This is part of the summary of Course 2.4 Perception at Erasmus University Rotterdam.
I put a lot of effort into making these summaries and included pictures and graphs to make things as understandable as possible. I managed to get quite a high grade on the course exam at the end (8.8).
Note thoug...
Course 2.4 Perception
Problem 3: Perception and decision making
Literature: Wolfe, Goldstein
Methods to study senses
1. Thresholds
- Gustav Fechner (1801-1887): true founder of experimental psychology
o Wishes to explain relation between mind (psycho-) and body (physics)
o Fechner´s law: proportional increase of subjective sensation to the logarithm of stimulus Intensity
= as stimulus intensifies, bigger changes are required to detect a difference
o Absolute threshold = the minimum intensity of a stimulus that is needed to be detected
- Ernst Weber (1795-1878): interested in touch
o Tested accuracy of sense of touch (smallest distance between 2 points that we don’t feel as one)
= two-point touch threshold
o also judgement of lifted weights (compare weight to standard weight)
small difference easily detected when standard was light
heavier weight need greater difference
→ JND (Just Noticeable Difference) or difference threshold
o JND change in systematic way:
Smallest detectable weight change is 1/40th of standard weight
“Weber fractions”
Smallest detectable length of line change 1/100
→ found constant ra o for every measure (brightness, tone/pitch, me)
→ excep ons: when measure is extreme (small/large)
o Fechner named mathematical formula/ general rule: K=∆ /
- Psychophysical methods: measurement of absolute threshold
o Method of constant stimuli
Stimuli of different intensities are presented → par cipant replies
“yes”/ “no” or “same/different”
Stimuli of same intensity presented multiple times (important bc
thresholds vary); random order
Stimuli needs to be perceived 50% of the time→ fluctua ons of the
nervous system → some mes threshold is detected, other mes
not.
E.g. hearing test
() inefficient if many stimuli below/above the threshold are presented (waste of time)
(+) simple
o Method of limits
Set of tones are presented in increasing/decreasing order → listener reports when he first hears the
tone
Average of crossover points → threshold
o Method of adjustment
Same as method of limits, but this time participant adjusts intensity of the stimulus
2. Scaling
- Discover magnitude of subjective perception (“Make the other light 2x as light as this one.”)
o Magnitude estimation: participants rate experience by their own (or given) scale
o Steven´s power law = describes relation between stimulus and subjective sensation. States the sensation is
proportional to the stimulus magnitude raised to an exponent
S = ab
Exponent ˂ 1: sensation grows slower than stimulus
E.g. sensation of electric shock has exponent of 3.5 (4x increase feels 128x more painful)
o Cross modality matching: participant matches perceived magnitude of stimuli to a different type
E.g. loudness of tone to brightness of light → similari es of variance
Different when it comes to taste: PROP (molecule that some humans have and others don’t)
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper LauraLie. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €3,24. Je zit daarna nergens aan vast.