scholarly journals Sensory Adaptation in the Whisker-Mediated Tactile System: Physiology, Theory, and Function

2021 ◽  
Vol 15 ◽  
Author(s):  
Mehdi Adibi ◽  
Ilan Lampl
Keyword(s):  
Neural Coding ◽  
Sensory Input ◽  
Somatosensory System ◽  
Sensory Stimulation ◽  
Coincidence Detection ◽  
Sensory Adaptation ◽  
Response Dynamics ◽  
Neuronal Adaptation ◽  
Tactile Stimuli ◽  
Tactile System

In the natural environment, organisms are constantly exposed to a continuous stream of sensory input. The dynamics of sensory input changes with organism's behaviour and environmental context. The contextual variations may induce >100-fold change in the parameters of the stimulation that an animal experiences. Thus, it is vital for the organism to adapt to the new diet of stimulation. The response properties of neurons, in turn, dynamically adjust to the prevailing properties of sensory stimulation, a process known as “neuronal adaptation.” Neuronal adaptation is a ubiquitous phenomenon across all sensory modalities and occurs at different stages of processing from periphery to cortex. In spite of the wealth of research on contextual modulation and neuronal adaptation in visual and auditory systems, the neuronal and computational basis of sensory adaptation in somatosensory system is less understood. Here, we summarise the recent finding and views about the neuronal adaptation in the rodent whisker-mediated tactile system and further summarise the functional effect of neuronal adaptation on the response dynamics and encoding efficiency of neurons at single cell and population levels along the whisker-mediated touch system in rodents. Based on direct and indirect pieces of evidence presented here, we suggest sensory adaptation provides context-dependent functional mechanisms for noise reduction in sensory processing, salience processing and deviant stimulus detection, shift between integration and coincidence detection, band-pass frequency filtering, adjusting neuronal receptive fields, enhancing neural coding and improving discriminability around adapting stimuli, energy conservation, and disambiguating encoding of principal features of tactile stimuli.

scholarly journals Neural mechanisms of selective attention in the somatosensory system

2016 ◽  
Vol 116 (3) ◽  
pp. 1218-1231 ◽  
Author(s):  
Manuel Gomez-Ramirez ◽  
Kristjana Hysaj ◽  
Ernst Niebur
Keyword(s):  
Selective Attention ◽  
Neural Coding ◽  
Sensory Modality ◽  
Somatosensory System ◽  
The Body ◽  
Neural Mechanisms ◽  
Sensory Stimuli ◽  
Advantages And Disadvantages ◽  
Tactile Attention ◽  
Tactile Stimuli

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates.

Stimulus Generalization Using Nonvisual Stimuli with a Student Who Has Autism Spectrum Disorder and Visual Impairment

2021 ◽  
Vol 115 (2) ◽  
pp. 121-133
Author(s):  
Robin Arnall ◽  
Yors Garcia ◽  
Annette K. Griffith ◽  
Jack Spear
Keyword(s):  
Visual Impairment ◽  
Private School ◽  
Sensory Input ◽  
Language Skills ◽  
Autism Spectrum ◽  
Multiple Baseline ◽  
Stimulus Generalization ◽  
Baseline Design ◽  
Tactile Stimuli ◽  
Low Levels

Introduction: The main objective of this study was to determine whether stimulus symmetry, or untaught generalized relations among stimuli, could be demonstrated using audio and tactile stimuli (i.e., nonvisual). Methods: A modified alternating treatment within a concurrent multiple baseline design across nonvisual stimulus sets (i.e., tactile and audio) was implemented with Zach, an 11-year-old male diagnosed with autism and visual impairment, to teach two relations (sound–touch and sound–label) among stimuli. Following training, the researcher tested whether Zach could identify stimuli through an untaught relation (touch–label). The study presented here required a week to complete and was conducted at a private school for individuals with behavioral concerns. Results: During baseline, Zach demonstrated low levels of correct responses (average of 7% across all relations) for all skills. In the training phase (for only two of the three targeted skills, sound–touch and sound–label relations), Zach demonstrated proficiency for most stimuli used in the sets (average of 61% across relations). Finally, in the testing phase (the untaught touch–label relation), Zach demonstrated high levels of generalized acquisition (89%). Discussion: Results indicated that the procedure used in this study could be generalized to novel populations, including those with visual impairments, and that different forms of sensory input could be used, including auditory and tactile-based teaching. Implications for practitioners: Individuals working with learners with differing levels of visual impairment could utilize the demonstrated procedure to associate types of stimuli, using methods other than visual input. The procedure outlined would benefit a population that may require assistance with developing language skills but who also may have difficulties using common visual stimuli.

