Lecture 2 - Sensation and Perception Flashcards
Summary of the study methods in psychology
case studies, naturalistic observations and surveys (descriptive methods) and correlational methods, experimental methods and surveys
experiment
research methods that tests a hypothesis and makes conclusions about causality
independent variable
variable controlled and manipulated by experimenter
dependent variable
measure demonstrating the effects on the independent variable
reliability
consistency of a measure
validity
quality of a measure leading to correct conclusions
variance
measurement of spread between numbers in the data set
standard deviation
measures how far each number in the set is from the mean (large variance = higher curve)
sensation
process of DETECTING stimuli
perception
process of INTERPRETING sensory information
sensory adaptation
a reduction in sensory receptors to a stimulus after constant exposure (walk in room with strong scent, dont notice after a while)
selective attention
focus on a subset of information more relevant to us
what are the two ways of makings sense of stimuli
bottom-up and top-down processing
bottom-up processing
we allow stimulus itself to shape our perception without any preconception
top-down processing
we use our background knowledge and expectations to interpret what we see
psychophysics
study of relationships between stimuli and perception of those stimuli
absolute threshold
smallest amount of stimulus that can be detected 50% of the time
difference threshold
smallest amount of difference between two stimuli that can be detected 50% of the time
signal detection theory
the analysis of sensory and decision-making processes in the presence of uncertainty
retina
allow us to see, contain three photoreceptors (rods, cones and specialized ganglion cells responding to brightness)
rods
sensitive to light, good at seeing dim light
cones
ability to see colours and sharp images, function best under bright light
primary colours of paint
red, yellow and blue
primary colours of light
red, green and blue
What theory is Helmholtz known for
trichromatic theory
Trichromatic theory
suggests that the eye contains 3 types of receptors (red, blue, green) which are compared to perceive colours
What are Hering-Hurvich known for
Opponent-Process theory (believed that the way we view colors is based on a system of opposing colors)
depth
visual perception which the brain constructs through 2D and 3D images
how can the human eye perceive depth?
monocular cues (from one eye) and binocular cues (from two eyes)
monocular cues to depth perception
interposition, relative size, relative height, texture gradients, perspective convergence (parallel lines), shadow and motion parallax
illusions
result from our use of monocular cues to judge depth
binocular cues
binocular disparity cue (different optical immages produced on the reitans of both eyes) and convergence cue (two eyes rotate inwards to project images on retinas)
Gestalt approach
emphasize that organisms perceive entire patterns of configurations, not merely individual components
principles of Gestalt approach
figure-ground, proximity, similarity, closure, continuity and common region
Figure-ground
the spontaneous division of a scene into a main figure (what attracts attention) and ground (what does not)
proximity
objects closer together tend to be grouped together
similarity
similar stimuli are grouped together
closure
perceive objects as complete rather than focusing on the gaps that the object might contain
continuity
points that form smooth lines when connected are probaby grouped together
common region
items within a boundary are perceived as a group
