Ch.4 Flashcards
Transduction
Process of converting an external energy or substance into electrical activity within neurons. (External stimulus, like a light, or sound into electrical signals within neurons)
Sense receptor
Specialize cell responsible for converting external stimuli into neural activity for a specific sensory system. 
Sensory adaptation
Process in which activation is greatest when stimulus is first detected. 
-Our response declines in strength, after a few seconds, we no longer notice it. 
-adaptation takes place at the level of the sensory receptor.
Absolute threshold
Lowest level of a stimulus needed for the nervous system to detect a change 50% of the time. 
Psychophysics
The study of how we perceive sensory stimuli based on their physical characteristics
Just noticeable difference (JND)
The smallest change in the intensity of a stimulus that we can detect. 
-Relevant to our ability to distinguish a stronger stimulus from a weaker stimulus, like a soft noise from a slightly louder noise. 
Weber’s law
Principle stating there is a constant proportional relationship between the JND and the original stimulus intensity.
-The stronger the stimulus, the bigger the change needed for a change in stimulus intensity to be noticeable. 
Signal detection theory
Theory regarding how stimulus are detected under different conditions
-Signal to noise ratio: It becomes harder to detect a signal as background noise increases.
-Response biases: Tendency 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. 
•True positive, or hit: People can afford that they’ve heard a sound when it was present.
•False negative, or miss: Deny hearing a sound when it was present.
•False positive, or a false alarm: Report hearing a sound that wasn’t there.
•True negative, or correct rejection: Deny hearing the sound that wasn’t there. 
Specific nerve energies
States that even though there are many distinct stimulus energies like light, sound, or touch— the sensation we experience is determined by the nature of the sense receptor, not the stimulus.
-Ex: rub eyes shortly after Waking up, try to notice phosphenes— vivid sensations of light caused by pressure on your eye’s receptor cells. It doesn’t matter to our brain whether light or touch activated the sense receptor: Our brains react the same way either case. That is once our Visual sense receptor send signals to the cortex, the brain interprets the input as visual, regardless of how our receptors were stimulated in the first place. 
McGurk affect
This effect demonstrates that we integrate visual and auditory information when processing spoken language, and our brains automatically calculate the most probable sound given the information from the two sources.
-Hearing “ba”, seeing “ga” and our brains best guess is at integrating the two conflicting sources of information is “da”.
Rubber Hand illusion
Shows how our senses of touch, and sight interact to create a false perceptual experience.
Synesthesia
A condition in which people experience Cross-modal sensations
Examples-
Mirror-touch synesthesia: A person experiences the same sensation that another person experiences, such as Touch. 
Lexical-gustatory synesthesia: Words associated with specific tests or textures.
Chromesthesia: Sounds trigger the experience of colour.
Personification: Numbers, letters, or days of the week take on personality characteristics and sometimes have characteristic appearances.
Number-form synesthesia: Numbers are imagines as mental maps.
Spatial sequence synesthesia: certain certain sequences of numbers, dates, or months are perceived as closer or farther in space.
Graphemes-colour synesthesia: And which 6 may always seem red and a 5 green.
Lexical-taste synesthesia: Words have associated tastes and in still others synesthesias letters take on “personality traits.”
Selective attention
Process of selecting one sensory channel and ignoring or minimizing others
-The major brain regions that control selective attention is the reticular activating system and forebrain. These areas activate regions of the cerebral cortex, such as the frontal cortex. 
Filter theory of attention
Views attention as a bottleneck through which information passes. This mental filter enables us to pay attention to important stimuli and ignore others. 
Cocktail party effect
Refers to our ability to pick out important messages, like 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 focussed elsewhere
Change blindness
Failure to detect obvious changes in one’s environment. 
Binding problem
When we perceive an apple, different regions of the brain process different aspects of it. Yet somehow—we don’t Really know how— Oh brains manage to combined or bind these diverse pieces of information into a unified whole. 
-One hypothesis is that rapid coordination activity across multiple cortical areas assist in binding.
-Binding May explain many aspects of perception and attention. When we see the world rely on shape, motion, colour, and depth cues, each which requires different amount of time to detect individually.
Pupil
Circular hole through which light enters the eye.
-Responds with the pupillary reflex to decrease the amount of light allowed into them. This reflex occurs Simultaneously in both eyes.
-Dilation (expansion) of the pupil also a psychological significance. our pupils dilate when we’re trying to process complex information. They also dilated when we view someone we find physically attractive.
Cornea and lens
Cornea: part of the eye containing transparent cells that focus light on the retina.
Lens: part of the eye that changes curvature to keep images in focus.
Accommodation
Changing the shape the lens to focus on objects near or far.
-“flat” (Long and skinny) Enables us to see distant objects.
-“fat” (Short and wide) Enables us to focus on nearby objects. 
Myopia and Hyperopia
Myopia (Nearsightedness)- Images are focussed in front of the rear of the eye, due to the cornea being too steep or our eyes being too long. Inability to see far objects well, with an intact ability to see close objects clearly.
Hyperopia (Farsightedness)- Results when our cornea is too flat or our eyes are too short. Inability to see near objects well, with an intact ability to see far objects clearly.
