Dear forum participants,
I'm measureing neuronal activity and eye movements in awake cats in
response to various stimuli. Now I want to manipulate the visual
stimuli on the fly, as a function of eye-position.
For presentation of visual stimuli I recently moved to the
psychophysics toolbox. As the intended manipulations of the visual
stimuli are computationally intensive, we are using a Power Mac G4
(867 Mhz, OS 9.2). Sadly, it has no serial port anymore, only usb,
firewire and ethernet. My eye-tracker (Fourward technology, dual
purkinje eye-tracker) gives analog output. (This is sampled
simultaneously with the neural signals in a dedicated system,
independent of the visual stimulation.)
Thus, I've to do a strategic decision on how to link the
analog signals to the video hardware. After reading messages 190 and
following, 581, 584, and a few others I see 3 options:
First, use a second computer (mac or pc) to A/D convert the
eye-tracker signals and communicate them to the Mac via ethernet,
setup some communication from within matlab/psychophysics toolbox.
Problem: Does this interfere with the rush function? Are functions
available to read (synchronously ?) from the ethernet port every 40ms
or so?
Second, use a boxed A/D converter which connects to the USB
port. Problem: I've found such devices only for the serial port. I've
not found Mathlab routines to read from the USB port.
Third, put in an interface card (maybe National Instruments)
into the Mac and do everything from within one matlab script.
Problem: I gather, that support of NI for Mac based solutions is
getting patchy, and that the Matlab data aquisition toolbax and
psychophysics toolbax do not really mix well.
To make things slightly easier, I do not need perfect timestamps on
the eye-positions, as the eye-tracker signal is already digitized in
another, closed system. A log for post -hoc analysis what happened is
enough.
Do you have experience, recommendations, relevant software pertaining
to this issue? Any comment is highly appreciated.
Best, Peter
--
PD Dr. Peter König +41-1-635 30 60
Institute of Neuroinformatics +41-1-635 30 53 (fax)
ETH - University Zürich http://www.ini.unizh.ch/~peterk
Winterthurerstr. 190 peterk@...
8057 Zürich
I'm measureing neuronal activity and eye movements in awake cats in
response to various stimuli. Now I want to manipulate the visual
stimuli on the fly, as a function of eye-position.
For presentation of visual stimuli I recently moved to the
psychophysics toolbox. As the intended manipulations of the visual
stimuli are computationally intensive, we are using a Power Mac G4
(867 Mhz, OS 9.2). Sadly, it has no serial port anymore, only usb,
firewire and ethernet. My eye-tracker (Fourward technology, dual
purkinje eye-tracker) gives analog output. (This is sampled
simultaneously with the neural signals in a dedicated system,
independent of the visual stimulation.)
Thus, I've to do a strategic decision on how to link the
analog signals to the video hardware. After reading messages 190 and
following, 581, 584, and a few others I see 3 options:
First, use a second computer (mac or pc) to A/D convert the
eye-tracker signals and communicate them to the Mac via ethernet,
setup some communication from within matlab/psychophysics toolbox.
Problem: Does this interfere with the rush function? Are functions
available to read (synchronously ?) from the ethernet port every 40ms
or so?
Second, use a boxed A/D converter which connects to the USB
port. Problem: I've found such devices only for the serial port. I've
not found Mathlab routines to read from the USB port.
Third, put in an interface card (maybe National Instruments)
into the Mac and do everything from within one matlab script.
Problem: I gather, that support of NI for Mac based solutions is
getting patchy, and that the Matlab data aquisition toolbax and
psychophysics toolbax do not really mix well.
To make things slightly easier, I do not need perfect timestamps on
the eye-positions, as the eye-tracker signal is already digitized in
another, closed system. A log for post -hoc analysis what happened is
enough.
Do you have experience, recommendations, relevant software pertaining
to this issue? Any comment is highly appreciated.
Best, Peter
--
PD Dr. Peter König +41-1-635 30 60
Institute of Neuroinformatics +41-1-635 30 53 (fax)
ETH - University Zürich http://www.ini.unizh.ch/~peterk
Winterthurerstr. 190 peterk@...
8057 Zürich