Sensation and Perception Flashcards
Sensation
The conversion of Physical Stimuli into Neurological Signals
Perception
It is the Processing of Sensory Information to Make Sense of its Significance
Where are Sensory Stimuli Transmitted
To the projection areas in the brain which further analyze the sensory input
What is a Threshold
The minimum stimulus that causes a change in signal transduction
What is Weber’s Law
The JND for a stimulus is proportional to the magnitude of the stimulus and this proportion is constant over most of the range of possible stimuli
What is the Signal Detection Theory
The effects of non-sensory factors such as experiences, motives, and expectations on perception of stimuli
What is Response Bias
It is examined using signal detection theory with four possible outcomes, hit, misses, false alarms and correct negatives.
Adaptation
A decrease in response to a stimulus over time
What is the Visual Pathway
The retina to the optic nerves to the chiasm to the optic tracts to the LGN of the thalamus to the visual radiations to the visual cortex
What is the Purpose of the Cochlea
To detect sound
What is the Purpose of the Utricle and Saccule
To detect linear acceleration
What is the purpose of the semicircular canals
To detect rotational acceleration
What is the Auditory Pathway
Cochlea to Vestibulocochlear nerve to MGN of the the thalamus to the auditory cortex
Smell is
detection o volatile or aerosolized chemicals by olfactory chemoreceptors (olfactory nerves)
Taste is
detection of dissolved compounds by taste buds in papillae
Somatosensation
Four touch modalities (pressure vibration, pain, and temperature)
What is Kinesthetic or Proprioception Sense
The ability to tell where one’s body is in space
What is Bottom Up Processing
It is data driven processing which is recognition of objects by parallel processing and feature detection. It is slower than top down processing but less prone to mistakes
What is Top Down Processing
It is conceptually driven processing which is recognition of an object by memories and expectations with little attention to detail. It is faster than bottom up processing but more prone to mistakes.
Define Gestalt Principles
Ways that the brain can infer missing parts of an image when it is incomplete
What are Gestalts Laws
- The law of proximity - elements close to each other are perceived as a unit
- The law of similarity - objects that are similar appear to be grouped together
- The law of good continuation says that elements that appear to follow the same pathway tend to be grouped together
- Subjective of Contours - perception of non-existent edges and corners in figures based on surrounding visual cues
- The Law of closure says that when a space is enclosed by a group of lines it is perceived as a complete or closed line.
- The law of Pragnanz - perceptual organization will always be as regular, simple, and symmetric as possible.
Sound Projects to the
Superior Olive
Outer Ear
consists of the pinna (auricle), external auditory canal, and tympanic membrane
Middle Ear
Eustachian tube
Inner Ear
Contains the bony labyrinth (filled with perilymph), within which is the membranous labyrinth (filled with endolymph).
The Membranous Labyrinth Consists of the
cochlea, utricle and saccule, and the semicircular canals
Ganglia
are collections of cell bodies outside the central nervous system
Absolute Threshold
The absolute threshold is the minimum of stimulus energy that is needed to activate a sensory system
The Threshold of Conscious Perception
is the minimum of stimulus energy needed that will create a signal large enough in size and long enough in duration to be brought into awareness.
The Difference Threshold (JND)
the minimum difference in magnitude between two stimuli before one can perceive this difference.
The Cornea
gathers and filters incoming light
The Iris
Divides the front of the eye into the anterior and posterior chamber. It contains two muscles the dilator and constrictor papillae which open and close the pupil.
The lens
refracts incoming light to focus it on the retina and is held in place by suspensory ligaments connected to the ciliary muscle.
The ciliary body
produces aqueous humor which drains through the canal of shclemm
The retina
contains rods and cones
Rods
Detect light and Dark
Cones
Detect color and come in three forms based on wavelength (short, medium, and long)
Macula
A part of the retina that mostly contains cones
Fovea
The center of the macula which contains only cones.
Rods and Cones
Synapse on bipolar cells which synapses on ganglion cells.
Amacrine and Horizontal Cells
integrate signals from the ganglion cells they also sharpen edges.
The bulk of the eye is
Supported by the vitreous on the inside and the sclera and choroid on the outside.
All Senses Occur Through
Parallel Processing
Parallel Processing
The ability to simultaneously analyze and combine information regarding color shape and motion.
Parovocellular Cells
Detect shape with high spatial resolution and low temporal resolution
Magnocellular Cells
Detect Motion with low spatial resolution and high temporal resolution.
The Optic Chiasm
contains fibers crossing from the nasal side of the retina (temporal visual fields) of both eyes
The visual radiations
run through the temporal and parietal lobes
Habituation
is the process of becoming used to a stimulus
Dishabituation (Resensitization)
A sudden increase in a response to a stimulus, usually due to a change in the stimulus or addition of another stimulus.
can occur when a second stimulus intervenes, causing a resensitization to the original stimulus.
