By sibylle.petersen - 5/31/2015
Dear all
I plan to use the Stop Signal Task in one of my studies. I have looked at the script in the task library and the paper by Verbruggen et al., 2008.
I am very unsure how to interpret the output. If anyone could briefly respond whether my ideas about how to interpret these values are correct (see below) I would be very grateful.
Thank you and have a good day
Sibylle
expressionsp_rs:p respond if signal?
expressionsssd: delay stop signal?
expressionsssrt :covert latency of the stop process?
expressionssr_rt: mean signal respond reaction time?
expressionsns_rt: reaction times no-signal trials?
expressionsns_hit: percentage hits no-signal trials?
expressionsmiss: percentage misses in no-signal trials?
expressionsz_score:probability to inhibit
expressionsp_value: probability to inhibit
|
By Dave - 5/31/2015
Sure. If you look at Verbruggen et al. (2008), p. 482, you'll find:
The following variables are estimated or calculated:
- mean p(respond|signal),
- mean SSD,
- SSRT,
- mean signal-respond RT,
- no-signal RT,
- percentage of correct responses on no-signal trials, and the
- percentage of missed responses on no-signal trials.
[...] will also calculate a
- z score and the corresponding
- p value
to indicate whether each subject inhibited significantly more or less than 50% of the time.
These correspond to
- expressions.p_rs
- expressions.ssd
- expressions.ssrt
- expressions.sr_rt
- expressions.ns_rt
- expressions.ns_hit
- expressions.miss
- expressions.z_score
- expressions.p_value
in the order given. The variable names follow those in the original program by Verbruggen et al.
|
|