1. The Social Use of Space 175 



G. Exploratory Behavior 



Ultimate exposure to some new configuration of stimuli represents the 

 common factor in the three phenomena encompassed by the term, "ex- 

 ploratory behavior." These three phenomena are: (a) the rise and decline 

 of a hyperactive state following exposure to a new configuration of stimuli 

 (see Section III, A, 4) ; (b) the rejection of new configurations (see Sec- 

 tion III, A, 3) ; and (c) the seeking of new configurations. We shall now 

 examine how the opportunity for expressing such behaviors alters an in- 

 dividual's attitude toward its physical and social environment. 



1. The Hyperactivity Phexomenon 



In an animal's normal habitat this phenomenon may be anticipated to 

 follow an encounter with a new configuration of stimuli at places in the 

 normal home range where it has not occurred during customary travels. 

 Field studies directed toward the elucidation of the consequences of such 

 encounters are essentially nonexistent. Pearson (1960), by photographing 

 marked mice as they move along their trailway systems, has found that, 

 following the experience of being trapped and handled, mice not only be- 

 come more active but also visit places within or near their normal home 

 range which are normally infrequently visited. My study of the reaction of 

 domesticated Norway rats following exposure to an activity alley (Sec- 

 tion III, A, 4) represent this same type of situation with the exception that 

 the induced state of hyperactivity must take place in the presence of the 

 new configuration of stimuli represented by the alley. 



Recall that the rat is placed in a compartment with an access door at 

 one end of the alley. It does not have to enter, but many rats do so rather 

 immediately. For example consider the 73 rats involved in the analysis of 

 distance of termination of trips shown in Fig. 3. Analyses (Fig. 6) have 

 been made of their hyperactivity during the initial 2.5 hours of their resi- 

 dence in the activity alley. From an initial high level, activity declines 

 exponentially over an approximate 3-4 hour period nearly to a base level 

 maintained on the average through each of the 12 hours of normal height- 

 ened activity during the next 3 days. This pattern is shown diagram- 

 matrically in sketch (1) of Fig. 41. Such heightened diffuse motor activity 

 lacks any aura of goal direction and will be designated by the symbol, 

 DMA. Such a configuration of new stimuli as is represented by the alley 

 will be designated as E. If a rat is placed again in the alley for 2 hours on 

 each of several consecutive days, no appreciable amount or duration of 

 DMA occurs on any day. This means that there has transpired an adjust- 



