week 3 Flashcards
sensation
the first stage in the functioning of the senses to represent stimuli from the environment
- stimulus –> process in receptors
- goal: detecting stimulus and its elementary properties
perception
a higher brain function –> mental process/state representing awareness and understanding of events and objects in the world
- goal: creating useful information of the surroundings
photoreceptors
cones (low light, no color) and roses (higher light, color) for vision
mechanoreceptors
hearing (hair cells) and touch (free nerve ending)
chemoreceptors
taste and smell
- chemical stimulus properties
receptors
physical stimuli –> transducing –> electrical action potential –> neurons –> specific brain regions –> processed & interpreted
somatosensory system
touch
gustatory system
taste
olfactory system
smell
vestibular system
equilibriuception –> balance
sensory cortex
cortical representation sites of the senses
- multiple brain regions at which sensory information is received and processed
receptive field
area in which stimulation leads to a response of a particular sensory neuron (line of orientation, direction of motion and shapes)
bottom-up processing
taking sensory information and then assembling/integrating it
top-down processing
use knowledge, motivation and expectations to interpet sensory information
Gestalt psychology
- sensory information –> patterns
- principles that help us make sense of complex scenes quickly and efficiently
- ‘the whole is greater than the sum of its parts’
- grouping principles (gestalt laws) –> perceive objects as patterns
principle of good continuation
points are sent as lines that belong together & objects that are overlapped are seen as different objects
law of pragnanz/principle of good figure/ principle of simplicity
every stimulus pattern in seen in such a wat that the resulting structure is as simple as possible
principe of similarity
similar things appear to be grouped together
proximity
close together –> belong together
examples gestalt psychology
- proximity
- similarity
- closure
- common fate
- Pragnanz/simplicity
- good continuation
closure
close figures in their mind
Bayesian inference/the Bayesian brain/predictive coding
actively perceiving the world –> explains our sensations while updating our expectations
prior
our initial belief about the probability of an outcome
likelihood
the extent to which the available evidence is consistent with the outcome
posterior
combines the prior and likelihood to form a new, updates belief or percept
helmholtz theory of unconscious inference
symbols or representations of the physical world that can be interpreted and disambiguated through converging evidence from different senses
likelihood principle
we perceive the object that is most likely to have caused the pattern of stimuli we have received
unconscious inference
our perceptions are the result of unconscious assumptions/inferences that we make about the environment
regulaties in the environment
frequently occurring characteristics
- physical regularities
- semantic regularities
physical regularities
- oblique effect: people perceive horizontals and verticals more easily than other orientations
- light-from-above assumption
semantic regularities
the characteristics associated with the functions carries out in different types of scenes
- scene schema: the knowledge of what a given scene typically contains
examples top-down processing
- Helmholtz
- regularities
- Bayan
data from the environment and experiences
example bottom-up processing
- Gestalt
principles are build in and over-ride the experience
perceptual illusions
- our experience is an interpretation
- rules and assumptions to interpret sensory information
- pinpoint specific brain regions
perceptual constancy
ability of perceptual systems to recognize the same object from widely varying sensory inputs
- bistable stimulus: some inputs can be perceives in two ways
inverse projections problem
the task of determining the object response for a particular image on the retina
- because of our knowledge (environment)
- viewpoint invariance: peoples ability to recognize an object from a different viewpoint
speech segmentation
when one word in a conversation ends and the next one begins
transitional probabilities
the likelihood that one sound will follow another (within an word)
statistical learning
the process of learning about transitional probabilities and other characteristics of language
- example: kids with made up words and light
perceptual process (7 steps)
1 stimulus in environment
2 stimulus hits the receptors
3 receptor processes
4 Nepal processing
5 perception
6 recognition
7 action
distal stimulus
in the environment
proximal stimulus
the representation of the object on the receptor
principle of transformation
stimuli and responses created by stimuli are transformed/changed between the distal stimulus and perception
sensory receptors
respond to environmental energy
transduction
1 transform environmental energy into electrical energy
2 shape perception by different properties
neural processing
changes in the signals that occur as they are transmitter through a maze of neurons
electrical signals
conscious experience of perception (awareness)
recognition
placing a object in a category
action
motor activities in response to the stimulus
visual form agnosia
inability to recognize objects
