Perspectives on human spatial cognition: memory, navigation, and environmental learning

Allocentric and contra-aligned spatial representations of a town environment in blind people

Evidence concerning the representation of space by blind individuals is still unclear, as sometimes blind people behave like sighted people do, while other times they present difficulties. A better understanding of blind people's difficulties, especially with reference to the strategies used to form the representation of the environment, may help to enhance knowledge of the consequences of the absence of vision. The present study examined the representation of the locations of landmarks of a real town by using pointing tasks that entailed either allocentric points of reference with mental rotations of different degrees, or contra-aligned representations. Results showed that, in general, people met difficulties when they had to point from a different perspective to aligned landmarks or from the original perspective to contra-aligned landmarks, but this difficulty was particularly evident for the blind. The examination of the strategies adopted to perform the tasks showed that only a small group of blind participants used a survey strategy and that this group had a better performance with respect to people who adopted route or verbal strategies. Implications for the comprehension of the consequences on spatial cognition of the absence of visual experience are discussed, focusing in particular on conceivable interventions.

Visuo-spatial path learning, stress, and cortisol secretion following military cadets' first parachute jump: the effect of increasing task complexity

The present field experiment examined how multi-trial visuo-spatial learning and memory performance are impacted by excessive arousal, instigated by a potentially life-threatening event (i.e., a first parachute jump). Throughout a parachute training activity, subjective and neuroendocrine (i.e., cortisol) stress levels were assessed of 61 male military cadets who were randomly assigned to a control (n = 30) or a jump stress condition (n = 31). Post-stress learning and memory capacity was assessed with a 10-trial path-learning task that permitted emergence of learning curves. Pre-activity cortisol concentrations indicated a significant neuroendocrine anticipatory stress response in the stress group. Following parachuting, subjective stress levels and salivary cortisol reactivity differed significantly between groups. Visuo-spatial path-learning performance was impaired significantly after jump stress exposure, relative to the control group. Moreover, examination of the learning curves showed similar learning and memory performance at onset of the trials, with curves bifurcating as the task became more complex. These findings are in accordance with leading theories that acknowledge a moderating effect of task complexity. In sum, the present study extends knowledge concerning anticipatory stress effects, endogenously instigated cortisol reactivity, and the influence of extreme arousal on visuo-spatial path learning.