Geography Reference
In-Depth Information
The limited lighting condition at night was characterised by the brightly lit
spotlight of the headlamp and weak ambient light originating from the diffusion
of lights in the surrounding urban region. The contrast between the spotlight and
ambient light was high, causing participants to mostly see features under the
spotlight. The results of the study reflected this restricted vista through an increased
perception of close features with notable visual salience under the spotlight. On one
hand, these features were relatively small and clearly bounded, such as “boulder”
and “standing rootstock”, which were lighted one by one at night whereas perceived
more as groups in daytime. On the other hand, the spotlight highlighted vegetation
features at close distance that the spotlight did not penetrate, such as “spruce trees”
and “tall grass”. These types of features did not necessarily contrast in the more
extended ambient light vista by daytime. The significantly higher use frequency of
the “Rocks” landmark group in the night than in the condition can thus be under-
stood to be caused by the restricted spotlight vista at night. The same applies vice
versa for the “Waters”; the dark colour of the water surface due to the lack of the
reflected ambient light made “Waters” invisible at night compared to during the
day. “Waters” were also distant from the route. Acoustic salience was only little
involved in the study, mainly related to the noises of vehicles.
Although the vistas at night were restricted to the spotlight of the headlamp, the
perception of distant and global landmarks was not completely missing, which
agrees with our hypothesis. We observed the use of distant lights as orientation
landmarks during the route traversal, most importantly lines of streetlamps that
efficiently provided the participants with the directions of distant roads and outdoor
tracks. The observation was confirmed statistically with the landmark concept
“streetlamp” being used significantly more frequently by the night participants
compared to the day participants. Even more convincingly, each night participant
mentioned “streetlamp” during the route traversal.
In daylight, the participants used another set of distant and global landmarks. No
individual landmark or landmark group was highlighted quantitatively, but the
experimenters
observations confirmed that when people can see far away, they
take the distant features in use as landmarks. The day participants used distant
landmarks, such as “water slide” and “traffic island”, in the “Structures” landmark
group during the route traversal, which did not occur in the night data at all. The
high salience of structures as landmarks in nature was confirmed in the experiment
(previously found in Sarjakoski et al.
2012
). The perception of some spatially
extensive features was also notable during the day, most clearly water landmarks
that were significantly more used compared to night. In addition, some spatially
extensive surface-related landmarks, such as “courtyard” and “slope ramp”, were
only mentioned in the day condition when they were visible over a wide area.
Surprisingly, the differences in the perception of landmarks between day and
night did not transfer to differences in the recall. With regards to the use amounts of
landmark groups, sketch maps were drawn similarly in both conditions. A similar
lack of difference in sketch maps between conditions occurred also in our previous
study considering different seasons (Kettunen et al.
2013
). People seem to recall
'
