Mental rotation: An event-related potential study with a validated mental rotation task

Event-related potentials (ERPs) were recorded while subjects performed a validated mental rotation task, taken from the cognitive psychology literature. These ERPs show a late posterior negativity relative to a baseline condition requiring all of the same perceptual and cognitive processes except for the mental rotation itself. Our tentative identification of this posterior negativity with mental rotation is further supported by the finding that it varies systematically with the amount of mental rotation required on a trial by trial basis in the experimental task. We conclude that this late negativity is an ERP marker of the mental rotation process, and that this process engages primarily posterior brain regions.     

Mental rotation of compound stimuli: The effects of task demands,practice, and figural goodness

Four experiments examined whether or not mental rotation of compound stimuli is a holistic process. Large letters (global aspect) composed of small letters (local aspect) were presented, and the format (normal vs. reflected) of each aspect was manipulated independently. In Experiment 1, the rate of mental rotation was compared under divided- and focused-attention instructions. The overall rate of mental rotation was faster under focused-attention instructions than under divided-attention instructions. Also, contrary to previous findings, in the divided-attention task, the slope of the rotation function was smaller when the stimulus configurations contained aspects with congruent formats (both aspects were normal or mirror-reversed letters) than when they contained aspects with incongruent formats (one normal and one mirror-reversed letter). This pattern of results is unlikely to be caused by the subjects' level of familiarity with the divided-attention task (Experiment 2), by postrotation processes (Experiment 3), or by stimulus attributes (figural goodness) confounded with the format-congruency variable (Experiment 4). The implications of these results for models of mental rotation of compound stimuli are discussed.     

Real three-dimensional objects: effects on mental rotation

The current experiment investigated real three-dimensional (3D) objects with regard to performance on a mental rotation task and whether the appearance of sex differences may be mediated by experiences with spatially related activities. 40 men and 40 women were presented with alternating timed trials consisting of real-3D objects or two-dimensional illustrations of 3D objects. Sex differences in spatially related activities did not significantly influence the finding that men outperformed women on mental rotation of either stimulus type. However, on measures related to spatial activities, self-reported proficiency using maps correlated positively with performance only on trials with illustrations whereas self-reported proficiency using GPS correlated negatively with performance regardless of stimulus dimensionality. Findings may be interpreted as suggesting that rotating real-3D objects utilizes distinct but overlapping spatial skills compared to rotating two-dimensional representations of 3D objects, and real-3D objects can enhance mental rotation performance.     

Mental rotation performance in soccer players and gymnasts in an object-based mental rotation task

In this study, the effect of motor expertise on an object-based mental rotation task was investigated. 60 males and 60 females (40 soccer players, 40 gymnasts, and 40 non-athletes, equivalent males and females in each group) solved a psychometric mental rotation task with both cube and human figures. The results revealed that all participants had a higher mental rotation accuracy for human figures compared to cubed figures, that the gender difference was reduced with human figures, and that gymnasts demonstrated a better mental rotation performance than non-athletes. The results are discussed against the background of the existing literature on motor experts, mental rotation performance as well as the importance of the testing situation and the test construction.     

Mental rotation of objects retrieved from memory: a functional MRI study of spatial processing

This functional MRI study examined how people mentally rotate a 3-dimensional object (an alarm clock) that is retrieved from memory and rotated according to a sequence of auditory instructions. We manipulated the geometric properties of the rotation, such as having successive rotation steps around a single axis versus alternating between 2 axes. The latter condition produced much more activation in several areas. Also, the activation in several areas increased with the number of rotation steps. During successive rotations around a single axis, the activation was similar for rotations in the picture plane and rotations in depth. The parietal (but not extrastriate) activation was similar to mental rotation of a visually presented object. The findings indicate that a large-scale cortical network computes different types of spatial information by dynamically drawing on each of its components to a differential, situation-specific degree.     

Mental rotation training: transfer and maintenance effects on spatial abilities

One of the aims of research in spatial cognition is to examine whether spatial skills can be enhanced. The goal of the present study was thus to assess the benefit and maintenance effects of mental rotation training in young adults. Forty-eight females took part in the study: 16 were randomly assigned to receive the mental rotation training (based on comparing pairs of 2D or 3D objects and rotation games), 16 served as active controls (performing parallel non-spatial activities), and 16 as passive controls. Transfer effects to both untrained spatial tasks (testing both object rotation and perspective taking) and visual and verbal tasks were examined. Across the training sessions, the group given mental rotation training revealed benefits in the time it took to make judgments when comparing 3D and 2D objects, but their mental rotation speed did not improve. When compared with the other groups, the mental rotation training group did show transfer effects, however, in tasks other than those practiced (i.e., in object rotation and perspective-taking tasks), and these benefits persisted after 1 month. The training had no effect on visual or verbal tasks. These findings are discussed from the spatial cognition standpoint and with reference to the (rotation) training literature.     