Retina, Fovea, and Acuity
-Membrane at the back of the eye responsible for converting light into neural activity.
-Central portion of the retina
-Sharpness of vision
Rods
Long and narrow, Enable us to see basic shapes and forms. Receptor cells in the retina allowing us to see low levels of light. There are no rods in the fovea. By relying on our Peripheral vision, We allow more light to fall onto our rods. Photopigment in rods is rhodopsin, vitamin A is needed to make it.
Dark adaptation- Time in dark before rods regain maximum light sensitivity. Takes about 30 minutes. 
Cones
Receptor cells in the retina allow us to see colour. Sensitive to detail; require more light than rods do. Different types of receptor cells contain photopigments, Chemicals that change following exposure to light.
Optic nerve
Nerve the trails from the retina to the brain. Contains the axons of ganglion cells. After the optic nerve leaves both eyes, they come to a fork in the road called the optic chiasm. half the axons cross the optic chiasm and the other half stay on the same side. optic nerve enters brain, becomes optic tracts. Optic track sends most of their axons to the visual part of the thalamus, then to the primary visual cortex called V1, the primary route for visual perception. The remaining axons go to structures in the midbrain particularly the superior colliculus. 
Blindspot
Region of the retina containing no rods and completely devoid of sense receptors. 
Feature detector cells
Feature detection- Our ability to use certain minimal patterns to identify objects.
Cell that detects lines and edges
Trichromatic theory
Idea that colour vision is based on our sensitivity to three primary colours, blue, green and red.
Colour blindness
Inability to see some or all colours. Is most often due to the absence or reduced number of one or more types of cones stemming from genetic abnormalities.
Monochromats- only have 1 type of cone, thereby lose all colour vision.
Dichromats- 2 Types of cones and are missing only one type.
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 or white
Visual agnosia
Is it deficit in perceiving objects. A person with this condition can tell us the shape and colour of an object, but can’t recognize or name it. 
Audition
Our sense of hearing. 
Pitch
Sounds have pitch, which corresponds to the frequency of the wave. Higher frequency corresponds to a higher pitch, lower frequency to lower pitch.
Timbre
Refers to the complexity or quality of Sound that makes musical instruments, human voices, or other sources sound unique.
Outer ear
Consisting of the Pinna (the part of the ear we see, namely it’s skin and cartilage flap) and ear canal, has the simplest function; it funnel sound waves onto the eardrum.
Middle ear
Contains the ossicles, The three tiniest bones in the body named, malleus, incus, and stapes. Often referred to as the Hammer, anvil, and stirrup. These ossicles vibrate the frequency sound waves, transmitting it from the eardrum to the inner ear.
Inner ear
Cochlea- bony, spiral-shaped sense organ used for hearing. It converts vibration into neural activity. Vibrations from sound waves disturb the fluid inside and travel to the base of the cochlea, where pressure is released and transduction occurs. Hair cells are where transduction of auditory information takes place. They convert acoustic information into action potentials. Hair cells contain cilia that protrude into the fluid of the cochlea. When sound waves travel through the cochlea, the resulting pressure deflects these Cilia exciting the hair cells. That information feeds into the auditory nerve, which travels to the brain through the thalamus which is sensory relay station.
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. 
Place theory
A specific place along the basilar membrane matches a tone with a specific pitch. 
Frequency Theory
Rate at which neurons fire the action potentials, reproduces the pitch.
Conductive deafness, Nerve deafness, and Noise-induced loss
•Is due to a malfunctioning of the ear, especially a failure of the eardrum or ossicles of the inner ear.
•Is due to damage to the auditory nerve.
•Loud sounds, especially those that last a long time or a repeated, can damage our hair cells. Is often accompanied by a tinnitus, a ringing, roaring, hissing, or buzzing sound in the ears that can be deeply disturbing. 
Olfaction and gastation
•Our sense of smell
•our sense of taste
Odours and basic tastes
Are airborne chemicals interact with receptors in the lining of our nasal passages. Olfactory receptors recognize or respond to individual odours by the shape of the odour molecules.
We’re Sensitive to 5 basic tastes— sweet salty, sour, bitter, and umami(meaty or savoury) there’s preliminary evidence for a 6th taste, one for fatty foods. Even a 7th, one for starch (“starchy”)
Taste buds
Bumps on the tongue called papillae contain taste buds. Sense receptors in the tongue that responds to sweet, salty, sour, bitter, umami, and perhaps fat.
(The commercial flavour enhancer accent consists almost entirely of MSG- monosodium glutamate)
Pheromones
Odourless chemical that serves as a social signal to members of one’s species.
Most mammals use the vomeronasal organ, Located in the bone between the nose and the mouth, to detect pheromones. Vomeronasal organ Doesn’t develop in humans, causing some to suggest that humans are insensitive to pheromones 
Somatosensory and proprioception
Our sense of touch, temperature, and pain. We sense light touch, pressure, and temperature with mechanoreceptors. Touch information Travels more quickly than information about pain stimuli. That’s because touch and pain have different functions. Touch informs us of our immediate surroundings and alerts us to urgent matters, such as when something feels hot to help us avoid severe burn, whereas pain alerts us to take care of injuries, which can often wait a little while.
