Different slopes for different folks: process analysis of spatial aptitude

Slower but more accurate mental rotation performance in aphantasia linked to differences in cognitive strategies

Mental rotation tasks are frequently used as standard measures of mental imagery. However, aphantasia research has brought such use into question. Here, we assessed a large group of individuals who lack visual imagery (aphantasia) on two mental rotation tasks: a three-dimensional block-shape, and a human manikin rotation task. In both tasks, those with aphantasia had slower, but more accurate responses than controls. Both groups demonstrated classic linear increases in response time and error-rate as functions of angular disparity. In the three-dimensional block-shape rotation task, a within-group speed-accuracy trade-off was found in controls, whereas faster individuals in the aphantasia group were also more accurate. Control participants generally favoured using object-based mental rotation strategies, whereas those with aphantasia favoured analytic strategies. These results suggest that visual imagery is not crucial for successful performance in classical mental rotation tasks, as alternative strategies can be effectively utilised in the absence of holistic mental representations.

Visual imagery vividness and mental rotation of characters: An event related potentials study

Recent behavioural evidence suggests that differences in the vividness of visual imagery (VVI) affect the way in which mental rotation (MR) tasks are accomplished. However, the role of VVI in MR tasks is still debated. We explored it using event-related brain potentials (ERPs) which allow to track the time course of MR processes with high temporal resolution. We assigned participants to two different groups based on their VVI and compared the rotation-related negativity (RRN), the electrophysiological correlate of MR. Accuracy did not differ in the two groups. However, the RRN offset was delayed in lower as compared to higher VVI individuals. The processing of MR as indexed by the RRN is longer in individuals with lower VVI, providing direct evidence for a role of VVI in MR processing.

Differential influence of habitual third-person vision of a body part on mental rotation of images of hands and feet

Left/right judgement (LRJ) tasks involve determining the laterality of presented hand or feet images. Allocentric images (third-person perspective; 3PP) take longer to identify than egocentric images (first-person perspective; 1PP), supporting that implicit motor imagery (IMI)-mentally manoeuvring one's body to match the shown posture-is used. While numerous cognitive processes are involved during LRJs, it remains unclear whether features of the individual (e.g., visual exposure, experience, task-dependent use) influence the type of recognition strategy used during LRJs (IMI versus non-IMI). To investigate whether an individual's routine visual exposure to hands/feet in 3PP disrupts the typical perspective-reaction time (RT) relationship in LRJs, hand therapists, podiatrists, and healthy controls completed online LRJ tasks of hand and feet images. A group-specific reduction in RT for only allocentric images would represent a switch to non-IMI strategies. The results show that routine visual exposure to feet in 3PP (podiatrists) results in quicker RTs only for allocentric images of feet, suggesting a switch from IMI to non-IMI (e.g., visual object-based recognition) strategies. In contrast, routine visual exposure to hands in 3PP (hand therapists) does not alter RT for allocentric images, suggesting maintenance of IMI. However, hand therapists have quicker RTs (vs other groups) for egocentric hand images, supporting enhanced sensorimotor processing for the hand, consistent with task-dependent use (precise hand use). Higher accuracy in health professionals (vs control) on both tasks supports enhanced body schema. Combined, this suggests that 3PP visual exposure to body parts and task-dependent use contribute to LRJ performance/recognition strategy.

Different representations and strategies in mental rotation

It is still debated whether holistic or piecemeal transformation is applied to carry out mental rotation (MR) as an aspect of visual imagery. It has been recently argued that various mental representations could be flexibly generated to perform MR tasks. To test the hypothesis that imagery ability and types of stimuli interact to affect the format of representation and the choice of strategy in performing MR task, participants, grouped as good or poor imagers, were assessed using four MR tasks, comprising two sets of 'Standard' cube figures and two sets of 'non-Standard' ones, designed by withdrawing cubes from the Standard ones. Both good and poor imagers performed similarly under the two Standard conditions. Under non-Standard conditions, good imagers performed much faster in non-Standard objects than Standard ones, whereas poor imagers performed much slower in non-Standard objects than Standard ones. These results suggested that (1) individuals did not differ in processing the integrated Standard object, whereas (2) in processing the non-Standard objects, various visual representations and strategies could be applied in MR by diverse individuals: Good imagers were more flexible in generating different visual representations, whereas poor imagers applied different strategies under different task demands.

Individual Differences in Mental Rotation

Two experiments tested the hypothesis that imagery ability and figural complexity interact to affect the choice of mental rotation strategies. Participants performed the Shepard and Metzler (1971) mental rotation task. On half of the trials, the 3-D figures were manipulated to create “fragmented” figures, with some cubes missing. Good imagers were less accurate and had longer response times on fragmented figures than on complete figures. Poor imagers performed similarly on fragmented and complete figures. These results suggest that good imagers use holistic mental rotation strategies by default, but switch to alternative strategies depending on task demands, whereas poor imagers are less flexible and use piecemeal strategies regardless of the task demands.

