Imageless Thought

The standard story about the demise of introspectionist psychology goes something like this:  Towards the beginning of the 20th Century, experimental psychologists relied on introspecting subjects to study the mind.  Members of one prominent school believed that each thought is reducible to sensory images (visual, auditory including verbal, proprioceptive, etc.).  Among other things, they would ask subjects to analyze their thoughts into images.  While doing something analogous, some other psychologists found that their subjects could not analyze all thoughts into images.  So they argued that there are imageless thoughts.

From then on, there was a long and inconclusive squabble, in which both camps produced different results, all based on subjects introspecting under the same conditions.  The first camp maintained their view that all thoughts are analyzable into images, while the second camp maintained that some thoughts are imageless.  The debate was widely seen as impossible to resolve on introspective grounds.  As a result, introspection was discredited and largely abandoned as a method of psychological investigation.

In Chap 2 of a relatively recent book (Sampling Inner Experience in Disturbed Affect, Plenum Press, 1993), psychologist Russell Hurlburt and collaborator Christy Monson offer a revision of this story.  They argue that researchers in both camps reported experiences that can be fairly described as imageless thoughts.  The difference was that the first camp did not describe them as such.  Instead, they reinterpreted or redescribed imageless thoughts in various ways.  For instance, in some cases they said that subjects were unable to analyze certain thoughts into images, or that the images were “too faint to describe”.  In short, Monson and Hurlburt argue that the classical disagreement over imageless thoughts was not empirical but purely theoretical.  It was not so much a debate over what the data are as over how the data should be interpreted.

I found Monson and Hurlburt’s alternative interpretation of the history of introspectionist provocative, but I lack the expertise and time to test their view.  Although they review a number of classical studies, their discussion is neither scholarly nor theoretically deep.  I wonder whether anyone knows of any recent discussion of this historical episode by professional historians or philosophers of psychology.  If there isn’t, here is a nice project for someone with the time and resources to investigate:  go out and test Monson and Hurlburt’s interpretation.  I’m sure there is something interesting to be said about this, especially in light of the recent surge of interest in introspection and data from first-person reports.

This is not merely a historical question.  The whole reason for Hurlburt to revisit the history of introspectionism is that he has found evidence of imageless thoughts, which he calls “unsymbolized thinking,” using a technique called “descriptive experience sampling method”, which is a technique for generating data from first-person reports.  Understandably, Hurlburt does not want his results to be dismissed on the grounds that they are based on (unreliable) introspection, so he takes the time to look at the old debate over imageless thought and finds that in his opinion, contrary to the standard story, introspecting subjects did agree that there are imageless thoughts.

Hurlburt has the good sense of claiming only that his subjects experience some thoughts as not involving images of any sort.  He does not claim that in fact, there are no images to be found in the subjects’ minds.  In this respect, he avoids the controversial theoretical claims made by classical introspectionists on introspective grounds.  Nevertheless, I find Hurlburt’s data fascinating and in need of explanation.