Looking at the hand modulates the brain responses to nociceptive and non-nociceptive somatosensory stimuli but does not necessarily modulate their perception

Previous studies have suggested that looking at the hand can reduce the perception of pain and the magnitude of the ERPs elicited by nociceptive stimuli delivered onto the hand. In contrast, other studies have suggested that looking at the hand can increase tactile sensory discrimination performance, and enhance the magnitude of the ERPs elicited by tactile stimulation. These opposite effects could be related to differences in the crossmodal effects between vision, nociception, and touch. However, these differences could also be related to the use of different experimental designs. Importantly, most studies on the effects of vision on pain have relied on a mirror to create the illusion that the reflected hand is a direct view of the stimulated hand. Here, we compared the effects of direct versus mirror vision of the hand versus an object on the perception and ERPs elicited by non-nociceptive and nociceptive stimuli. We did not observe any significant effect of vision on the perceived intensity. However, vision of the hand did reduce the magnitude of the nociceptive N240 wave, and enhanced the magnitude of the non-nociceptive P200. Our results confirm that vision of the body differentially affects nociceptive and non-nociceptive processing, but question the robustness of visual analgesia.

Movement preparation improves touch perception without awareness

Movements are often directed at external objects, such as when reaching out for a glass to drink from. Surprisingly, however, it is largely unknown how movement plans influence the identification of such external somatosensory stimuli. To address this, we cued participants to prepare for a speeded button press with their left/right thumb and presented a spatially-patterned somatosensory stimulus at either the same or the opposite thumb with equal probability. In contrast to many previous investigations that focused on self-produced somatosensory input and reported attenuated perception, we show that the identification of external stimuli (touch perception) is facilitated by movement preparation. In line with analogous studies in vision, this suggests that movement preparation automatically allocates processing resources (attention) to the location and/or body part of the planned movement. We further show that, in contrast to deliberate somatosensory preparation, participants do not become more confident in their touch perception following movement preparation. These data suggest that the perceptual improvement during movement preparation occurs outside of awareness. Such an unconscious facilitatory process will ensure that relevant parts of the environment are processed with high fidelity, while sparing conscious resources for monitoring other processes in the course of action.

Handedness in a virtual haptic environment: assessments from kinematic behavior and modeling

This study evaluated hand asymmetries in performance of a dexterous, controlled task under haptic feedback. Participants punctured a virtual membrane with a pushing or pulling movement, using the left or right hand. For pulling movements, the dominant (right) hand exhibited faster average stopping latency and shorter skidding distance. When the kinematic data were fit to a three-phase model previously applied to this task (Klatzky et al., 2013), the right hand exhibited faster force decay attributable to biomechanical factors. Analyses of the aggregated performance measures and model parameters showed that the left and right hands are associated with two different distributions, supporting handedness effects. Furthermore, while the majority of participants expressed right-hand dominance, which was consistent with their self-reported hand preferences, others showed partial or no dominance. This approach could potentially be extended to quantify and differentiate individuals with difficulties in manual behavior due to abnormal motor control (e.g., dyspraxia), progressive deterioration (e.g., Parkinson's syndrome) or improvement (neural regrowth after transplant).

Perception of the material properties of wood based on vision, audition, and touch

Most research on the multimodal perception of material properties has investigated the perception of material properties of two modalities such as vision-touch, vision-audition, audition-touch, and vision-action. Here, we investigated whether the same affective classifications of materials can be found in three different modalities of vision, audition, and touch, using wood as the target object. Fifty participants took part in an experiment involving the three modalities of vision, audition, and touch, in isolation. Twenty-two different wood types including genuine, processed, and fake were perceptually evaluated using a questionnaire consisting of twenty-three items (12 perceptual and 11 affective). The results demonstrated that evaluations of the affective properties of wood were similar in all three modalities. The elements of "expensiveness, sturdiness, rareness, interestingness, and sophisticatedness" and "pleasantness, relaxed feelings, and liked-disliked" were separately grouped for all three senses. Our results suggest that the affective material properties of wood are at least partly represented in a supramodal fashion. Our results also suggest an association between perceptual and affective properties, which will be a useful tool not only in science, but also in applied fields.

