1. Introduction to Perception Flashcards
what is perception?
it can be defined in 2 ways
sensory processes like receptor activation and neural firing
mental activity that mediates between sensation and awareness, interpreting what our senses are telling us
Sensation
the process of encoding energy or chemicals in the environment in terms of neural signals
a basic experience elicited by a simple stimulus
more concerned with your own physical experience
ex: the warm of skin, this is egocentric as what is warm can vary from person to person
Perception
the organization and interpretation of neural signals, making them meaningful
more complex conscious experiences produced by integrating sensations
more concerned with identifying stimuli
ex: when you see the stove is red, and producing heat that you can fee;, you know that its 30 cm away from you can can burn you
what are some reasons to study perception
- understanding basic research
-determine how underlying mechanisms function
-it is the first step in understanding cognition
-to know why orange juice tastes bad after brushing your teeth - to solve practical problems
-develop solutions for disabled people, like braille, glasses
-to produce substitutes for the world, like stereos and VR
-to produce substitutes for the observer. like robotic vision in the mars rover
Underdetermination
the central problem in perception
the world is 3D, the image on our retina is 2D, yet we think of the world in 3D
hypothetically we don’t have enough info to translate our 2D perception into 3D
Distal Stimulus
the object in the real world
the stimulus itself
an apple on the table, a finger poking your arm, basil sniffing my leg
Proximal Stimulus
the pattern of energy or chemicals impinging on our receptors
what we sense
the pattern of photos on our retina, kinetic energy on our skin, sound energy hitting the eardrum
structuralism
analyze the conscious processes into basic “elements”; specify how the elements become connected
breaking complex things into smaller components
the issue with this school of thought is that perception is holistic, not elemental, you can separate all the chemicals in a lemon that our brain knows is a lemon
Edward Titchner
structuralist
relied on introspection, the analysis of one’s own conscious experience because you can’t study anyone else’s
Wilhelm Wundt
had the first psych lab in 1879, the university of Leipzig
Gestalt Psychology
gestalt means “form/configuration”
opposed to structuralism, decomposition to elementary components loses information
a holistic approach that emphasized consciousness
specify the relationship among stimuli, the whole is different than the sum of its parts, has emergent properties
founded by Max Wertheimer
Constructivism
perceiving is an active process, affected by our knowledge and experience
we must interpret ambiguous information provided by the environment
the goal is to determine how existing knowledge influences perception
Ecological Approach
we should study perception in natural settings
the idea that enough mental information is available in the environment to make mental processes unnecessary
bc absolutely zero processing occurs when you open ur eyes, 100% real no cap
bottom up view of processing
JJ Gibson
followed the ecological approach
proposed that information was directly picked up from the environment
Information-Processing Approach
describes the flow of incoming sensory information via hypothesized internal processes
information is analyzed to decode and interpret it
does not differentiate between sensation, perception, and cognition
highly influential in cognitive psych
Computational approach (CA)
assumes the mind is an information processor that receives, stores, retrieves, transforms, and transmits information
Has 3 levels of analysis
1. computational theory
2. representation and algorithm
3. hardware implimentation
computational theory (CA)
level 1 of CA
what is the system doing?
ex: what does it mean to see? to taste?
how can you study something if you don’t know what it is
representation and algorithm (CA)
level 2 of CA
what is a percept? how is it being processed?
do the eyes function like cameras? Is there an “inner screen” in our heads? (No)
our eyes process a lot of information before anything is sent to the brain
hardware implementation (CA)
what physical “machinery” does this?
what neural circuits allow us to see?
neurophysiological approach
based on reductionism: the understanding of behaviour via studying the underlying biological processes
the idea that things are easier to understand after dividing them
more important for sensation than perception
Doctrine of specific nerve energies
Muller 1837
percept depends on which nerve has been activated, leak seeing light when the optic nerve is activated
different sensory nerves go to differ brain regions
Perception and evolution
what are the evolutionary advantages of a particular sense
perception and coding/representation
how is a stimulus encoded into our sensory neurons and represented in the brain
Modularity and perception
how are different aspects of a stimulus analyzed
integration and perception
how are these different aspects recombined to form a whole percept?
processing and perception
how do top-down/existing knowledge structures and bottom-up/incoming sensory data processes interact?
subjectivity and perception
how well does our perceptual experience represent objective reality?
action
any motor activity
aftereffect
a sensory experience that occurs after prolonged experience of visual motion in one particular direction
angnosia
a neurological condition characterized by the inability to recognize or interpret sensory stimuli despite having intact sensory functions.
For instance, someone with visual agnosia may see an object but cannot identify it. Agnosia is typically associated with brain damage or dysfunction.
amusia
a condition in which brain damage interferes with the perception of music but does not interfere with other aspects of auditory processing
direct perception/gibsonian approach
a condition in which brain damage interferes with the perception of music but does not interfere with other aspects of auditory processing
another name for the ecological approach
doctrine of specific nerve energies
the argument that it is the specific neurons activated that determine the particular type of experience
Functional magnetic resonance imaging (fMRI):
a neuroimaging technique that generates an image of the brain on the basis of the blood levels in different areas of the brain, which correlate with activity levels in those regions
microelectrode
a device so small that it can penetrate a single neuron in the mammalian central nervous system without destroying the cell
neural response
the signal produced by receptor cells that can then be sent to the brain
neuroimaging
technologies that allow us to map living intact brains as they engage in ongoing tasks
neuropsychology
the study of the relation of brain damage to changes in behavior
Phenomemology
our subjective experience of perception
prosopagnosia
face agnosia, resulting in a deficit in perceiving faces`
psychophysics
the study of the relation between physical stimuli and perception events
receptors
specialized sensory neurons that convert physical stimuli into neural responses
sensation
the registration of physical stimuli on sensory receptors
stimulus
an element of the world around us that impinges on our sensory systems
transduction
the process of converting a physical stimulus into an electrochemical signal
unconscious inference
perception is not adequately determined by sensory information, so an inference or educated guess is part of the process; this inference is not the result of active problem solving but rather of a nonconscious cognitive process
Weber’s Law
a just-noticeable difference between two stimuli is related to the magnitude or strength of the stimuli
Discuss why understanding sensation and perception is important.
