Chapter 4 Flashcards
simple stimulation of a sense organ
Sensation
the organization, identification, and interpretation of a sensation in order to form a mental representation
Perception
when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the CNS
Transduction
methods that measure the strength of a stimulus and the observer’s sensitivity to that stimulus
Psychophysics
the minimal intensity needed to just barely detect a stimulus in 50% of the trials
Absolute Threshold
the minimal change in a stimulus that can be just barely detected (also known as a difference threshold).
Just Noticeable Difference (JND)
the just noticeable difference of a stimulus is a constant proportion despite variations in intensity.
Weber’s Law
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 decision criterion (correct responses include correct rejection and hits).
Signal Detection Theory
sensitivity to prolonged stimulation tends to decline over time as an organism adopts to current conditions
Sensory Adaptation
the ability to see fine detail
Visual Acuity
3 Properties of Light Waves
Length (color/hue)
Amplitude (brightness)
Purity (saturation/richness)
smooth outer tissue of the eye
Cornea
hole in the coloured part of the eye
Pupil
coloured part of the eye; muscle that controls the size of the pupil
Iris
layer of light sensitive tissue lining the back of the eyeball
Retina
the process which the eye maintains a clear image on the retina
Accommodation
Nearsightedness is called; when the eyeball is too long; images focused in front of the retina
Myopia
Farsightedness is called; when the eyeball is too short; images focused behind the retina
Hyperopia
Two Types of Photoreceptor Cells
Cones
Rods
photoreceptor cell that detects colour, operates under normal daylight conditions, allows us to focus on details
Cones
photoreceptor cell that becomes active under low-light conditions for night vision; more sensitive than cones; only sense shades of grey
Rods
120 million of these are distributed around each retina everywhere except the fovea
Rods
6 million of these are in the retina, packed in the fovea
Cones
an area of the retina where vision is the clearest and there are no rods
Fovea
cells that collect neural signals from the rods and cones and transmit them to the outermost layer of the retina
Bipolar Cells
neurons that organize signals from rods and cones and send them to the brain
Retinal Ganglion Cells (RCGs)
a bundle of 1.5 million retinal ganglion cells that leave the eye through a hole in the retina.
Optic Nerve
a location in the visual field that produces no sensation on the retina
Blind Spot
part of the occipital lobe; also called the primary visual cortex
Area V1
the rainbow of hues and accompanying wavelengths
Visible Spectrum
Three Types of Cones
Red - long wavelength
Green - medium wavelength
Blue - short wavelength
a genetic disorder where one of the cone types is missing (or two or even three)
Colour Deficiency
staring too long at one colour, fatiguing the cones that respond to that colour
Colour Afterimage
pairs of visual neurons work in opposition (red-sensitive against green-sensitive, blue-sensitive against yellow-sensitive).
Colour-opponent System
two distinct pathways that project from the occipital cortex to visual areas in other parts of the brain
Visual Streams
a visual stream that travels across the occipital lobe into lower levels of the temporal lobes; includes brain areas representing an object’s shape and identity; a “what” pathway
Ventral Stream
a visual stream that travels up from the occipital lobe to the parietal lobes (and some of middle and upper temporal lobes); connects with brain areas identifying location and motion of an object; “where” pathway, should be called the “how” pathway.
Dorsal Stream
the inability to recognize objects by sight
Visual Form Agnosia
the brain’s capacity to perform many activities at the same time.
Parallel Processing
how the brain links features together so that we see unified objects in our visual world rather than free-floating or miscombined features.
Binding Problem
a perceptual mistake whereby the brain incorrectly combines features from multiple objects
Illusory Conjunction
focused attention is not required to detect the individual features that make up a stimulus, such as the colour, shape, size, and location of letters, but is required to bind those individual features together.
Feature-integration Theory
a view that argues that we have feature detectors to aid in visual perception, face detectors, building detectors
Modular View
a view that argues the pattern of activity across multiple brain regions that identifies any viewed object
Distributed Representation
a principle that states that even as aspects of sensory signals change, perception remains consistent
Perceptual Constancy
Gestalt Perceptual Grouping Rules
Simplicity Closure Continuity Similarity Proximity Common Fate
a basic rule in science is that the simplest explanation is usually the best
Simplicity
we tend to fill in missing elements of a visual scene, allowing us to perceive edges that are separated by gaps as belonging to complete objects
Closure
edges or contours that have the same orientation have good continuation
Continuity
regions that are similar in colour, lightness, shape, or texture are perceived as belonging to the same object
Similarity
objects that are close together tend to be grouped together
Proximity
elements of a visual image that move together are perceived as parts of a single moving object
Common Fate
an object recognition theory where an object you have seen before is stored in memory as a template, and your memory compares the templates with the current retinal image and selects the template that most closely matches the current image
Image-based Object Recognition Theory
a mental representation that can be directly compared to a viewed shape in the retinal image
Template
an object recognition theory where the brain deconstructs objects we see into a collection of parts
Parts-based Object Recognition Theory
aspects of a scene that yield information about depth when viewed with only one eye; rely on the relationship between distance and size
Monocular Depth Cues
Different Monocular Depth Cues
Familiar Size Relative Size Linear Perspective Texture Gradient Interposition Relative Height in the Image
the difference in the retinal images of the two eyes that provides information about depth
Binocular Disparity
errors of perception, memory, or judgement in which subjective experience differs from objective reality
Illusions
a famous illusion where a room in a trapezoidal shape makes you perceive an object that is farther away as larger. Two people of the same height will appear different
Ames Room
perception of movement as a result of alternating signals appearing in rapid succession in different locations.