Sexual Issues in Treating Trauma Survivors

The effect of interpersonal trauma on sexuality can be profound. The field of sexual trauma is complex empirically and clinically, with contradictory theories and conflicting data. Research definitions and treatment protocols for child sexual abuse are very imprecise. There are no firm, empirically proven guidelines for treating men and women who have been sexually abused as children or adolescents. Overt sexual abuse (OSA) in children and adolescents is defined here as molestation, rape, or incest. Research has shown that OSA may, but does not necessarily, lead to sexual dysfunction in adulthood. The effects of OSA are worsened by concurrent types of family of origin abuse, such as emotional abuse or physical abuse. One factor that seems related to the varying impact of OSA on adult sexuality is the patients’ family of origin experience with nonsexual Milestones of Sexual Development. Without positive experiences with touch, trust and empathy, the ability to relax and be soothed, and power, the effects of OSA are potentiated and complicated. Sexuality is embodied, so experiences with touch are particularly important when working with OSA. A three-color Body Map technique which assesses stored associations to touch is provided. The concept of developmental sexual trauma (DST) is introduced as a way to label traumagenic family events which potentiate OSA or negatively effect sex but which are not explicitly sexual in origin. Strategies to assess and treat OSA are reviewed. Body Maps are recommended to assess and treat sexual trauma.

Point pressure sensitivity in early stage Parkinson's disease

A number of sensory changes occur in the earliest stages of Parkinson's disease (PD), some of which precede the expression of the classic motor phenotype by years (e.g., olfactory dysfunction). Whether point pressure sensitivity (PPS), a cutaneous measure of light touch mediated by myelinated Aβ fibers, is altered in early PD is not clear. Prior studies on this point are contradictory and are based on non-forced-choice threshold tests that confound the sensitivity measure with the response criterion. While α-synuclein pathology, a defining feature of PD, is present in the skin of PD patients, it is restricted to unmyelinated nerve fibers, suggesting PPS may be spared in this disease. We determined PPS thresholds using a state-of-the-art forced-choice staircase threshold test paradigm in 29 early stage PD patients and 29 matched controls at 11 body sites: the center of the forehead and the left and right forearms, index fingers, palms, medial soles of the feet, and plantar halluces. The patients were tested, in counterbalanced sessions, both on and off dopamine-related medications (DRMs). PPS was not influenced by PD and did not correlate with DRM l-DOPA equivalents, scores on the Unified Parkinson's Disease Rating Scale, side of the major motor disturbances, or SPECT imaging of the striatal dopamine transporter, as measured by technetium-99m TRODAT. However, PPS thresholds were lower on the left than on the right side of the body (p=0.008) and on the upper extremities relative to the toes and feet (ps<0.0001). Positive correlations were evident among the thresholds obtained across all body sectors, even though disparate regions of the body differed in terms of absolute sensitivity. This study indicates that PPS is not influenced in early stage PD regardless of whether patients are on or off DRMs.

The effects of verbal cueing on implicit hand maps

The use of position sense to perceive the external spatial location of the body requires that immediate proprioceptive afferent signals be combined with stored representations of body size and shape. Longo and Haggard (2010) developed a method to isolate and measure this representation in which participants judge the location of several landmarks on their occluded hand. The relative location of judgements is used to construct a perceptual map of hand shape. Studies using this paradigm have revealed large, and highly stereotyped, distortions of the hand, which is represented as wider than it actually is and with shortened fingers. Previous studies using this paradigm have cued participants to respond by giving verbal labels of the knuckles and fingertips. A recent study has shown differential effects of verbal and tactile cueing of localisation judgements about bodily landmarks (Cardinali et al., 2011). The present study therefore investigated implicit hand maps measuring through localisation judgements made in response to verbal labels and tactile stimuli applied to the same landmarks. The characteristic set of distortions of hand size and shape were clearly apparent in both conditions, indicating that the distortions reported previously are not an artefact of the use of verbal cues. However, there were also differences in the magnitude of distortions between conditions, suggesting that the use of verbal cues may alter the representation of the body underlying position sense.

