Haptic Task Research Articles

Visual experience shapes bodily representation of emotion.

Philosophers and experimentalists have long debated whether bodily representation of emotion is grounded in our sensory experience. Indeed, we are used to observe emotional reactions expressed through the bodies of others, yet it is still unknown whether this observation influences how we experience affective states in our own bodies. To delve into this question, we developed a naturalistic haptic task and asked a group of early (n = 20) and late (n = 20) blind, as well as sighted individuals (n = 20) to indicate where in the body they perceive changes associated with affective states. Our results show that visual experience shapes bodily representation of emotion. Blind and sighted individuals attribute different importance to body regions in relation to specific emotional states, as sighted people focus more on visceral sensations, while blind report as more relevant the mouth and the hand areas. We also observe differences in the coherence of bodily maps of specific emotions, such as aggressiveness, for which early and late blind are homogenous in reporting the mouth, while sighted subjects demonstrate a scattered pattern of activation across the body. Finally, our findings show that blind people rely on a different organization of affect, as only sighted categorize bodily maps of emotion through the valence and arousal dimensions. In summary, we demonstrate that sensory experience impacts the bodily representation of affect by modulating the relevance that different body parts have in emotional reactions, modifying the weights attributed to interoceptive and exteroceptive signals, and changing how emotions are conceptualized in the body. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Tactile expectancy modulates occipital alpha oscillations in early blindness

Alpha oscillatory activity is thought to contribute to visual expectancy through the engagement of task-relevant occipital regions. In early blindness, occipital alpha oscillations are systematically reduced, suggesting that occipital alpha depends on visual experience. However, it remains possible that alpha activity could serve expectancy in non-visual modalities in blind people, especially considering that previous research has shown the recruitment of the occipital cortex for non-visual processing. To test this idea, we used electroencephalography to examine whether alpha oscillations reflected a differential recruitment of task-relevant regions between expected and unexpected conditions in two haptic tasks (texture and shape discrimination). As expected, sensor-level analyses showed that alpha suppression in parieto-occipital sites was significantly reduced in early blind individuals compared with sighted participants. The source reconstruction analysis revealed that group differences originated in the middle occipital cortex. In that region, expected trials evoked higher alpha desynchronization than unexpected trials in the early blind group only. Our results support the role of alpha rhythms in the recruitment of occipital areas in early blind participants, and for the first time we show that although posterior alpha activity is reduced in blindness, it remains sensitive to expectancy factors. Our findings therefore suggest that occipital alpha activity is involved in tactile expectancy in blind individuals, serving a similar function to visual anticipation in sighted populations but switched to the tactile modality. Altogether, our results indicate that expectancy-dependent modulation of alpha oscillatory activity does not depend on visual experience. Significance statementAre posterior alpha oscillations and their role in expectancy and anticipation dependent on visual experience? Our results show that tactile expectancy can modulate posterior alpha activity in blind (but not sighted) individuals through the engagement of occipital regions, suggesting that in early blindness, alpha oscillations maintain their proposed role in visual anticipation but subserve tactile processing. Our findings bring a new understanding of the role that alpha oscillatory activity plays in blindness, contrasting with the view that alpha activity is task unspecific in blind populations.

Measures of Spatial Orientation: Spatial Bias Analogs in Visual and Haptic Tasks.

The primary sensory modality for probing spatial orientation can vary among psychophysical tasks. In the subjective visual vertical (SVV) task, a visual stimulus is used to measure perceived vertical orientation, while a haptic stimulus is used in the subjective haptic vertical (SHV) task. Here we examined disparity in SHV and SVV task results and asked whether it could be related to biases in probing different spatial estimates by each task. Forty-two healthy volunteers (mean ± SD age, 25 ± 10 years; 19 females; 21 left handed) were recruited. The effect of a task to measure spatial orientation was calculated as the difference between SHV and SVV values, and with the head upright and tilted 20° laterally. There was a task bias regardless of head position related to hand use in the haptic task but not handedness (mean head upright ± SEM: left hand, −3.7 ± 1.1°; right hand, 7.9 ± 1.0°). When this task bias was subtracted out, there was a similar spatial bias using each hand in the SHV task that was also comparable to the SVV task (mean head with left tilt: left hand, 3.9 ± 0.7°; right hand, 4.4 ± 0.7°; SVV, 4.9 ± 0.7°; mean head with right tilt: left hand, −4.6 ± 0.9°; right hand, −4.6 ± 0.8°; SVV, −4.7 ± 1.0°). These findings show that the disparity in visual and haptic measures of spatial orientation is primarily related to a modality-specific bias, and once the effect of hand use is removed from the haptic measurements, the spatial bias becomes comparable to the visual task.

