Different Types Of Stimuli Research Articles

Explicit and Implicit Preference for Symmetry Across Object Categories

Symmetry affects aesthetic judgements, and it has been extensively studied at least for faces and abstract objects. We examined the role of bilateral symmetry on aesthetic judgements across different types of stimuli. It is important to test if symmetry is equally effective in the context of objects expected to be symmetrical, e.g., faces, and objects that are almost never symmetrical, e.g., landscapes. We used the following categories: angular shapes, smooth shapes, landscapes, flowers, female faces, and male faces. We selected these image categories considering their differing degrees of curvature, familiarity to the viewer, and tendency to be perceived as ensembles, as opposed to standalone objects. We also included blobs, manipulating landscapes into blurry tessellated patterns featuring patches of color, to remove familiarity while preserving the appearance of ensembles. For each item in these categories, images were modified to obtain perfect bilateral symmetry. We collected both explicit ratings and implicit measures of symmetry preference. For landscapes, there was a clear preference for the non-symmetrical (original) version. We observed a dissociation between explicit and implicit measures. Implicit measures demonstrated positive associations for all categories.

Conservation of the cooling agent binding pocket within the TRPM subfamily.

Transient receptor potential (TRP) channels are a large and diverse family of tetrameric cation-selective channels that are activated by many different types of stimuli, including noxious heat or cold, organic ligands such as vanilloids or cooling agents, or intracellular Ca2+. Structures available for all subtypes of TRP channels reveal that the transmembrane domains are closely related despite their unique sensitivity to activating stimuli. Here, we use computational and electrophysiological approaches to explore the conservation of the cooling agent binding pocket identified within the S1-S4 domain of the Melastatin subfamily member TRPM8, the mammalian sensor of noxious cold, with other TRPM channel subtypes. We find that a subset of TRPM channels, including TRPM2, TRPM4, and TRPM5, contain pockets very similar to the cooling agent binding pocket in TRPM8. We then show how the cooling agent icilin modulates activation of mouse TRPM4 to intracellular Ca2+, enhancing the sensitivity of the channel to Ca2+ and diminishing outward-rectification to promote opening at negative voltages. Mutations known to promote or diminish activation of TRPM8 by cooling agents similarly alter activation of TRPM4 by icilin, suggesting that icilin binds to the cooling agent binding pocket to promote opening of the channel. These findings demonstrate that TRPM4 and TRPM8 channels share related ligand binding pockets that are allosterically coupled to opening of the pore.

Conservation of the cooling agent binding pocket within the TRPM subfamily.

Transient Receptor Potential (TRP) channels are a large and diverse family of tetrameric cation selective channels that are activated by many different types of stimuli, including noxious heat or cold, organic ligands such as vanilloids or cooling agents, or intracellular Ca 2+ . Structures available for all subtypes of TRP channels reveal that the transmembrane domains are closely related despite their unique sensitivity to activating stimuli. Here we use computational and electrophysiological approaches to explore the conservation of the cooling agent binding pocket identified within the S1-S4 domain of the Melastatin subfamily member TRPM8, the mammalian sensor of noxious cold, with other TRPM channel subtypes. We find that a subset of TRPM channels, including TRPM2, TRPM4 and TRPM5, contain pockets very similar to the cooling agent binding pocket in TRPM8. We then show how the cooling agent icilin modulates activation of TRPM4 to intracellular Ca 2+ , enhancing the sensitivity of the channel to Ca 2+ and diminishing outward-rectification to promote opening at negative voltages. Mutations known to promote or diminish activation of TRPM8 by cooling agents similarly alter activation of TRPM4 by icilin, suggesting that icilin binds to the cooling agent binding pocket to promote opening of the channel. These findings demonstrate that TRPM4 and TRPM8 channels share related ligand binding pockets that are allosterically coupled to opening of the pore.

Stimulus type shapes the topology of cellular functional networks in mouse visual cortex

On the timescale of sensory processing, neuronal networks have relatively fixed anatomical connectivity, while functional interactions between neurons can vary depending on the ongoing activity of the neurons within the network. We thus hypothesized that different types of stimuli could lead those networks to display stimulus-dependent functional connectivity patterns. To test this hypothesis, we analyzed single-cell resolution electrophysiological data from the Allen Institute, with simultaneous recordings of stimulus-evoked activity from neurons across 6 different regions of mouse visual cortex. Comparing the functional connectivity patterns during different stimulus types, we made several nontrivial observations: (1) while the frequencies of different functional motifs were preserved across stimuli, the identities of the neurons within those motifs changed; (2) the degree to which functional modules are contained within a single brain region increases with stimulus complexity. Altogether, our work reveals unexpected stimulus-dependence to the way groups of neurons interact to process incoming sensory information.