Flexibly weighted integration of tactile reference frames

To estimate the location of a tactile stimulus, the brain seems to integrate different types of spatial information such as skin-based, anatomical coordinates and external, spatiotopic coordinates. The aim of the present study was to test whether the use of these coordinates is fixed, or whether they are weighted according to the task context. Participants made judgments about two tactile stimuli with different vibration characteristics, one applied to each hand. First, they always performed temporal order judgments (TOJ) of the tactile stimuli with respect to the stimulated hands that were either crossed or uncrossed. The resulting crossing effect, that is, impaired performance in crossed compared to uncrossed conditions, was used as a measure of reference frame weighting and was compared across conditions. Second, in dual judgment conditions participants subsequently made judgments about the stimulus vibration characteristics, either with respect to spatial location or with respect to temporal order. Responses in the spatial secondary task either accented anatomical (Experiment 1) or external (Experiment 2) coding. A TOJ crossing effect emerged in all conditions, and secondary tasks did not affect primary task performance in the uncrossed posture. Yet, the spatial secondary task resulted in improved crossed hands performance in the primary task, but only if the secondary judgment stressed the anatomical reference frame (Experiment 1), rather than the external reference frames (Experiment 2). Like the anatomically coded spatial secondary task, the temporal secondary task improved crossed hand performance of the primary task. The differential influence of the varying secondary tasks implies that integration weights assigned to the anatomical and external reference frames are not fixed. Rather, they are flexibly adjusted to the context, presumably through top-down modulation.

Discriminating speech rhythms in audition, vision, and touch

We investigated the extent to which people can discriminate between languages on the basis of their characteristic temporal, rhythmic information, and the extent to which this ability generalizes across sensory modalities. We used rhythmical patterns derived from the alternation of vowels and consonants in English and Japanese, presented in audition, vision, both audition and vision at the same time, or touch. Experiment 1 confirmed that discrimination is possible on the basis of auditory rhythmic patterns, and extended it to the case of vision, using 'aperture-close' mouth movements of a schematic face. In Experiment 2, language discrimination was demonstrated using visual and auditory materials that did not resemble spoken articulation. In a combined analysis including data from Experiments 1 and 2, a beneficial effect was also found when the auditory rhythmic information was available to participants. Despite the fact that discrimination could be achieved using vision alone, auditory performance was nevertheless better. In a final experiment, we demonstrate that the rhythm of speech can also be discriminated successfully by means of vibrotactile patterns delivered to the fingertip. The results of the present study therefore demonstrate that discrimination between language's syllabic rhythmic patterns is possible on the basis of visual and tactile displays.

Tactual perception of liquid material properties

In this paper, studies into the tactual perception of two liquid material properties, viscosity and wetness, are reviewed. These properties are very relevant in the context of interaction with liquids, both real, such as cosmetics or food products, and simulated, as in virtual reality or teleoperation. Both properties have been the subject of psychophysical characterisation in terms of magnitude estimation experiments and discrimination experiments, which are discussed. For viscosity, both oral and manual perception is discussed, as well as the perception of the viscosity of a mechanical system. For wetness, the relevant cues are identified and factors affecting perception are discussed. Finally, some conclusions are drawn pertaining to both properties.

From body shadows to bodily attention: automatic orienting of tactile attention driven by cast shadows

Body shadows orient attention to the body-part casting the shadow. We have investigated the automaticity of this phenomenon, by addressing its time-course and its resistance to contextual manipulations. When targets were tactile stimuli at the hands (Exp.1) or visual stimuli near the body-shadow (Exp.2), cueing effects emerged regardless of the delay between shadow and target onset (100, 600, 1200, 2400ms). This suggests a fast and sustained attention orienting to body-shadows, that involves both the space occupied by shadows (extra-personal space) and the space the shadow refers to (own body). When target type became unpredictable (tactile or visual), shadow-cueing effects remained robust only for tactile targets, as visual stimuli showed no overall reliable effects, regardless of whether they occurred near the shadow (Exp.3) or near the body (Exp.4). We conclude that mandatory attention shifts triggered by body-shadows are limited to tactile targets and, instead, are less automatic for visual stimuli.

A multi-digit tactile motion stimulator

BACKGROUND

One of the hallmarks of haptic exploration is that it typically involves movement between skin and object. Explored objects may contact multiple digits simultaneously so information about motion must be integrated across digits, a process about which little is known.

