Sensory Input

More than precisely, all sensory input is into the alar plate of the rhombencephalon or the alar plate of the midbrain (vision) or the forebrain (olfaction).

From: Development of Nervous Systems , 2007

Other Sensory Modalities in Slumber

Ricardo A. Velluti , in The Auditory Arrangement in Sleep (Second Edition), 2018

Summary

Sensory input and subsequent processing are definitely nowadays in slumber, merely bear witness different characteristics than during wakefulness. The interaction between sleep and sensory physiology is an important factor because whatsoever sufficiently intense sensory stimulation always produces an awakening, from any phase of sleep.

Interestingly plenty, each sensory system has an efferent pathway, with centrifugal projections catastrophe in about all core afferents and on the receiver itself. Therefore, incoming sensory information can alter the physiology of sleep and wakefulness, and these states modulate incoming information.

Normal slumber depends on many aspects of sensory input. Neural networks that command slumber and wakefulness are modulated by many sensory inputs, a proportion of the 'passive' effects must be associated with active mechanisms of sleep. Gains or losses sensory inputs produce imbalances in neuronal networks involved in the sleep–wake cycle, irresolute their relative proportions of active and not being mere passive processes. For example, the almost consummate deafferentation in cats caused a state of drowsiness in these animals (Vital-Durand and Michel, 1971).

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Introduction to geriatric forensic evaluations

Karen Reimers , in The Clinician's Guide to Geriatric Forensic Evaluations, 2019

Sensory input and perception

Sensory input and perception may bear witness a variety of disturbances associated with underlying psychiatric, neurological, or medical conditions. These could include various sensory modalities like visual, auditory, tactile, olfactory, and/or gustatory. There may be distortions or misperceptions of external or internal stimuli. Misperceptions are distortions that include changes in size, object, shape, intensity, or sound, of stimuli. These could occur in the setting of sensory import disorders, or temporal limbic epilepsy. Hallucinations or other internally created stimuli may occur in various clinical states, including psychosis, dementia, and acute defoliation (Holzer et al., 2018).

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Hyperacuity

Grand. Westheimer , in Encyclopedia of Neuroscience, 2009

Sensory input is funneled through individual receptors discretely tiling their domain. Although their input may overlap, they even so form an ensemble of compartmentalized units, each with a unique signature. The resolution limit is traditionally defined by the grain of this ensemble (e.chiliad., visual acuity matches the foveal cone mosaic). However, some localization capabilities are better, often by an club of magnitude, than the packing of the ensemble elements (east.chiliad., in vernier alignment of ii visual features tin exist equally good as one-tenth of a cone diameter). Such functioning transcending apparent receptive field limits has counterparts in other modalities and in other kinds of neural processing and is called hyperacuity, to distinguish it from acuity, which is customarily associated with the bigotry of ii stimuli as split up.

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Vibrissa Movement, Awareness and Sensorimotor Control

D. Kleinfeld , in Encyclopedia of Neuroscience, 2009

Brain Stem Loop

Sensory input from reaction forces generated in the follicles leads to a signal that transverses the IoN and projects to one or all iv nuclei that form the trigeminal circuitous ( Effigy 4 ). These include the principal sensory nucleus (PrV) and the 3 spinal nuclei, denoted oralis (SpVO), interpolaris (SpVI), and caudalis (SpVC). The afferents form several somatotopic representations, referred to as barrelettes, of the ipsilateral vibrissae. Efferents from the PrV, SpVC, and SpVI nuclei project to motor neurons in the lateral subnucleus of the ipsilateral facial nucleus, which sends motor output to the muscles of the mystacial pad. This completes the lowest-gild brain stem sensorimotor loop (* in Effigy four ).

The trigeminal nuclei further collaborate amongst each other. Neurons in the PrV nucleus receive excitatory input from both the SpVC and SpVI nuclei and inhibitory input from the SpVi nucleus. The latter forms a local inhibitory loop that, possibly in concert with descending inputs from high-gild areas, provides a means to filter sensory data at the level of the brain stem.

