Some effects of frustration in a free responding operant situation

In several experiments, rats and pigeons were reinforced on a chained schedule which varied in its second component but which always had a variable interval schedule as its first component. Occasionally, the reward which normally followed responding in the second component was omitted. On these frustrative non-reward occasions responding immediately subsequent to non-reward was sometimes elevated and sometimes depressed. The relevance of the elevation and depression effects to behavioural measures of frustration in the double runway was discussed.