Apparent Motion
when people fail to detect changes to the visual details of a scene
Change Blindness
a failure to perceive objects that are not the focus of attention
Inattentional Blindness
how often the peak in air pressure passes the ear; measured in cycles/sec (Hz); corresponds with pitch
Frequency (wavelength)
how high or low a sound is
Pitch
the height of a sound wave relative to the threshold for human hearing; corresponds to loudness
Amplitude
a sound’s intensity
Loudness
sound waves’ mix of frequency; corresponds to timbre
Complexity
a listener’s experience of sound quality or resonance
Timbre
3 Parts of the Human Ear
Outer Ear
Middle Ear
Inner Ear
part of the human ear that collects sound waves and funnels them towards the middle ear; consists of the pinna, auditory canal, and the eardrum
Outer Ear
visible part of the ear on the outside of the head
Pinna
part of the human ear that transmits vibrations to the inner ear; behind the eardrum; contains the 3 smallest bones in the body (hammer, anvil, stirrup); transmits and intensifies vibrations from the eardrum to the inner ear
Middle Ear
part of the human ear that transduce vibrations into neural impulses; consists of the cochlea
Inner Ear
fluid filled tube that is the organ of auditory transduction in the ear
Cochlea
a structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid
Basilar Membrane
specialized auditory receptor neurons embedded in the basilar membrane which release neurotransmitter molecules
Hair Cells
an area of the cerebral cortex where action potentials travel to; also called the primary auditory cortex
Area A1
the auditory feature that allows you to locate the source of a sound
Spatial Auditory Feature
an auditory feature that allows identification of sounds
Non-spatial Auditory Feature
the frequencies our ears are most sensitive to
1000-3500 Hz
Two Mechanisms to Encode Soundwave Frequency
The Place Code
The Temporal Code
different frequencies stimulate neural signals at specific places along the basilar membrane; used for high frequencies
The Place Code
the process where the cochlea registers low frequencies via the firing rate of action potentials entering the auditory nerve
Temporal Code
Two Main Causes of Hearing Loss
Conductive Hearing Loss
Sensorineural Hearing Loss
the type of hearing loss where the eardrum or ossicles are damaged and cannot conduct sound waves effectively to the cochlea, but the cochlea is normal
Conductive Hearing Loss
the type of hearing loss where there is damage to the cochlea, the hair cells, or the auditory nerve; happens to most people when they age
Sensorineural Hearing Loss
an electronic device that replaces the function of hair cells and may partially restore hearing
Cochlear Implant
active exploration of the environment by touching and grasping objects with our hands.
Haptic Perception
rare inherited disorder, impairs pain perception, children are at an increased risk of dying during childhood because they will do things to harm themselves without knowing (scratching so hard that they gouge into their skin).
Congenital Insensitivity to Pain
pain that has persisted after the time it takes tissue to heal and is without apparent biological value; feeling too much pain
Chronic Pain
sensory information from internal and external areas converge on the same nerve cells in the spinal cord
Referred Pain
the theory 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
Gate-control Theory of Pain
a region of the midbrain where neural feedback comes from
Periaqueductal Grey (PAG)
the three fluid filled semicircular canals and adjacent organs located next to the cochlea in each inner ear
Vestibular System
smell is called
Olfaction
taste is called
Gustation
smell and taste combine to produce
Flavour
receptor cells initiating the sense of smell (ORNs).
Olfactory Receptor Neurons
a brain structure located above the nasal cavity beneath the frontal lobes
Olfactory Bulb
biochemical odourants emitted by other members of its species that can affect the animal’s behaviour or physiology
Pheromones
small bumps on the tongue that consist of 100s of taste buds
papillae
the organs of taste transduction; mouth contains 5000-10 000; each of these contain 50-100 taste receptor cells
taste buds
5 Primary Taste Sensations
Salt Sour Bitter Sweet Umami (savoury)
another taste sensation considered as fat
Oleogustus
replaced introspection
psychophysics