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The Constructed Approach to Embodied Knowledge

Rolf Pfeifer , ... Olaf Sporns , in Handbook of Cognitive Science, 2008

Sensory inputs are oftentimes incomplete and ambiguous, and pose, for case, significant challenges for traditional approaches to automobile vision, which often require visual inputs segmented into objects, prepro-cessed, or brought into approved formats for efficient processing ( Palmeri & Gauthier, 2004). In an elegant set of robot experiments, Metta & Fitzpatrick, 2003 demonstrated how embodied interaction can be exploited to disambiguate and segment a complex visual scene. Working with the humanoid robot "Cog," they investigated the potential role of experimental manipulation (e.k., reaching for, touching and displacing objects within the visual field) in generating visual information nigh object boundaries and affordances such equally rolling. For case, exploratory activity by the robot resulted in the deportation of a solid object against a static (a priori unknown) groundwork, generating a correlated motion field that closely corresponded to the shape of the object (Figure seven.3). These motion signals represent structured data that was absent earlier the robot's exploratory actions. Note that active exploration can exist practical even if the background changes, and that allows extracting data apropos the affordances of the segmented objects—a "passive" strategy is not sufficient. This case demonstrates the pivotal role of self-generated embodied interaction in inducing statistical structure. In other words, information structure emerges while the interaction is taking identify.

Figure 7.3. Disambiguation and sectionalization of visual scene through embodied interaction. (A) Arm extending into a workspace, poking an object, and retracting. (B) Shape of the object is identified from the tap using simple paradigm differencing (Metta & Fitzpatrick, 2003). Segmentation in this case is not a footling chore—the edges of the table and cube are aligned, the colors of the cube and the table are not well separated, and there are shadows that may change. (See color plate)

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Cerebellar Workout and Learning

John H. Freeman , in International Review of Neurobiology, 2014

3.1 CS pathway

Sensory input conveying the CS to the cerebellum originates in the various subcortical sensory nuclei. Animals that accept been decorticated or have lesions of the primary sensory cortex show filibuster eyeblink conditioning but are impaired when the interval between the onset of the CS and onset of the US is greater than virtually 400  ms (Galvez, Weible, & Disterhoft, 2007; Steinmetz, Harmon, & Freeman, 2013). The auditory CS pathway includes sensory nucleus projections through the inferior colliculus to the medial auditory thalamus (Campolattaro, Halverson, & Freeman, 2007; Freeman, Halverson, & Hubbard, 2007; Halverson & Freeman, 2006, 2010a; Halverson et al., 2010; Halverson, Poremba, & Freeman, 2008). The medial auditory thalamus and so projects to the lateral pontine nuclei (Campolattaro et al., 2007; Halverson & Freeman, 2010a), which so send their mossy cobweb project to the cerebellar cortex and nuclei. The visual CS pathway includes retinal projections to the ventral lateral geniculate and nucleus of the optic tract, which both project in parallel to the medial pontine nuclei (Halverson, Hubbard, & Freeman, 2009; Halverson & Freeman, 2010b; Steinmetz, Kiss, & Freeman, 2013). The medial pontine nuclei so send a mossy fiber project to the cerebellum. Stimulation of the mossy fiber pathway tin can exist used every bit a CS in eyeblink conditioning when paired with a peripheral Us such as periorbital stimulation (Freeman & Rabinak, 2004; Freeman, Rabinak, & Campolattaro, 2005; Steinmetz, Lavond, & Thompson, 1989; Steinmetz, Rosen, Chapman, Lavond, & Thompson, 1986; Steinmetz, Rosen, Woodruff-Pak, Lavond, & Thompson, 1986). The cerebellum sends feedback to the medial auditory thalamus and pontine nuclei during eyeblink conditioning.

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Topographic Maps in the Brain

J.H. Kaas , in International Encyclopedia of the Social & Behavioral Sciences, 2001

3 The Evolution of Maps

Sensory inputs to brain stem nuclei grade orderly arrangements during evolution, and these nuclei course orderly connections with other nuclei, which in turn projection to cortical areas in an orderly fashion and so on. The rough guild in at least the early stations of this sequential procedure seems to depend on intrinsic factors in the brain. More than specifically, it has long been hypothesized that afferents are chemically labeled according to some gradient, and target neurons are also chemically labeled with a comparable gradient across the target structure. Thus, the neurons find chemic matches and a topographic map is created. Nonetheless, chemical or molecular matching is not the only factor in the development of brain maps, since at that place is much testify that the development of such maps can exist altered by changes in the sensory environs that induce changes in neural action patterns. The details of sensory maps appear to be fine tuned by an adjustment and sorting of local connections in largely adaptive ways in response to variations in patterns of sensory activation. The claim is that neurons that fire together wire together. Co-active neurons with overlapping connections maintain and strengthen their synapses on shared target neurons, while neurons that do not respond at the same fourth dimension tend to weaken and lose synapses on their shared target neurons. Thus, neurons with uncorrelated activity patterns tend to segregate their terminations and so as to activate separate groups of neurons in the next construction. This allows maps to adjust and compensate for losses or additions of inputs, and maps in a sequence to adjust to each other.

