Somatosensory Specializations in Mammals

2021 ◽  
Author(s):  
Jon H. Kaas
Keyword(s):  
Somatosensory Cortex ◽  
Somatosensory System ◽  
Primary Somatosensory Cortex ◽  
Local Environments

Early mammals were small with little neocortex that included a somatosensory system with a mediolateral strip of primary somatosensory cortex and three or four adjoining somatosensory fields. As early mammals radiated out and adapted to local environments, their somatosensory systems adjusted and became specialized in many ways. Most of these specializations were most obvious as disproportionally enlarged representations of important sensory surfaces of the skin in primary somatosensory cortex. These enlarged representations included those of the bill of the duckbilled platypus, the nose of the star-nosed mole, the teeth and tongue of monkeys, the glabrous hand of raccoons, the wing of bats, and the tactile tail of some monkeys. These and other specializations enhanced the ability of these mammals to adapt to their environments and to precisely evaluate relevant sensory events and make appropriate behavioral adjustments.

Revisiting parallel and serial processing in the somatosensory system

2007 ◽  
Vol 30 (2) ◽  
pp. 208-209 ◽  
Author(s):  
Preston E. Garraghty
Keyword(s):  
Somatosensory Cortex ◽  
Scientific Community ◽  
Somatosensory System ◽  
Primary Somatosensory Cortex ◽  
Related Issue ◽  
Serial Processing ◽  
Cortical Areas ◽  
Number Of Factors ◽  
In Series

AbstractThe issue of whether information is processed in parallel or in series in the somatosensory system is complicated by a number of factors. Included among these is the failure on the part of the scientific community to reach a consensus as to what actually constitutes the primary somatosensory cortex (SI) in higher primates. A second, related issue is the marked difference in the organization of the cortical areas subserving somatosensation across species.

scholarly journals Layer-specific activation of sensory input and predictive feedback in the human primary somatosensory cortex

2019 ◽  
Vol 5 (5) ◽  
pp. eaav9053 ◽  
Author(s):  
Yinghua Yu ◽  
Laurentius Huber ◽  
Jiajia Yang ◽  
David C. Jangraw ◽  
Daniel A. Handwerker ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Sensory Input ◽  
Specific Activity ◽  
Predictive Coding ◽  
Somatosensory System ◽  
Middle Layer ◽  
Predictive Processing ◽  
Primary Somatosensory Cortex ◽  
Imaging Data ◽  
Deep Layers

When humans perceive a sensation, their brains integrate inputs from sensory receptors and process them based on their expectations. The mechanisms of this predictive coding in the human somatosensory system are not fully understood. We fill a basic gap in our understanding of the predictive processing of somatosensation by examining the layer-specific activity in sensory input and predictive feedback in the human primary somatosensory cortex (S1). We acquired submillimeter functional magnetic resonance imaging data at 7T (n = 10) during a task of perceived, predictable, and unpredictable touching sequences. We demonstrate that the sensory input from thalamic projects preferentially activates the middle layer, while the superficial and deep layers in S1 are more engaged for cortico-cortical predictive feedback input. These findings are pivotal to understanding the mechanisms of tactile prediction processing in the human somatosensory cortex.

scholarly journals Reach Out and Touch Someone: Anticipatory Sensorimotor Processes of Active Interpersonal Touch

2014 ◽  
Vol 26 (9) ◽  
pp. 2171-2185 ◽  
Author(s):  
Sjoerd J. H. Ebisch ◽  
Francesca Ferri ◽  
Gian Luca Romani ◽  
Vittorio Gallese
Keyword(s):  
Social Behavior ◽  
Somatosensory Cortex ◽  
Temporal Cortex ◽  
Somatosensory System ◽  
Primary Somatosensory Cortex ◽  
Human Hand ◽  
Skin Contact ◽  
Interpersonal Touch ◽  
Medial Pfc ◽  
Sensorimotor Processes

Anticipating the sensorimotor consequences of an action for both self and other is fundamental for action coordination when individuals socially interact. Somatosensation constitutes an elementary component of social cognition and sensorimotor prediction, but its functions in active social behavior remain unclear. We hypothesized that the somatosensory system contributes to social haptic behavior as evidenced by specific anticipatory activation patterns when touching an animate target (human hand) compared with an inanimate target (fake hand). fMRI scanning was performed during a paradigm that allowed us to isolate the anticipatory representations of active interpersonal touch while controlling for nonsocial sensorimotor processes and possible confounds because of interpersonal relationships or socioemotional valence. Active interpersonal touch was studied both as skin-to-skin contact and as object-mediated touch. The results showed weaker deactivation in primary somatosensory cortex and medial pFC and stronger activation in cerebellum for the animate target, compared with the inanimate target, when intending to touch it with one's own hand. Differently, in anticipation of touching the human hand with an object, anterior inferior parietal lobule and lateral occipital-temporal cortex showed stronger activity. When actually touching a human hand with one's own hand, activation was stronger in medial pFC but weaker in primary somatosensory cortex. The findings provide new insight on the contribution of simulation and sensory prediction mechanisms to active social behavior. They also suggest that literally getting in touch with someone and touching someone by using an object might be approached by an agent as functionally distinct conditions.

scholarly journals Motor Skill Learning-Induced Functional Plasticity in the Primary Somatosensory Cortex: A Comparison Between Young and Older Adults

2020 ◽  
Vol 12 ◽  
Author(s):  
Claudia Predel ◽  
Elisabeth Kaminski ◽  
Maike Hoff ◽  
Daniel Carius ◽  
Arno Villringer ◽  
...  
Keyword(s):  
Older Adults ◽  
Motor Learning ◽  
Somatosensory Cortex ◽  
Motor Skill ◽  
Somatosensory System ◽  
Skill Learning ◽  
Primary Somatosensory Cortex ◽  
Motor Skill Learning ◽  
Abductor Pollicis Brevis ◽  
Age Range

While in young adults (YAs) the underlying neural mechanisms of motor learning are well-studied, studies on the involvement of the somatosensory system during motor skill learning in older adults (OAs) remain sparse. Therefore, the aim of the present study was to investigate motor learning-induced neuroplasticity in the primary somatosensory cortex (S1) in YAs and OAs. Somatosensory evoked potentials (SEPs) were used to quantify somatosensory activation prior and immediately after motor skill learning in 20 right-handed healthy YAs (age range: 19–35 years) and OAs (age range: 57–76 years). Participants underwent a single session of a 30-min co-contraction task of the abductor pollicis brevis (APB) and deltoid muscle. To assess the effect of motor learning, muscle onset asynchrony (MOA) between the onsets of the contractions of both muscles was measured using electromyography monitoring. In both groups, MOA shortened significantly during motor learning, with YAs showing bigger reductions. No changes were found in SEP amplitudes after motor learning in both groups. However, a correlation analysis revealed an association between baseline SEP amplitudes of the N20/P25 and N30 SEP component and the motor learning slope in YAs such that higher amplitudes are related to higher learning. Hence, the present findings suggest that SEP amplitudes might serve as a predictor of individual motor learning success, at least in YAs. Additionally, our results suggest that OAs are still capable of learning complex motor tasks, showing the importance of motor training in higher age to remain an active part of our society as a prevention for care dependency.

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