Chapter 3 Sensation and Perception

Chapter 3 sensation and perception 1. How we sense and perceive the world - Sensation - the process of receiving a stimulus energies from the external environment and transforming those energies into neural energy - Perception - the process of organizing and interpreting sensory information so - Top down processing - the operation in sensation and perception, launched by that it makes sense. cognitive processing at the brains higher levels that allows the organism to sense what is happening and to apply that framework to information from the world - Absolute threshold - the minimum amount of stimulus energy that a person can - Difference threshold - the degree of difference that must exist between two - Weber's law - the principle that two stimuli must differ by a constant minimum - Subliminal perception - the detection of information below the level of conscious - Signal detection theory - an approach to perception that focuses on decision detect stimuli before the difference is detected. percentage (rather than a constant amount) to be perceived as different awareness. making about stimuli in the presence of uncertainty - Selective attention - the act of focusing on specific aspect of experience while - Perceptual set - a predisposition or readiness to perceive something in a ignoring others particular way. - Sensory adaptation - a change in the responsiveness of the sensory system based on average level of surrounding stimulation. 2. The visual system - Retia- 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 but not very useful - Cones - the receptor cell in the retina that allows for colo perception - Optic nerve - the structure at the abc of the eye, made up oif axons of the for color vision. ganglion cells that carries visual information to the brain for further processing - Visual cortex - located in the occipital lobe, the part of the cerebral cortex - Feature detectors - neurons in the brain's visual system that respond to particular involved in vision. feathers of a stimulus - Parallel processing - the simultaneous distribution of information across different - Binding - in the sense of vision, the bringing together and integration of what is neural pathways. 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 wheres another cell might be excited by yellow and inhabited by blue - Figure ground relationship - the principle by which we organize the perceptual - Gestalt psychology - a school of thought interested in how people naturally field into stimuli that stands out (figure) and those that are left over(ground) 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 the images in left - Convergence - a binocular cue to depth and distance in which the muscle and right eyes and on the way the two eyes work together. movements in an individual's two eyes provide information about how deep and / or far away something is - Monocular cues - powerful depth cues available from the image on one eye, either the right or the left. - Apparent movements 0 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 3. The auditory system - Outer ear - the outermost part of the ear consisting of the pinna and the external auditory canal. - Middle ear - the part of the ear that channels and amplifies sound through the - The hammer, anvil, and stirrup are also called the ossicles these are the tiniest eardrum, hammer, anvil, and stirrup the inner ear bones in the body - Inner ear - the part of the ear that includes the oval window, cochlea and basilar membrane and whose function is to convert sound waves into neural impulses and send them to the brain. - Place theory - theory on how the inner ear registers the frequency of sound, starting that each frequency produces vibrations at a particular spot on the basilar membrane - Frequency theory - theory on how the inner ear registers the frequency of sound, starting that the perception of a sound's frequency depends on how often the auditory nerve fires. - Volley principle - principal addressing limitations of the frequency theory of hearing staring that a cluster if nerve cells fire neural impulses in rapid succession producing a volley of impulses - Auditory nerve - the nerve structure that receives information about sound from the hair cells of the inner ear and carries these neural impulses to the brain auditory nerve. 4. Other senses - Thermoreceptors - sensory nerve endings under the skin that respond to changes in temperature at or near the skin and provide input to keep the body's temperature at 98.6 degrees fahrenheit - Pain - the sensation that warns an individual of damage to the body - Papillae - rounded bumps above the tongue’s surface that contain the taste buds, the receptors for taste. (tongue has 10,000 taste buds) - Olfactory epithelium - the lining of the roof of the nasal cavity, containing a sheet of receptor cells for smell. - Kinesthetic sense - senses that provide information about movement, posture, and orientation. - Vestibular sense - sense that 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 the body.