lesson 4 modularity and consciousness Flashcards
Sensation
simple stimulation of a sense organ. It is the basic registration of light, sound, pressure, odor,
or taste as parts of your body interact with the physical world.
Perception
occurs in your brain as sensation is registered there: It is the organization, identification, and
interpretation of a sensation in order to form a mental representation.
transduction
when sense receptors convert physical signals from the environment into neural signals that are sent to
the central nervous system
what makes sensory receptors sensitive
each is uniquely sensitive to a particular type of energy. The eye is sensitive to light (but
not to sound); the skin to mechanical pressure (but not to visible light). The eye is sensitive to mechanical
pressure, too, but only a little bit. If you close your eye and push on your eyelid with your finger, you might see
sparkly dots. This mechanical pressure is registered by the receptors in your eye as light, not touch. You perceived light when sensory receptors in the eye were stimulated, even though the
stimulus was not light
what physical constrain limits the amount of neurons we have
shape of a woman’s pelvis limits max head size, limits number of neurons, limits capacity for processing sensory information
sensory adaptation
sensitivity to
prolonged stimulation tends to decline over time as an organism adapts to current (unchanging) conditions.
troxler fading
Stare at the central black dot in image. After several seconds, the grey cloud around the dot will disappear- another example of adaptation (or feeling tongue in mouth, or sensation of pants)
psychophysics
methods that
systematically relate the physical characteristics of a stimulus to an observer’s perception.
absolute threshold
the minimal intensity needed
to just barely detect a stimulus in 50% of the trials. A threshold is a boundary (like A candle flame 30 miles away on a clear, dark
night)
sensitivity
how responsive we are to faint stimuli
acuity
how well we can distinguish two very similar stimuli
just noticeable different (jnd)
the minimal change in a stimulus (e.g., in its loudness or brightness) that can just barely be detected
*not fixed, depends on sense measured and intensity of standard (original) stimulus
weber’s law
for every sense domain, the change in a stimulus that is just noticeable is a constant ratio of the standard
stimulus, over a range of standard intensities.
if you picked up a 1-ounce envelope, then a 2-
ounce envelope, you’d probably notice the difference between them. But if you picked up a 20-pound package, then a 20-pound, 1-ounce package, you’d probably detect no difference
Signal detection theory (SDT)
a way of analyzing data from psychophysics experiments that measures an
individual’s perceptual sensitivity (how effectively the perceptual system represents sensory events) while also
taking noise, expectations, motivations, and goals into account
what two things must happen to perceive a stimulus
the strength of the sensory evidence for that stimulus
the amount of evidence necessary for your perceptual system to “decide” that the stimulus is present, known as the decision criterion
visual acuity
ability to see fine detail
what part of light determines hue (color)
length of light wave
what part of light determines intensity
amplitude (how high the peaks are)
what part of light determines saturation (richness of color)
purity (when light source emitting only one wavelength)
how do eyes detect light
Light that reaches the eyes passes first through a clear, smooth outer tissue called the cornea, which bends the
light wave and sends it through the pupil, a hole in the colored part of the eye. This colored part is the iris, which is a translucent, doughnut-shaped muscle that controls the size of the pupil and hence the amount of light that can enter the eye
retina
layer of light sensitive tissue lining back of eyeball
accomodation
process by which the eye maintains a clear image on the retina
if eyeball too long what does it lead to
nearsight (myopia)
if eyeball too short what does it lead to
farsight (hyperopia)
what are the types of photoreceptor cells
Cones detect color,
operate under normal daylight conditions, and allow us to focus on fine detail. Rods become active only under
low-light conditions, for night vision
blind spot
location in the visual field that produces no sensation on the retina (test: close left eye and stare at cross, move paper until dot gone)
area v1
the part of the
occipital lobe that contains the primary visual cortex
what pathway
The ventral (lower) stream travels across the occipital lobe into the lower levels of the temporal lobes and
includes brain areas that represent an object’s shape and identity. Because this stream represents what an
object is, it is often called the “what” pathway
where pathway
The dorsal (upper) stream travels up from the occipital lobe to the parietal lobes (including some of the