There are many types of evidence that maps adjust to sensory changes during evolution. Usually, this evidence comes from some sort of experiment where some sensory input is removed or altered. Normal inputs aggrandize to actuate neurons formerly devoted to the removed or weakened inputs. Other evidence comes from the variations observed in maps in nature. Rats and mice accept morphological maps of the whiskers of the confront in S1. Each whisker activates neurons in a small oval of cortical tissue that resembles a barrel, and is commonly chosen a cortical barrel. Rats and mice ordinarily have the aforementioned number of whiskers, and there is ane butt in S1 for each whisker. Likewise there is one butt-similar construction for each whisker for the termination of afferents from the face in the brain stem, and in the ventroposterior nucleus of the thalamus. Thus, maps at three levels of the somatosensory system precisely match the arrangement and number of whiskers on the side of the face. This friction match could be due to innate developmental mechanisms, such as the matching of connections betwixt levels as a result of a chemic lawmaking, but this appears to exist unlikely.

Mice take been institute that differ in the number of whiskers by having ane or 2 more or less than the normal number, and in these mice the maps at all three levels match exactly the increment or decrease in whiskers. Thus, somehow the receptors in the skin are informing the central maps about their organizational state. In a similar style, the star-nosed mole has 11 sensory rays or protrusions from each side of its olfactory organ, and processed sections of somatosensory cortex reveal eleven respective bands of tissue in S1, one for each ray. Eleven bands are also seen in S2, the ventroposterior nucleus, and the somatosensory brain stem. Moles with 10 or 12 rays have been found, and 10 or 12 bands are then seen in all iv brain structures in these moles. This matching of maps from ane level to the next and with the peripheral receptor canvas would be well-nigh easily achieved by a system that uses natural activity patterns to fine-tune its maps.

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New Perspectives on Early on Social-cognitive Development

Judit Ciarrusta , ... Grainne McAlonan , in Progress in Brain Research, 2020

3.2 Emotions and the limbic cluster

Sensory input can have neutral, positive or negative valence attributed to it. The limbic arrangement encompassing structures such as the insula, the cingulate cortex, the parahippocampal gyrus, hypothalamus and amygdala is responsible for assigning and acting on emotional value of sensory stimuli ( Esperidião-antonio et al., 2017). Thus, sensory cortices (higher up) receive master data from well-defined thalamo-cortical pathways (Toulmin et al., 2015), while the limbic cluster gathers multimodal data and therefore is in a position to aspect value and motivate complex behavior (Mogenson et al., 1980).

Despite the apparently mature country of the somatosensory cortex at nascence, a baby requires further environmental stimulation through concrete contact and manipulation of objects to permit further refinement of neural circuitry through experience. For a comprehensive review of behavioral studies on social touch and human development please refer to (Cascio et al., 2019). Still, to our cognition only two studies have investigated affective impact in infancy using MRI. The authors argued cutaneous stimulation with a brush activates C-tactile fibers, which are responsible of encoding socio-affective information and can therefore be used to investigate social touch in early infancy. Gentle skin stroke elicited activation in the somatosensory, thalamus, precuneus, occipital, frontal and insular cortices, regions associated with both sensory and emotional processing (Tuulari et al., 2019; Williams et al., 2015).

Emotional stimulation delivered via auditory input in the second one-half of the first year has demonstrated that infants respond differently to sounds with diverse emotional connotation. Listening to angry voices was associated with higher activation of the inductive cingulate, the caudate, the thalamus and hypothalamus (Graham et al., 2013) and listening to sad voices elicited greater responses in the insula and orbitofrontal cortex (Blasi et al., 2011) in 6–12 month old infants. However, happy voices elicited responses in the auditory cortex equivalent to neutral sounds (Blasi et al., 2011). These studies advise the limbic cluster and surrounding structures are fix to respond to stimuli with negative valence from an early age. While such studies have made important outset steps, there remain gaps. For instance, studies in older children suggest that advantage circuits are likewise recruited in response to familiar voices (such as the mother's) (Abrams et al., 2016; Liu et al., 2019), but whether the "rewarding" backdrop of auditory stimuli drive maturing circuits in the infant has all the same to be explored.

