Staircases as contextual cues that help minimize energetic costs

Staircase climbs are habitually avoided, and staircase steepness is overestimated. Visual impressions of staircase slant reliably precede each taxing climb and may act as salient, visual cues, prompting behaviour that supports an ‘economy of action’ (Proffitt, 2006). The thesis adapted the contextual cueing paradigm with natural scenes (cf. Brockmole & Henderson, 2006b) to test for search and learning biases by scene content with staircases. For this, target letters, L and T, were placed near and far from staircases, and in scenes without staircases (three stimulus categories). Eighteen scenes were repeated across blocks, six of each stimulus category. Response latencies and eye movements were recorded. Chapter three investigated search biases in initial eye movements in response to the first presentation of novel, natural scenes of the three stimulus categories. Findings support the notion that early eye movements were biased towards the incidental scene content of staircases in 36 novel real-world scenes (N = 118); this bias was magnified for staircases with more steps, independent of target locations. Chapter two investigated contextual cueing by content of 18 natural scenes, six of each category, repeated across eight blocks (N = 64); for 27 of these participants, target locations were changed relative to staircase location in the ninth block. Steeper learning slopes across the eight repetitions were observed for targets located near staircases compared to the other stimulus categories. Interruptions to learning, due to changes in target locations in the ninth block, were a function of the distance to staircase location pre and post changes, consistent with the observed differential learning. Interruptions were equally strong within and between two nine-block learning sessions (N = 40) that were separated by a 24-hour break. This additional finding is obtained from a subsequent contextual cueing study, presented in chapter four, and speaks to a major involvement of episodic memory in the learning reported in this thesis. In sum, the findings highlight a capacity of staircase percepts to bias initial visual search, and to facilitate short- and longer-term associative learning near staircases. Overall, the results suggest staircases may be salient stimuli for cognitive processes that manage energetic resources