The suppression of spontaneous face touch and resulting consequences on memory performance of high and low self-touching individuals

Spontaneous touching of one's own face (sFST) is an everyday behavior that occurs primarily in cognitively and emotionally demanding situations, regardless of a persons’ age or gender. Recently, sFST have sparked scientific interest since they are associated with self-inoculation and transmission of respiratory diseases. Several studies addressed the need to reduce sFST behaviors without discussing the underlying functions of this spontaneous behavior. In addition, the question of why this behavior occurs very frequently in some individuals (high self-touching individuals, HT) but less frequently in others (low self-touching individuals, LT) has not yet been addressed. For the first time, we distinguished between HT and LT and investigated the behavioral consequences of sFST suppression in these two groups. For this purpose, we examined performance outcomes of 49 participants depending on sFST behaviors during a haptic working memory task. In addition, we assessed personality traits of HT and LT using the Freiburg Personality Inventory (FPI-R). The results of our study reveal that suppressing sFST in HT is negatively related to memory performance outcomes. Moreover, HT show tendencies to differ from LT in certain personality traits. Our results highlight the relevance of distinguishing between HT and LT in future studies of sFST.

Mental Rotation Skill Shapes Haptic Exploration Strategies

Haptic exploration strategies have been traditionally studied focusing on hand movements and neglecting how objects are moved in space. However, in daily life situations touch and movement cannot be disentangled. Furthermore, the relation between object manipulation as well as performance in haptic tasks and spatial skill is still little understood. In this study, we used iCube, a sensorized cube recording its orientation in space as well as the location of the points of contact on its faces. Participants had to explore the cube faces where little pins were positioned in varying number and count the number of pins on the faces with either even or odd number of pins. At the end of this task, they also completed a standard visual mental rotation test (MRT). Results showed that higher MRT scores were associated with better performance in the task with iCube both in term of accuracy and exploration speed and exploration strategies associated with better performance were identified. High performers tended to rotate the cube so that the explored face had the same spatial orientation (i.e., they preferentially explored the upward face and rotated iCube to explore the next face in the same orientation). They also explored less often twice the same face and were faster and more systematic in moving from one face to the next. These findings indicate that iCube could be used to infer subjects' spatial skill in a more natural and unobtrusive fashion than with standard MRTs.

Inter-personal motor interaction is facilitated by hand pairing

The extent to which hand dominance may influence how each agent contributes to inter-personal coordination remains unknown. In the present study, right-handed human participants performed object balancing tasks either in dyadic conditions with each agent using one hand (left or right), or in bimanual conditions where each agent performed the task individually with both hands. We found that object load was shared between two hands more asymmetrically in dyadic than single-agent conditions. However, hand dominance did not influence how two hands shared the object load. In contrast, hand dominance was a major factor in modulating hand vertical movement speed. Furthermore, the magnitude of internal force produced by two hands against each other correlated with the synchrony between the two hands’ movement in dyads. This finding supports the important role of internal force in haptic communication. Importantly, both internal force and movement synchrony were affected by hand dominance of the paired participants. Overall, these results demonstrate, for the first time, that pairing of one dominant and one non-dominant hand may promote asymmetrical roles within a dyad during joint physical interactions. This appears to enable the agent using the dominant hand to actively maintain effective haptic communication and task performance.

