Clockwise rotation of perspective view improves spatial recognition of complex environments in aging

Abstract

Deciphering the human spatial cognition system involves the development of simple tasks to assess how our brain works with shapes and forms. Prior studies in the mental rotation field disclosed a clockwise rotation bias on how basic stimuli are perceived and processed. However, there is a lack of a substantial scientific background for complex stimuli and how factors like sex or aging could influence them. Regarding the latter point, it is well known that our spatial skills tend to decline as we grow older. Hence, the hippocampal system is especially sensitive to aging. These neural changes underlie difficulties for the elderly in landmark orientation or mental rotation tasks. Thus, our study aimed to check whether the effect of clockwise and anticlockwise rotations in the spatial recognition of complex environments could be modulated by aging. To do so, 40 young adults and 40 old adults performed the ASMRT, a virtual spatial memory recognition test. Results showed that young adults outperformed old adults in all difficulty conditions (i.e., encoding one or three boxes positions). In addition, old adults were affected more than young adults by rotation direction, showing better performance in clockwise rotations. In conclusion, our study provides evidence that aging is particularly affected by the direction of rotation. We suggest that clockwise bias could be linked with the cognitive decline associated with aging. Future studies could address this with brain imaging measures.

Figure 1

Stimuli sequence (from left to right) of one trials of higher difficulty level (three boxes) of the ASMRT. In the memorization phase, participants need to retain the position of the boxes colored in green. In the recognition phase, ten images were displayed one after another. For each of them, participants needed to identify if the green box was in the same place as the previously memorized. Every recognition image, as seen in the sample images, was in a different orientation when compared with the memory image.

Figure 2

Final step of the angle and direction calculation for the ASMRT. Crossing the angles of the memory image and the recognition image in the zenith plane, we can obtain the difference between both angles (named α—green line—and β—purple line—, respectively) and the direction of the recognition image rotation, representing the exact viewpoint rotation between both images (angle and direction, represented in angle Y).

Figure 3

Rotation angle (in degrees) of each viewpoint of recognition image as a function of Difficulty (one box and three boxes) and Direction (clockwise and anticlockwise).

Figure 4

Mean percentage of false alarms as a function of Age (young < 30 years, older > 60 years, Panel A) and Difficulty (one box and three boxes, Panel B). Triple asterisk means p-value < .001.

Figure 5

Mean percentage of false alarms as a function of Difficulty (one box and three boxes) and Direction (clockwise and anticlockwise). Triple asterisk means p-value < .001.