The advantage of mentally rotating clockwise

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

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.

Brain Activation of Patients With Obsessive-Compulsive Disorder During a Mental Rotation Task: A Functional MRI Study

Functional neuroimaging studies have implicated alterations in frontostriatal and frontoparietal circuits in obsessive-compulsive disorder (OCD) during various tasks. To date, however, brain activation for visuospatial function in conjunction with symptoms in OCD has not been comprehensively evaluated. To elucidate the relationship between neural activity, cognitive function, and obsessive-compulsive symptoms, we investigated regional brain activation during the performance of a visuospatial task in patients with OCD using functional magnetic resonance imaging (fMRI). Seventeen medication-free patients with OCD and 21 age-, sex-, and IQ-matched healthy controls participated in this study. Functional magnetic resonance imaging data were obtained while the subjects performed a mental rotation (MR) task. Brain activation during the task was compared between the two groups using a two-sample t-test. Voxel-wise whole-brain multiple regression analyses were also performed to examine the relationship between obsessive-compulsive symptom severity and neural activity during the task. The two groups did not differ in MR task performance. Both groups also showed similar task-related activation patterns in frontoparietal regions with no significant differences. Activation in the right dorsolateral prefrontal cortex in patients with OCD during the MR task was positively associated with their total Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores. This study identified the specific brain areas associated with the interaction between symptom severity and visuospatial cognitive function during an MR task in medication-free patients with OCD. These findings may serve as potential neuromodulation targets for OCD treatment.

Cueing the Necker cube: Pupil dilation reflects the viewing-from-above constraint in bistable perception

We hypothesized that a perceptually ambiguous or bistable object (Necker cube) can be more effectively biased to assume a point of view-from-above (VFA) than from below the object by cueing attention. Participants viewed a Necker cube in which one surface was temporarily shaded so as to prime a specific perspective on the cube. Subsequently, the standard (wireframe) Necker cube was viewed for 3 seconds, and participants reported what perspective they had seen initially and whether their perception shifted to the alternative perspective during the brief viewing. Concomitantly, pupil size was monitored with an eye-tracker to obtain an index of cognitive effort. There were two conditions: passive viewing and forced attention to sustain the initially primed perspective. We confirmed the presence of a VFA bias with forced attention, which was accompanied by reduced attentional effort, as indexed by a reduced pupil diameter, compared with the view-from-below. Participants showed no bias during passive viewing. We suggest that the level of intensive attention, when retrieving and maintaining a specific view from memory, is mirrored in the size of the eye pupils and may reflect ecological constraints on visual perception.

Perspective taking as virtual navigation? Perceptual simulation of what others see reflects their location in space but not their gaze

Other peoples' (imagined) visual perspectives are represented perceptually in a similar way to our own, and can drive bottom-up processes in the same way as own perceptual input (Ward, Ganis, & Bach, 2019). Here we test directly whether visual perspective taking is driven by where another person is looking, or whether these perceptual simulations represent their position in space more generally. Across two experiments, we asked participants to identify whether alphanumeric characters, presented at one of eight possible orientations away from upright, were presented normally, or in their mirror-inverted form (e.g. "R" vs. "Я"). In some scenes, a person would appear sitting to the left or the right of the participant. We manipulated either between-trials (Experiment 1) or between-subjects (Experiment 2), the gaze-direction of the inserted person, such that they either (1) looked towards the to-be-judged item, (2) averted their gaze away from the participant, or (3) gazed out towards the participant (Exp. 2 only). In the absence of another person, we replicated the well-established mental rotation effect, where recognition of items becomes slower the more items are oriented away from upright (e.g. Shepard and Meltzer, 1971). Crucially, in both experiments and in all conditions, this response pattern changed when another person was inserted into the scene. People spontaneously took the perspective of the other person and made faster judgements about the presented items in their presence if the characters were oriented towards upright to them. The gaze direction of this other person did not influence these effects. We propose that visual perspective taking is therefore a general spatial-navigational ability, allowing us to calculate more easily how a scene would (in principle) look from another position in space, and that such calculations reflect the spatial location of another person, but not their gaze.