The study of sensation and perception sheds light on the basic nature of what it is to be human. Sensation is the registration of physical stimuli on sensory receptors, and perception is the process of creating conscious perceptual experience from sensory input.
Our sense of touch is composed of multiple systems designed to sense different features of the environment. Heat, coldness, pain, itchiness, and soft touch are all implemented by separable sensory systems
Describe how transduction transforms a physical signal into a neural signal.
Sensory systems transduce physical signals into neural responses, which are sent to the brain for processing. The brain processes the signals, determines their meaning, and decides on appropriate actions. Perception also produces a characteristic phenomenology, which is the purely subjective experience we get when perceiving the world.
Illustrate the history of the study of sensation and perception.
ancient Egyptians, aristotle, Germans physiologists and psycho physics, gestalt psychology, ecological approach/direct perception, informational processing, the computational approach
Understand the impact of neuroscience on our understanding of sensation and perception.
Neuroscience also addresses issues of sensation and perception. Neuroscience research includes single-cell recording, neuropsychology, and neuroimaging. Neuroscience allows us to understand the brain mechanisms involved in sensory processes.
the myth of the 5 senses
originated from aristotle.
humans have more than five sensory systems, and the concept of just five senses does not encompass all ways in which we gather information from our environment.
Eight Different Human Sensory Systems
Vision: Perception of light and color.
Audition (Hearing): Perception of sound.
Olfaction (Smell): Detection of odor molecules.
Gustation (Taste): Detection of flavors.
Somatosensation (Touch): Detection of pressure, temperature, pain, and texture.
Proprioception: Awareness of body position and movement.
Vestibular System: Balance and spatial orientation.
Interoception: Awareness of internal bodily states, such as hunger, thirst, or heartbeat.
Sensation vs. Perception
Difference: Sensation is the raw data received from sensory organs, while perception is the brain’s interpretation of this data to create a meaningful experience.
what is transduction and why is it important?
Transduction is the process by which sensory receptors convert physical stimuli (e.g., light, sound waves, or chemicals) into electrical signals that the brain can interpret. For example, in vision, light is transduced into electrical impulses by the photoreceptor cells in the retina.
Importance to Perception: Without transduction, the brain would not be able to process sensory stimuli. It is the bridge between the external world and the brain’s ability to perceive it.
Why is phenomenology difficult to address in science
Phenomenology is challenging to address scientifically because it involves subjective, first-person experiences that are hard to measure or verify objectively. Scientific methods typically rely on third-person observations and measurable data, making it difficult to directly study consciousness.
Hermann von Helmholtz
Hermann von Helmholtz was a 19th-century German physicist and physiologist who made significant contributions to the study of sensory perception, particularly in hearing and vision.
View of Color Vision: Helmholtz proposed the Trichromatic Theory of color vision, which suggests that the human eye has three types of color receptors sensitive to red, green, and blue light. According to this theory, all the colors we perceive are combinations of these three primary colors.
Ewald Hering
Ewald Hering proposed the Opponent-Process Theory, which suggested that color perception is controlled by three opposing pairs: red-green, blue-yellow, and black-white. According to Hering, these pairs work in opposition, meaning when one color in the pair is stimulated, the other is inhibited.
importance of unconscious inference in the constructivist approach
In the constructivist approach to perception, the brain is viewed as actively constructing our perceptual experience based on incomplete sensory information and prior experiences, using unconscious inferences to fill in the gaps.
JND
just noticeable difference
the minimum difference between two stimuli that a person can detect at least 50% of the time. It is a threshold for detecting changes in sensory input.
Real-world Example: the difference between adding 100 grams to a 1kg weight vs 10 grams. people would be much less likely to notice the 10 grams added
Direct Perception vs. Information-Processing View
The direct perception view emphasizes immediate perception without mental intermediaries, while the information-processing view sees perception as requiring cognitive operations and the manipulation of sensory data.
Cognitive Impenetrability
Refers to the idea that certain perceptual processes are unaffected by higher-level cognitive processes like beliefs, desires, or expectations. For example, the perception of visual illusions remains stable even if we know that what we see is not real.
Cognitive Penetration
Occurs when cognitive factors (such as knowledge or expectations) influence what and how we perceive. For example, knowing that an object is far away might alter our perception of its size.
Cognitive Impenetrability vs. Cognitive Penetration
Cognitive impenetrability suggests a separation between perception and cognition, while cognitive penetration implies that perception can be influenced by cognitive factors.
Time to Collision (TTC)
the time remaining before an object in motion will collide with an observer or another object, based on the object’s current velocity and distance. This is crucial in activities like driving, where estimating the TTC helps avoid collisions.
Size-arrival effect
This phenomenon refers to the tendency for larger objects to be perceived as arriving sooner than smaller objects, even when they are moving at the same speed. This bias can affect judgments in situations like driving, where larger vehicles may be judged to arrive sooner than smaller ones, leading to miscalculations in time to collision.
