<p>Usually, a study participant is viewing stimuli on a computer screen while their EEG is recorded through the hardware provided by a manufacturer. To later synchronize the EEG data to stimuli, an experimenter will send so-called 'markers' from the stimulation computer to the EEG hardware so that the markers are encoded in realtime together with the EEG data.</p>

<p>Why do most manufacturers use the old-fashioned <a href="https://en.wikipedia.org/wiki/Parallel_port" rel="nofollow noreferrer">parallel port</a> for that?</p>

<p>I know, that the parallel port allows for a <em>parallel</em> transmission of up to 8 bits (i.e., 255 possible marker values and one '0' marker to indicate 'no marker') ... however, while that is a clear advantage, it comes at the cost of using a legacy port that is not available on modern computers.</p>

<p>Couldn't we just use a USB port to send data serially (in smaller bit packages) ... and then join these bits to a byte (8bits) to get the same number of possible markers? USB would in theory be fast enough to even compensate for the extra time needed to 'buffer' single bits and then encoding them as a byte.</p>

<p>Am I getting something wrong?</p>

<p>Why is the parallel port still so prevalent for this specific application (EEG)?</p>

CC BY-SA 3.0
2017-11-28T05:52:04.923Z
There are various reasons. Perhaps transmission speed (originally better for parallel and nobody bothered changing). Perhaps for the ability to put a separate data stream on each line/bit. Someone familiar with medical equipment may be able to give a precise answer; I think this would be better to ask on [*Electrical Engineering SE*](https://electronics.stackexchange.com/).
user3169
CC BY-SA 3.0
2017-11-28T05:56:25.763Z
" it comes at the cost of using a legacy port that is not available on modern computers" is not really valid, because you are referring to consumer use computers that have no need vs. dedicated industrial systems (I suppose, unless you can identify specific equipment).
user3169
CC BY-SA 3.0
2017-11-30T11:41:51.640Z
@user3169, most scientists that I know use consumer grade hardware for their research - i.e., usual laptops or desktop computers. So I would still consider using the parallel port a "cost". Concerning your other comment, I agree that a different stack exchange might yield more answers. Can we somehow migrate this question?
S.A.
CC BY-SA 3.0
2017-12-01T02:39:22.610Z
You can flag your question to the moderator, and ask if they can migrate it. Otherwise you would have to re-post on the other site.
user3169
<eeg>
Why are EEG markers usually sent over the parallel port?
S.A.
# Why are EEG markers usually sent over the parallel port?

(Asked by: username_0 on 2017-11-27)

Usually, a study participant is viewing stimuli on a computer screen while their EEG is recorded through the hardware provided by a manufacturer. To later synchronize the EEG data to stimuli, an experimenter will send so-called 'markers' from the stimulation computer to the EEG hardware so that the markers are encoded in realtime together with the EEG data.

Why do most manufacturers use the old-fashioned [parallel port](https://en.wikipedia.org/wiki/Parallel_port) for that?

I know, that the parallel port allows for a *parallel* transmission of up to 8 bits (i.e., 255 possible marker values and one '0' marker to indicate 'no marker') ... however, while that is a clear advantage, it comes at the cost of using a legacy port that is not available on modern computers.

Couldn't we just use a USB port to send data serially (in smaller bit packages) ... and then join these bits to a byte (8bits) to get the same number of possible markers? USB would in theory be fast enough to even compensate for the extra time needed to 'buffer' single bits and then encoding them as a byte.

Am I getting something wrong?

Why is the parallel port still so prevalent for this specific application (EEG)?

**Tags:** eeg

> **Comments:**
> **username_1**: There are various reasons. Perhaps transmission speed (originally better for parallel and nobody bothered changing). Perhaps for the ability to put a separate data stream on each line/bit. Someone familiar with medical equipment may be able to give a precise answer; I think this would be better to ask on [*Electrical Engineering SE*](https://electronics.stackexchange.com/).  
> **username_1**: " it comes at the cost of using a legacy port that is not available on modern computers" is not really valid, because you are referring to consumer use computers that have no need vs. dedicated industrial systems (I suppose, unless you can identify specific equipment).  
> **username_0**: @username_1, most scientists that I know use consumer grade hardware for their research - i.e., usual laptops or desktop computers. So I would still consider using the parallel port a "cost". Concerning your other comment, I agree that a different stack exchange might yield more answers. Can we somehow migrate this question?  
> **username_1**: You can flag your question to the moderator, and ask if they can migrate it. Otherwise you would have to re-post on the other site.  

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