Where Are the Months? Mental Images of Circular Time in a Large Online Sample

People may think about time by mentally imaging it in some spatial form, or as "spacetime." In an online survey, 76,922 Norwegian individuals positioned two dots corresponding to the months of December and March on what they imagined to be their appropriate places on a circle. The majority of respondents placed December within a section of the circumference ranging from 11:00 to 12:00 o'clock, but a group of respondents chose positions around the diametrically opposite 6:00 o'clock position. A similar relationship occurred for March, where most respondents chose a position ranging from 2:30 to 3:00 o'clock but a group of respondents chose positions around 9:00 o'clock. About half of the respondents (N = 39,797) continued to fill out an online questionnaire probing their mental images related to the "year" concept. This clarified that 75% of respondents "saw" the months unfolding in a clockwise direction versus 19% in a counter clockwise fashion. Moreover, while a majority (70%) stated that they imagined the year as a "circle," the rest indicated the use of other mental images (e.g., ellipses and spirals, lines and squares, idiosyncratic or synesthetic spatial forms). We found only weak effects or preferences for spatial forms based on respondents' gender, handedness, age, or geographical location.

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.

Which properties of the visual stimuli predict the type of representation used in mental rotation?

Two modes of internal representation, holistic and piecemeal transformation, have been reported as a means to perform mental rotation (MR) tasks. The stimulus complexity effect has been proposed as an indicator to disentangle between these two representation types. However, the complexity effect has not been fully confirmed owing to the fact that different performances could result from different types of stimuli. Moreover, whether the non-mirror foils play a role in forcing participants to encode all the information from the stimuli in MR tasks is still under debate. This study aims at testing the association between these two common types of representation with different stimuli in MR tasks. First, the numbers of segments and vertices in polygon stimuli were manipulated to test which property of the visual stimuli is more likely to influence the representation in MR tasks. Second, the role of non-mirror foils was examined by comparing the stimulus complexity effect in both with- and without-non-mirror foils conditions. The results revealed that the segment number affected the slope of the linear function relating response times to rotation angle, but the vertex number in the polygons did not. This suggests that a holistic representation was more likely to be adopted in processing integrated objects, whereas a piecemeal transformation was at play in processing multi-part objects. In addition, the stimulus complexity effect was observed in the with-non-mirror foils condition but not in the without-non-mirror foils one, providing a direct evidence to support the role of non-mirror foils in MR tasks.

Mental rotation and the human body: Children's inflexible use of embodiment mirrors that of adults

Adults' mental rotation performance with body-like stimuli is enhanced if these stimuli are anatomically compatible with a human body, but decreased by anatomically incompatible stimuli. In this study, we investigated these effects for kindergartners and first-graders: When asked to mentally rotate cube configurations attached with human body parts in an anatomically compatible way, allowing for the projection of a human body, children performed better than with pure cube combinations. By contrast, when body parts were attached in an anatomically incompatible way, disallowing the projection of a human body, children performed worse than with pure combinations. This experiment is of specific interest against the background of two different theoretical approaches concerning imagery and the motor system in development: One approach assumes an increasing integration of motor processes and imagery over time that enables older children and adults to requisition motor resources for imagery processes, while the other postulates that imagery stems from early sensorimotor processes in the first place, and is disentangled from it over time. The finding that children of the two age groups tested show exactly the same effects as adults when mentally rotating anatomically compatible and incompatible stimuli is interpreted in favour of the latter approach. Statement of contribution What is already known on this subject? In mental rotation, adults perform better when rotating anatomically possible stimuli as compared to rotating standard cube combinations. Performance is worse when rotating anatomically impossible stimuli. What does this study add? The present study shows that children's mental transformations mirror those of adults in these respects. In case of the anatomically impossible stimuli, this highlights an inflexible use of embodiment in both age groups. This is in line with the Piagetian assumption of imagery being based on sensorimotor processes.

