Cartesian Reflex Project

The Cartesian Reflex Project University of Massachusetts-Amherst John W. Moore Robert J. Polewan Christopher M. Vigorito

Summer 2007 Information

"I blink, therefore I am."

The Cartesian Reflex Project seeks to reestablish human eyelid conditioning as a paradigm for research and teaching. The term Cartesian reflex comes from Descartes’s 1649 observation about how we cannot resist blinking when a friend thrusts his hand toward our eyes, even though we know that the friend would not strike us. Our involuntary blink, a violation of a social contract of a sort, was taken by Descartes as evidence against free will as the sole explanation of human behavior. For Descartes, involuntary reflexive action is evidence for the dualism for which he is famous; the reason he is often referred as the father of physiological psychology. Like conditioned eyeblink responses, Cartesian reflexes are eyelid movements that anticipate a feared or expected event.

This preliminary webpage illustrates the basic procedure for establishing anticipatory eyelid closure to a `blink' command. The resulting CR, the Cartesian reflex, resembles eyeblink CRs observed with more conventional `unconditioned stimuli' such as an air puff (humans) or electric shock (rabbits). The `blink' US serves the same purpose while side-stepping concerns about human subject well-being. Future posting will detail the wide range of applications of these methods in the domains of learning theory and affective/emotional variables in learning and performance. The heart of the project is a menu-driven protocol generator and low-cost hardware component that permits detection of eyelid movements. The system requires a computer, plug-in analog-digital converter, and recording potentiometer with power supply.

Research Aims 1. Classical conditioning (e.g., basic parameters, occasion setting, temporal uncertainty).

2. Instrumental conditioning (e.g., incentives for criterion lid movements, devaluation, partial reinforcement).

3. Assessment of computational learning theories.

4. Comparisons of movements of upper eyelid (superior aspect of lid) with the lateral aspect of the eyebrow, as described in the August 5th, 2003 edition of the New York Times regarding facial muscles and emotional expression (see Paul Ekman's research).

Teaching Aims
Laboratories were once common features of Learning courses, but they have given way to Computer Rats in virtual worlds. We believe that students will be excited about performing and serving in real experiments, experiments which could well be significant platforms for research at the level of honors theses and up.

(Click images to make larger)

Example of Presentation and Protocol Generation

The CS (the green cirle) and the US (the word "Blink") present together.

The program menus that establish the CS, US, and ISI. Implementation by Christopher Vigorito.

Differential Conditioning Procedure At the beginning of the experiment, subjects received the following instructions projected on a computer monitor: "Thank you for participating in this study. You will see a series of squares on the monitor. Sometimes the work "Blink" will appear within the square. Your task is to blink when the word "Blink" appears. The experiment will begin shortly."

The experiment began by the screen projecting a uniform green field. CS+ was presented for 16 trials. In addition, there were four nonreinforced trials. This phase was designed to establish and evaluate a CR. The intertrial interval (ITI) was 5 seconds. This phase was followed without interruption by a series 80 trials, 40 to CS+ and 40 to CS- presented in a random order.

The CS+ was a gray square on the green surround. The duration of the square was 1000 ms. The word "Blink" appeared in the center of the square 500 ms after the square’s onset, for a CS-US interval (ISI) of 500 ms. The CS- was another gray square of a lighter shade and somewhat smaller. This square was also projected for 1000 ms per trial, but without the blink command. Differential conditioning procedures dictate that only one screen appear per trial. That is the two figures do not appear simultaneously but are separated by at least 5 seconds, the ITI.

Subject 1

(A subject wearing the headgear to record eyelid movement. The recording device is the same as used with rabbits,see below).

Data for Subject 1

The above figure shows the average eyeblink topography of the 40 CS+ trials and the 40 CS- trials for the differential conditioning procedure in which the a 1000 ms tone was presented. The word "Blink" was presented 500 ms after CS onset and coterminated with the CS. This subject is a 67 year old male with some visual impairment. Discrimination performance for this subject was very poor: The average CR amplitude (distance from baseline in mm) at the point of US onset was 1.76 mm to CS+ and 1.37 mm to CS-.

Subject 2

Subject 2 is received the same protocol and instructions as subject 1.

Data for Subject 2

The above figure shows the average eyeblink topography of the 40 CS+ trials and the 40 CS- trials for the differential conditioning procedure in which the a 1000 ms tone was presented. The word "Blink" was presented 500 ms after CS onset and coterminated with the CS. This subject is a 31 year old male with some visual impairment. Discrimination performance for this subject was excellent but not perfect: The average CR amplitude (distance from baseline in mm) at the point of US onset was 8.23 mm to CS+ and 1.89 mm to CS-.

Publications

Polewan, R. J., Vigorito, C. M., Nason, C. D., Block, R. A., & Moore, J. W. (2006). A Cartesian reflex assessment of face processing. Behavioral and Cognitive Neuroscience Reviews, 5, 3-23. (PDF)

Paper reprints available upon request.

Data & Reports Sample data. Spring 2004 data & reports (password protected).

Links The Moore Laboratory Homepage UMass Psychology Department A Neuroscientist's Guide to Classical Conditioning