«Оddball»-парадигма электроэнцефалограммы/вызванных потенциалов для изучения восприятия эмоций

<p style="text-align: justify;">Assessment of evoked potentials using electroencephalography is a classic method for determining a person's response to different types of stimuli. The literature describes EPs that are specific markers of emotional perception. To date, many stimulus bases have been developed and validated for use in EEG EP paradigms, among which images of human faces with emotional expression stand out. It is possible that the perception of this type of stimulus may have its own specificity — for example, it may occur faster than the perception of other classes of images, since it represents a more significant biological signal. In this review, we wanted to show the features of using affective images in the oddball paradigm, focusing on the use of human faces with emotional expression. This paradigm also belongs to the EEG/EP paradigms, but it has several features. The advantages of this technique are, firstly, its higher sensitivity compared to other paradigms with the presentation of emotional images. Secondly, it is possible, during the passive presentation of visual stimuli, to analyze the rapid automatic reactions that, according to previous studies, accompany the perception of faces. Perhaps the most effective images in the oddball EEG/EP paradigm will be facial expressions. The obtained data by using this paradigm are presented. The data obtained data show differences in both the amplitude and spatial components of the EP associated with different facial expressions — happy/angry.</p>

Designing a Motion-Onset Visual-Evoked Potential-Based Brain–Computer Interface to Control a Computer Game

Brain-computer interface (BCI) establishes an alternative direct communication channel between the brain and computer or other external devices. Motion-onset visual evoked potential (mVEP) related to the individual perception of movement is among synchronous BCI system that utilizes external stimulus. mVEPs stimulation paradigm is like an oddball stimulation paradigm. Researchers have recently been investigating mVEPs to control a computer game. To control a computer game, they used translation stimulus to evoke these potentials in EEG brain signals. In this study, we examine designing a computer game with four different types of stimuli, including translation, contraction, expansion, and rotation. We also used time-domain and wavelet coefficients for the feature extraction. Also, we used different types of linear discriminant analysis (LDA) classification methods, including least absolute shrinkage and selection operator (LASSO), stepwise LDA (SWLDA); moreover, and spatial-temporal discriminant analysis (STDA) for detecting the target stimulus. Our results demonstrate that contraction, expansion, and rotation stimuli, as well as translation, could be employed to control a BCI game. Our results showed that subjects got higher scores, game accuracy control, and information transfer rate using the rotation stimulus with SWLDA/STDA classification methods.

Evaluation of Different Types of Stimuli in an Event-Related Potential-Based Brain-Computer Interface Speller under Rapid Serial Visual Presentation.

Rapid serial visual presentation (RSVP) is currently a suitable gaze-independent paradigm for controlling visual brain-computer interfaces (BCIs) based on event-related potentials (ERPs), especially for users with limited eye movement control. However, unlike gaze-dependent paradigms, gaze-independent ones have received less attention concerning the specific choice of visual stimuli that are used. In gaze-dependent BCIs, images of faces-particularly those tinted red-have been shown to be effective stimuli. This study aims to evaluate whether the colour of faces used as visual stimuli influences ERP-BCI performance under RSVP. Fifteen participants tested four conditions that varied only in the visual stimulus used: grey letters (GL), red famous faces with letters (RFF), green famous faces with letters (GFF), and blue famous faces with letters (BFF). The results indicated significant accuracy differences only between the GL and GFF conditions, unlike prior gaze-dependent studies. Additionally, GL achieved higher comfort ratings compared with other face-related conditions. This study highlights that the choice of stimulus type impacts both performance and user comfort, suggesting implications for future ERP-BCI designs for users requiring gaze-independent systems.

Memory retrieval effects as a function of differences in phenomenal experience.

Conscious experience and perception are restricted to a single perspective. Although evidence to suggest differences in phenomenal experience can produce observable differences in behavior, it is not well understood how these differences might influence memory. We used fMRI to scan n = 49 participants while they encoded and performed a recognition memory test for faces and words. We calculated a cognitive bias score reflecting individual participants' propensity toward either Visual Imagery or Internal Verbalization based on their responses to the Internal Representations Questionnaire (IRQ). Neither visual imagery nor internal verbalization scores were significantly correlated with memory performance. In the fMRI data, there were typical patterns of activation differences between words and faces during both encoding and retrieval. There was no effect of internal representation bias on fMRI activation during encoding. At retrieval, however, a bias toward visualization was positively correlated with memory-related activation for both words and faces in inferior occipital gyri. Further, there was a crossover interaction in a network of brain regions such that visualization bias was associated with greater activation for words and verbalization bias was associated with greater activation for faces, consistent with increased effort for non-preferred stimulus retrieval. These findings suggest that individual differences in cognitive representations affect neural activation across different types of stimuli, potentially affecting memory retrieval performance.

