Level Of Sensory Input Research Articles

Future trends in brain aging research: Visuo-cognitive functions at stake during mobility and spatial navigation.

Aging leads to a complex pattern of structural and functional changes, gradually affecting sensorimotor, perceptual, and cognitive processes. These multiscale changes can hinder older adults' interaction with their environment, progressively reducing their autonomy in performing tasks relevant to everyday life. Autonomy loss can further be aggravated by the onset and progression of neurodegenerative disorders (e.g., age-related macular degeneration at the sensory input level; and Alzheimer's disease at the cognitive level). In this context, spatial cognition offers a representative case of high-level brain function that involves multimodal sensory processing, postural control, locomotion, spatial orientation, and wayfinding capabilities. Hence, studying spatial behavior and its neural bases can help identify early markers of pathogenic age-related processes. Until now, the neural correlates of spatial cognition have mostly been studied in static conditions thereby disregarding perceptual (other than visual) and motor aspects of natural navigation. In this review, we first demonstrate how visuo-motor integration and the allocation of cognitive resources during locomotion lie at the heart of real-world spatial navigation. Second, we present how technological advances such as immersive virtual reality and mobile neuroimaging solutions can enable researchers to explore the interplay between perception and action. Finally, we argue that the future of brain aging research in spatial navigation demands a widespread shift toward the use of naturalistic, ecologically valid experimental paradigms to address the challenges of mobility and autonomy decline across the lifespan.

Violence without a Face: the Analysis of Testimonies of Women Who Were Sexually Assaulted During the War in Croatia and Bosnia and Herzegovina.

This study examined testimonies of women who were sexually assaulted multiple times by multiple unknown offenders. In these testimonial narratives, it is possible to detect specific modalities of traumatic event expression. This expression lacks any spatial, temporal, auditory or emotional determinants of the event. These fourteen women (out of 17) were imprisoned and forcefully isolated in detention camps or private houses in the occupied territories of Croatia and Bosnia and Herzegovina, during the war. At the same time, some of these women were raped by the offenders that were previously known to them. The average length of detention was 141 days among the seventeen victims (range of 7 to 395 days), while the average time from the first day of imprisonment to the first day of testimony was 311 days (range of 30 to 889 days). Based on the narrative descriptions of the events acquired from these testimonies, our analysis showed that these expressions differed when the offender was known to the victim, contrasted to the situation when the offender was completely unknown. This finding has a significant implication in victim's testimony at judicial hearings. Specifically, women that were raped by unknown perpetrator(s) were often unable to provide persuasive testimony and their recollection of the events was deemed insufficient for the further prosecution. Testimonies in these cases substantially lacked in vividness and were devoid of visuospatial determinants of the rape event. Consequently, this often resulted in the case's dismissal. The unusual and problematic expression of these traumatic memories might indicate that these events were not properly stored in the conceptual form of memory. Ultimately, victims could not make any coherent recollection or reconstruct the cascade of events by using perceptual information. We argue that this could be due to an aberrant mechanism of memory storage and difficulties that emerge on the level of sensory input. This problem needs to be further examined and correspondingly accounted for since it can exert significant influence on judicial outcomes in the domain of sexual assault cases worldwide.

Temporal Dynamics of Inhalation-Linked Activity across Defined Subpopulations of Mouse Olfactory Bulb Neurons ImagedIn Vivo

In mammalian olfaction, inhalation drives the temporal patterning of neural activity that underlies early olfactory processing. It remains poorly understood how the neural circuits that process incoming olfactory information are engaged in the context of inhalation-linked dynamics. Here, we used artificial inhalation and two-photon calcium imaging to compare the dynamics of activity evoked by odorant inhalation across major cell types of the mouse olfactory bulb (OB). We expressed GCaMP6f or jRGECO1a in mitral and tufted cell (MTC) subpopulations, olfactory sensory neurons (OSNs), and two major juxtaglomerular interneuron classes and imaged responses to a single inhalation of odorant. Activity in all cell types was strongly linked to inhalation, and all cell types showed some variance in the latency, rise times, and durations of their inhalation-linked response. Juxtaglomerular interneuron dynamics closely matched that of sensory inputs, while MTCs showed the highest diversity in responses, with a range of latencies and durations that could not be accounted for by heterogeneity in sensory input dynamics. Diversity was apparent even among “sister” tufted cells innervating the same glomerulus. Surprisingly, inhalation-linked responses of MTCs were highly overlapping and could not be distinguished on the basis of their inhalation-linked dynamics, with the exception of a subpopulation of superficial tufted cells expressing cholecystokinin (CCK). Our results are consistent with a model in which diversity in inhalation-linked patterning of OB output arises first at the level of sensory input and is enhanced by feedforward inhibition from juxtaglomerular interneurons which differentially impact different subpopulations of OB output neurons.

