Table 2.

Configuration of contextual stimuli that comprised each context type.

Experiment	Context type	Tactile stimulus (floor)	Visual stimulus (walls)	Olfactory stimulus
1	1	Smooth Plexiglas	Black	Lemon
	2	Wire mesh	Clear Plexiglas	Almond
2	1	Wire mesh	Clear Plexiglas	Strawberry
	2	Smooth Plexiglas	Black	Lemon
	3	Bar floor	Black and white vertical stripes	Almond
3	1	Smooth Plexiglas	Black	Lemon
	2	Wire mesh	Clear Plexiglas	Almond

Inserts were placed over the floors of the operant chambers to create smooth Plexiglas or wire mesh tactile stimuli. Walls were covered with paper to create black or black and white striped visual stimuli. Drops (3–4) of lemon or almond extract were placed inside the waste pan or a strawberry air freshener was taped outside the door to serve as olfactory stimuli.