Traversing the succession of space to place to home: a kinesthetic comprehension of the body as it forms an epistemology of space

ABSTRACT This research investigates how the kinesthetic body forms knowledge of an environment and how that knowledge transforms with the involvement of participants. A Practice as Research (PAR) methodology employs the body as primary agent in cognition. Choreographic and improvisational movement devices assist the task of tracing cognition in participants’ home environment. These devices include haptic and visual perception tasks, spatial behavior, spatial patterning, and habitual movement analysis. Research participants include professional dancers and students within a university setting. The experiential learning theories of John Dewey, David Kolb, and Alice Kolb shift a spatial paradigm of one to a group, egalitarian paradigm. Illuminated through this research is the body’s significant role in forming theoretical and practical knowledge. Body and environment exist as one.

Gender Differences in Haptic Parallelity Matching

Previous studies have reported gender differences in performance when two bars have to be set parallel to each other haptically, with females having significantly larger deviations than males. Recent results comparing male participants with and without action video game experience showed that the former performed significantly better than the latter in the aforementioned haptic parallelity task. Considering that males more often engage in action video gaming, the observed performance differences between male and female participants might be related to gaming experience rather than gender. This was investigated in the current study by comparing haptic parallelity performance in males with action video gaming experience and in males and females without this experience. The results showed that male participants with as well as without action video gaming experience performed significantly better than female participants. These results suggest that differences in haptic parallelity matching between males and females seem to be related to gender, rather than action video gaming experience. When performing the parallelity task visually, no significant differences were found between the three groups, corroborating earlier hypotheses that women are less able to ignore the bias of the egocentric hand-centered reference frame than men when haptically paralleling orientations.

Haptic Perception in Extreme Obesity: qEEG Study Focused on Predictive Coding and Body Schema.

Haptic perception (HP) is a perceptual modality requiring manual exploration to elaborate the physical characteristics of external stimuli through multisensory integrative cortical pathways. Cortical areas exploit processes of predictive coding that collect sensorial inputs to build and update internal perceptual models. Modifications to the internal representation of the body have been associated with eating disorders. In the light of this, obese subjects were selected as a valid experimental model to explore predictive coding in haptic perception. To this purpose, we performed electroencephalographic (EEG) continuous recordings during a haptic task in normally weighted versus obese subjects. EEG power spectra were analyzed in different time intervals. The quality of haptic performance in the obese group was poorer than in control subjects, though exploration times were similar. Spectral analysis showed a significant decrease in theta, alpha and beta frequencies in the right temporo-parietal areas of obese group, whereas gamma bands significantly increased in the left frontal areas. These results suggest that severe obesity could be characterized by an impairment in haptic performances and an altered activation of multisensory integrative cortical areas. These are involved in functional coding of external stimuli, which could interfere with the ability to process a predicted condition.

Trigeminal input, pupil size and cognitive performance: From oral to brain matter

It has been observed that, in patients affected by temporomandibular disorders (TMDs) and edentulism, a left–right asymmetry in electromyographic (EMG) activity of masseter muscles during clenching and in pupil size at rest (anisocoria) is present. Both are greatly reduced by an orthotic-prosthetic correction. In parallel, the correction significantly improves cognitive performance. These effects are possibly due to the recovery of a cortical balance, via Locus Coeruleus (LC) modulation, whose activity is powerfully affected by the sensorimotor trigeminal input. The role of this functional axis was further investigated in subjects without overt occlusal or dental problems.In these individuals, the EMG asymmetry was significantly correlated to anisocoria at rest, with the dental arches open or in contact. Also in normal subjects, both the EMG and the pupil asymmetry during clenching could be significantly reduced by an orthotic (bite) correction.Closing the arches without bite increased anisocoria and reduced performance in the Spinnler-Tognoni matrices test, as well as the mydriasis induced by a haptic task. When the bite was interposed, anisocoria was reduced, while both performance and task-related mydriasis were enhanced. Since pupil size is considered a proxy of the LC activity, these results suggest that asymmetric occlusion biases the LC discharge and the hemispheric excitability, possibly via a sensorimotor trigeminal imbalance. Removing the anisocoria through bite correction re-establishes a symmetric LC discharge, improving performance and enhancing task-related mydriasis. Therefore, occlusal balancing may represent a tool for improving subjective performance and may be exploited for training and rehabilitative purposes.

