, Wernicke’s patients could speak, but the speech they produced made no sense and they seemed to have difficulty understanding what was said to this. The deficit in speech comprehension without a loss in speech production is now called “Wernicke’s aphasia” Their brain damage was on the left side of the brain as well, but much closer to the back of the brain than patients with Broca’s aphasia
