sensations n perceptions Flashcards
what is the reticular theory?
how is it discovered?
reticular theory
- nervous system is an undifferentiated network called reticulum
- signals flow continuouosly
discovered through staining tech by golgi. neurons are interconnected fibers, forming a “reticulum” (a mesh-like structure).
what is the neuron doctrine?
cajal 1894
neurons separated by small gaps
- neurons processes independently
- signals pass intermittently
Broca’s area and Wernicke’s area are connected by a bundle of nerve fibers called the ________.
arcuate fasciculus
what is arcuate fasciculus
white matter tract that connects broca’s and wernicke’s
where is broca’s? (which lobe and which areas of Brodmann)
frontal lobe
Brodmann areas 44 and 45
where is wernicke’s? (which lobe and which areas of Brodmann)
temporal lobe
Brodmann area 22
left hemisphere of brain is for ____ and right hemisphere is for ____.
language; memory
what is the wada test?
determine which hemisphere of the brain controls language and memory
injecting a barbiturate (usually sodium amytal) into one hemisphere of the brain via the carotid artery, temporarily “numbing” it
allows doctors to observe how language and memory function when one hemisphere is temporarily shut down
what is prosopagnosia? where is damaged in the brain to cause this?
inability to recognise faces
FFA: fusiform face area
seeing faces in things is called ________
pareidolia
**a result of the brain’s pattern recognition system, which evolved to help us quickly identify faces, an important social cue
animal models is to ablation as neurological patients is to _________
lesion
ablation vs lesion
Ablation is a controlled, experimental method of creating brain damage, while lesion refers to any damaged area, whether caused intentionally or by injury/disease.
what are 4 factors/problems hindering computers to recognise objects like humans do?
inverse projection problem - difficulty in determining the 3D structure of an object from a 2D image
noise/occlusion/blur
viewpoint variance
scene complexity (separating figure from ground)
direct perception is known as _______ processing while constructive perception is known as ___________ processing.
explain each one.
bottom-up
- comes from stimuli in envt
- stimuli identified, put together, then recognised
top-down
- construct perceptions using info based on expectations
what is helmholz theory of unconscious inference?
we make quick, automatic guesses about the world around us based on our past experiences
inferences happen unconsciously
fill in gaps based on past experiences
helmholz (fill in gaps), semantic regularities, and physical regularities (lighting, gravity, object continuity) are part of ______ processing/perceptual organisation.
top-down
what is the oblique effect?
people perceive vertical and horizontal lines more clearly and accurately than oblique (diagonal) lines
**reasons:
- more common inenvironment (e.g., buildings, trees, roads)
- retina is structured to be more sensitive to vertical and horizontal orientations
what is semantic regularities?
predictable and meaningful patterns in envt based on knowledge and experience
gestalt principles are examples of ______ processing/perceptual organisation.
it states that the combined ____ is ____ than the sum of its ___. grouping is performed through _____ basic principles.
bottom-up
whole; more; parts
simple
name the 6 gestalt principles
pragnatz - simplest structure
good continuation - objects continue even when partially blocked
similarity - similar in appearance (such as color, shape, or size) tend to be grouped together
proximity - Objects that are close to each other in space are perceived as being related or grouped together
completion - dotted pictures (“fill in” missing information to complete a shape or object)
multistability - images or patterns can be interpreted in more than one way
what is bayesian inference? which processing is it under? topdown or bottomup?
method of reasoning and decision-making based on probability theory
top-down processing
Prior: You start with a belief based on previous experiences (e.g., in your region, there’s a 30% chance of rain tomorrow).
Likelihood: you receive new evidence—let’s say you observe dark clouds. Based on weather patterns, dark clouds have a high probability of leading to rain.
Posterior: After combining the prior (30%) with the new evidence (dark clouds), you update your belief and now believe there’s an 80% chance of rain tomorrow.
what are the 2 environmental regularities under top-down processing called?
semantic
physical
does the gestalt principles discount knowledge or top-down effects?
no
dorsal stream in the brain is responsible for processing spatial information, thus answers the questions of ___ and ____.
where and how
ventral stream in the brain processes object recognition and answers the question of _____.
what
_______ stream in the brain processes object recognition and answers the question of what.
ventral
_________ stream in the brain is responsible for processing spatial information, thus answers the questions of where and how.
dorsal
up or down
ventral is ___ while dorsal is ____
down (eg. temporal); up (eg. parietal)
what is crossmodal perception?
ability of our brain to integrate and process sensory information from different sensory modalities (like sight, sound, touch, taste, and smell) to create a unified perception of the world.