middle and upper levels of the temporal lobes) and includes brain areas that identify where an object is and
how it is moving. Because the dorsal stream allows us to perceive spatial relations,
researchers originally dubbed it the “where” pathway
Neuroscientists later
argued that because the dorsal stream is crucial for guiding actions, such as aiming, reaching, or tracking
with the eyes, the “where” pathway is more appropriately called a “perception for action” pathway
damage in ventral stream can cause
ability to identify objects by sight was greatly impaired,
although ability to identify them by touch was normal. This suggests that visual representation of objects,
but not memory for objects, was damaged (shown clock, dont know it’s a clock until you touch it)
damage in dorsal stream
have difficulty using vision to
guide reaching and grasping (know it’s a clock but dont know where it is to grab it)
However, they can still identify objects they see
because their ventral streams are intact (two streams are distinct)
binding problem
how the brain links features together so that we see unified objects in our visual world rather
than free-floating or miscombined features
parallel processing
brain’s capacity to perform
many activities at the same time
illusory conjunction
a perceptual mistake whereby the brain incorrectly combines features from multiple objects
perceptual contrast
although the sensory
information from two things may be very similar, we perceive the objects as different (black and blue or white and gold dress)
gestalt principles
simplicity, closure, continuity, similarity, proximity, common fate
perceptual organization
process of grouping and segregating
features to create whole objects organized in meaningful ways (like seeing illusion of face/vase, we flit back and forth between interpretations because they look so similar)
size and distance illusion is based on what principle
When
you view two objects that project the same retinal image size, the object you perceive as farther away will be perceived as larger. Such illusions are typically constructed to be viewed from just one vantage point—for this reason, they are called forced perspective illusions (ames room)
multisensory
stimulating multiple senses at the same time
ventriloquist illusion
You depend on your visual system for reliable information about spatial location; when you see a moving mouth, simultaneously with hearing speech, you perceive the speech as coming from that mouth. We “believe” our visual system over our auditory system when it comes to determining the
spatial location of an event.
change blindness
when people
fail to detect changes to the visual details of a scene. occurs even when major details of a scene are changed—changes that we incorrectly believe we
couldn’t possibly miss (watching one thing in video and missing 26)
inattentional blindness
a failure to perceive objects that are not the focus of attention (watching phone while driving can cause crash)
what does sense of hearing depend on
changes in air pressure unfolding over time
what does frequency (sound) correspond do
perception of pitch; low frequency is low pitch sound and vice versa
what does amplitude (sound) correspond do
perception of loudness; low amplitude is soft sound and vice versa
what does complexity (sound) correspond do
perception of timbre; simple complexity is pure tone and v
what does learning involve
the acquisition, from experience, of new knowledge, skills, or responses that results in a relatively permanent change in the state of the learner.
habituation
a general process in which repeated or prolonged exposure to a stimulus
results in a gradual reduction in responding.
sensitization
occurs when presentation of
a stimulus leads to an increased response to a later stimulus
what did behaviorism dismiss
insistence on measuring only observable, quantifiable behavior and its dismissal of mental activity as irrelevant and unknowable
Classical conditioning
when a neutral stimulus produces a response after being paired with a stimulus that naturally produces a
response (pavlov dogs spit), conditioning produces learned behaviors
distal senses
olfaction vision audition
proximal senses
touch taste
Visual form agnosia
damage to what pathway (ventral), cant identify objects but can see them
hemispatial neglect
damage to what pathway (ventral) can only process one side at a time, draw full clock on one side only, dont even eat food on that side
grasping deficits
damage to where pathway (dorsal) and cant grasp on to things and cant tell where they are
expectancy effect
dont see anything in picture of dots until i tell you there is something now you can make it out
hard wiring
causes us to see human like attributes in everything
causes us to expect certain outcome like ball going certain way when hit
features of modules
domain specific (do one specific thing, like whatsapp cant give you directions
features of modules
domain specific (do one specific thing, like whatsapp cant give you directions
