Laptops running eprime

[Leisha Wharfield]

This does help. The experiments we are running are actually very simple, 
and I will review the critical timing information for eprime to be sure 
I understand your method.

Thanks,

Leisha

Jeff Maxwell wrote:

>short of using a photodiode / oscilliscope, which is ideal, i believe
>your best bet would be to enable onset logging for all slide objects
>and export the relevant .edat onset timing columns to excel -- i've
>not generally observed the logged timing values to offer a different
>story from photodiodes.  in excel, subtract each slide onset time from
>the subsequent slide onset time to yield a new column of
>interslide_onset times.  compare this list of actual (logged) onset
>values to your expected values -- if you test without
>jitter/variation, all difference scores should be identical. 
>deviations in this column show trials on which the timing did not
>match your expectations.  but be careful not to look at the
>slide_offset values for verification, as the slides will appear to
>"offset" whenever the prelease is reached, even though they remain on
>the screen for the entire prerelease period.  so just use
>slide_onsets.
>
>enabling cumulative timing w/ prereleases and disabling vertical
>onsets and offsets are important, in my experience, for achieving the
>best timing.  the tradeoff is that your slide/images can be drawn
>starting from any point on the screen during the first frame, which
>shouldn't really matter unless you are using a backward visual masking
>paradigm or the like.
>
>i hope some of this helps,
>max
>
>--
>Jeffrey S. Maxwell
>Laboratory for Brain Imaging & Behavior
>Laboratory for Affective Neuroscience
>jsmaxwell at wisc.edu
>(608) 263 3672
>http://brainimaging.waisman.wisc.edu/~maxwell/
>
>
>
>On 1/5/06, Leisha Wharfield <leisha at decisionresearch.org> wrote:
>  
>
>> Thanks. I'm looking at 2 gigs of memory for each laptop. I'm loading
>>multiple images per slide, too. But I can load the background first, pause,
>>then load the actual stimulus. This should help me control refresh time, but
>>how do I measure it to be sure?
>>
>> Leisha
>>
>>
>> Jeff Maxwell wrote:
>>
>> for what it's worth, i verified stimulus/screen timing on some HP
>>Pavillion notebook computers with a photodiode and there were no
>>problems whatsover. it very pleasantly surprised me. i used
>>cumulative timing, disabled the sync to vertical onsets and offsets,
>>and then pushed the limits down to stimuli of ~50 msec (3 frame)
>>duration.
>>
>>the only time timing was ever an issue was when i was reading in
>>multiple image files per slide object. i was able to remove this
>>problem by (a) reading the stimuli into a buffer before calling them
>>in the eprime procedure and (b) without pre-loading the images, using
>>a pavillion with more memory (1 GB) and a better video card.
>>
>>cheers,
>>jeff
>>
>>
>>On 1/5/06, Michael J. Crowley <michael.crowley at yale.edu> wrote:
>>
>>
>> Dear Leisha,
>>If I remember correctly, there were some issues with refresh rates of
>>laptops so
>>that timing may not be as accurate as you want. This may be neglibile for
>>decision research. You may want to have a regular CRT to plug into. I think
>>some of this is addressed in the list serve archive.
>>best,
>>Mike
>>Quoting Leisha Wharfield <leisha at decisionresearch.org>:
>>
>>
>>
>> I'm pricing out laptops to run a simple eprime task at various
>>locations. Do any of you have recommendations for laptops that work well
>>for this? So far the HP Pavilions and Dell Latitude or Inspiron are
>>looking good. I'm steering clear of Celeron processors and I don't think
>>I can use MacIntosh, right?
>>
>>Any problems to report? Any praise for specific laptops?
>>
>>Thanks,
>>
>>Leisha Wharfield
>>Decision Research
>>Eugene, Oregon USA
>>
>>
>>
>> Michael J. Crowley, Ph.D.
>>
>>Yale Child Study Center
>>230 South Frontage Rd.
>>New Haven, CT 06520
>>
>>
>>
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>>
>>--
>>Jeffrey S. Maxwell
>>Laboratory for Brain Imaging & Behavior
>>Laboratory for Affective Neuroscience
>>jsmaxwell at wisc.edu
>>(608) 263 3672
>>http://brainimaging.waisman.wisc.edu/~maxwell
>>    
>>