Intro & the Chemical Senses Flashcards
What is perception?
Perception is giving meaning to a detected stimulus (interpretation of a sensation)
What is Psychophysics?
The study of the relationship between the private
experience of sensation (psycho) and the outside
world (physics)
What are 2 chemical senses?
Smell = olfaction Taste = gustation
What is the absolute threshold?
An absolute threshold is the level of stimulus energy that is needed to correctly detect the stimulus, 50% of the time (e.g. a ticking watch 6 meters away in silence)
What are the stimuli called that are only detected less than 50% of the time?
Subliminal
What are the stimuli called that are detected more than 50% of the time?
Supraliminal
What is JND?
Just noticeable difference: the smallest amount of physical difference in stimuli before people noticed that there was a difference
What does Weber’s law state?
The JND is proportional to the standard measure (e.g. JND occurs from 40g to 5 grams plus 1 g is noticeable, but in 4kg change isn’t noticed when 1g is added, noticed when 100g are added)
When doesn’t Weber’s law stack up?
When there are incredible small or incredibly large intensities
What does Fechner’s law state?
Our psychological experience of sensations increases less quickly than actual increase in the physical stimulus
What is Steven’s power law?
The relationship between subjective sensation and stimulus intensity follows a power law (and changes depending on the sensation eg. pain increase faster than light)
What are the 3 laws that explore the relationship between sensation and stimulus?
Weber’s JND
Fechner’s Law (equation for JND)
Steven’s Power Law
Which sensation had the highest score on Steven’s Power law and which had the lowest?
Electric Shock (2nd warmth) Brightness (2nd smell)
What is cross modality matching used for?
to determine whether people’s sensations of stimuli intensity is similar or not
What senses are generally similar between people and which generally differ?
Similar: hearing & vision
Differ: smell & taste
What do you call the chemical compounds that we can smell?
Odourants
Where is the centre of smell detection?
at the olfactory epithelium
What does the olfactory epithelium contain?
olfactory receptor cells
olfactory sensory neurons (OSNs)