Pierce & Hall model Flashcards
What is the attention model for pierce and hall?
effectivity of CS
The more you learn on a trial > the more the CS attracts attention!
How does surprisingness CS work?
attention on CS regulated by how surprising the US was on trial n-1
If US was very surprising on n-1 trial than a lot of attention on CS.
Surprisingness of US only a proactive effect on attention
Influence on next trial > (n+1)
What is the formula of salience for pierce and hall ?
αA = variable
αAn (on current trial) (salience) = |λn-1 – VAn-1|
λn-1 = associative strength US on trial n-1
VAn-1 = associative strength of CSA on trial n-1
|λn-1 – VAn-1| = absolute difference
What is the formula of change in associative strength ?
Change in associative strength of CS A (ΔVA) is a function of:
ΔVA = SA αA λ
SA = intensity of CS-A
αA = associability CS-A
λ = intensity US
OR: ΔVAn = SA |λn-1 – VAn-1| λn
What is salience?
Ability to draw attention of CS= SALIENCE of a stimulus
What is the assumption regarding the first trial?
Additional assumption = that each CS has positive association on first trial!
Trial2 αAn = |λn-1 – VAn-1|»_space; salience big > on trial1 VA was 0, dus SA αA λ big.
Trial3 αAn smaller than on trial2, want op trial 2 was VA already positive so |λn-1 – VAn-1| smaller than on trial2.
SA αA λ smaller than on trial 2
As trials goes on: λn-1 – VAn-1| gets smaller
VAn-1 = closer to 1
What is blocking according to P-H?
Blocking A+ followed by AB+
Fase 1 (A+ training): VA = 1 en αA = 0
Fase 2 (AB+ training)
first trial: αB zal (as a new stimulus) will have a normal starting value, bigger than zero 0
ΔVB = SB αB λ will not be 0 on first trial !!
next trial(s): αBn = |λn-1 – VABn-1|= 0 want VABn-1 = 1 because VAn-1 = 1, so no more learning = blocking vanaf 2e trial
What is latent inhibition according to PH?
Pre-exposure CS alone - without US
αAn = |λn-1 – VAn-1| will be equal to 0 (λn-1 and VAn-1 = 0)
Consequence:
On first CS-US together trial > no learning!
“adjustment” αA on next trials
How does unblocking work?
Unblocking trough weaker or stronger US on compound trial possible!
|λn-1 – VAn-1| > absolute difference is what matters > under or over prediction is the same
Dus: also after 1st compound trial learning further…