Affect and prefrontal hemodynamics during exercise under immersive audiovisual stimulation: Improving the experience of exercise for overweight adults

ObjectiveResearch on methods of improving the affective experience of exercise remains limited, especially for low-active overweight adults. We investigated the effectiveness of a virtual-reality headset and headphones in improving affective responses over conventionally delivered audiovisual stimulation. MethodsLow-active, overweight adults (16 women, 5 men; age: 34.67 ± 9.62 years; body mass index: 28.56 ± 4.95 kg/m²; peak oxygen uptake for men: 29.14 ± 6.56 mL/kg/min, for women: 22.67 ± 4.52 mL/kg/min, mean ± SD) completed 15-min sessions of recumbent cycling at the ventilatory threshold: (a) high immersion (HI, virtual reality headset and headphones), (b) low immersion (LI, television screen and speakers), and (c) Control. During-exercise pleasure and post-exercise enjoyment were self-reported. Oxygenation of the right dorsolateral prefrontal cortex (dlPFC) was assessed with near infrared spectroscopy. ResultsHigher pleasure was reported during HI than during LI and Control (Condition × Time interaction; p < 0.001, ηp2 = 0.43). Participants who reported a preference for low exercise intensity showed higher dlPFC oxygenation during Control, but this difference diminished during LI and HI (Condition × Time × Preference interaction; p = 0.036, ηp2 = 0.10). ConclusionCompared with conventionally delivered audiovisual stimulation, using a virtual-reality headset strengthens the dissociative effect, further improving affective responses to exercise at the ventilatory threshold among overweight, low-active adults. Presumably by competing with interoceptive afferents at the level of sensory input, audiovisual stimulation may lessen reliance on cognitive efforts to attenuate declining affect, as indicated by lower right dlPFC activity, particularly among participants disinclined toward high exercise intensity.

Rediscovering TNAP in the Brain: A Major Role in Regulating the Function and Development of the Cerebral Cortex.

The presence of alkaline phosphatase (AP) activity in the neural tissue has been described decades ago. However, only recent studies clarified the isotype, regional distribution and subcellular localization of the AP expressed in the cerebral cortex of diverse mammalian species including the human. In the primate brain the discovery that the bone AP isotype (TNAP) is expressed provided the opportunity of a deeper understanding of the role of this enzyme in neuronal functions based on the knowledge acquired by studying the role of the enzyme in hypophosphatasia, mostly in bone mineralization. TNAP exhibits widespread substrate specificity and, in the brain, it is potentially involved in the regulation of molecules which play fundamental roles in signal transmission and development. In light of these observations, the localization of TNAP in the human cerebral cortex is of high significance when considering that epilepsy is often diagnosed in hypophosphatasia. Here we overview our results on the identification of TNAP in the primate cerebral cortex: TNAP exhibits a noticeably high activity in the synapses and nodes of Ranvier, is specifically present in layer 4 of the sensory cortices and additionally in layer 5 of prefrontal, temporal and other associational areas in human. Our studies also indicate that bone AP activity depends on the level of sensory input and that its developmental time-course exhibits characteristic regional differences. The relevance of our findings regarding human cortical physiology and brain disorders are discussed.