scholarly journals Relationship Between Physiological Response Type (RA and SA) and Vibrissal Receptive Field of Neurons Within the Rat Trigeminal Ganglion

2006 ◽  
Vol 95 (5) ◽  
pp. 3129-3145 ◽  
Author(s):  
Steven C. Leiser ◽  
Karen A. Moxon
Keyword(s):  
Trigeminal Ganglion ◽  
Three Dimensional ◽  
Receptive Fields ◽  
Somatosensory System ◽  
Response Type ◽  
Physiological Level ◽  
Somatotopic Organization ◽  
Tactile Stimuli ◽  
Distinct Features ◽  
The Relationship

Cells within the trigeminal ganglion (Vg) encode all the information necessary for the rat to differentiate tactile stimuli, yet it is the least-studied component in the rodent trigeminal somatosensory system. For example, extensive anatomical and electrophysiological investigations have shown clear somatotopic organization in the higher levels of this system, including VPM thalamus and SI cortex, yet whether this conserved schemata exists in the Vg is unknown. Moreover although there is recent interest in recording from vibrissae-responsive cells in the Vg, it is surprising to note that the locations of these cells have not even been clearly demarcated. To address this, we recorded extracellularly from 350 sensory-responsive Vg neurons in 35 Long-Evans rats. First, we determined three-dimensional locations of these cells and found a finer detail of somatotopy than previously reported. Cells innervating dorsal facial features, even within the whisker region, were more dorsal than midline and ventral features. We also show more cells with caudal than rostral whisker receptive fields (RF), similar to that found in VPM and SI. Next, for each vibrissal cell we determined its response type classified as either rapidly (RA) or slowly (SA) adapting. We examined the relationship between vibrissal RF and response type and demonstrate similar proportions of RA and SA cells responding to any whisker. These results suggest that if RA and SA cells encode distinct features of stimuli, as previously suggested, then at the basic physiological level each whisker has similar abilities to encode for such features.

scholarly journals The anticipation and perception of affective touch in women with and recovered from Anorexia Nervosa

2020 ◽  
Author(s):  
Laura Crucianelli ◽  
Benedetta Demartini ◽  
Diana Goeta ◽  
Veronica Nisticò ◽  
Alkistis Saramandi ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Reward Processing ◽  
Healthy Controls ◽  
Top Down ◽  
Ct Afferents ◽  
Tactile Stimuli ◽  
Successful Recovery ◽  
Secondary Result ◽  
Ct System ◽  
Tactile System

AbstractDisruptions in reward processing and anhedonia have long being considered as possible contributors to the aetiology and maintenance of Anorexia nervosa (AN). Recently, interoceptive deficits have also been observed in AN, including reduced tactile pleasure. However, the extent to which this tactile anhedonia is specifically liked to an impairment in a specialized, interoceptive C tactile system originating at the periphery, or a more top-down mechanism in the processing of pleasant tactile stimuli remains debated. Here, we investigated two related hypotheses. First, we examined whether the differences, between patients with AN and healthy controls in the perception of pleasantness of touch stimuli delivered in a CT-optimal manner versus a CT non-optimal manner would also be observed in patients recovered from AN. This is important as tactile anhedonia in acute patients may be the secondary result of prolonged malnutrition, rather than a deficit that contributed to the development of the disorder. Second, we examined whether these three groups would also differ in their top-down, anticipatory beliefs about the perceived pleasantness of different materials touching the skin, and to what degree such top-down beliefs and related impairments in alexithymia and interoceptive sensibility would explain any differences in perceived tactile plesantness. To this end, we measured the anticipated pleasantness of various materials touching the skin and the perceived pleasantness of light, dynamic stroking touches applied to the forearm of 27 women with AN, 24 women who have recovered and 30 healthy controls using C Tactile (CT) afferents-optimal (slow) and non-optimal (fast) velocities. Our results showed that both clinical groups anticipated tactile experiences and rated delivered tactile stimuli as less pleasant than healthy controls, but the latter difference was not related to the CT optimality of the stimulation. Instead, differences in how CT optimal touch were perceived were predicted by differences in top-down beliefs, alexithymia and interoceptive sensibility. Thus, this study concludes that tactile anhedonia in AN is not the secondary result of malnutrition but persists as a trait even after otherwise successful recovery of AN and also it not linked to a bottom-up interoceptive deficit in the CT system, but rather to a learned, defective top-down anticipation of pleasant tactile experiences.

