Chapter 2 - Sensation and Perception Flashcards
Sensation
Conversion of physical, electromagnetic, auditory and other information in to a neural impulse.
Perception
Processing of sensory information in the CNS and categorizing it.
Distal vs Proxima Stimuli
Distal Stimuli = Stimuli that emit proximal stimuli but are NOT directly sensed.
Proximal Stimuli = Stimuli that is directly sensed (sight, touch, thermosensation, etc.)
Absolute Threshold
Minimum level of stimuli needed to fire nerve impulses and cause sensation.
Threshold of conscious perception
Level of intensity that must occur to be consciously perceived by the brain.
Threshold of subliminal perception
Level of intensity that must occur to be received by the CNS but not consciously perceived.
Difference Threshold/ Just Noticeable Difference
Magnitude of the difference between two stimuli needed to be perceived as different from each other.
Webbers Law
Calculation for the JND.
Change in Stimulus / Original Magnitude
Example:
440Hz and 443Hz
3/440 = 0.68%
Signal Detection Theory
Internal and external factors influence on perception thresholds.
Signal Detection Theory Testing
Noise Trial = Stimulus
Catch Trial = No stimulus
Hit = Stimulus identified
Miss = Stimulus ignored
False Alarm = Absence of stimulus misidentified.
Correct Negative = Absence of stimulus identified.
Adaptation
Decrease in the perception of constant stimulus over time.
Sclera
Whites of eyes
Eye Blood Supply
Coroidal and retinal vessels
Retina
Contains rods and cones
Cornea
Clear dome at the front of the eye
that gathers and focuses light on on the pupil.
Anterior Chamber (eye)
Between the cornea and the iris
Posterior Chamber (eye)
Between the iris and the lens
Iris
Colored part of the eye consisting of dilator and constrictor pupillae
Choroid
Vascular layer of the eye, provides nutrients to the retina.
Ciliary Body
Production of aqueous humor
Aqueous Humor
Front part of the eye, drains into canal of Schlemm
Vitreous humor
Rear part of the eye, supports the retina
Lens
Controls refraction of light onto the retina
Accommodation
Changing of lens shape by the ciliary muscle to change focus.
Duplicity Theory of Vision
Existence of light/dark detection and color detection (rods and cones)
Rods
Light/ dark detection. Highly sensitive to photons. Contain ONE pigment, rhodopsin.
Macula
Central section of the retina that contains cones.
Fovea
Middle of the macula that contains only cones. Region of highest visual acuity.
Optic Disk
Region that has no rods or cones where the optic nerve leaves the eye.
Bipolar Cells
Cells directly synapsed to multiple rods and cones that carry information on to the ganglion cells.
Ganglion Cells (eye)
Cells that are synapsed to multiple bipolar cells. Axons of which form the optic nerve.
Pathway of light perception (cornea to visual cortex)
Cornea
Pupil
Lens
Retina (rods and cones)
Bipolar Cells
Ganglion Cells
Optic Nerve
Optic Chiasm
Optic Tract
Lateral Geniculate Nucleus
Visual Cortex (occipital lobe)
Amacrine and Horizontal Cells
Recieve input from multiple retinal cells in the same region. Accentuates differences between visual information in each bipolar cell and contributes to contrast detection.
Temporal vs Nasal Retinal Fibers
Temporal = Runs on the outer edge. No crossover
Nasal = Runs on the inner edge. Crossover at the optic chiasm.
Lateral Geniculate Nucleus
Located in the Thalamus, receives and transmits visual signals from the optic nerves to the visual cortex.
Parallel Processing
Ability to process multiple aspects of stimuli at once. Color, shape, form, motion.
Parvocellular cells
Cells in the LGN with high color and detail acuity, but poor temporal (motion) resolution.
Magnocellular cells
Cells in the LGN with high motion detection but poor detail resolution.
Binocular Neurons
Neurons in the visual cortex that are responsible for depth perception.
Feature Detection
Parallel recognition of color, form, motion, etc. information to identify stimuli.
Pinna/ Auricle
Outer ear, channels sound into the inner ear.
Tympanic Membrane
Receives sound input from the external auditory canal.
Malleus
Hammer bone connected to the tympanic membrane and the incus
Incus
Anvil bone connected to the malleus and stapes
Stapes
stirrup bone connected to the incus and the oval window
Bony Labyrinth
Outer hollow region in the temporal bone housing in the membranous labyrinth.
Membranous Labyrinth
Continuous collection of tubes and chambers responsible for hearing and equilibrium.
Endolymph
Potassium-rich fluid in the membranous labyrinth.
Perilymph
Fluid that transmits and protects inner ear structures.
Cochlea
Spiral-shaped organ responsible for hearing. Contains stereocilia.
Vestibule
Contains the utricle and saccule.
Utricle and Saccule
Detects linear acceleration using otoliths.
Semicircular Canals
Detects rotational acceleration.
Medial Geniculate Nucleus
Auditory relay from vestibulocochlear nerve to the auditory cortex in the temporal lobe.
Inferior Colliculus Role in Hearing
Startle reflex and vestibulo-ocular reflex (eye following)
Sound Pathway (Auricle to Auditory Cortex)
Pinna
External Auditory Canal
Tympanic Membrane
Malleus
Incus
Stapes
Oval Window
Perylimph in Cochlea
Basilar Membrane
Hair Cells
Vestibulocochlear Nerve
Brainstem
Medial Geniculate Nucleus
Auditory Cortex
Smell Pathway (Nose to Limbic System)
Nasal passages
Olfactory Epithelium
Olfactory Nerves
Olfactory Bulb
Olfactory Tract
Limbic System and Higher Order Brain Regions
Taste Pathway
Chemoreceptors on Taste Buds
Brainstem
Taste Center (Thalamus)
Higher order Brain Regions
Somatosensation Receptors
Pacinian corpuscles (deep pressure, vibration)
Meissner corpuscles (light touch)
Merkel Disks (deep pressure, texture)
Ruffini Endings (stretch)
Free Nerve Endings (pain and temperature)
Kinesthetic Sense
Proprioception, ability to tell where one’s body is in space.
Bottom Up Processing
Data driven detection by parallel processing and feature detection. Longer but less error prone.
Top Down Processing
Memory and expectation driven. Quick but error prone.
Perceptual Organization
Using bottom up and top down processing together to get a more rounded understanding.
Gestalt Principles
General rules for completing incomplete stimuli.
Proximity, similarity, good continuation, subjective contours, closure.