To Move or Not to Move: Development of Fine-Tuning of Object Motion in Haptic Exploration

Recognizing objects through touch is a complex task based on integrating information coming from multiple senses and motor commands guiding the exploratory motions. To gain insight into the development of exploratory strategies in children, in this study, we addressed the question: how does exploration change when the stimulus becomes freely movable rather than fixed? We tested whether the possibility to move the object ushers in a strategic advantage, reducing the time and the number of touches necessary. We analyzed how school-aged children explore iCube, which is a sensorized cube measuring its orientation in space and contacts location. We tasked participants with finding specific cube faces; they could only touch the static cube, move and touch it, or move, touch, and look at it. Visuo-haptic performances were adult-like at seven years of age, whereas haptic exploration was less effective until nine years. The fine-tuning of object movements as a function of task constraints, e.g., the availability of the vision or blind haptic task, increased significantly with age. Shedding light on how different factors shape haptic exploration could help researchers in the pursuit of detecting the occurrence of abnormal exploratory behaviors early on during the development, providing a novel approach to detecting perceptual problems.

Characterizing Functional Upper Extremity Movement in Haptic Virtual Environments.

Haptic virtual environments have been used to assess cognitive and fine motor function. For tasks performed in physical environments, upper extremity movement is usually separated into reaching and object manipulation phases using fixed velocity thresholds. However, these thresholds can result in premature segmentation due to additional trajectory adjustments common in virtual environments. In this work, we address the issues of premature segmentation and the lack of a measure to characterize the spatial distribution of a trajectory while targeting an object. We propose a combined relative distance and velocity segmentation procedure and use principal component analysis (PCA) to capture the spatial distribution of the participant's targeting phase. Synthetic data and 3D motion data from twenty healthy adults were used to evaluate the methods with positive results. We found that these methods quantify motor skill improvement of healthy participants performing repeated trials of a haptic virtual environment task.

Task-Irrelevant Sound Corrects Leftward Spatial Bias inBlindfolded Haptic Placement Task.

We often rely on our sense of vision for understanding the spatial location of objects around us. If vision cannot be used, one must rely on other senses, such as hearing and touch, in order to build spatial representations. Previous work has found evidence of a leftward spatial bias in visual and tactile tasks. In this study, we sought evidence of this leftward bias in a non-visual haptic object location memory task and assessed the influence of a task-irrelevant sound. In Experiment 1, blindfolded right-handed sighted participants used their non-dominant hand to haptically locate an object on the table, then used their dominant hand to place the object back in its original location. During placement, participants either heard nothing (no-sound condition) or a task-irrelevant repeating tone to the left, right, or front of the room. The results showed that participants exhibited a leftward placement bias on no-sound trials. On sound trials, this leftward bias was corrected; placements were faster and more accurate (regardless of the direction of the sound). One explanation for the leftward bias could be that participants were overcompensating their reach with the right hand during placement. Experiment 2 tested this explanation by switching the hands used for exploration and placement, but found similar results as Experiment 1. A third Experiment found evidence supporting the explanation that sound corrects the leftward bias by heightening attention. Together, these findings show that sound, even if task-irrelevant and semantically unrelated, can correct one's tendency to place objects too far to the left.

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation.

Current scientific literature provides evidence that trigeminal sensorimotor activity associated with chewing may affect arousal, attention, and cognitive performance. These effects may be due to widespread connections of the trigeminal system to the ascending reticular activating system (ARAS), to which noradrenergic neurons of the locus coeruleus (LC) belongs. LC neurons contain projections to the whole brain, and it is known that their discharge co-varies with pupil size. LC activation is necessary for eliciting task-related mydriasis. If chewing effects on cognitive performance are mediated by the LC, it is reasonable to expect that changes in cognitive performance are correlated to changes in task-related mydriasis. Two novel protocols are presented here to verify this hypothesis and document that chewing effects are not attributable to aspecific motor activation. In both protocols, performance and pupil size changes observed during specific tasks are recorded before, soon after, and half an hour following a 2 min period of either: a) no activity, b) rhythmic, bilateral handgrip, c) bilateral chewing of soft pellet, and d) bilateral chewing of hard pellet. The first protocol measures level of performance in spotting target numbers displayed within numeric matrices. Since pupil size recordings are recorded by an appropriate pupillometer that impedes vision to ensure constant illumination levels, task-related mydriasis is evaluated during a haptic task. Results from this protocol reveal that 1) chewing-induced changes in performance and task-related mydriasis are correlated and 2) neither performance nor mydriasis are enhanced by handgrip. In the second protocol, use of a wearable pupillometer allows measurement of pupil size changes and performance during the same task, thus allowing even stronger evidence to be obtained regarding LC involvement in the trigeminal effects on cognitive activity. Both protocols have been run in the historical office of Prof. Giuseppe Moruzzi, the discoverer of ARAS, at the University of Pisa.

