semantic memory knowledge memory main questions how do we gain knowledge? how is our knowledge...
TRANSCRIPT
Semantic MemoryKnowledge memory
Main questions
How do we gain knowledge?
How is our knowledge represented and organised in the mind-brain?
What happens when we access information?
(Note 2nd and 3rd questions are strongly related.)
Semantic MemoryKnowledge memory
Main questions
How do we gain knowledge?
How is our knowledge represented and organised in the mind-brain?
What happens when we access information?
Test predictions of semantic network model
Semantic Memory
Important tasklexical decision task
make a word-nonword judgement fora letter string
murget
higgle
beer
stout
Semantic Memory
Important tasklexical decision task
make a word-nonword judgement fora letter string
Priming paradigmexamine the influence of one stimulus on the
production of (e.g., naming of) or lexical decision for another stimulus
AnimalBreathes
Skin
Fish
Gills
Tail fin
Trout
Swims
Eel
Perch
Gills
Gills
Gills
Spread of activation means that some nodes willbe more highly activated following the activation of a related concept
Decisions for or naming of some concept (node) should be facilitated by the activation of a related concept
Example: Activation of “fish” should facilitate (speed up)the lexical decision RT for “salmon” compared to anunrelated concept (e.g., chair – salmon)
Test some predictions of the semantic network
Use of word naming as a task(name/read a word as quickly possible)
Fruit
P
Loftus & Loftus (1974)presented fruit – P (subject gives a name of fruit starting with P)investigated idea that priming dissipates with time immediate vs. delayed repetition of category
Reasoning: 1 trial could prime performance on a later trial(priming across or between trials)
If activation decreases with time, then there should be more priming on an immediate trial compared to a delayed trial
Loftus & Loftus (1974)
Prime TargetTrial 1 fruit A (initial trial)Trial 2 fruit P (immediate, lag = 0)
Prime TargetTrial 1 fruit A (initial trial)Trial 2 vehicle TTrial 3 fish STrial 4 fruit P (delayed, lag = 2)
Prediction: Naming RT should be lower (faster) for the immediate trial compared to the delayed trial.
Naming RT as a Function of Condition
Condition
1400
RT (ms)
initial trial lag = 0 lag = 2 Category Repeat
2300
Naming RT as a Function of Condition
Condition
1400
RT (ms)
initial trial lag = 0 lag = 2 Category Repeat
2300
1st trialprimedlater trials
Naming RT as a Function of Condition
Condition
1400
RT (ms)
initial trial lag = 0 lag = 2 Category Repeat
2300
moreprimingfor lag=0than lag=2
Loftus & Loftus (1974)
Prime TargetTrial 1 fruit A (initial trial)Trial 2 fruit P (immediate, lag = 0)
Prime TargetTrial 1 fruit A (initial trial)Trial 2 vehicle TTrial 3 fish STrial 4 fruit P (delayed, lag = 2)
Prediction: Naming RT should be lower (faster) for the immediate trial compared to the delayed trial.Prediction upheld. Conclusion: Activation decreases with time.
Other examples
nurse
doctor
nurse (prime)
doctor (target, right after prime)
(make a lexical decision for “doctor” or pronounce “doctor”)
Does “nurse” prime “doctor”?
Compare RT for
nurse – doctor (related condition)
shoe – doctor (unrelated condition)
nurse – doctor RT < shoe – doctor RT xxx – doctor RT (neutral) blank – doctor RT (neutral)
Difference is a priming score.
Basic semantic priming effect:
Presentation of nurse speeds up (facilitates) lexical decision or proununciation time of doctor compared to a control condition
Basic semantic priming effect:
Is spread of activation automatic?
Evidencemediated priming
effects at short SOAs
effects at short SOAs despite exectancy
Basic semantic priming effect:
Is spread of activation automatic?Evidence Mediated priming (Lorch & Balota, 1986)
nurse related to doctor, doctor related to lawyernurse not related to lawyer
nurse – primelawyer – target
nurse facilitates pronunciation time for lawyer!
Priming is mediated by doctor!i.e., activation spreads from nurse to doctor to lawyer
Basic semantic priming effect:
Is spread of activation automatic?
Choosing the right control condition
Evidenceeffects at short SOAs
effects at short SOAs despite exectancy
Control condition: shoe (prime) - doctor (target)
What if shoe affects decision RT for doctor?!
That is, maybe shoe – doctor is not a good control condition.
Need a better control condition: xxx (not a word)
Does nurse affect decision RT for doctor?Does shoe affect decision RT for doctor?
What if shoe affects decision RT for doctor?