Visual emotional input has not been directly examined using fMRI, withal socially salient stimuli such as faces take been used to investigate infant's social engagement. 4–6 month sometime infants demonstrate confront specific activation in the fusiform gyrus, lateral occipital cortex, superior temporal sulcus (STS) and medial prefrontal cortex (Deen et al., 2017), suggesting an early orientation to social-like stimuli. However, this is the only study to date studying confront processing in infancy using MRI, and the early developmental trajectory of the brain circuitry underpinning human expertise in face processing requires farther study (Powell et al., 2018).

Task dependent fMRI studies in very immature children are extremely challenging, thus resting state approaches have been more than widely adopted. Functional connectivity analyses accept increased our understanding of the maturation of functional connections betwixt limbic structures. Stronger connectivity between the amygdala and the inductive insula in the perinatal menstruum has been associated with stronger fear response of the same infants at 6 months (Graham et al., 2016; Thomas et al., 2019). Higher levels of connectivity between amygdala and insula, frontal cortex, caudate and cerebellum at a neonatal time point of scanning has likewise been associated with higher levels of behavioral inhibition, depression/withdraw, anxiety and separation distress at the age of 2 (Rogers et al., 2017). The connectivity between limbic structures and the rest of the encephalon continues changing up to the age of 5 with meaning shifts in positive and negative connectivity betwixt amygdala and postcentral cortex, equally well as the occipital lobe amongst other structures (Gabard-durnam et al., 2018).

In decision, similar sensory systems, limbic and paralimbic structures appear to be functional from nascency and likely ensure social input and processing pathways mature in parallel with the multisensory integration mechanisms being consolidated throughout the starting time year of life.

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Smell and Taste

Thomas A. Cleland , Christiane Linster , in Handbook of Clinical Neurology, 2019

Farther Evolution and Recommendations

Olfactory sensory input pathways diverge immensely after emerging from the relative clogging of the OB. As reviewed herein, these secondary olfactory projections innervate a wide diversity of structures deriving from several singled-out telencephalic pallial and subpallial tissues as well as diencephalic, midbrain, and brainstem structures. Many of these structures are highly interconnected with i some other via associational projections, and each receives characteristic extrinsic and neuromodulatory inputs from other regions of the brain that can influence neuronal responses and complex behavior (eastward.grand., Oettl et al., 2016). While these structures and projections are remarkably conserved among vertebrates, there also are numerous species-specific variations that presumably derive from the divergent adaptive needs of each species, both in terms of novel or absent-minded projections and in terms of the relative densities of projection patterns amid secondary and tertiary olfactory structures. Lacking specific knowledge of what purposes most of these structures serve, or fifty-fifty of the physiologic and adaptive tasks that must exist performed by the organism and for which information technology requires olfactory perceptual data, which framework for analysis is likely to be the most conducive to elucidating an understanding of these structures over fourth dimension?

Information technology may exist counterproductive to call up of secondary olfactory structures every bit primarily "olfactory" in nature. In particular, it may exist misleading to guess such structures primarily on the basis of the purported smell selectivity of private neurons, or even of ensembles. Aside from the typically unwarranted assumptions about mechanism that necessarily underlie statistical measures of selectivity, it is unlikely that always-increasing specificity is the general goal of all secondary processing. Rather, a functional approach is likely to be stronger: for what diverse purposes might a given organism require olfactory sensory data, and what elements of those information are needed for the organism to respond adaptively? How precise must an olfactory identification be to meet the organism's needs, and what are the likely costs of imitation positive errors compared with imitation negatives? Even if maximally specific smell identification were prerequisite to all determination processes utilizing olfactory information—an unlikely possibility—neural activeness based increasingly on contingency and less on the concrete characteristics of the stimulus would exist expected as the response cascade proceeds beyond primary sensory areas in the brain. In some tissues, studying how the categorization of different olfactory stimuli changes, for example, may be more indicative than measuring how theoretically orthogonal their representations may be.