Also have body position sense, called proprioception, or kinesthetic sense, and a sense of Equilibrium or balance called the vestibular sense. 
Pain threshold 
Pain comes in many varieties. Sharp, stabbing, throbbing, burning, and aching. Many types of pain receptors relate to paincausing stimulus, thermal, chemical, or mechanical. acute- short lived. Chronic- long lived.
Gate control model
Idea the pain is blocked or gated from consciousness by normal mechanisms in the spinal cord. Because pain demands attention, distraction is an effective way of short-circuiting painful Sensations. 
Phantom pain
Pain or discomfort felt in an amputated limb
Proprioreceptors
To sense muscle stretch and force. From these two sources of information we can tell what our bodies are doing even with our eyes closed. Two kinds of proprioreceptors. Stretch receptors in bedded in our muscles and force detectors in bedded in our muscles tendons. 
Semicircular Canal’s
Three fluid filled canals in the inner ear responsible for our sense of balance
Parallel processing, Bottom-up Processing, Top-down processing
Ability to attend to many sense modalities simultaneously.
Bottom up- Processing in which a whole is constructed from parts. Starts with the raw stimuli we perceive and ends up with our synthesizing them into a meaningful concept.
Top down- Conceptually driven processing influenced by beliefs and expectancies. Starts with our beliefs and expectations which we then impose on the raw stimuli we perceive.
Perceptual set
Set formed when expectations influence perception
Perceptual Constancy
The process by which we perceived stimuli consistently across Varied conditions. Without perceptual constancy, we’d be hopelessly confused because we’d be seeing our world as continually changing. There are several kinds of perceptual constancy shape, size, and colour. 
Subjective contours and
Gestalt Principles
Our brains provide missing information about outlines.
Ex: Kanizsa square.
Gestalt Principles are rules governing how we perceive objects as wholes within their overall context. Gestalt Is a German word roughly meaning “whole”
Main gestalt principles:
1) Proximity. Objects physically close to each other tend to be perceived as unified wholes.
2) Similarity. All things being equal, we see similar objects as composing a whole, much more so than dissimilar objects. 
3) Continuity. We still perceive objects as wholes even if other objects block part of them.
4) Closure. When partial visual information is present our brains fill in what’s missing.
5) Symmetry. We perceive objects that are Systematically arranged as wholes more often than those that aren’t.
6) Figure-ground. Perceptually, we make an instantaneous decision to focus attention on what we believe to be the central figure, and largely ignore what we believe to be the background.
Fusiform gurus
Plays a central role in face recognition.
Tasting disgusting food and viewing facial expressions of disgust both activate in the gustatory cortex.
Phi Phenomenon
Moving closer to and farther from the certain clever designs produces the illusion of motion. Shows that our perceptions of what moving and what’s not are based only on partial information, With our brains taking their best guesses at what’s missing.
Depth perception
Ability to judge distance and three-dimensional relations. We use two kinds of cues to gauge depth monocular depth cues and binocular depth cues.
Monocular depth cues
Monocular- Stimuli that enables us to judge depth using only one.
•Relative size: All things being equal more distant objects looks similar than closer objects.
•Texture gradient: The texture of objects becomes less apparent as objects move further away
•Interposition: One object that’s closer blocks our view of an object behind it. From this fact, we know which object is closer and which is farther away.
•Linear perspective: The outlines of rooms or buildings coverage as distance increases.
•height in plane: In a sense, distant objects tend to appear higher, and nearer objects lower.
•Light and shadow: Objects cast shadows to give us a sense of the three dimensional form. 
Binocular depth cues
Binocular- Stimuli that enables us to judge depth using two eyes.
•Binocular disparity: Like two lenses from a pair of binoculars, our left and right eyes transmit quite different information for near objects but see distant objects similarly.
•Binocular convergence: When we look at nearby objects, we focus on them reflexively by using our eye muscles to turn our eyes inward. 
Subliminal perception
Perception below the limen, of threshold or conscious awareness. For unclear reasons, the effects of subliminal information often vanishes when participants become aware of or even suspect attempt to influence them subliminally. 
Subliminal persuasion
Subthershold influences over our votes in election, product choices, and life decisions. Subliminally presented words related to thirst, such as a drink, may slightly influence how much people drink ,but specific words related to brand-name such as cola, don’t influence beverage choice.
Neurotransmitters that enhance sensitivity to taste are
Serotonin and norepinephrine. Usually these are enhanced by antidepressants
When using the word ‘wavelength’ to describe light or sound, we are referring to _____ for vision and _____ for hearing.
+
The property of sound that is most similar to the brightness of light is?
Hue and pitch.
Loudness- the amplitude or height of the sound wave, measured in decibels. Loud noise results in increased wave amplitudes b/c there’s more mechanical disturbances.
Brightness- when light reaches an object, part of that light is reflected by the object and part gets absorbed. Perception of brightness is influenced directly by the intensity (or amount) of the reflected light that reaches our eyes.
