Unit 3
Sensation- The process of receiving stimulus energies from the external environment and transforming those energies into neural energy
Perception- The process of organizing and interpreting sensory information so that it makes sense (providing meaning)
Bottom-up Processing- The operation in sensation and perception in which sensory receptors register information about the external environment and send it up to the brain
Top-down Processing- The operation in sensation in perception, launched by cognitive processing at the brain’s higher levels, that allow the organism to sense what is happening and apply that framework to information from the world
Sensory Receptors- Specialized cells that detect stimulus information and transmit it to sensory nerves and the brain
Frequency- Sensory Neurons will transmit more frequent currents rather than stronger currents if a light is super bright for example
Photoreception- Detection of light, perceived as sight
Mechanoreception- Detection of pressure, vibration, and movement, perceived as touch, hearing, and equilibrium
Chemoreception- Detection of chemical stimuli, perceived as smell and taste
Synaesthesia- One sense induces an experience in another sense
Occipital lobes- visual information
Temporal lobes- hearing
Parietal lobes- pain, touch, and temperature
Extrasensory Perception (ESP)- a person can detect information from the world without receiving concrete sensory input (Sixth sense)
Absolute Threshold- The minimum amount of stimulus energy that a person can detect
Noise- Irrelevant and competing stimuli
Difference Threshold- The degree of difference that must exist between two stimuli before the difference is detectable
Weber’s Law- The principle that two stimuli must differ by a constant minimum percentage to be perceived as different
Subliminal Perception- The detection of information below the level of conscious awareness
Signal Detection Theory- An approach to perception that focuses on decision making about stimuli in the presence of uncertainty
Selective Attention- The act of focusing on a specific aspect of experience while ignoring others
Perceptual Set- A predisposition or readiness to perceive something in a particular way.
Sensory Adaptation- A change in the responsiveness of the sensory system based on the average level of surrounding stimulation
Inattentional blindness- The failure to detect unexpected events when attention is engaged by a task
Cocktail party effect- the ability to focus on one voice among many in a crowded or noisy situation
3.2
Light- A form of electromagnetic energy that can be described in terms of wavelengths
Sclera- Outer white part of the eye that help maintain the shape and protect from injury
Iris- The colored part of the eye
Pupil- Appears black is the opening in the center which has muscles that can control the size of the pupil which regulates the amount of light that enters the eye
Cornea- A clear membrane at the front of the eye does most of the bending of light to back of eye
Lens- A transparent and somewhat flexible, disk-like structure filled with gelatin-like material helps with the finer details of reception
Retina- The multilayered light-sensitive surface in the eye that records electromagnetic energy and converts it to neural impulses for processing in the brain
Rods- The receptor cells in the retina that are sensitive to light bot not very useful for color vision
Cones- The receptors that we use for color perception
Fovea- Most important part of the retina which has the best vision (located in middle)
Optic Nerve- The structure at the back of the eye, made up of axons of the ganglion cells, that carries visual information to the brain for further processing
Blind Spot- The area on the retina where there are no cones or rods
Visual Cortex- Located in the occipital lobe, the part of the cerebral cortex involved in vision
Feature Detectors- Neurons in the brains visual system that respond to particular features of a stimulus
Parallel Processing- The simultaneous distribution of information across different neural pathways
Binding- The bringing together and integration of what is processed by different neural pathways or cells
Trichromatic theory- Theory stating that color perception is produced by three types of cone receptors in the retina that are particularly sensitive to different, but overlapping, ranges of wavelengths
Opponent-process Theory- Theory stating that cells in the visual system respond to complementary pairs of red-green and blue-yellow colors; a given cell might be excited by red and inhibited by green whereas another cell might be excited by yellow and inhibited by blue
Figure-ground Relationship- The principle by which we organize the perceptual field into stimuli that stand out and those that are left over
Gestalt Psychology- A school of thought interested in how people naturally organize their perceptions according to certain patterns
Depth Perception- The ability to perceive objects three dimensionally
Binocular Cues- Depth cues that depend on the combination of both our eyes to work together
Convergence- Another binocular cue to depth and distance in which the muscle movements in an individual's two eyes provide information about how deep or far away something is
Monocular cues- Powerful depth cues available from the image in one eye
Apparent Movement- The perception that a stationary object is moving
Perceptual Constancy- The recognition that objects are constant and unchanging even though sensory input about them is changing
Disparity- the difference between the images in the two eyes to determine depth
3.3
Wavelength- Determines the sound waves frequency
Pitch- The perceptual experience of the frequency of a sound (high like whistle or low like horn)
Outer Ear- Consists of the pinna and external auditory canal
Pinna- The outer, visible part of the ear which collects sounds and channels them into the interior of the ear
Auditory Canal- Sound waves move from outside to middle ear through this
Middle Ear- Channels and amplifies the sound through the eardrum, hammer, anvil, and stirrup to the inner ear
Eardrum- separates the outer ear from the middle ear and vibrates in response to sound
Oval Window- Opening to the inner ear
Inner Ear- The oval window, cochlea, and basilar membrane which converts sound waves into neural impulses and sends them to the brain.
Place Theory- Each frequency produces vibrations at a particular place on the basilar membrane
Frequency Theory- Theory on how the inner ear registers the frequency of sound, stating that perception of a sounds frequency depends on how often the auditory nerve fires
Volley Principle- Cluster of nerve cells can fire neural impulses in rapid succession, producing a volley of impulses
Auditory Nerve- The nerve structure that receives information about sound from hair cells in the inner ear and carries these impulses to the brain's auditory areas
3.4
Touch- We use touch to detect mechanical energy, or pressure against the skin
Thermoreceptors- Sensory nerve endings under the skin that respond to changes in temperatures at or near the skin and provide input to keep the body's temperature t 98.6*
Pain- The sensation that warns us of damage to the body
Papillae- Rounded bumps above the tongues surface that contain the taste buds, the receptors for taste
Olfactory Epithelium- lines the roof of the nasal cavity and contains a sheet of receptor cells for smell
Kinesthetic Senses- Provide information about movement, posture, and orientation
Vestibular Sense- Provides information about balance and movement
Semicircular Canals- Three fluid-filled circular tubes in the inner ear containing the sensory receptors that detect head motion caused when an individual tilts or moves the head and or body