NEW METHOD

To fill this gap, we have developed a stimulator that allows for the simultaneous and independent delivery of motion stimuli to multiple digits. The stimulator consists of individual units that deliver motion with three degrees of freedom: rotation (to produce motion), vertical excursion (to control depth of indentation into the skin) and arm orientation (to control the direction of motion). Each degree of freedom is controlled by a single motor. The compact design of the simulator allows for the side-by-side arrangement of the stimulator units such that they impinge upon adjacent fingers.

RESULTS

To demonstrate the functionality of the stimulator, we performed a series of psychophysical experiments that investigate the perception of motion on multiple fingers. We find that, while the sensitivity to changes in motion direction is equivalent whether stimuli are presented to the same or to different fingers, the perceived direction of motion depends on the relative configuration of the digits.

COMPARISON WITH EXISTING METHODS

We replicated the results of previous experiments investigating motion discrimination with a single digit and were able to extend these findings by investigating motion perception across multiple digits.

CONCLUSION

The novel motion stimulator will be an invaluable tool to investigate how motion information is integrated across multiple digits.

Considering the senses in the diagnosis and management of dementia

Associations between dementia and impairments in hearing, vision, olfaction and (to a lesser degree) taste have been identified. Hearing impairment has been shown to precede cognitive decline, but it is not clear if the hearing loss is an early marker of dementia or a modifiable risk factor. Olfactory impairment is seen in many neurodegenerative conditions, but it has been shown that those with dementia have particular difficulties with the recognition and identification of odours rather than the detection, suggesting a link to impairment of higher cognitive function. Olfactory impairment has been shown to be predictive of conversion from mild cognitive impairment to Alzheimer's disease with 85.2% sensitivity. As cognitive function deteriorates, the world is experienced at a sensory level, with reduced ability to integrate the sensory experiences to understand the context. Thus, people with dementia are very sensitive to sensory experiences and their environment needs to be managed carefully to make it understandable, comfortable, and (if possible) therapeutic. Light can be used to stabilise the circadian rhythm, which may be disturbed in dementia. Music therapy, aromatherapy, massage and multisensory stimulation are recommended by NICE for the management of behavioural and psychological symptoms of dementia (BPSD), although the mechanisms behind such interventions are poorly understood and evidence is limited. Sensory considerations are likely to play a greater role in dementia care in the future, with the development of purpose-built dementia care facilities and the focus on non-pharmacological management strategies for BPSD.

Oscillatory activity in neocortical networks during tactile discrimination near the limit of spatial acuity

Oscillatory interactions within functionally specialized but distributed brain regions are believed to be central to perceptual and cognitive functions. Here, using human scalp electroencephalography (EEG) recordings combined with source reconstruction techniques, we study how oscillatory activity functionally organizes different neocortical regions during a tactile discrimination task near the limit of spatial acuity. While undergoing EEG recordings, blindfolded participants felt a linear three-dot array presented electromechanically, under computer control, and reported whether the central dot was offset to the left or right. The average brain response differed significantly for trials with correct and incorrect perceptual responses in the timeframe approximately between 130 and 175ms. During trials with correct responses, source-level peak activity appeared in the left primary somatosensory cortex (SI) at around 45ms, in the right lateral occipital complex (LOC) at 130ms, in the right posterior intraparietal sulcus (pIPS) at 160ms, and finally in the left dorsolateral prefrontal cortex (dlPFC) at 175ms. Spectral interdependency analysis of activity in these nodes showed two distinct distributed networks, a dominantly feedforward network in the beta band (12-30Hz) that included all four nodes and a recurrent network in the gamma band (30-100Hz) that linked SI, pIPS and dlPFC. Measures of network activity in both bands were correlated with the accuracy of task performance. These findings suggest that beta and gamma band oscillatory networks coordinate activity between neocortical regions mediating sensory and cognitive processing to arrive at tactile perceptual decisions.