Mental rotation of letters,pictures, and three-dimensional objects in German dyslexic children

This study examines mental rotation ability in children with developmental dyslexia. Prior investigations have yielded equivocal results that might be due to differences in stimulus material and testing formats employed. Whereas some investigators found dyslexic readers to be impaired in mental rotation, others did not report any performance differences or even superior spatial performance for dyslexia. Here, we report a comparison of mental rotation for letters, three-dimensional figures sensu Shepard and Metzler, and colored pictures of animals or humans in second-grade German dyslexic readers. Findings indicate that dyslexic readers are impaired in mental rotation for all three kinds of stimuli. Effects of general intelligence were controlled. Furthermore, dyslexic children were deficient in other spatial abilities like identifying letters or forms among distracters. These results are discussed with respect to the hypotheses of a developmental dysfunction of the parietal cortex or a subtle anomaly in cerebellar function in dyslexic readers.     

Effects of plane rotation,task, and complexity on recognition of familiar and chimeric objects

We examined the effects of plane rotation, task, and visual complexity on the recognition of familiar and chimeric objects. The effects of rotation, with response times increasing linearly and monotonically with rotation from the upright, were equivalent for tasks requiring different degrees of visual differentiation of the target from contrasting stimuli--namely, (1) deciding whether the stimulus was living or nonliving (semantic classification), (2) deciding whether the stimulus was an object or a nonobject (object decision), and (3) naming. The effects of complexity, with shorter response times to more complex stimuli, were most apparent in semantic classification and object decision and were additive with the effects of rotation. We discuss the implications of these results for theories of the relationship between the process of normalization and the determining of object identity.     

Mental rotation of letters, pictures, and three-dimensional objects in German dyslexic children.

This study examines mental rotation ability in children with developmental dyslexia. Prior investigations have yielded equivocal results that might be due to differences in stimulus material and testing formats employed. Whereas some investigators found dyslexic readers to be impaired in mental rotation, others did not report any performance differences or even superior spatial performance for dyslexia. Here, we report a comparison of mental rotation for letters, three-dimensional figures sensu Shepard and Metzler, and colored pictures of animals or humans in second-grade German dyslexic readers. Findings indicate that dyslexic readers are impaired in mental rotation for all three kinds of stimuli. Effects of general intelligence were controlled. Furthermore, dyslexic children were deficient in other spatial abilities like identifying letters or forms among distracters. These results are discussed with respect to the hypotheses of a developmental dysfunction of the parietal cortex or a subtle anomaly in cerebellar function in dyslexic readers.     

Mental rotation in blind and sighted adolescents: The effects of haptic strategies

IntroductionWhen observing blind persons in a situation of mental rotation, it is more usual to emphasize their lack of visual experience than their expertise concerning tactile exploration. Nevertheless, it seems important to verify whether the procedures of tactile exploration developed by young blind persons enable them to recognize a shape whatever its orientation in space.ObjectiveThe objective of this study was to compare blind adolescents and sighted adolescents in a situation of mental rotation, with raised patterns.MethodIn this perspective, a group of blind adolescents and a group of sighted adolescents – matched for age and sex – have been observed during two task of mental rotation.ResultsThe results show that the blind adolescents are always faster, and they perform better when the rotation task concerns simple shapes. A fine analysis of the strategies of tactile exploration deployed by the subjects allows us to identify several procedures that are specific to the blind adolescents. These exploratory procedures allow them to compensate for the lack of visual experience, up to a certain level of complexity in the shapes.ConclusionThese results suggest that the recognition of 2D shapes after rotation in space is not necessarily problematic for the blind. These results are discussed in relation with recent work on the haptic competence of blind persons.     

Improving spatial abilities through mindfulness: effects on the mental rotation task

In this study, we demonstrate a previously unknown finding that mindful learning can improve an individual’s spatial cognition without regard to gender differences. Thirty-two volunteers participated in the experiment. Baselines for spatial ability were first measured for the reaction time on the mental rotation task. Next, the participants were randomly assigned to either a mindful or mindless learning condition. After learning, the mental rotation task showed that those in the mindful learning condition responded faster than those in the mindless learning condition. This study provides promising evidence for applying mindful learning to education.     

The dimensionality of the remember-know task: a state-trace analysis

This article addresses the issue of whether the remember-know (RK) task is best explained by a single-process or a dual-process model. All single-process models propose that remember and know responses reflect different levels of a single strength-of-evidence dimension. Thus, across conditions in which response criteria are held constant, these models predict that the RK task is unidimensional. Many dual-process models propose that remember and know responses reflect two qualitatively distinct processes underlying recognition memory, often characterized as recollection and familiarity. These models predict that the RK task is bidimensional. Using data from 37 studies, the author conducted a state-trace analysis to determine the dimensionality of the RK task. In those studies, non-memory-related differences between conditions were eliminated via decision criteria constrained to be constant across all levels of the independent variables. The results reveal little or no evidence of bidimensionality and lend additional support to the unequal-variance signal detection model. Other arguments supporting a bidimensional interpretation are examined, and the author concludes there is insufficient evidence for the RK task to be used to identify qualitatively different memory components.     