In brusk, a functional arroyo to understanding the contributions of secondary olfactory structures to cognition and man wellness might be to hypothesize an information-processing task to which a given structure might contribute, to appraise what elements of olfactory sensory information would exist required in order for information technology to fulfill that task, and to predict what cellular and network mechanisms would be required in order to excerpt this information from the ensemble activity of the projection neurons that innervate information technology. Given the known interest of olfactory structures in many encephalon disorders, including epilepsy (Restrepo et al., 2014; Vaughan and Jackson, 2014), Alzheimer'due south disease (Velayudhan and Lovestone, 2009; Roberts et al., 2016), and Parkinson'southward disease (Zhu et al., 2016), a more than complete agreement of these interacting systems is crucial to our understanding of the function and vulnerabilities of the healthy brain (Wilson et al., 2014).

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Breathe, Walk and Chew: The Neural Challenge: Function Ii

James P. Lund , in Progress in Brain Enquiry, 2011

Effects of chronic pain on motor systems

Another sensory input that has profound effects on motor programs comes from nociceptors within the moving torso part (due east.g., run into modulation of jaw-opening reflex in a higher place when elicited by nociceptive inputs). Withal, when pain becomes chronic, its effects on muscles and motor programs seem to change. Since the start of the twentieth century, it has been more often than not believed that chronic nociceptor activation cause muscle hyperactivity leading to abnormal movement patterns, spasms, and fatigue, which would lead to even more than pain. It was proposed that this perpetual pain machine, called the "Fell Cycle" by Travell et al. (1942), underlies most chronic muscle pain conditions, including fibromyalgia, chronic lower back hurting, tension-type headache, and temporomandibular dysfunction. Nosotros began to exam the predictions of the Vicious Cycle hypothesis in the tardily 1980s and presented our findings at XIIth Symposium of the Groupe de recherche sur le système nerveux central (Lund et al., 1991). We analyzed information from studies that compared motor function of groups of controls to subjects suffering from the 4 chronic pain conditions listed higher up, plus delayed onset muscle soreness. The data showed clearly the resting or postural activity of sore muscles was no greater than command levels, while the activity of agonist muscles went downwardly, not upwardly, during forceful wrinkle. However, there was a slight only significant increment in antagonist activity in some reports. The event of these changes in motor output produced maximum voluntary wrinkle levels that were significantly lower in the patient groups, while the velocity and amplitude of movements went down. Clearly, this could not result from the action of a Vicious Cycle, so nosotros proposed a new style of viewing the interaction between chronic pain and motor systems, which nosotros named the hurting-accommodation model.

We and others and then tested the hurting-adaptation model past inducing tonic hurting in normal human subjects and animals. Nosotros showed that infusions of painful hypertonic saline into the masseter muscle of normal human volunteers acquired both tonic pain and a reduction of jaw-opening reflex aamplitude (Lund et al., 1981), and that the same stimulus did not cause resting hyperactivity (Stohler et al., 1996). We and then began to study the influence of tonic pain on CPGs past applying baneful pressure level to the zygoma of decerebrate rabbits on mastication induced by stimulation of the corticobulbar tracts (Schwartz and Lund, 1995). Bicycle elapsing was significantly increased, while the amplitude and velocity of motility went down.

Arendt-Nielsen et al. (1996) found that painful infusions of hypertonic saline into the dorsal paraspinal muscles of men acquired a dramatic increase in the amount of EMG activity recorded during the swing phase of locomotion, the phase in which the muscles deed as antagonists and when they are usually almost silent. The EMG pattern caused by tonic nociceptor stimulation mimics the 1 that they recorded from chronic lower back pain patients. In club to study more directly the furnishings of tonic nociceptor stimulation on a CPG, we infused hypertonic saline into the masseters during fictive mastication in a decerebrate rabbit while we recorded from the digastric motoneuron puddle and from phasically active neurons in the rostral parvocellular reticular formation and adjacent rostral Vth spinal nucleus (Westberg et al., 1997). Nociceptor simulation caused a significant reduction in the area of digastric motoneuron bursts and increased the interburst interval and cycle duration. The firing design of the interneurons likewise changed significantly during nociceptor stimulation, fifty-fifty though only one had nociceptive sensory field. Furthermore, there was a strong temporal relationship between the change in tiptop firing of the interneuronal population and digastric flare-up termination.

Thus it seems probable that tonic noxious inputs have general furnishings on CPGs that tend to lengthen cycle and stage duration, reduce agonist bursts, and increase antagonist activity. As we outset suggested at the XIIth symposium, the outcome of painful inputs on motor patterns such as mastication and locomotion is therefore not vicious but adaptive, because these changes seem to diminish the probability of cocky-induced tissue harm.

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