In touch with your emotions: oxytocin and touch change social impressions while others' facial expressions can alter touch

Interpersonal touch is frequently used for communicating emotions, strengthen social bonds and to give others pleasure. The neuropeptide oxytocin increases social interest, improves recognition of others' emotions, and it is released during touch. Here, we investigated how oxytocin and gentle human touch affect social impressions of others, and vice versa, how others' facial expressions and oxytocin affect touch experience. In a placebo-controlled crossover study using intranasal oxytocin, 40 healthy volunteers viewed faces with different facial expressions along with concomitant gentle human touch or control machine touch, while pupil diameter was monitored. After each stimulus pair, participants rated the perceived friendliness and attractiveness of the faces, perceived facial expression, or pleasantness and intensity of the touch. After intranasal oxytocin treatment, gentle human touch had a sharpening effect on social evaluations of others relative to machine touch, such that frowning faces were rated as less friendly and attractive, whereas smiling faces were rated as more friendly and attractive. Conversely, smiling faces increased, whereas frowning faces reduced, pleasantness of concomitant touch - the latter effect being stronger for human touch. Oxytocin did not alter touch pleasantness. Pupillary responses, a measure of attentional allocation, were larger to human touch than to equally intense machine touch, especially when paired with a smiling face. Overall, our results point to mechanisms important for human affiliation and social bond formation.

Effect of ageing on tactile transduction processes

With advancing age, a decline in the main sensory modalities including touch sensation and perception is well reported to occur. This review mainly outlines the peripheral components of touch perception highlighting ageing influences on morphological and functional features of cutaneous mechanical transducers and mechanosensitive ion channels, sensory innervation, neurotransmitters and even vascular system required to ensure efferent function of the afferent nerve fibres in the skin. This, in conjunction with effect of ageing on the skin per se and central nervous system, could explain the tactile deficit seen among the ageing population. We also discuss appropriate tools and experimental models available to study the age-related tactile decline.

Pain relief by touch: a quantitative approach

Pain relief by touch has been studied for decades in pain neuroscience. Human perceptual studies revealed analgesic effects of segmental tactile stimulation, as compared to extrasegmental touch. However, the spatial organisation of touch–pain interactions within a single human dermatome has not been investigated yet. In 2 experiments we tested whether, how, and where within a dermatome touch modulates the perception of laser-evoked pain. We measured pain perception using intensity ratings, qualitative descriptors, and signal detection measures of sensitivity and response bias. Touch concurrent with laser pulses produced a significant analgesia, and reduced the sensitivity in detecting the energy of laser stimulation, implying a functional loss of information within the ascending Aδ pathway. Touch also produced a bias to judge laser stimuli as less painful. This bias decreased linearly when the distance between the laser and tactile stimuli increased. Thus, our study provides evidence for a spatial organisation of intrasegmental touch–pain interactions.

The social brain: neurobiological basis of affiliative behaviours and psychological well-being

The social brain hypothesis proposes that the demands of the social environment provided the evolutionary pressure that led to the expansion of the primate brain. Consistent with this notion, that functioning in the social world is crucial to our survival, while close supportive relationships are known to enhance well-being, a range of social stressors such as abuse, discrimination and dysfunctional relationships can increase the risk of psychiatric disorders. The centrality of the social world to our everyday lives is further exemplified by the fact that abnormality in social behaviour is a salient feature of a range of neurodevelopmental and psychiatric disorders. This paper aims to provide a selective overview of current knowledge of the neurobiological basis of our ability to form and maintain close personal relationships, and of the benefits these relationships confer on our health. Focusing on neurochemical and neuroendocrine interactions within affective and motivational neural circuits, it highlights the specific importance of cutaneous somatosensation in affiliative behaviours and psychological well-being and reviews evidence, in support of the hypothesis, that a class of cutaneous unmyelinated, low threshold mechanosensitive nerves, named c-tactile afferents, have a direct and specific role in processing affiliative tactile stimuli.

