Psych 101 UBC Midterm 2

Sensation

simple stimulation of a sense organ

Perception

the organization, identification and interpretation of a sensation to form a mental representation

Sensation occurs

at the level of sensory organ

Perception occurs

at the level of the brain

Blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

Transduction

The conversion from sensory stimulus energy to action potential.

when sensors convert external physical signals into encoded neural signals sent to the central nervous system; how sensory organs communicate with the brain

psychophysics

methods that measure the strength of a stimulus and the observer's sensitivity to that stimulus

absolute threshold

The sensitivity of a given sensory system to the relevant stimuli

the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time

psychophysics was tested by

Gustov Fechner

just noticeable difference (JND) or difference threshold

the minimal change in a stimulus that can just barely be detected

how much difference in stimuli is required to detect a difference between them

Weber's Law

The difference threshold is a constant fraction of the original stimulus

states that the just noticeable difference between two stimuli is a constant proportion despite variation in intensity

signal detection theory (SDT)

the response to a stimulus depends in both a persons sensitivity to a stimulus in the presence of noise and the person's response criterion

The ability to identify a stimulus when it is embedded in a distracting background

noise

all other stimuli coming from the internal and external environment

SDT light present your response no

miss

SDT light present your response yes

hit

SDT light not present your response yes

false alarm

SDT light not present your response no

correct rejection

sensory adaptation

the process whereby sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions

we often don’t perceive stimuli that remain relatively constant over prolonged periods of time

our sensory system is more interested in changes or constant stimulation?

changes

visual acuity

the ability to see fine detail

purpose of vision

to traduce visual energy in the world into neural signals

wavelength

The distance between two peaks

wavelength determines

colour

amplitude

height of a wave as measured from the highest point on the wave (peak or crest) to the lowest point on the wave (trough)

amplitude determines

brightness

purity

how many other lights are interfering

purity determines

saturation/richness of colour

path of a light through your eye

cornea, pupil,iris,lens,retina

vision is clearest at the

fovea

retina

a layer of light-sensitive tissue lining the back of the eyeball; the interface between the eye and the brain

accomidation

the process by which the eye maintains a clear image on the retina

cones

photoreceptors that detect color, operate under normal daylight conditions and allow us to focus on fine detail

cones detect

colour, detail, daytime vision

rods

photoreceptors that become active under low-light conditions for night vision

located throughout the remainder of the retina. Rods are specialized photoreceptors that work well in low light conditions, and while they lack the spatial resolution and color function of the cones, they are involved in our vision in dimly lit environments as well as in our perception of movement on the periphery of our visual field

Are rods or cones more sensitive to light?

rods

fovea

an area of the retina where vision is the clearest and there are no rods at all

myopia

nearsightedness (distant blurry)

hyperopia

farsightedness (close blurry)

blind spot

a location in the visual field that produces no sensation on the retina.. Even when light from a small object is focused on the blind spot, we do not see it

Area V1

the part of the occipital lobe that contains the primary visual cortex

Colour-opponent system

theory stating that pairs of visual neurons work in opposition

visual form agnosia

the inability to recognize objects by sight

parallel processing

the brains capacity to perform multiple activities at the same time

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

information from a patch of photoreceptors is organized by which cells?

bipolar and retinal ganglion

order in receptive field

cone patch, bipolar cells, axon, retinal ganglion, optic nerve

trichromatic colour vision

Colour vision occurs through the operation of three sets of cones, each maximally sensitive to a different wavelength of light

all colors in the spectrum can be produced by combining red, green, and blue

three types of cones

short, medium, long

short cone colour

blue

medium cone colour

green

long cone colour

red

colour blindness caused by

damage to medium and long cones

retinal ganglion cells

receive inputs from opposing cones within the same receptive field

opposing red field

green

opposing blue field

yellow

opposing yellow field

blue

opposing green field

red

each eye is split into two fields. Who side of the brain deals with each half?

the opposite side of the brain

path of visual signal

retina, optic tract, optic chasm, lateral geniculate nucleus of thalamus, primary visual cortex

illusory conjunction

a perceptual mistake whereby the brain incorrectly combines features from multiple objects

feature integration theory

the idea that focused attention is not required to detect the individual features that comprise a stimulus, but is required to bind those individual features together

perceptual constancy

a perceptual principle stating that even as aspects of sensory signals change, perception remains consistent

dorsal streams

where/action pathway

dorsal stream: occipital lobe to...

parietal lobe

where/action pathway

identifies the location and motion of an object

ventral stream

what/perception pathway

ventral stream: occipital lobe to...

temporal lobe

what/perception pathway

defines the shape and identity of an object

feature detectors work through

parallel processing

who looked into feature-integration theory?

Treismen and Smidt

binding process depends on...

parietal lobe in the dorsal stream

HM case study?

no right/left lobes, had many illusory conjunctions

Fmri shows during binding process

upper/prosterior regions of parietal active

fusiform facial area located in..

temporal lobe

modular view

specialized brain areas, or modules, detect and represent objects

distributed representation

the pattern of activity across multiple brain regions that identifies any viewed object, including faces

Gestalt perceptual grouping rules

modules of pattern perception govern how the features and regions of things fit together

simplicity

we select the simplest. most likely interpretation of an image

closure

the tendency to complete figures that are incomplete (connect gaps)

Continuity

edges or contours with the same orientation are grouped (two crossing lives not two vs)

similarity

the tendency to perceive things that look similar to each other as being part of the same group

proximity

objects that are close together tend to be grouped together

common fate

elements of a visual image that move together are perceived as parts of a single moving object

template

a mental representation that can be directly compared to a viewed shape in the retinal image

image-based object recognition

an object you have seen before is stored in memory as a template

monocular depth cues

aspects of a scene that yield information about depth when viewed with only one eye

Geons

the deconstruction of objects into parts (parts)

familiar size

how large an object is based on experience

interposition

one object is placed in front of another

relative size

differences in retinal image size

linear perspective

lines getting closer towards the back of images show distance

texture gradient

seen as size of pattern elements change

binocular disparity

the difference in the retinal images of the two eyes that provides information about depth

change blindness

failing to notice changes in the environment

apparent motion

the perception of movement as a result of alternating signals appearing in rapid succession in different locations

inattentional blindness

a failure to perceive objects that are not the focus of attention

pitch

How high or low a sound is

loudness

a sound's intensity

timbre

a listener's experience of sound quality or resonance

same level of loudness, yet they still sound quite different. This is known as the timbre of a sound. Timbre refers to a sound’s purity, and it is affected by the complex interplay of frequency, amplitude, and timing of sound waves.

frequency

refers to the number of waves that pass a given point in a given time period and is often expressed in terms of hertz (Hz), or cycles per second. Longer wavelengths will have lower frequencies, and shorter wavelengths will have higher frequencies....


pitch perfection