Representation of tactile signals in primate supplementary motor area

1993 ◽  
Vol 70 (6) ◽  
pp. 2690-2694 ◽  
Author(s):  
R. Romo ◽  
S. Ruiz ◽  
P. Crespo ◽  
A. Zainos ◽  
H. Merchant
Keyword(s):  
Reaction Time ◽  
Decision Process ◽  
Sensory Input ◽  
Supplementary Motor Area ◽  
Motor Area ◽  
Control Task ◽  
Categorization Task ◽  
Tactile Stimuli ◽  
Time Period ◽  
All Speeds

1. We have studied the neuronal activity in the supplementary motor area (SMA) of two monkeys who categorized the speed of moving tactile stimuli delivered to the glabrous skin of the hand ipsilateral to the site of cortical recording and contralateral to the responding arm. 2. A large number of SMA neurons responded to the stimuli of all speeds (176 of 522) but only when those stimuli controlled behavior. 3. A second class of SMA neurons responded differentially in the categorization task (35 during the stimuli and 51 during the reaction time period) and predicted its outcome. 4. To dissociate the interrupt target switches presses from the tactile categorization responses, sixteen neurons, which responded to the stimuli in all speeds, and 11 neurons, which discharged differentially, were tested in a visual control task. None of these two classes of neurons responded in this situation. 5. It is concluded that the SMA ipsilateral to sensory input and contralateral to the responding arm is involved in the sensory decision process in this somesthetic categorization task.

Somatosensory Processing in the Human Inferior Prefrontal Cortex

2002 ◽  
Vol 88 (3) ◽  
pp. 1400-1406 ◽  
Author(s):  
Matthew C. Hagen ◽  
David H. Zald ◽  
Tricia A. Thornton ◽  
José V. Pardo
Keyword(s):  
Inferior Frontal Gyrus ◽  
Sensory Stimulation ◽  
Brain Regions ◽  
Somatosensory Processing ◽  
Somatosensory Stimulation ◽  
Tactile Stimuli ◽  
Somatosensory Cortices ◽  
Frontal Operculum ◽  
Frontal Activity ◽  
Ventral Area

Three inferior prefrontal regions in the monkey receive afferents from somatosensory cortices: the orbitofrontal cortex (OFC), the ventral area of the principal sulcus, and the anterior frontal operculum. To determine whether these areas show responses to tactile stimuli in humans, we examined data from an ongoing series of PET studies of somatosensory processing. Unlike previous work showing ventral frontal activity to hedonic (pleasant/unpleasant) sensory stimulation, the tactile stimuli used in these studies had a neutral hedonic valence. Our data provide evidence for at least two discrete ventral frontal brain regions responsive to somatosensory stimulation: 1) the posterior inferior frontal gyrus (IFG) and adjacent anterior frontal operculum, and 2) the OFC. The former region (posterior IFG/anterior frontal operculum) may have a more specific role in attending to tactile stimuli.