Concurrent visual and tactile steady-state evoked potentials index allocation of inter-modal attention: a frequency-tagging study

We investigated effects of inter-modal attention on concurrent visual and tactile stimulus processing by means of stimulus-driven oscillatory brain responses, so-called steady-state evoked potentials (SSEPs). To this end, we frequency-tagged a visual (7.5Hz) and a tactile stimulus (20Hz) and participants were cued, on a trial-by-trial basis, to attend to either vision or touch to perform a detection task in the cued modality. SSEPs driven by the stimulation comprised stimulus frequency-following (i.e. fundamental frequency) as well as frequency-doubling (i.e. second harmonic) responses. We observed that inter-modal attention to vision increased amplitude and phase synchrony of the fundamental frequency component of the visual SSEP while the second harmonic component showed an increase in phase synchrony, only. In contrast, inter-modal attention to touch increased SSEP amplitude of the second harmonic but not of the fundamental frequency, while leaving phase synchrony unaffected in both responses. Our results show that inter-modal attention generally influences concurrent stimulus processing in vision and touch, thus, extending earlier audio-visual findings to a visuo-tactile stimulus situation. The pattern of results, however, suggests differences in the neural implementation of inter-modal attentional influences on visual vs. tactile stimulus processing.

Functional signature of recovering cortex: dissociation of local field potentials and spiking activity in somatosensory cortices of spinal cord injured monkeys

After disruption of dorsal column afferents at high cervical spinal levels in adult monkeys, somatosensory cortical neurons recover responsiveness to tactile stimulation of the hand; this reactivation correlates with a recovery of hand use. However, it is not known if all neuronal response properties recover, and whether different cortical areas recover in a similar manner. To address this, we recorded neuronal activity in cortical area 3b and S2 in adult squirrel monkeys weeks after unilateral lesion of the dorsal columns. We found that in response to vibrotactile stimulation, local field potentials remained robust at all frequency ranges. However, neuronal spiking activity failed to follow at high frequencies (≥15 Hz). We suggest that the failure to generate spiking activity at high stimulus frequency reflects a changed balance of inhibition and excitation in both area 3b and S2, and that this mismatch in spiking and local field potential is a signature of an early phase of recovering cortex (<two months).

The role of decreasing contact temperatures and skin cooling in the perception of skin wetness

Cold sensations are suggested as the primary inducer of the perception of skin wetness. However, limited data are available on the effects of skin cooling. Hence, we investigated the role of peripheral cold afferents in the perception of wetness. Six cold-dry stimuli (producing skin cooling rates in a range of 0.02-0.41°C/s) were applied on the forearm of 9 female participants. Skin temperature and conductance, thermal and wetness perception were recorded. Five out of 9 participants perceived wetness as a result of cold-dry stimuli with cooling rates in a range of 0.14-0.41°C/s, while 4 did not perceive skin wetness at all. Although skin cooling and cold sensations play a role in evoking the perception of wetness, these are not always of a primary importance and other sensory modalities (i.e. touch and vision), as well as the inter-individual variability in thermal sensitivity, might be equally determinant in characterising this perception.

Haptic feedback from manual contact improves balance control in people with Parkinson's disease

Parkinson's disease (PD) degrades balance control. Haptic (touch and proprioception) feedback from light contact with a stationary surface inadequate to mechanically stabilize balance improves balance control in healthy people. In this study we tested whether PD impairs use of haptic cues independent of mechanical support to control balance. We measured postural sway in thirteen individuals with PD (H&Y 1-3, median=2, Q1=2, Q3=2) and thirteen age-matched controls balancing in a widened, sharpened Romberg stance in four conditions: eyes-closed, no manual contact; eyes-closed light-touch contact (<1N), eyes-closed, unrestricted contact; and eyes-open, no contact. To determine whether PD-severity affects any of these balance strategies, PD participants were tested on- and off-medication, and using the more- and less-affected body side in the stance and manual contact. Individuals with PD simultaneously maintained non-supportive fingertip contact and balance in this task without practice. PD participants swayed more than control participants (ML CP p=0.010; shoulder p<0.001), but manual contact reduced sway. Non-supportive manual contact stabilized balance more than vision (p<0.05). PD-severity factors had no significant effect (p>0.05). We conclude the effect of PD on balance is not specific to vision or haptic feedback. Nevertheless, haptic cues from manual contact, independent of mechanical support, improve balance control in individuals with PD. We discuss the implication that PD or associated dopaminergic pathways do not directly affect haptic feedback balance control mechanisms, including arm/posture coordination and proprioceptive integration.