Adults\u2019 spatial scaling: evidence from the haptic domain

The current study investigated adults’ spatial-scaling abilities using a haptic localization task. As a first aim, we examined the strategies used to solve this haptic task. Secondly, we explored whether irrelevant visual information influenced adults’ spatial-scaling performance. Thirty-two adults were asked to locate targets as presented in maps on a larger or same-sized referent space. Maps varied in size in accordance with different scaling factors (1:4, 1:2, 1:1), whereas the referent space was constant in size throughout the experimental session. The availability of irrelevant, non-informative vision was manipulated by blindfolding half of the participants prior to the experiment (condition without non-informative vision), whereas the other half were able to see their surroundings with the stimuli being hidden behind a curtain (condition with non-informative vision). Analyses with absolute errors (after correcting for reversal errors) as the dependent variable revealed a significant interaction of the scaling factor and non-informative vision condition. Adults in the blindfolded condition showed constant errors and response times irrespective of scaling factor. Such a response pattern indicates the usage of relative strategies. Adults in the curtain condition showed a linear increase in errors with higher scaling factors, whereas their response times remained constant. This pattern of results supports the usage of absolute strategies or mental transformation strategies. Overall, our results indicate different scaling strategies depending on the availability of non-informative vision, highlighting the strong influence of (even irrelevant) vision on adults’ haptic processing.

Children with cerebral palsy display abnormal somatosensory cortical activity during a haptic exploration task

Children with cerebral palsy display abnormal somatosensory cortical activity during a haptic exploration task

Haptic exploration attenuates and alters somatosensory cortical oscillations.

Several behavioural studies have shown the sensory perceptions are reduced during movement; yet the neurophysiological reason for this is not clear. Participants underwent stimulation of the median nerve when either sitting quietly (i.e. passive stimulation condition) or performing haptic exploration of a ball with the left hand. Magnetoencephalographic brain imaging and advanced beamforming methods were used to identify the differences in somatosensory cortical responses. We show that the neural populations active during the passive stimulation condition were strongly gated during the haptic exploration task. These results imply that the reduced haptic perceptions might be governed by gating of certain somatosensory neural populations. Several behavioural studies have shown that children have reduced sensory perceptions during movement; however, the neurophysiological nexus for these altered perceptions remains unknown. We used magnetoencephalographic brain imaging and advanced beamforming methods to address this knowledge gap. In our experiment, a cohort of children (aged 10-18years) underwent stimulation of the median nerve when either sitting quietly (i.e. passive stimulation condition) or performing haptic exploration of a ball with the left hand. Our results revealed two novel observations. First, there was a relationship between the child's age and the strength of the beta (18-26Hz) response seen within the somatosensory cortices during the passive stimulation condition. This suggests that there may be an age-dependent change in the processing of peripheral feedback by the somatosensory cortices. Second, all of the cortical regions that were active during the passive stimulation condition were almost completely gated during the haptic task. Instead, the haptic task involved neural oscillations within Brodmann area 2, which is known to convey less spatially precise tactile information but is involved in the processing of more complex somatosensations across the respective digits. These results imply that the reduced somatosensory perceptions seen during movements in healthy children may be related to the gating of certain neural generators, as well as activation of haptic-specific neural generators within the somatosensory cortices. The utilization of such haptic-specific circuits during development may lead to the enhanced somatosensory processing during haptic exploration seen in healthy adults.