Need a control condition: xxx
Does nurse affect decision RT for doctor?Does shoe affect decision RT for doctor?
Compare RT for nurse – doctor (related condition)
xxx – doctor (control or neutral condition) shoe – doctor (unrelated condition)
Compare RT for nurse – doctor (related condition)
xxx – doctor (control or neutral condition) shoe – doctor (unrelated condition)
nurse – doctor RT < xxx – doctor RT
Facilitation
Compare RT for nurse – doctor (related condition)
xxx – doctor (control or neutral condition) shoe – doctor (unrelated condition)
shoe – doctor RT > xxx – doctor RT
Inhibition
Neely (1976)related, unrelated, and neutral primes
also manipulated prime-target SOA basic idea:
shorter SOA—decision based on automatic processes
longer SOA—decision based on automatic + controlled processes
see OverheadFigure 6.10 from Ashcraft (1998)
RT (in ms) as a function of prime-target condition and SOA
Prime-TargetCondition SOA RT
Neutral 360 592Related 360 575 (17 ms facilitation)Unlrelated 360 611 (19 ms inhibition)
Neutral 600 588Related 600 543 (45 ms facilitation)Unlrelated 600 598 (10 ms inhibition)
Neutral 2000 606Related 2000 554 (52 ms facilitation)Unlrelated 2000 625 (19 ms inhibition)
RT (in ms) as a function of prime-target condition and SOA
Prime-TargetCondition SOA RT
Neutral 360 592Related 360 575 (17 ms facilitation)Unlrelated 360 611 (19 ms inhibition)
Neutral 600 588Related 600 543 (45 ms facilitation)Unlrelated 600 598 (10 ms inhibition)
Neutral 2000 606Related 2000 554 (52 ms facilitation)Unlrelated 2000 625 (19 ms inhibition)
Neely (1976)Results show facilitation and inhibitionResults show an increase in facilitation from SOA of about 350 to an SOA of 600
Why should facilitation increase?
Two types of processes at work?
Maybe initial facilitation is automatic.Maybe extra facilitation is due to controlled
processes.
Neely (1977)related, unrelated, and neutral primesalso manipulated SOA
AND expectancy (thought to reflect controlled processing,which should take some time to be able to be used)
Neely (1977)
Expectancy (thought to reflect controlled processing,which should take some time to be used effectively)
see bird prime, expect a type of bird as a target
bird
robin
bird
dove
bird
arm
Neely (1977)
Expectancy (thought to reflect controlled processing,which should take some time)
see bird prime, expect a type of bird as a target
sometimes get a type of bird as a target
on occasion, get a word from a different category as a target
see Overhead Figure 6.11 (left panel) from Ashcraft (1998)
Only facilitation at first (short SOA), no inhibitionfacilitation effect based on automatic processing(the expectancy hasn’t had time to kick in)
As SOA increases, faciliation and inhibition increaseincreases based on controlled processing(the expectancy has now kicked in and is being used)
Neely (1977)Expectancy (see Table 6.2 from Ashcraft, 1998)(thought to reflect controlled processing,which should take some time)
see body prime, expect part of a building as a target(i.e., expect a category shift)
body
window
body
roof
body
door
body
heart
Neely (1977)Expectancy (see Table 6.2 from Ashcraft, 1998)(thought to reflect controlled processing,which should take some time)
see body prime, expect part of a building as a target(i.e., expect a category shift)
sometimes get part of a building as a target(expected, but not actually related to the prime)
on occasion, get a body part as a target (actually related to the prime, but not expected)
see Overhead Figure 6.11 (right panel) in Ashcraft (1998)
Expected Shift, but Unrelated prime-target (e.g. body – door)
No facilitation at first (short SOA),But facilitation at longer SOAs
No effect based on automatic processingLater facilitation based on controlled processing
(the expectancy)
Related prime-target, but not expected(e.g., body – heart)
Facilitation for short SOA (even though not expected)Inhibition for later trials (even though related)
Initial facilitation effect based on automatic processing(*occurs despite expecting an unrelated target)
Later inhibition effect on controlled processing(the expectancy)
Facilitation in 250-ms SOA condition for related, but unexpected target provides strong evidence for the idea priming is automatic—consistent with the idea of spread of activation.
Evidence from longer SOAsControlled processes can contribute quite a bit to inhibition and facilitation effects.
Semantic Memory
Main questionsHow do we gain knowledge?How is our knowledge represented and organised in the mind-brain?What happens when we access information?
1) Good evidence for automatic activation of related
information (spread of activation). 2) Activation drops fairly quickly. 3) Controlled processes affect performance and need
to be dealt with in terms of theory.