Mentalizing Another's Visual World-A Novel Exploration via Motion Aftereffect

Past research on level 2 visual perspective-taking (VPT) has mostly focused on understanding the mental rotation involved when one adopts others' perspective; the mechanisms underlying how the visual world of others is mentally represented remain unclear. In three studies, we addressed this question by adopting a novel VPT task with motion stimuli and exploring the aftereffect on motion discrimination from the self-perspective. Overall the results showed a facilitation aftereffect when participants were instructed to take the avatar's perspective. Meanwhile, participants' self-reported perspective-taking tendencies correlated with the aftereffect for both instructed and spontaneous VPT tasks, when the “to-be-adopted” perspective required the participants to mentally transform their self-body clockwise. Specifically, while facilitation was induced for participants with low self-reported perspective-taking tendencies (e.g., viewing a leftward motion stimulus under another's perspective enhanced subsequent perception of leftward motion from the self-perspective), those with high self-reported perspective-taking tendencies showed an adaptation aftereffect (e.g., viewing a leftward motion stimulus under another's perspective weakened subsequent perception of leftward motion from the self-perspective). For these individuals, the adaptation effect indicated the engagement of direction-selective neurons in processing of the subsequent congruent-direction motion from self's perspective. These findings suggest that motion perception from different perspectives (self vs. another) may share the same direction-selective neural circuitry, and this possibility depends on observers' general perspective-taking tendencies.

An event-related potential study on the time course of mental rotation in upper-limb amputees

OBJECTIVE

Mental rotation of body parts involves sequential cognitive processes, including visual processing, categorization and the mental rotation process itself. However, how these processes are affected by the amputation of a limb is still unclear.

METHODS

Twenty-five right upper-limb amputees and the same number of matched healthy controls participated in a hand mental rotation task. Thirty-two-channel electroencephalography (EEG) was recorded and the event-related potentials (ERPs) were analyzed.

RESULTS

In the early visual processing phase, amputees and controls showed a similar P100. During the categorization phase, the amputees exhibited a decreased N200 compared with controls, and the decline was positively correlated with the time since amputation. In the mental rotation phase, controls had a larger ERP for the right upright hand than for the left upright hand, while amputees had a larger ERP for the left (intact) upright hand than for the right (affected) upright hand.

CONCLUSIONS

Early visual processing was not affected by limb amputation. However, the perceptual salience of hand pictures decreased and the intact hand gained more significance in the amputees.

SIGNIFICANCE

Event-related potentials had the capability of showing the differences in categorization and mental rotation phases between amputees and controls.

In touch with mental rotation: interactions between mental and tactile rotations and motor responses

Although several process models have described the cognitive processing stages that are involved in mentally rotating objects, the exact nature of the rotation process itself remains elusive. According to embodied cognition, cognitive functions are deeply grounded in the sensorimotor system. We thus hypothesized that modal rotation perceptions should influence mental rotations. We conducted two studies in which participants had to judge if a rotated letter was visually presented canonically or mirrored. Concurrently, participants had to judge if a tactile rotation on their palm changed direction during the trial. The results show that tactile rotations can systematically influence mental rotation performance in that same rotations are favored. In addition, the results show that mental rotations produce a response compatibility effect: clockwise mental rotations facilitate responses to the right, while counterclockwise mental rotations facilitate responses to the left. We conclude that the execution of mental rotations activates cognitive mechanisms that are also used to perceive rotations in different modalities and that are associated with directional motor control processes.

