click below
click below
Normal Size Small Size show me how
The Senses
Term | Definition |
---|---|
Lens | Bends entering light rays and focuses them onto retina. |
Cornea | Transparent window covering lens. |
Iris | Colored ring around pupil, controls the size of the pupil. |
Pupil | Opening in the center of eye that regulates the amount of light entering the eye - dilates in darkness and constricts in bright light. |
Cones | Visual receptors for color and daylight vision. |
Fovea | Tiny spot in center of retina that contains only cones, visual activity is greatest from here. |
Rods | Visual receptors for night and peripheral vision in black and white. |
Retina | Neural tissue lining in the back of the surface of eye that absorbs light, processes images, and sends information to the brain. |
Optic disk (blind spot) | A hole in the retina where optic nerve exits the eye. |
Psychophysics | How physical stimuli are translated into psychological experience - first area of psychology to be studied. |
Threshold | Point at which stimulus if first detected - the least amount of light at which you would notice it. |
Absolute threshold | Minimum amount of stimulus an organism can detect 50% of the time. |
Just noticeable difference (JND) / difference threshold | Smallest difference in amount of stimulation that a specific sense can detect. |
Weber's Law | States that size of a JND is in constant proportion to the size of the initial stimulus. (Tell difference between 31 and 30 oz weight) |
Fechner's Law | Magnitude of sensory experience is proportional to the logarithm of stimulus intensity - number of JNDs that stimulus is absolute threshold. |
Reversible figures | Drawing compatible with two different perceptions that can switch back and forth. |
Perceptual set | Readiness to perceive a stimulus in a certain way. |
Impossible figures | Objects that can be represented in 2D figures but can't exist in 3D space. |
Gestalt Principles | The whole is greater than the sum of the parts. |
Figure/Ground | What you are looking at vs the background. |
Phi phenomenon | Illusion of movement formed by presenting visual stimuli in rapid succession. |
Bottom up processing | Progression from individual elements to the whole. |
Top down processing | Progression from the whole to the elements. |
Subjunctive contours | Perception of contours where none actually exist. |
Closure | Filling in the missing elements. |
Proximity | Grouping together things that are closer. |
Similarity | Grouping together things that look the same. |
Distal stimulus | Stimulus that lays outside the body. |
Proximal stimulus | Stimulus energies that impinge directly on the senses. |
Binocular depth cues | Clues about distance based on the differing vies of both eyes. |
Retinal disparity | Objects within 25 feet project slightly different views on retina in each eye. |
Convergence | Sensing objects converging towards each other as objects get closer. |
Monocular depth cues | Distance cues only requiring one eye. |
Motion parallax | Images at different distances move across retina at different rates. |
Pictorial cues | Shading, elevation, texture gradient, linear perspective, interposition. |
Steps in which light is processed by eye | Lens, Rods and Cones in retina, neural impulses to Bipolar cells in retina, activate Ganglion cells, Optic nerve sends info to Thalamus, sends info to Occipital lobe. |
Parallel processing | Simultaneously extracting visual information from the same visual input - reason for blind sight . |
Color vision | Wavelength is perceived as color (high frequency - violet, low frequency - red). |
Trichromatic theory | States that eye has three types of receptors, and each is sensitive to a different color (red, green, blue). Proof - mix of colors create all others, color blindness, found that there are 3 types of cones. |
Opponent process theory | Color perception depend on receptors that make antagonist responses to three pairs of colors (red/green, yellow/blue, black/white). Takes both theories to explain color vision. |
Color blindness | Not being able to differentiate between two colors - most common - red/green. |
Farsightedness | Caused by eyeball that is too short or cornea is too flat. Causes light rays to come into focus behind retina. |
Nearsightedness | Caused by eyeball that is too wide or cornea is too steep. Causes light rays to come into focus in front of retina. |
Accomodation | Process by which eye lens change shape to focus on near or far objects on the retina. |
Steps in which sound is processed by ear | Pinna (outer ear), Tympanic membrane (ear drum) vibrates Ossicles (small bones) which vibrate Oval window in cochlea. Basilar membrane in cochlea vibrates Hair cells which create action potentials which travel down auditory nerve to Thalamus. |
Transduction | Process by which sensory system converts stimulus energy to neural signals. (Cochlea / Retina). |
Place Theory | States that you hear different pitches due to different activity in basilar membrane triggered by sound waves. (Explains high pitches well). |
Frequency Theory | States that the entire basilar membrane vibrates with same pitch as sound waves and fires neural impulses at the same rate (Explains low pitches well). |
Volley principle | States that neurons alternate firing while others "reload." |
Auditory Localization | States that you need 2 ears to localize sound to tell difference in density and time to reach ear (easier to locate sounds on side than anywhere else). |
Conduction Hearing Loss | When eardrum is punctured / ossicles damaged |
Hearing Aids | Help amplify vibrations that are weak, usually high frequencies. Don't fix damage of nerves / hair cells unless you get cochlea implants. |
Nerve Deafness | When there is damage to the cochlea's hair cells or the nerves associated with them. Can't be 'rejuvenated' or fixed. |
Chemical senses | Only taste and smell, not hearing nor sight. |
Gustatory system | Sense with 4 primary properties being salty, sweet, bitter, sour. (Tastebuds are receptors) |
Taste properties | Only taste if dissolved in water, taste preference changes with nutritional needs / influence by social processes, if no smell lose the sense of taste to certain extent, |
Super tasters | People with 4 times as more tastebuds as regular people - usually female, more sensitive to sweet / bitter. |
Olfactory system | Only sense not routed by thalamus, volatile chemicals dissolved in mucus, no primary odors. |
Touch system | Stimulation of the sensory receptors on the skin processed by somatosensory cortex in parietal lobe. Warmth, cold, pressure, pain. |
Receptive fields | Areas with high amount of pressure sensors (tickling usually happens). |
Somatosensory cortex | Bulk of it is devoted to fingers, tongue, and lips. Tells warmth and cold (if both, feel hot). |
Pain | Has 2 types of pathways depending on the type of sense you receive. People without it usually die by early adulthood. |
Fast pathway | The sharp pain when you first cut yourself that hits at a fraction of a second. |
Slow pathway | The less localized pain after a sharp pain. |
Gate control theory | States that something must open for pain signals to go through, if distracted, they don't open. |
Kinesthetic system | Monitors the position of various parts of the body - receptors in joints and muscles that tell you where they are. |
Vestibular system | Monitors the body's location in space and responds to gravity. Determines position by flow of hairs in semicircular canals of ear. Is why you get dizzy after spinning (doesn't happen in space). |
Signal detection theory | States that the feeling of a stimulus does not only relate to its intensity, but also motivation, expectations, experience, and alertness. Predicts weak signals as ratio of hits, misses, correction detention, and false alarms. |
Cocktail party effect | States that hearing your name being said stands out from surrounding noise. |
Subliminal perception | A registration of sensory input without conscious awareness |
Sensory adaptation | A gradual decline in perception to a prolonged stimulation |
Optic chiasm | The point at which optic nerves from inside half of each half cross over and project to opposite half of eye. |
Door in the face technique | Making large request likely to turned down in order to increase chance that smaller request will be granted. |
Perceptual constancy | Tendency to experience stable perception in the face of continually changing input (door changing shape, person changing size). |
Size constancy | Objects coming closer don't appear to grow larger. |
Amplitude | In sight, brightness. In hearing, loudness. |