PSYC 101 - Midterm 2 Comprehensive Study Set (Ch.3 and Ch.4)

Transduction

Process of converting an external energy or substance into electrical activity within neurons.

Sense Receptor

Specialized cell responsible for converting external stimuli into neural activity for a specific sensory system.

Sensory Adaptation

Process in which activation is greatest when a stimulus is first detected, and afterwards sensitivity gradually declines due to prolonged stimulation.

Psychophysics

The study of quantitative relations between psychological events and physical events or, more specifically, between perceptions and the stimuli that produce them; coined by Gustav Fechner in 1860.

Absolute Threshold

Lowest level of a stimulus needed for the nervous system to detect a change 50 percent of the time.

Just Noticeable Difference (JND)

The smallest change in the intensity of a stimulus we can detect.

Weber’s Law

A principle stating that the change in a stimulus that will be just noticeable is a constant ratio of the original stimulus. Also states that the stronger the stimulus, the bigger the change needed for a change in stimulus intensity to be noticeable.

Signal Detection Theory

Theory regarding how stimuli are detected in different conditions.

Signal-to-Noise Ratio

The phenomenon that it becomes harder to detect a signal as background noise increases.

Response Biases

Tendencies to make one type of guess over another when we’re in doubt about whether a weak signal is present or absent under noisy conditions.

Specific Nerve Energies

Doctrine which states that even though there are many distinct stimulus energies, the sensation we experience is determined by the nature of the sense receptor, not the stimulus.

Phosphenes

Vivid sensations of light caused by pressure on your eye’s receptor cells.

McGurk Effect

An effect that demonstrates that we integrate visual and auditory information when processing spoken language, and that our brains automatically calculate the most probable sound given the information from the two sources.

Synesthesia

A condition in which people experience cross-modal (interaction between two sensory modalities) sensations.

Mirror-Touch Synesthesia

A sensation in which a person experiences the same sensation that another person experiences, such as touch.

Lexical-Gustatory Synesthesia

A sensation in which words are associated with specific tastes or textures.

Chromesthesia

When sounds trigger the experience of colour; in cases of misophonia, sounds trigger strong emotions such as anger or fear.

Personification

When numbers, letters, or days of the week take on personality characteristics and sometimes have a characteristic appearance.

Number-Form Synesthesia

A sensation in which numbers are imagined as mental maps.

Spatial Sequence Synesthesia

A sensation in which certain sequences of numbers, dates, or months are perceived as closer or farther in space.

Selective Attention

Process of selecting one sensory channel and ignoring or minimizing others; mainly controlled by the reticular activating system and forebrain, which activate regions of the cerebral cortex (such as the frontal cortex) during this process.

Filter Theory of Attention

Theory created by Donald Broadbent in 1957 that views attention as a bottleneck through which information passes. This mental filter enables us to pay attention to important stimuli and ignore others.

Dichotic Listening

A task in which people hear two different messages, one delivered to each ear. When asked to ignore messages delivered to only one of the ears, people seem to know nothing about the messages from either side.

Cocktail Party Effect

The human ability to pick out an important message (I.e, our name) in a conversation that doesn’t involve us.

Inattentional Blindness

Failure to detect stimuli that are in plain sight when our attention is focused elsewhere.

Change Blindness

Failure to detect obvious changes in one’s environment.

Hue

Colour of light.

Brightness

Depends on not only the amount of reflected light, but also on the overall lighting surrounding the object; our perception of this is influenced directly by the intensity (or amount) of the reflected light that reaches our eyes.

Additive Colour Mixing

The mixing of varying amounts of red, blue, and green light.

Subtractive Colour Mixing

The mixing of varying amounts of yellow, cyan, and magenta in paint or ink.

Sclera

The white of the eye; maintains the ball shape of the eyeball.

Iris

The coloured part of the eye (usually blue, brown, green, or hazel); controls how much light enters our eyes.

Pupil

Circular hole through which light enters the eye; it’s size is controlled by the iris.

Pupillary Reflex

The closing of the pupil; a reflex response to light or objects coming toward us. Occurs simultaneously in both eyes.

Cornea

Curved, transparent layer covering the iris and pupil; contains transparent cells that focus light on the retina.

Lens

Part of the eye that changes curvature to keep images in focus.

Accomodation

Changing the shape of the lens to focus on objects near or far.

Presbyopia

The loss of flexibility in the lens due to aging.

Retina

Neural tissue lining the inside back surface of the eye, responsible for light absorption, light processing, and converting light into neural information and neural activity.

Fovea

Central portion of the retina containing only cones.

Acuity

Sharpness of vision.

Rods

Receptor cells in the retina allowing us to see in low levels of light. Also play a key role in peripheral vision.

Dark Adaptation

The process in which the eyes become more sensitive to light in low illumination; takes about 30 minutes.

Cones

Receptor cells in the retina allowing us to see in daylight and in colour. Better for fine details than their counterpart.

Photopigments

Chemicals that change following exposure to light.

Rhodopsin

The photopigment found in rods.

Ganglion Cells

Cells in the retinal circuit that contain axons, and that bundle all their axons together and depart the eye to reach the brain.