Multiple tooth-losses during development suppress age-dependent emergence of oscillatory neural activities in the oral somatosensory cortex

Tooth and tooth-related organs play important roles in not only mastication, but also sensory perception in the oral region. In general, sensory neural inputs during the developmental period are required for the maturation of functions in the sensory cortex. However, whether maturations of oral somatosensory cortex (OSC) require certain levels of sensory input from oral regions has been unclear. The present study investigated the influence of multiple tooth-losses during the developmental period on age-dependent emergence of rhythmic activities of population neurons in the OSC. Low-frequency electrical stimulation was delivered to layer IV and field potentials were recorded from layer II/III in the OSC of rat brain slices. In control rats, N-methyl- d-aspartate (NMDA) receptor-dependent oscillation at 8–10 Hz appeared during postnatal weeks 2–3. In rats with extraction of multiple teeth at 17–18 days old, oscillation did not appear even at maturity, whereas in rats with multiple teeth extracted at 37–38 days old, oscillation appearances were maintained in maturity. Thus, emergence of oscillation in the OSC was suppressed by multiple tooth-losses during postnatal 2–3 weeks. These results suggest that sufficient neural inputs from the teeth and tooth-related organs during developmental periods are essential for maturation of neural functions in the OSC.

A Lunar Clock Changes Shielding Pigment Transparency in Larval Ocelli of Clunio marinus

Living in the tidal zones of the sea requires synchronization with the dominant environmental influences of tidal, solar, and lunar periodicity. Endogenous clocks anticipate those geoclimatic changes and control the respective rhythms of vital functions. But the underlying mechanisms are only partly understood. While the circadian clocks in animals are investigated employing neurobiological, molecular, and genetic approaches, clocks with a lunar periodicity have been studied with reference to development and behavior only. Sites of their pacemakers, zeitgeber receptors, and coupled endocrine components are unknown. Here, a lunar‐rhythmic change of shielding pigment transparency in the larval ocelli of the intertidal midge Clunio marinus is demonstrated for the first time as a possible access to the neurobiology of lunar timing mechanisms. We studied third instar larvae (Vigo strain) throughout the lunar cycle by light‐ and electron-microscopy as well as by x‐ray fluorescence analysis for the identification of the pigment. Moonlight detection is a prerequisite for photic synchronization of the lunar clock. The larval ocelli of Clunio putatively may function as moonlight receptors and are also controlled by the circalunar clock itself, hence being primary candidates for tracing input and output pathways of the lunar pacemaker. Additionally, the demonstration of a reversible optical change of shielding pigment transparency in Clunio is a novel finding, not reported so far in any other animal species, and reveals a mechanism to enhance photosensitivity under the condition of very dim light. It represents a remarkable change of a sense organ from an imaging device to a radiometer. Its restriction to the developmental stage susceptible to lunar timing elucidates a unique sensory strategy evolved at the level of sensory input. It also raises basic questions about the biochemistry of optically active pigments, like melanin, and their intracellular control.

Elucidating brain‐behaviour relationship in child psychiatric disorders and its clinical impact

Elucidating brain‐behaviour relationship in child psychiatric disorders and its clinical impact

Improvement of Visual Perceptual Capabilities by Feedback Structures for Robotic System FRIEND

The main aim behind the design of rehabilitation robotic systems is to support disabled people in daily life situations as well as in the working environment. This requires the autonomous execution of different tasks. In order to achieve the ability of the robotic system to operate autonomously, the sensor system for the scene observation providing the necessary inputs for the manipulator control is essential. In this paper, the main emphasis is on the development and integration of the closed-loop controls at the visual sensory input level in order to increase the robustness of the vision-based system control. Moreover, the integration of additional sensors in order to support the vision system and to increase the reliability of the whole robotic system is discussed.

The timing game

In two publications presented as a contest, Hopfield and Brody propose a mechanism for detecting groups of neurons receiving similar levels of sensory input.

Fine structure and distribution of antennal sensilla of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae).