Improving Clinical Proficiency Using a 3-Dimensionally Printed and Patient-Specific Thoracic Spine Model as a Haptic Task Trainer.

Advanced haptic simulators for neuraxial training are expensive, have a finite life, and are not patient specific. We sought to demonstrate the feasibility of developing a custom-made, low-cost, 3-dimensionally printed thoracic spine simulator model from patient computed tomographic scan data. This study assessed the model's practicality, efficiency as a teaching tool, and the transfer of skill set into patient care. A high-fidelity, patient-specific thoracic spine model was used for the study. Thirteen residents underwent a 1-hour 30-minute training session prior to performing thoracic epidural analgesia (TEA) on patients. We observed another group of 14 residents who were exposed to the traditional method of training during their regional anesthesia rotation for thoracic epidural placement. The TEA was placed for patients under the supervision of attending anesthesiologists, who were blinded to the composition of the study and control groups. As a primary outcome, data were collected on successful TEAs, which was defined as a TEA that provided full relief of sensation across the entire surgical area as assessed by both a pinprick and temperature test. Secondary outcomes included whether any assistance from the attending physician was required and failed epidurals. A total of 27 residents completed the study (14 in the traditional training, 13 in the study group). We found that the residents who underwent training with the simulator had a significantly higher success rate (11 vs 4 successful epidural attempts, P = 0.002) as compared with the traditional training group. The control group also required significantly more assistance from the supervising anesthesiologist compared with the study group (5 vs 1 attempt requiring guidance). The number needed to treat (NNT) for the traditional training group was 1.58 patients over the study period with a 95% confidence interval of 1.55 to 1.61. By using patient-specific, 3-dimensionally printed, thoracic spine models, we demonstrated a significant improvement in clinical proficiency as compared with traditional teaching models.

The development of haptic processing skills from childhood to adulthood by means of two-dimensional materials.

Research into haptic perception has mostly focused on 3-dimensional objects, and more needs to be known about the processing of 2-dimensional materials (e.g., raised dots and lines and raised-line shapes, patterns and pictures). This study examines the age-related changes in various skills related to the haptic exploration of 2-dimensional raised-line and dot materials and how these skills are related to haptic picture perception. Ninety-one participants, aged 4 years to adult, were asked to perform a series of haptic tasks that entailed (a) finding dots and following lines; (b) matching elements based on texture, shape, and size; (c) matching elements based on spatial location and orientation; (d) memorising sequences of dots and shapes; and (e) identifying complete and incomplete raised-line pictures. On all the tests, the results showed that scores improved with age. Shape discrimination scores accounted for variability in comprehension scores for outline pictures. We suggested that identifying tactile pictures by touch improved with age and mainly depended on the improvement of shape discrimination skills. (PsycINFO Database Record

Neurophysiological evidence for enhanced tactile acuity in early blindness in some but not all haptic tasks

Previous research assessing the presence of enhanced tactile skills in early-blind (EB) population obtained conflicting results. Most of the studies relied on behavioral measures with which different mechanisms leading to the same outcome go unnoticed. Moreover, the scarce electrophysiological research that has been conducted focused exclusively on the processing of microgeometric properties. To clarify the extent of superior tactile abilities in EBs using high-density multichannel electrophysiological recordings, the present study compared the electrophysiological correlates of EBs and sighted controls (CON) in two tactile discrimination tasks that targeted microgeometric (texture) and macrogeometric (shape) properties. After a restricted exploration (haptic glance), participants judged whether a touched stimulus corresponded to an expected stimulus whose name had been previously presented aurally. In the texture discrimination task, differences between groups emerged at ∼75 ms (early perceptual processing stages) whereas we found no between-group differences during shape discrimination. Furthermore, for the first time, we were able to determine the latency at which EBs started to discriminate micro- (EB: 170 ms; CON: 230 ms) and macrogeometric (EB: 250 ms; CON: 270 ms) properties. Altogether, the results suggest different electrophysiological signatures during texture (but not shape) discrimination in EBs, possibly due to cortical reorganization in occipital areas and their increased connectivity with S1.