Greg Detre
5/3/00
reaction time (RT) � measure of the processing taking place
Coltheart�s patient
Normal subjects
Evetts + Humphreys (1981)
mask-prime-target-mask
priming = the unfinsihed/unconscious processing has left some activation which speeds up the processing of the target
lower case = prime
inference = abstract letter recognition independent of lower/upper case
Interactive Activation model � Rumelhart & McClelland (1981)
all information processing is done by a flow of excitation/inhibition between nodes which represent information about the outside world or about the model�s knowledge of the domain
knowledge = which patterns at input are consistent with stored knowledge
i.e. which central state corresponds best with the current state of the world
information-processing = a network of nodes in parallel with a flow of excitation/inhibition between them
system�s decision about the stimulus = the unit which reaches threshold most quickly, though other units may also be less active
constraint satisfaction = the node with most excitatory inputs = most active
decision = the best bet about the input
given all the sources of information (stored knowledge and stimulus input)
mutual inhibition then suppresses alternatives on the same level
degraded stimulus �/span> preference due to word level
inhibition which �/span> � letter-level activation which �/span> back up to word level
= +ve feedback (+ rich get richer)
Word superiority effect � Reicher 1969
when presented with word, rather than just a letter, followed by a mask
subjects find it easier to detect a letter in a word than the letter in isolation
Scarborough et al (1977) � reading a word aloud
Oldfield & Wingfield (1965) � name a picture
the more common, the quicker (frequency effect)
if you repeat it, the quicker (repetition effect)
if it follows a known pattern (regularity effect)
frequency/regularity interaction
differences in speed of processing (pronunciation time)
�/span> inferences about the nature of storage/representation
information is not stored like a dictionary/hard disk
it adapts to the use made of it
= advantage if the world is predictable