Optic Nerve

Nerve that travels from the retina to the brain; contains the axon of ganglion cells.

Optic Chiasm

Point at which the optic nerves from the inside half of each eye cross over and project to the opposite half of the brain.

Optic Disk / Blind Spot

Region of the retina containing no rods and completely devoid of sense receptors.

Feature Detection

Our ability to use certain minimal patterns to identify objects.

Feature Detector

Neuron that responds selectively to very specific features of (more complex) stimuli.

Trichromatic Theory

Idea that colour vision is based on our sensitivity to three primary sensory colours.

Colour Blindness

Inability to see some or all colours.

Opponent Process Theory

Theory that we perceive colours in terms of three pairs of opponent colours: either red or green, blue or yellow, and black and white.

Blindness

A dramatic reduction in the ability to see; more specifically, the presence of vision less than or equal to 20/200 on the Snellen eye chart.

Blindsight

The ability of blind people with damage to their cortex to make correct guesses about the appearance of things around them.

Echolocation

A phenomenon in which certain animals, such as bats, dolphins, and many whales, emit sounds and listen to their echoes to determine their distance from a wall or barrier.

Visual Agnosia

A deficit in perceiving objects.

Audition

Our sense of hearing.

Timbre

Complexity or quality of sound that makes musical instruments, human voices, or other sources sound unique.

Outer Ear

Consists of the pinna, and ear canal; funnels sound waves into the eardrum.

Pinna

The part of the ear we see - namely, its skin and cartilage flap.

Middle Ear

Contains the ossicles.

Ossicles

The three tiniest bones in the body, named the Malleus, Incus, and Stapes. Also referred to as the Hammer, Anvil, and Stirrup. These bones vibrate at the frequency of the sound wave, transmitting it from the eardrum to the inner ear.

Cochlea

Bony spiral-shaped sense organ used for hearing.

Organ of Corti

Tissue containing the hair cells necessary for hearing.

Basilar Membrane

Membrane supporting the organ of corti and hair cells in the cochlea.

Hair Cells

Embedded into the organ of corti and basilar membrane; where transduction of auditory information takes place, converting acoustic information into action potentials.

Place Theory

A theory that states a specific place along the basilar membrane matches a tone with a specific pitch.

Frequency Theory

Theory that states that the rate at which neurons fire the action potentials faithfully reproduces the pitch; works well up to 100 Hz because many neurons have maximal firing rates near that limit.

Volley Theory

A variation of frequency theory that works for tones between 100 and 5000 Hz. According to this theory, sets of neurons fire at their highest rate, slightly out of sync with each other to reach overall rates.

Conductive Deafness

Deafness due to a malfunctioning of the ear, especially a failure of the eardrum or the ossicles of the inner ear.

Nerve Deafness

Deafness due to damage to the auditory nerve.

Vibration

Mechanical energy travelling through the air.

Olfaction

Our sense of smell.

Gustation

Our sense of taste.

Taste Bud

Sense receptor in the tongue that responds to sweet, salty, sour, bitter, umami, and perhaps fat.

Papillae

Bumps on the tongue that contain numerous taste buds.

Pheromone

Odourless chemical that serves as a social signal to members of one’s species.

Somatosensation

Our sense of touch, temperature, and pain.

Proprioception

Our sense of our body’s position. Also known as kinesthetic sense.

Vestibular Sense

Our sense of equilibrium or balance.

Mechanoreceptors

Specialized nerve endings on the ends of sensory nerves in the skin that we use to sense light touch, deep pressure, and temperature.

Free Nerve Endings

Far more plentiful than specialized nerve endings; we use these to sense touch, temperature, and especially pain.

Pain Threshold

Each kind of pain-producing stimulus has this; a point at which we perceive a stimulus as painful.

Gate Control Model

Idea that pain is blocked or gated from consciousness by neural mechanisms in the spinal cord.

Phantom Pain

Pain or discomfort felt in an amputated limb.

Proprioceptors

Used to sense muscle stretch and force.

Semicircular Canals

Three fluid-filled canals in the inner ear responsible for our sense of balance.

Human Factors Psychology

A field of psychology that optimizes technology to better suit our sensory and perceptual capabilities.

Nociceptors

Pain receptors. There are four types - Mechanical, Thermal, Chemical, and Polymodal.

Mechanical Nociceptors

Nociceptors that respond to excess pressure or deformation or breaks in the skin.

Thermal Nociceptors

Nociceptors that are activated by different levels of temprature.

Chemical Nociceptors

Nociceptors that respond to a number of chemicals such as spices, venom, environmental irritants and endogenous chemicals that arise from changes in tissues.

Polymodal Nociceptors

Nociceptors that sense more than one type of pain stimuli.

Parallel Processing

The ability to attend to many sense modalities simultaneously.

Bottom-Up Processing

Processing in which a whole is constructed from parts; begins with perception of raw stimuli.

Top-Down Processing

Conceptually driven processing influenced by beliefs and experiences; begins with beliefs and expectations which are then imposed onto raw stimuli.

Perceptual Set

Set formed when expectations influence perceptions.