Intro to Psych - Exam 2: Chapter 4 - Sensation & Perception

Sensation vs Perception

Receiving sensory input

Perception

Interpreting sensory input

Role of Sensory Receptors in Sensation and Perception

Specialized cells that detect stimulus information and transmit it to sensory (afferent) nerves and the brain

Top-Down vs Bottom-Up Processing

Launched by cognitive processing at brain’s higher levels. Allows the organism to sense what is happening and to apply that framework to information from the world

Bottom-Up Processing

Sensory receptors register info about external environment and sent it to brain for interpretation

Outcomes Associated with signal detection theory (e.g., hits, correct rejection, etc.)

Signal Detection Theory - an approach to perception that focuses on decision making about stimuli under conditions of uncertainty

Outcomes:

Hit (true positive) - the signal is present, and the observer correctly says “yes”

Miss (false negative) - the signal is present, but the observer incorrectly says “no”

False Alarm (false positive) - the signal is absent, but the observer incorrectly says “yes”

Correct Rejection (true negative) - the signal is absent, and the observer correctly says “no”

Mechanoreceptors, Chemoreceptors, & Photoreceptors

Mechanoreceptors - specialized sensory receptors that convert mechanical pressure, touch, vibration, stretch, or motion into electrical signals for the CNS

Chemoreceptors - specialized sensory cells or neurons that detect chemical substances in the body or external environment and convert them into electrical signals

• helps body maintain homeostasis by signaling the nervous system to adjust breathing, heart rate, and chemical levels

Photoreceptors - specialized light-detecting neurons located in the retina at the back of the eye (rods, cones)

Phantom Limb Pain

Condition where a person feels painful sensations – such as burning, shooting, cramping, or electric shocks – in an arm, leg or other body part that has been removed or amputated

Rods

The receptor cells in the retina that are sensitive to light but not very useful or color vision

Cones

The receptor cells in the retina that allow for color perception

Cocktail Party Effect

The human brain’s ability to focus on a single voice or conversation while filtering out background noise and other overlapping chatter

Umami’s Taste

A pleasant meaty, brothy flavor

Colorblindness

Reduced ability to see or distinguish between certain colors caused by absent or malfunctioning cone cells in the retina

Subliminal perception

The detection of information below the level of conscious awareness

Stroop effect

Delay in reaction time when you try to name the ink color of a word that spells different, conflicting color name

• Failure of selective attention

Inattentional Blindness

A psychological phenomenon where you fail to notice a fully visible, unexpected object or event because your attention is intensely focused on something else

Perceptual Set

A predisposition or readiness to perceive something in a particular way

Perceptual Constancy

The recognition that objects are constant and unchanging even though sensory input about them is changing

Gestalt Principles

A school of thought interested in how people naturally organize their perceptions according to certain patterns

Location of Smell in the brain

The olfactory cortex and the limbic system

Absolute Threshold

The minimum amount of.stimulus energy that a person can detect

Weber’s Law

Principle that two stimuli must differ by a constant minimum percentage (rathter than a constant amount) to be perceived as different

Attention

The process of focusing awareness on a narrow aspect of the environment

Selective Attention

The act of focusing on a specific aspect of experience while ignoring others

Sensory Adaptation

A change in the responsiveness of the sensory system based on the average level of surrounding stimulation

Retina

The multilayered, light-sensitive surface in the eye that records electromagnetic energy and converts it to neural impulses for processing in the brain

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

Feature Detectors

Neurons in the brain’s visual system that respond to particular features of a stimulus

Parallel Processing

The simultaneous distribution of information across different neural pathways

Binding

For vision - 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 cells 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 (figure) and those that are left over (ground)

Depth Perception

The ability to perceive objects three-dimensionally

Binocular Cues

Depth cues that depend on the combination of the images in the left and right eye and on the way the two eyes work together

Monocular cues

Powerful depth cues available from the image in one eye, either the right or left

Convergence

A binocular cue to depth and distance in which the muscle movements in an individual’s two eyes provide information about how deep and/or far away something is

Apparent Movement

The perception that a stationary object is moving

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 sound through the eardrum, hammer, anvil, and stirrup to the inner ear

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 regarding how the inner ear registers the frequency of sound, stating that each frequency produces vibrations at a particular spot on the basilar membrane

Frequency Theory

Theory regarding how the inner ear registers the frequency of sound, stating that the perception of a sound’s frequency depends on how often auditory nerve fires

Volley Principle

Modification of frequency theory stating that a cluster of nerve cells can fire neural impulses in rapid succession, producing a volley of impulses

Thermoreceptors

Sensory nerve endings under the skin that respond to changes in temperature at or near the skin’s surface and provide input to keep the body’s temperature at 98.6 degrees fahrenheit

Papillae

Rounded bumps about the tongue’s surface that contain the taste buds

Olfactory Epithelium

The lining of the roof of the nasal cavity, containing a sheet of receptor cells for smell

Kinesthetic Senses

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 body