This commentary addresses the target article's discussion of “navigation in multilayer environments” pace Jeffery et al.'s review of Montello and Pick's (1993) study, which “demonstrated that human subjects who learned two separate and overlapping routes in a multilevel building could subsequently integrate the relationship of these two routes. However, it was also established that pointing between these vertically aligned spaces was less accurate and slower than were performances within a floor” (sect. 3.3, para. 5). By questioning the underlying methodology we point out how horizontal learning and also vertical learning of multifloored environments influence spatial memory, which extends the findings reported by Jeffery et al.
Existing studies on spatial memory in complex buildings (Büchner et al. Reference Büchner, Hölscher, Strube, Vosniadou, Kayser and Vosniadou2007; Hölscher et al. Reference Hölscher, Meilinger, Vrachliotis, Brösamle and Knauff2006; Montello & Pick Reference Montello and Pick1993) have suggested that humans have a tendency to memorize such environments as a collection of floors. Yet this might stem from the fact that environments were also explored by floors, of greater length than the height of vertical junctions (staircases). In Thibault et al. (Reference Thibault, Pasqualotto, Vidal, Droulez and Berthoz2013), we have studied this potential bias with a learning and recognition experiment, for an object-in-place task, under carefully controlled conditions.
First, a virtual building was designed for the experiment as a repetition of rooms having the same height and length, connected by equivalent horizontal and vertical passages. Second, a group of 28 participants – the floor learners – learned the simulated space by watching a computer movie depicting floor-by-floor travel; similarly, 28 other participants – the column learners – observed the building according to a column-by-column route (i.e., travelling by elevators across floors). One landmark was visible in each visited room of the building. Third, we equated the sequence of landmarks encountered by floor-learning and column-learning participants (we changed the positions of the landmarks in the virtual building for each group to achieve this).
We then observed the performances of the two groups in a recognition phase where the participants viewed a camera movement from one room to an adjacent one, either following a segment of the learned path (a familiar segment) or a shortcut (a novel segment). After being moved, they had to indicate the correct object (among three distractors) that was there during the learning phase.
Under these controlled conditions, we detected a positive influence of the learning route, by floors and also by columns, on spatial memory performances (in terms of accuracy and response times). We found that participants processed familiar segments of the learned path more accurately than novel ones, not only after floor learning (80% correct answers in horizontal [familiar] trials vs. 63.5% in vertical [novel] trials) – which is in line with Montello and Pick's (1993) finding cited in section 3.3 of the target article (see the first two sentences of sect. 3.3, para. 5) – but, crucially, also after column learning. Participants who learned the multilevel building by a column-by-column route performed better in the recognition of landmarks within a column compared to the recognition of landmarks across columns, that is, within a floor (66% correct answers in vertical [familiar] trials vs. 48% in horizontal [novel] trials).Footnote
1
This finding suggests a key role of the learning mode on the exploitation of spatial memory, which extends the findings reported by Jeffery et al.
As a complement, we here point out our own methodological limits:
-
1. Our work does not use a navigational task but an object-in-place one, which differs from the task considered by Jeffery et al. In our experiment, the participants viewed a camera movement – that is, they were not free to change their direction of movement and to update their navigation strategy.
-
2. Our experiment was conducted in a rectilinear environment: The participants cannot explore the (x, y) plane, but only the x-axis. This can be a restricted case for the bicoded map model proposed by the authors.
This commentary addresses the target article's discussion of “navigation in multilayer environments” pace Jeffery et al.'s review of Montello and Pick's (1993) study, which “demonstrated that human subjects who learned two separate and overlapping routes in a multilevel building could subsequently integrate the relationship of these two routes. However, it was also established that pointing between these vertically aligned spaces was less accurate and slower than were performances within a floor” (sect. 3.3, para. 5). By questioning the underlying methodology we point out how horizontal learning and also vertical learning of multifloored environments influence spatial memory, which extends the findings reported by Jeffery et al.
Existing studies on spatial memory in complex buildings (Büchner et al. Reference Büchner, Hölscher, Strube, Vosniadou, Kayser and Vosniadou2007; Hölscher et al. Reference Hölscher, Meilinger, Vrachliotis, Brösamle and Knauff2006; Montello & Pick Reference Montello and Pick1993) have suggested that humans have a tendency to memorize such environments as a collection of floors. Yet this might stem from the fact that environments were also explored by floors, of greater length than the height of vertical junctions (staircases). In Thibault et al. (Reference Thibault, Pasqualotto, Vidal, Droulez and Berthoz2013), we have studied this potential bias with a learning and recognition experiment, for an object-in-place task, under carefully controlled conditions.
First, a virtual building was designed for the experiment as a repetition of rooms having the same height and length, connected by equivalent horizontal and vertical passages. Second, a group of 28 participants – the floor learners – learned the simulated space by watching a computer movie depicting floor-by-floor travel; similarly, 28 other participants – the column learners – observed the building according to a column-by-column route (i.e., travelling by elevators across floors). One landmark was visible in each visited room of the building. Third, we equated the sequence of landmarks encountered by floor-learning and column-learning participants (we changed the positions of the landmarks in the virtual building for each group to achieve this).
We then observed the performances of the two groups in a recognition phase where the participants viewed a camera movement from one room to an adjacent one, either following a segment of the learned path (a familiar segment) or a shortcut (a novel segment). After being moved, they had to indicate the correct object (among three distractors) that was there during the learning phase.
Under these controlled conditions, we detected a positive influence of the learning route, by floors and also by columns, on spatial memory performances (in terms of accuracy and response times). We found that participants processed familiar segments of the learned path more accurately than novel ones, not only after floor learning (80% correct answers in horizontal [familiar] trials vs. 63.5% in vertical [novel] trials) – which is in line with Montello and Pick's (1993) finding cited in section 3.3 of the target article (see the first two sentences of sect. 3.3, para. 5) – but, crucially, also after column learning. Participants who learned the multilevel building by a column-by-column route performed better in the recognition of landmarks within a column compared to the recognition of landmarks across columns, that is, within a floor (66% correct answers in vertical [familiar] trials vs. 48% in horizontal [novel] trials).Footnote 1 This finding suggests a key role of the learning mode on the exploitation of spatial memory, which extends the findings reported by Jeffery et al.
As a complement, we here point out our own methodological limits:
1. Our work does not use a navigational task but an object-in-place one, which differs from the task considered by Jeffery et al. In our experiment, the participants viewed a camera movement – that is, they were not free to change their direction of movement and to update their navigation strategy.
2. Our experiment was conducted in a rectilinear environment: The participants cannot explore the (x, y) plane, but only the x-axis. This can be a restricted case for the bicoded map model proposed by the authors.