Chapter 5: Sensation & Perception Flashcards
What is the difference between sensation and perception?
Sensation is the physical manner in which sensory receptors detect stimuli, and perception is the way the brain perceives and consciously experiences a stimulus
What is the doctrine of specific nerve energies?
The principle that different sensory modalities exist because sensory organs stimulate different nerve pathways leading to different area of the brain, which is called anatomical code
Alex consistently sees colours associated with certain words. What condition might Alex have?
Synesthesia
What is functional coding?
It is used to figure out what our sensory receptors are sensing. Information about which cells are firing, as well as the amount and rate of cells firing forms a functional code
A volunteer is put in a dark room with a black screen. The screen then changes to green. Researchers ask the volunteer to say when he notices the shade of green change. What are the researchers testing?
The volunteer’s difference threshold
What is the absolute threshold?
The minimum amount of energy or quantity of a stimulus needed to be reliably detected at least 50% of the time it is presented
For a stimulus threshold, how is a “just noticeable difference” expressed?
A Weber fraction
Signal detection theory is a psychophysical theory that divides the detection of a sensory signal into a _______ process and a _______ process.
sensory, decision
True or false: there is a bear in the woods and Bob does not hear it. This is an example of a miss.
True
True or false: there is not a bear in the woods but Bob hears one. This is an example of a correct rejection.
False. This is an example of a false alarm
If there is a bear in the woods and Bob hears it, what is it an example of?
A hit
True or false: there is not a bear in the woods and Bob does not hear one. This is an example of a correct rejection
True
Not being conscious of the feeling of wearing clothes all the time is an example of what?
Sensory adaptation
What is the difference between selective attention and inattentional blindness?
Selective attention selects focus on environmental sensations, whereas inattentional blindness is the failure to perceive something you are looking at because you are not attending to it
Define hue, saturation,
and brightness
Hue: the colour (wavelength)
Saturation: the colourfulness
(width of wavelength)
Brightness: (height of waves)
What regulates the amount of light let into the pupil of the eye?
The pupil and the iris, which is the round muscle that adjusts the pupil
The white outer layer of the eye is called the _______.
sclera
The lens of the eye…
focuses light onto the back of the eye.
The retina is neural tissue at the back of the eye that detects light. It has 2 different types of photoreceptors. What are they?
Cones: detect light, near the center
Rods: detect movement, more outer
Once photoreceptors detect light, how does it relay the signals to the brain?
Photoreceptors pass the signals through bipolar neurons, where they are collected by the ganglion cells, which relay the signal to the optic nerve
What is the area in the retina lacking any rods or cones?
Optic disk
This visual system detects specific aspects of the visual world, like line configurations, but most notably faces
Feature-detector cells. The group of cells above the cerebellum detect faces and cells near the occipital cortex respond stronger to body parts
What is the trichromatic theory (AKA the Young-Helmholtz Theory)?
This theory states that colour vision is determined by 3 different cone types: short, medium, and long, which are sensitive to their corresponding wavelengths (L: red, M: green, S: blue)
What is the opponent-process theory?
We perceive colours in terms of opposite ends of a spectrum. Cells in the retina and thalamus respond in opposite fashion to short and long wavelengths.
e.g. specific colour cones getting “tired” and leaving a negative afterimage
______ ______ were among the first to study how people visually organize the world into meaningful units and patterns
Gestalt psychologists
Gestalt principles describe strategies used by the visual system to group sensory information into units
This stream of signals extends from the visual cortex to the parietal lobe. It guides interaction with objects and is responsible for depth/motor perception
The dorsal stream (AKA “where/how” or “action” stream)
Binocular depth cues are distance cues based on differing perspectives of eyes. What is convergence and retinal disparity?
Convergence: when eye muscles contract so both eyes focus on an object
Retinal disparity: difference in perspective of each eye
Stereopsis is the sense of _____
depth
What are monocular cues?
The way we sense depth for things beyond 50 ft. It depends only on one eye and uses things like interpositions, which is when an object is interposed between the viewer and a second object
The ventral (“what”) stream is a visual pathway which extends from the visual cortex to the temporal lobe. What function does it serve?
The ventral stream is home to the fusiform face area which is responsible for object and face recognition
What experiment showed that the fusiform face area was responsible visual expertise not specific to faces?
The greeble experiment
What are perceptual consistencies?
The accurate perception of objects as stable or unchanged despite changes in sensory patterns. When sensory cues are misinterpreted, perceptual illusions can occur
What measures loudness, pitch, and timbre?
Loudness: amplitude (dB)
Pitch: frequency (Hz)
Timbre: complexity
What is the name for people who have an unusually large number of small, densely packed papillae on their tongue?
Supertasters. They have tastes much stronger than a normal person
What is nociception?
The sense of pain signalled by nociceptors. Fast fibres detect sharp, immediate pain. Slow fibres detect chronic, dull pain
What is the gate-control theory?
The theory that says the experience of pain impulses depend on whether pain impulses get past a neurological “gate” before getting to the brain
People who feel pain from an appendage or organ that has been removed experience what is called ______ ______.
phantom pain
Treatment can involve the use of a mirror to trick the brain
What is kinesthesis?
It tells us where our body parts are located and their orientations
