To Rotate or Not to Rotate: Strategy Flexibility in the Mental Rotation Task
Abstract: Rotational transformation of a mental image, or mental rotation, is
a key component of spatial thinking. Yet, despite extensive research, an open question
remains: is mental rotation covert simulation of motor rotation? The present work addressed
this question, advancing and experimentally evaluating the multi-strategy view of mental
rotation. This theory posits that mental rotation ... read moreis covert motor simulation (claim 1) but
widespread use of the mental rotation task (MRT) has obfuscated this fact. We argue that
the MRT does not solely engage mental rotation but rather integrates both motoric (i.e.
mental rotation) and analytic strategies that rely on visual comparison of key object
features (claim 2). Three experiments examined strategy use in the MRT. In Experiment 1 we
tracked physical rotation of MRT figures. Supporting the first claim, we found behavioral
similarities between mental and physical rotation, suggesting comparable underlying
cognitive processes. Interestingly, individuals did not rotate to a match, as is commonly
assumed, but rather to an off-axis orientation. In Experiment 2 we analyzed physical
rotation that mirrored covert mental rotation processes. Supporting the second claim, we
found that participants differentially biased cognitive strategies based on task
difficulty, preferentially using mental rotation for easy trials and analytic strategies
for difficult. Experiment 3 quantified transient changes in EEG power that reflect distinct
cognitive processes. Supporting the first claim, we observed sensorimotor mu suppression, a
neurophysiological correlate of motor simulation and imagery, suggesting mental rotation
involves covert motor simulation. Analyses of raw EEG and independent component activations
revealed that mu suppression decreased as task difficulty increased. At the same time,
frontal midline theta enhancement and parietal alpha suppression increased, which reflect
increased use of working memory and visuospatial representation processes, respectively.
This difficulty-dependent trade-off between cognitive processes supports the second claim.
We suggest that the ability to flexibly and automatically choose between mental simulation
and more analytic forms of thinking is a key component of spatial intelligence. Future
research should continue to consider the impact of strategies and strategy flexibility in
spatial task performance. Doing so can inform domain-general processes and have real world
implications across a variety of domains.
Thesis (Ph.D.)--Tufts University, 2016.
Submitted to the Dept. of Psychology.
Advisor: Holly Taylor.
Committee: Robert Jacob, Tad Brunyé, Marianna Eddy, and Jeffrey Zacks.
Keywords: Cognitive psychology, and Neurosciences.read less