Individual differences in spatial mental imagery

In this article, we report a new image-scanning paradigm that allowed us to measure objectively individual differences in spatial mental imagery--specifically, imagery for location. Participants were asked to determine whether an arrow was pointing at a dot using a visual mental image of an array of dots. The degree of precision required to discriminate "yes" from "no" trials was varied. In Experiment 1, the time to scan increasing distances, as well as the number of errors, increased when greater precision was required to make a judgement. The results in Experiment 2 replicated those results while controlling for possible biases. When greater precision is required, the accuracy of the spatial image becomes increasingly important--and hence the effect of precision in the task reflects the accuracy of the image. In Experiment 3, this measure was shown to be related to scores on the Paper Folding test, on the Paper Form Board test, and on the visuospatial items on Raven's Advanced Progressive Matrices--but not to scores on questionnaires measuring object-based mental imagery. Thus, we provide evidence that classical standardized spatial tests rely on spatial mental imagery but not object mental imagery.

Warning: subtle aspects of strategy assessment may affect correlations among spatial tests

In this study, preliminary to a larger experiment, 42 participants completed four different spatial tests and, after each test, a strategy questionnaire. For half of the participants, visualizational strategies were presented first in this questionnaire, and for the other half, analytical strategies. The order of strategy descriptions had effects on the strategies reported and on the intercorrelations among the spatial tests and between the spatial tests and an inductive-reasoning test. In the group first presented with visualizational strategies, intercorrelations among the spatial tests were higher and correlations with the reasoning test were lower than in the group first presented with analytical strategies. Bootstrap analyses with 100 random splits of the sample confirmed this result. The findings are interpreted as indications of a priming effect by the strategy descriptions which affected the way participants dealt with subsequent tests. Implications for strategy assessment are discussed.

Individual skill differences and large-scale environmental learning

Spatial skills are known to vary widely among normal individuals. This project was designed to address whether these individual differences are differentially related to large-scale environmental learning from route (ground-level) and survey (aerial) perspectives. Participants learned two virtual environments (route and survey) with limited exposure and tested on judgments about relative locations of objects. They also performed a series of spatial and nonspatial component skill tests. With limited learning, performance after route encoding was worse than performance after survey encoding. Furthermore, performance after route and survey encoding appeared to be preferentially linked to perspective and object-based transformations, respectively. Together, the results provide clues to how different skills might be engaged by different individuals for the same goal of learning a large-scale environment.

Orientation invariance in naming rotated objects: individual differences and repetition priming

In naming drawings of complex common objects, unpracticed naming times increase with rotation away from the upright, but this orientation effect is attenuated with practice. In principle, attenuation could result from learning to extract orientation-invariant information or from learning view-specific representations at the trained orientations. We contrasted these approaches by examining repetition priming for prime-target pairs presented on successive trials in either the same orientation (horse at 51 degrees primes horse at 51 degrees) or a different orientation (horse at 154 degrees primes horse at 51 degrees), for two subgroups of subjects. One subgroup showed no orientation effect, even when unpracticed, and a correspondingly high generalization of priming across different views. The other subgroup initially showed high sensitivity to misorientation and little priming across orientations but, with sufficient practice, came to show no orientation effect and complete generalization of priming. Thus, some subjects always used orientation-invariant procedures, whereas others learned to do so.

Process generalization and the prediction of performance on mental imagery tasks

Kosslyn (1980, 1983) theorized that performance measures on imagery tasks may vary as a function of the existence of independent processes in imaging ability. The present study determined whether improvement can be made in performance on such tasks with practice. It also considered whether performance on such tasks improves with practice and whether this improvement generalizes. Experiment 1 determined whether improvement in a mental rotation task generalizes to improvement in a geometric analogies task, with both tasks weighted in Kosslyn's find process, but not in a line drawing memory task weighted in Kosslyn's regenerate process. In Experiment 2, we examined generalization in improvement from a geometric analogies task to a mental rotation task. In Experiment 3, we tested whether improvement in an animal imagery task (Kosslyn, 1975) generalizes to improvement in a line drawing memory task, with both tasks weighted in Kosslyn's regenerate process, but not to improvement in a mental rotation task. Performance improved with practice on all tasks. Furthermore, performance improved from one task to another only if both tasks loaded on the same process.

Mental rotation in perspective problems

The present paper demonstrates that mental rotation as used in the processing of disoriented objects (Cooper and Shepard 1973) can also be used as an explanatory concept for the processing of perspective problems in which the task is to imagine how an environment will appear from another vantage point. In a cognitive map, subjects imagined an initial line of vision and subsequently processed a reorientation stimulus, requesting them to imagine a turn over 0, 45, 90, 135, or 180 degrees. Time for a reorientation increased linearly with the size of the imaginary turn up to 135 degrees and decreased for turns of 180 degrees; apparently, about-faces were relatively easy to imagine. The increment of reorientation time between 0 and 135 degrees was larger for maps presented in unfamiliar orientations such as South-West up. Both the increment and the interaction with familiarity are consistent with an explanation in terms of mental rotation.

Hemisphere differences for components of mental rotation

The hemispheric functional lateralization of components of mental rotation performance was investigated. Twenty right-handed males were presented with rotated alphanumerics and unfamiliar characters in the left or right visual field. Subjects decided if the laterally presented stimulus was identical to or a mirror image of a center standard stimulus. Reaction time and errors were measured. Previous mental rotation findings were replicated and the visual field variable produced significant effects for both dependent measures. An overall right visual field advantage was observed in the latency data, suggesting a left hemisphere superiority for at least one component process of the task. A significant interaction in the error data showed that alphanumerics produced less errors in the right visual field than in the left visual field, consistent with a left hemisphere superiority for processing verbal symbolic material. No such hemispheric difference in accuracy was found for unfamiliar characters.