Using the heartbeat as an input device, the Toxicorama – an installation exhibited at the Mediatechnology exposition of the Leiden University in 2003 – performes interaction by the principle of biofeedback. While sitting on a chair in an igloo shaped tent and wired with electrodes to a heart rate monitor, the user controls images and sounds with its heartbeat. The video, which is projected onto the tent, contains psychedelic and hypnotic samples. Together with the sound they let the user experience an estranged environment.

The biofeedback is realized with a heart rate monitor, borrowed from the Leiden University Medical Centre. The heart rate is measured by electrodes on the body of the user and is confirmed by the device with a beeping sound. This is captured by a microphone connected to the Max/MSP software which plays sound and video based on the users heart rate. After a short period when the user has become familiar with the biofeedback the software changes the sound and video. 61 users (28 females and 33 males), were researched on how they reacted on the images and sounds by means of a questionnaire and the measurement of the heartbeat.

The Toxicorama tent
Testing the heart rate monitor with Max/MSP
Heart rate monitor (from LUMC)
Inside the tent

Problem description

How can some of the bodily functions be used – beside the well-known manual – to make an interface for an audiovisual program. Is it possible to simulate a hallucinogenic drugs experience by that interface?

Project goal

In the end the last goal was simplified. In favor of the aimed mental manipulation the preventive objective was skipped.

Video and Sound

The video contains the following segments:

#1 (00:00:00 - 00:00:10)

Black and white block pattern showing the inverse image at the pace of the users heartbeat.

#2 (00:00:10 - 00:00:30)

Black and white block pattern fading horizontal (motion-blur) at the pace of the users heartbeat.

#3 (00:00:30 - 00:00:50)

Pinched black and white block pattern resets to former black and white block pattern at the pace of the users heartbeat.

#4 (00:00:50 - 00:01:10)

Black and white block pattern that pinches at the pace of the heartbeat, the inverse of segment #3. The volume of the sound of the heartbeat increases in 20 seconds from 120 dB to 155dB and stays at this level.

#5 (00:01:10 - 00:01:35)

Segment #4 is zoomed out and repeated in a pattern while rotating.

#6 (00:01:35 - 00:01:55)

Rotating black and white block pattern that transforms at the pace of the users heartbeat in an arc-form and is zoomed out and displayed as a pattern.

#7 (00:01:55 - 00:02:15)

Black and white block pattern that is twirled like a spiral at the pace of a users heartbeat. The sound of the heartbeat is replaced with a sample of a vinyl record scratch.

#8 (00:02:15 - 00:02:40)

As #7 but with the difference that the black and white block pattern fades from black and white into red and white while twirling.

#9 (00:02:40 - 00:03:00)

Black and white block pattern of which it's rows move at a heartbeat and create an illussion of sloping rows. Also the sound of the heartbeat returns.

#10 (00:03:00 - 00:03:30)

Black and white block pattern where each block moves one block to the right at the pace of a users heartbeat.

#11 (00:03:30 - 00:04:03)

Black and white block pattern which fades to white at the pace of a users heartbeat.

Conclusions heartbeat measuring

Heartbeat average of 61 users (28 females and 33 males)

The heartbeat fluctuates during the four minutes the user spends in the Toxicorama. The values of the average visitor meander around 75 bpm. There are three moments that surmounts that number to 80, at segment 8 and 10. Segment 5 has a strong visual impact, but that can also be said of segment 3 and 4 so this is no sufficient explanation. Possibly it is because the volume of the heartbeat on the earphone is gradually made stronger. This could cause that the visitor (unconsciously) thinks that he hears his own heartbeat going faster. This is an example of biofeedback, where the heartbeat changes the users perception.

Segment 8 has the addition of color that could explain the speeding up of the heartbeat.For the high speed of the heartbeat in segment 10 there is no good explanation. It is the same segment as number 1 which has no strong visual impact. Maybe it is because the visitor has experienced a lot of stimuli during the almost four minutes when he is entering segment 10.

Conclusions questionnaire

Review of the Toxicorama in Mare (in dutch)

"... Maar er is ook de technische vertaling van een LSD-trip of een migraine-aanval: Toxicorama, een koepeltentje waarop een beamer pulserende blokpatronen projecteert. Wie erin gaat zitten, met koptelefoon en een hartslagmeter die terugkoppelt naar de machinerie, loopt de kans om behoorlijk glazig weer naar buiten te kruipen. ‘We hebben er wel aan gedacht om het als drugsvoorlichting voor scholieren te gebruiken’, zegt Ruud Bakker, ‘maar ja, straks vinden die het geweldig.’... " - Mare (nr. 2, 11-09-2003), Artikel over de Media Technology expositie


Download the Toxicorama project files and use them with Max/MSP and Jitter from Cycling '74.

Screenshot main patch Max/MSP

The Toxicorama was created by Hein Boekhout and Ruud Bakker as part of the Master Mediatechnology at Leiden University.