Visual image retention does not contribute to modulation of event-related potentials by mental rotation

Rotation of a visual image in mind is associated with a slow posterior negative deflection of the event-related potential (ERP), termed rotation-related negativity (RRN). Retention of a visual image in short-term memory is also associated with a slow posterior negative ERP, termed negative slow wave (NSW). We tested whether short-term memory retention, indexed by the NSW, contributes to the RRN. ERPs were recorded in the same subjects in two tasks, a mental rotation task, eliciting the RRN, and a visual short-term memory task, eliciting the NSW. Over both right and left parietal scalp, no association was found between the NSW and the RRN amplitudes. Furthermore, adjusting for the effect of the NSW had no influence on a significant association between the RRN amplitude and response time, an index of mental rotation performance. Our data indicate that the RRN reflects manipulation of a visual image but not its retention in short-term memory.

Cognitive alterations in motor imagery process after left hemispheric ischemic stroke

BACKGROUND

Motor imagery training is a promising rehabilitation strategy for stroke patients. However, few studies had focused on the neural mechanisms in time course of its cognitive process. This study investigated the cognitive alterations after left hemispheric ischemic stroke during motor imagery task.

METHODOLOGY/PRINCIPAL FINDINGS

Eleven patients with ischemic stroke in left hemisphere and eleven age-matched control subjects participated in mental rotation task (MRT) of hand pictures. Behavior performance, event-related potential (ERP) and event-related (de)synchronization (ERD/ERS) in beta band were analyzed to investigate the cortical activation. We found that: (1) The response time increased with orientation angles in both groups, called "angle effect", however, stoke patients' responses were impaired with significantly longer response time and lower accuracy rate; (2) In early visual perceptual cognitive process, stroke patients showed hypo-activations in frontal and central brain areas in aspects of both P200 and ERD; (3) During mental rotation process, P300 amplitude in control subjects decreased while angle increased, called "amplitude modulation effect", which was not observed in stroke patients. Spatially, patients showed significant lateralization of P300 with activation only in contralesional (right) parietal cortex while control subjects showed P300 in both parietal lobes. Stroke patients also showed an overall cortical hypo-activation of ERD during this sub-stage; (4) In the response sub-stage, control subjects showed higher ERD values with more activated cortical areas particularly in the right hemisphere while angle increased, named "angle effect", which was not observed in stroke patients. In addition, stroke patients showed significant lower ERD for affected hand (right) response than that for unaffected hand.

CONCLUSIONS/SIGNIFICANCE

Cortical activation was altered differently in each cognitive sub-stage of motor imagery after left hemispheric ischemic stroke. These results will help to understand the underlying neural mechanisms of mental rotation following stroke and may shed light on rehabilitation based on motor imagery training.

The advantage of ambiguity? Enhanced neural responses to multi-stable percepts correlate with the degree of perceived instability

Artwork can often pique the interest of the viewer or listener as a result of the ambiguity or instability contained within it. Our engagement with uncertain sensory experiences might have its origins in early cortical responses, in that perceptually unstable stimuli might preclude neural habituation and maintain activity in early sensory areas. To assess this idea, participants engaged with an ambiguous visual stimulus wherein two squares alternated with one another, in terms of simultaneously opposing vertical and horizontal locations relative to fixation (i.e., stroboscopic alternating motion; von Schiller, 1933). At each trial, participants were invited to interpret the movement of the squares in one of five ways: traditional vertical or horizontal motion, novel clockwise or counter-clockwise motion, and, a free-view condition in which participants were encouraged to switch the direction of motion as often as possible. Behavioral reports of perceptual stability showed clockwise and counter-clockwise motion to possess an intermediate level of stability compared to relatively stable vertical and horizontal motion, and, relatively unstable motion perceived during free-view conditions. Early visual evoked components recorded at parietal–occipital sites such as C1, P1, and N1 modulated as a function of visual intention. Both at a group and individual level, increased perceptual instability was related to increased negativity in all three of these early visual neural responses. Engagement with increasingly ambiguous input may partly result from the underlying exaggerated neural response to it. The study underscores the utility of combining neuroelectric recording with the presentation of perceptually multi-stable yet physically identical stimuli, in revealing brain activity associated with the purely internal process of interpreting and appreciating the sensory world that surrounds us.