Task 1 - Reaction Time Flashcards
What is reaction time defined as?
the time interval between the onset of a stimulus and the overt response to that stimulus
- trials should be repeated frequently, to get a reliable mean RT
- assumption: pp intends to be as fast as possible without making errors
What is relevant to know about errors, when looking at RT?
- considering the speed-accuracy tradeoff
- delete error trials to increase RT accuracy
what is the speed-accuracy tradeoff?
- when increasing speed, the number of errors will increase (= reduction in accuracy)
- when decreasing speed, the number of errors will decrease (= increase in accuracy)
- goal: to find the theoretical definition
= unbiased RT (optimum) - to counter it: RT tasks are being repeated with different instructions (= different RT means that will be averaged) -> differnt conditions will result in different extreme emphasise
What is important about anticipation in RT?
participants anticipating a stimulus may affect reaction time
= Predictability influences reaction time
= may underly the speed-accuracy trade-of
What is important about outliers in RT?
- outliers should be removed from RT means, since they confound the general analysis
- normal to remove them from lvl1 analysis, but not from lvl2 (= fraud)
What are Donder´s 3 tasks ?
Donder´s substraction methods
- Simple reaction time (a)
- Go/ no-go reaction time (c)
- choice reaction time (b)
can calculate the:
= duration of response selection (B-C)
= duration of stimulus discrimination (C-A)
What are stages? Theory 1
- two independent stages
- A: task identification of a digit (incl. output)
- B: serial comparison of this code to the representation
- degradation of the stimulus would lead to an increase of the duration of only A, no effect on B
- Additivity (= independence btw. 2 processes)
What is the substraction method?
- construct two task that differ only in a single component of processing
- measure reaction time in tasks
- substract reaction time
- outcome is the duration of the single component
= deleting mental operations from RT
What does pure insertion mean?
The duration of all other processing stages remains the same, when an extra stage is added
= no overlapping processes
! tends to be violated by default?
What does seriality mean? Relevance in Donder´s?
- Processing stages are carried out in a serial manner
- successive stages
- necessary for: sum of durations of individual stages = total RT
- one of the assumptions of Donder´s substraction method (+ Sternberg´s additive factor model)
What is Sternberg´s additive factor model?
A subtraction paradigm presupposes knowledge about the processes/ stages involved in RT
aim: Discover people´s processing stages
assumes seriality + refuses pure insertion
What is the importance of interaction in AFM?
Interaction
= effect of one factor modulated the effect of the other factor
= difference between the simple effects
<-> additivity
if two manipulations mutually modify each other´s effect (= interaction), they must affect some stage in common
What are the language factorial experiments?
factors: independent variables in an experiment
closely linked to AFM
What is the diffusion model?
provide a theory that explains the distribution of RTs of correct responses and errors in a 2 choice RT task
-> information grows in tiny steps
assumes:
- information accumulates continuously during the time between stimulus onset and response
- random noise in the information, due to which response times and outcomes vary from trial to rial
What is the random walk?
- process that underlies the diffusion model
- the information accumulates (incl noise)
- accumulation draws graph to upper/ lower threshold
- if threshold is reached -> reaction occurs
- random noise leads to different reactions
