2 WALTER S. HUNTER , 



In the present experiments, two main factual questions arise : 

 (i) How long after the determining stimulus has disappeared 

 can an animal wait and still react correctly? (2) Does the 

 animal give any behavior cues as to its method of solving the 

 problem? If so, what are they? With these data given, there 

 remains the task of interpretation. If a selective response has 

 been initiated and controlled by a certain stimulus, and if the 

 response can still be made successfully in the absence of that 

 stimulus, then the subject must be using something that func- 

 tions for the stimulus in initiating and guiding the correct 

 response. Our investigation thus forces us to the considera- 

 tion of the functional presence of a representative factor in the 

 behavior of animals and children. Not only this, but the prob- 

 lem of the nature of this representative factor confronts us. Is 

 it an overt motor attitude, or not? If not, is it sensory or imag- 

 nal, i.e., ideational? 



In the interpretative study, I shall proceed on the assump- 

 tion that an"mals are conscious. What the nature of this con- 

 sciousness is, it will be the task of this paper to help determine. 

 (If the reader does not choose to follow this line of interpreta- 

 tion, he may state everything in neurological terms without 

 marring the significance of this discussion.) But a propos of 

 the term "image" or "idea," let it be said once for all that 

 wherever these terms are used by the present writer with refer- 

 ence to animal consciousness, they should be supplemented by 

 the phrase "or functionally equivalent process." I use the 

 structural term chiefly for the sake of its brevity. 



II. CRITICAL REVIEW OF HISTORICAL DATA 



In the interpretative discussion at the close of the present 

 monograph, we shall be confronted with the possibility that 

 images or ideas ^ may have guided the reactions of the sub- 

 jects. In that discussion, we shall assume that there is no 

 necessity that psychology postulate such a representative factor 

 save where successful reactions occur in the absence of the stim- 



' In the literature, it has been taken for granted that the question of the exist- 

 ence of images and that of the existence of ideas in animal consciousness is the 

 same. I shall proceed on the assumption that images are centrally aroused pro- 

 cesses, while ideas may be either peripherally or centrally conditioned. The essence 

 of the idea is not its origin (or content), but its function. This point will be ampli- 

 fied in the final divisions of this monograph. The present statement will suffice 

 for a definition of terms. 