The effects of sleep and touch therapy on symptoms of fibromyalgia and depression

BACKGROUND

Many alternative interventions are practiced in an effort to reduce symptoms of fibromiyalgia. The aim of this study was to determine the effects of sleep and touch therapy accompanied by music and aromatherapy on the symptoms of fibromyalgia and depression.

METHODS

The study was carried out between September 2009 and March 2011 in the Physical Medicine and Rehabilitation Polyclinic in Trabzon, Turkey. The sample consisted of 162 female patients and had been diagnosed with fibromyalgia at least 6 months prior to the study. Since the sample contains two intervention groups and one control group, each group was assigned 54 patients. Data were collected through a Personal Information Form, a Fibromyalgia Symptom Form and the Beck Depression Index. The study employed a pre-test/post-test control group design. A paired sample t-test was used in the comparisons of the in-group scale points; the chi-square in the intergroup comparisons, and the McNamer test in the in-group comparisons.

RESULTS

After the interventions, it was observed that the depression levels in the touch-music-aroma therapy group showed a larger decrease (before: 22.01±5.3; after: 14.52±3.7) than in the sleep-music-aroma therapy group (before: 24.81±5.1; after: 20.16±4.9) and control groups (before: 23.73±4.4; after: 21.05±2.6). Symptoms such as restless sleep, headache, morning fatigue, exhaustion, feeling like crying and bowel complaints were also significantly reduced (P<0.05).

CONCLUSION

It is suggested that nurses providing healthcare to FMS patients should also offer these patients aromatherapy, sleep, music and touch therapies.

Reduction of propofol injection pain by utilizing the gate control theory

Background

Propofol is the most commonly using intravenous hypnotic for the induction and maintenance of general anesthesia. However, pain on propofol injection is a well known adverse event. Currently, acute and chronic pain can be controlled by utilizing the "gate control" theory.

Methods

Patients were randomized to receive lidocaine (0.5 mg/kg; Group L), touch on IV injection site (Group T), combination lidocaine (0.5 mg/kg) and touch on IV injection site (Group B), or normal saline (Group S) with venous occlusion for 1 minute, followed by administration of propofol (0.5 mg/kg) into the largest dorsal vein of the hand. Immediately after administering propofol, an investigator blinded to the group assignments asked the patient about pain at the injection site and assessed pain intensity using a 4-point verbal rating scale (0 = none, 1 = mild, 2 = moderate, 3 = severe).

Results

A significant decrease in the incidence of pain on propofol injection was achieved in group L (37%) and group B (23%) compared to either group T (80%) and group S (83%) (P < 0.001). But, the incidence of moderate and severe pain was significantly lower in group L (7%), group T (20%) and group B (0%) when compared to group S (53%) (P < 0.05).

Conclusions

Light touch and rubbing reduced pain, although while, they did not reduce the incidence of pain, they reduced the intensity of pain. This method might be considered as an alternative to other treatments but may be contraindicated for use with other drugs.

Genetic Analysis of the Touch Response in Zebrafish (Danio rerio)

Both mammals and zebrafish possess mechanosensory neurons that detect tactile sensation via free nerve endings. However, the basis for mechanotransduction and the unique cellular properties of these sensory neurons are poorly understood. We review the advantages of zebrafish for studies of the biological mechanisms involved in touch sensitivity. Importantly, Granato and colleagues (1996) demonstrated that a simple touch assay efficiently recovers mutations that affect sensory neurons.

Mechanosensor Channels in Mammalian Somatosensory Neurons

Mechanoreceptive sensory neurons innervating the skin, skeletal muscles and viscera signal both innocuous and noxious information necessary for proprioception, touch and pain. These neurons are responsible for the transduction of mechanical stimuli into action potentials that propagate to the central nervous system. The ability of these cells to detect mechanical stimuli impinging on them relies on the presence of mechanosensitive channels that transduce the external mechanical forces into electrical and chemical signals. Although a great deal of information regarding the molecular and biophysical properties of mechanosensitive channels in prokaryotes has been accumulated over the past two decades, less is known about the mechanosensitive channels necessary for proprioception and the senses of touch and pain. This review summarizes the most pertinent data on mechanosensitive channels of mammalian somatosensory neurons, focusing on their properties, pharmacology and putative identity.