The fine structure and distribution of various types of antennal sensilla in three nymphal stages and in adults of both solitary-reared (solitary) and crowd-reared (gregarious) phases of the desert locust, Schistocerca gregaria, were investigated by scanning and transmission electron microscopy. Four types of sensilla were identified: sensilla basiconica, s. trichodea, s. coeloconica and s. chaetica. S. basiconica contain up to 50 sensory neurons, each of which displays massive dendritic branching. The sensillar wall is penetrated by a large number of pores. In contrast, s. trichodea contain one to three sensory neurons that branch to give five or six dendrites in the sensillar lumen; the sensillum wall is penetrated by relatively few pores. The s. coeloconica are situated in spherical cuticular pits on the antennal surface. The s. coeloconica are of two types: one type contains one to three sensory neurons with double sensillar walls penetrated by slit-like pores, whereas the second type contains four sensory neurons with non-porous double sensillar walls. The s. chaetica have a flexible socket and a thick non-porous sensillum wall and contain four sensory neurons that send unbranched dendrites to a terminal pore. A fifth sensory neuron of the s. chaetica terminates in a tubular body at the base of the hair. S. basiconica and coeloconica are normally distributed over the entire antennal flagellum, with a concentration in the middle segments; s. trichodea have three areas of concentration on the 5th, 10th and 14th flagellar segments. Sensilla chaetica are most abundant on the terminal segment. Locusts raised in solitary conditions have more olfactory sensilla (s. basiconica and s. coeloconica) than crowd-reared locusts. The difference in sensillar numbers is more evident in adults than in nymphs. These results suggest that differences in the odour-mediated behaviour of nymphs and adults, and between the phases of S. gregaria, may be attributable to differences at the sensory input level.

Sensory deprivation and chronic pain: A review of the literature

Aims and objectives: The aim of this paper is to explore the literature into the use of 'Snoezelen' (Sensory Stimulation) for the management of chronic pain. Within the literature there are a number of research studies which have investigated the concept of sensory deprivation and these are considered. The studies indicate the potential of sensory input as a field of research in particular relation to the care of patients within hospital settings where they are removed from their 'normal' level of sensory input and could subsequently experience sensory deprivation. The relationship between sensory restriction and chronic pain is emphasized. This links with investigations of sensory stimulation (Snoezelen) as a potential strategy for the management of chronic pain.Conclusions: In conclusion, it is suggested that sensory deprivation cannot exist and the term 'sensory restriction' would be more appropriate. It is proposed that there is a need to develop a tool to assist carers in identifying the existence of sensory restriction in their specific client groups to provide a basis for intervention.

Role of Sensory and Cognitive Information in the Enhancement of Certainty and Linking for Novel and Familiar Foods

Expected and actual liking for novel and familiar foods were examined under various conditions of sensory and verbal information with 121 subjects who differed in food neophobia. The possible mediating roles uncertainty about product identity and resemblance to familiar foods were also investigated. Subjects were divided into three verbal information groups (no information; product name; ingredient and use information) balanced for neophobia, age and gender. All groups rated test samples under three sensory conditions: (1) appearance only, (2) appearance and smell and (3) appearance, smell and taste. Neophilics rated novel foods more favorably than did neophobics. Accumulating sensory experience (appearance, smell, taste) decreased liking for novel foods but increased liking for familiar foods. Verbal information generally increased liking for all samples. Liking and certainty of product identity were curvilinearly related for novel foods, but linearly related for familiar foods. Liking for products judged to closely resemble the test product predicted up to 64% of the variability in expected and actual liking. Eight weeks later, subjects rated one of the two novel foods higher than in the first exposure, but no other exposure effects were observed. Our data suggest that information (possibly via reduced uncertainty), resemblance to more familiar foods, and exposure contribute to reducing initially negative responses to novel foods; furthermore, neophobia decreases liking for novel foods similarly at all levels of sensory input (visual, smell and taste).

Levels of anxiety and depression in spinal cord-injured patients

To test the hypothesis that the experience of anxiety or depression correlates with the degree of sensory input, the levels of anxiety and depression in 19 quadriplegic and 16 paraplegic patients were compared by administering Zung self-rating scales. The majority of patients scored within the normal range. Quadriplegic patients were not significantly more depressed or anxious than paraplegic patients, and levels of spinal cord lesions were not associated with any significant differences in scores. These results suggest that the level of sensory input is unlikely to play a dominant role in anxiety and depression.

Temporal experience as a function of sensory stimulation and motor activity.

This study was concerned with establishing quantifiable continua of phenomenal temporal judgments. Using 6 levels of sensory input and 3 levels of motor behavior, a linear relationship was found between sensory input and temporal estimations for a 90-sec. interval. Both sensory input and motor behavior had significant effects, but not the interaction. It was postulated that the so-called unfilled interval could be better understood if it could be related to various levels of information input.