The Potential of Rhythmic Sensory Stimulation Treatments for Persons with Alzheimer’s Disease

2017 ◽  
Vol 9 (3) ◽  
pp. 167
Author(s):  
Amy Clements-Cortes ◽  
Lee Bartel ◽  
Heidi Ahonen ◽  
Morris Freedman
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Visual Stimulation ◽  
Somatosensory System ◽  
Sensory Stimulation ◽  
Case Vignette ◽  
Music Listening ◽  
Study Results ◽  
Study Support ◽  
Study Participants

Background: Rhythmic Sensory Stimulation (RSS) is a treatment being implemented for persons diagnosed with a variety of disorders such as fibromyalgia and Alzheimer’s disease (AD). This paper provides qualitative results of observations and interactions of AD study participants who received both RSS and visual stimulation sessions for six weeks. A case vignette is also provided. Objective: The study proposed that RSS could stimulate the auditory and somatosensory system at 40Hz with the potential for improvements in cognition for persons with AD. Method: 18 participants at three stages of AD participated: mild, moderate and severe. Participants received a total of 13 sessions in this AB cross-over design study. Results: Qualitative findings from the study support RSS as a potential treatment for persons with AD to increased alertness, stimulate discussion, and increase interaction and awareness of surroundings. Conclusion: Further research needs to explore the effect of the frequency of sessions provided, the duration of effects, and whether AD severity interacts with the RSS treatment. Further investigations could also study the effect of auditory 40Hz stimulation alone, as well as the inclusion of music listening during the RSS sessions. 

Supervised Spike-Timing-Dependent Plasticity: A Spatiotemporal Neuronal Learning Rule for Function Approximation and Decisions

2013 ◽  
Vol 25 (12) ◽  
pp. 3113-3130 ◽  
Author(s):  
Jan-Moritz P. Franosch ◽  
Sebastian Urban ◽  
J. Leo van Hemmen
Keyword(s):  
Function Approximation ◽  
Sensory Input ◽  
Learning Rule ◽  
Animal Learn ◽  
Spike Timing ◽  
Time Dependent ◽  
Stable Configuration ◽  
Spike Timing Dependent Plasticity ◽  
Dependent Plasticity ◽  
Tactile System

How can an animal learn from experience? How can it train sensors, such as the auditory or tactile system, based on other sensory input such as the visual system? Supervised spike-timing-dependent plasticity (supervised STDP) is a possible answer. Supervised STDP trains one modality using input from another one as “supervisor.” Quite complex time-dependent relationships between the senses can be learned. Here we prove that under very general conditions, supervised STDP converges to a stable configuration of synaptic weights leading to a reconstruction of primary sensory input.

scholarly journals A Multisensory fMRI Investigation of Nociceptive-Preferential Cortical Regions and Responses

2021 ◽  
Vol 15 ◽  
Author(s):  
Xiaoxia Zhang ◽  
Linling Li ◽  
Gan Huang ◽  
Li Zhang ◽  
Zhen Liang ◽  
...  
Keyword(s):  
Sensory Input ◽  
Sensory Stimulation ◽  
Brain Regions ◽  
Nociceptive Stimulation ◽  
Functional Roles ◽  
Sensory Modalities ◽  
Cortical Regions ◽  
Nociceptive Input ◽  
Healthy Participants ◽  
Different Parts

The existence of nociceptive-specific brain regions has been a controversial issue for decades. Multisensory fMRI studies, which examine fMRI activities in response to various types of sensory stimulation, could help identify nociceptive-specific brain regions, but previous studies are limited by sample size and they did not differentiate nociceptive-specific regions and nociceptive-preferential regions, which have significantly larger responses to nociceptive input. In this study, we conducted a multisensory fMRI experiment on 80 healthy participants, with the aim to determine whether there are certain brain regions that specifically or preferentially respond to nociceptive stimulation. By comparing the evoked fMRI responses across four sensory modalities, we found a series of brain regions specifically or preferentially involved in nociceptive sensory input. Particularly, we found different parts of some cortical regions, such as insula and cingulate gyrus, play different functional roles in the processing of nociceptive stimulation. Hence, this multisensory study improves our understanding of the functional integrations and segregations of the nociceptive-related regions.

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