The effects of task and practice on search for invisibly displaced objects

The ability to successfully search for an invisibly displaced object is frequently assumed to relate to the emergence of mental representation at around 2 years of age. However, little is known about what is actually being measured in the typical “stage 6” object permanence search task. Two studies examined the effects of task factors and practice on invisible displacements and systematic search tasks to show that simple variations in ways of hiding an object change the child's ability to find it. Experiment 1 compared two common methods of presenting invisible displacements items to 36 children, approximately 2 years of age. One task was significantly easier than the other, despite the fact that they contained identical items that varied only in their order of presentation. Experiment 2 tested the effects of short-term practice on 18- and 24-month-olds' success on invisible displacements trials and on two systematic search tasks. Results indicate that too little practice inhibited performance in 18-month-olds, but that practice beyond an optimum level did not further affect their scores. In contrast, 24-month-olds continued to benefit from increased practice until they reached the maximum possible score. The findings are interpreted to mean that invisible displacements tasks may require only sensorimotor search strategies rather than representation. The findings also have implications for (a) research that attempts to relate object permanence to other variables and (b) programs that use object permanence as an assessment or screening measure.     

Mental rotation: cross-task training and generalization

It is well established that performance on standard mental rotation tasks improves with training (Peters et al., 1995), but thus far there is little consensus regarding the degree of transfer to other tasks which also involve mental rotation. In Experiment 1, we assessed the effect of mental rotation training on participants' Mental Rotation Test (MRT) scores. Twenty-eight participants were randomly assigned to one of three groups: a "One-Day Training," "Spaced Training," or "No Training" group. Participants who received training achieved higher scores on the MRT, an advantage that was still evident after 1 week. Distribution of training did not affect performance. Experiment 2 assessed generalization of mental rotation training to a more complex mental rotation task, laparoscopic surgery. Laparoscopic surgical skills were assessed using Fundamentals of Laparoscopic Surgery (FLS) tasks. Thirty-four participants were randomly assigned to a "Full Mental Rotation Training, MRT and FLS," "MRT and FLS," or "FLS-only" group. MRT results from Experiment 1 were replicated and mental rotation training was found to elicit higher scores on the MRT. Further, mental rotation training was found to generalize to certain laparoscopic surgical tasks. Participants who obtained mental rotation training performed significantly better on mental-rotation dependent surgical tasks than participants who did not receive training. Therefore, surgical training programs can use simple computer or paper-based mental rotation training instead of more expensive materials to enhance certain aspects of surgical performance of trainees.     

Mental rotation depends on the number of objects rather than on the number of image fragments

It is often intuitively assumed that disconnected image fragments result in a representation of separate objects. When objects are partly occluded, disconnected image fragments can still result in a representation of a single object, based on visual completion. In a simultaneous matching task, displays showing one object, partly occluded objects, or two objects were compared with each other. When only a translation was required to match pairs of displays, one-object displays were matched faster than both occluded-object and two-object displays, which did not differ significantly from each other. When mental rotation and translation were required, the one-object displays were again matched the fastest. In addition, an advantage for occluded-object displays compared with two-object displays was found. We conclude that when the generation of a mental representation is likely, object-based connectedness determines object matching. Mental rotation then seems to depend on the number of objects rather than on the number of image fragments.     

Mental rotation of faces

The effect of orientation upon face recognition was explored in two experiments, which used a procedure adapted from the mental rotation literature. In the first experiment, a linear increase in the RT of same-different judgments was found as the second of a pair of sequentially presented faces was rotated away from the vertical. Also, it was found that the effect of changing facial expression did not interact with orientation. In the second experiment, a linear relationship between RT and orientation was found in a task involving the recognition of famous faces. This recognition task was found to be more affected by inversion than was an expression classification task. These results are interpreted as evidence against the view that inverted faces are processed in a qualitatively different manner from upright faces, and are also inconsistent with the hypothesis that inversion makes faces difficult to recognize because facial expression cannot be extracted from an inverted face.     

Mental rotation and real-world wayfinding

Sex differences in mental rotation skills are a robust finding in small-scale laboratory-based studies of spatial cognition. There is almost no evidence in the literature, however, relating these skills to performance on spatial tasks in large-scale, real-world activities such as navigating in a new city or in the woods. This study investigates the connections between mental rotation skills as measured by the Vandenburg-Kuse Mental Rotations test and the performance of college students (n=211) navigating a 6-km orienteering course. The results indicate that mental rotation skills are significantly correlated with wayfinding performance on an orienteering task. The findings also replicate sex differences in spatial ability as found in laboratory-scale studies. However, the findings complicate the discussion of mental rotation skills and sex because women often performed as well as men despite having lower mean test scores. This suggests that mental rotation ability may not be as necessary for some women's wayfinding as it is for men's navigation.     

Mental rotation and perceptual uprightness

Performance in Cooper and Shepard’s (1973) mental rotation task was examined in the context of a model that defined the extent to which alphabet letters could be tilted from their normal orientation and still be perceptually upright. For letters with a broad range of orientations for which they remain perceptually upright, a nonlinear effect of orientation on reaction time was obtained (as in Cooper and Shepard). However, for letters with a narrow range of orientations for which they remain perceptually upright, reaction time was linearly related to orientation. The results supported the hypothesis that subjects in the Cooper and Shepard task would mentally rotate alphabet letters only when they were presented in orientations for which they were not perceptually upright.