The Stimulating Factors of Cognitive Memory and the Meaning and Influence of Cognitive Conception

This paper studies the stimulating factors of cognitive memory and the significance and influence of such factors on cognitive concepts. Through a comprehensive review of literature and experimental data, this paper explores how different types of stimuli affect individual memory and cognitive architecture. Through literature research combined with investigation and analysis, the relationship between the themes was further determined. It is found that stimuli can significantly affect the formation of cognitive concepts, thus changing individual learning and decision-making. And further research shows that different kinds of stimuli have a great degree of difference in the change of cognitive structure. Finally, based on this research, this paper analyzes how to solve the existing social problems.

Stimulus triggered release of actives from composite microcapsules based on sporopollenin from Lycopodium clavatum.

Smart drug delivery systems (SDDSs) are a paradigm shift in drug delivery, particularly in microencapsulation technology where the drug is released in response to an internal and/or external stimulus. In this study, a smart microencapsulation platform was developed using three different types of stimuli triggered release of a model active (rhodamine 6G) from sporopollenin from Lycopodium clavatum. Triggers were based on pH-, thermal- and near infrared light-sensitive polymer composition. Carbopol nanogel and methylcellulose were used as responsive aqueous polymers for pH and thermally triggered release, respectively. Methylcellulose loaded with active and gold nanoparticles was used for photothermal triggered release. The formulations were encapsulated into the empty cores of sporopollenin microcapsules using the compressed tablet technique. The pH triggered release of the active was achieved above pH 7, which was mediated by the swelling of the carbopol nanogel that forced its way out of the elastic trilite scars of the sporopollenin. Results from measuring the active fluorescent intensity and its content over time confirmed the crucial role of carbopol in the pH triggered release. For the thermo-sensitive polymer methylcellulose, it was found that the release of the active from methylcellulose loaded sporopollenin was triggered upon heating the system reaching 90% whereas it levelled out at 40% for methylcellulose-free sporopollenin. The maximum amount of active was released at around 55 °C, where the sol-gel transition of the methylcellulose starts. Photothermally triggered release using near infrared (NIR) laser revealed that the amount of active released from sporopollenin loaded with both gold nanoparticles and methylcellulose was approximately four times higher than that from sporopollenin loaded with methylcellulose/active only, confirming the key role of gold nanoparticles in the release via photothermal heating of the polymer formulation.

A DNA rotary nanodevice operated by enzyme-initiated strand resetting.

DNA nanostructures that respond to external stimuli have found applications in several areas such as biosensing, drug delivery and molecular computation. The use of different types of stimuli in a single operation provides another layer of control for the reconfiguration of nucleic acid nanostructures. This work demonstrates the use of a ribonuclease to "unset" a nucleic acid nanodevice based on the paranemic crossover (PX) DNA and specific DNA inputs to "reset" the structure into a juxtaposed DNA (JX2) configuration, resulting in a 180° rotation of the helical domains. Such operations would be useful in translational applications where DNA nanostructures can be designed to reconfigure on the basis of more than one stimulus.

A Cascade xDAWN EEGNet Structure for Unified Visual-Evoked Related Potential Detection.

Visual-based brain-computer interface (BCI) enables people to communicate with others by spelling words from the brain and helps professionals recognize targets in large numbers of images. P300 signals evoked by different types of stimuli, such as words or images, may vary significantly in terms of both amplitude and latency. A unified approach is required to detect variable P300 signals, which facilitates BCI applications, as well as deepens the understanding of the P300 generation mechanism. In this study, our proposed approach involves a cascade network structure that combines xDAWN and classical EEGNet techniques. This network is designed to classify target and non-target stimuli in both P300 speller and rapid serial visual presentation (RSVP) paradigms. The proposed approach is capable of recognizing more symbols with fewer repetitions (up to 5 rounds) compared to other models while possessing a better information transfer rate (ITR) as demonstrated on Dataset II (17.22 bits/min in the second repetition round) of BCI Competition III. Additionally, our approach has the highest unweighted average recall (UAR) performance for both 5 Hz ( 0.8134±0.0259 ) and 20 Hz ( 0.6527±0.0321 ) RSVP. The results show that the cascade network structure has better performance between both the P300 Speller and RSVP paradigms, manifesting that such a cascade structure is robust enough for dealing with P300-related signals (source code is available at https://github.com/embneural/Cascade-xDAWN-EEGNet-for-ERP-Detection).

Conscious sensations and protective reflexes driven by eye surface nerves in health and disease

The trigeminal primary sensory neurons that innervate the ocular surface, especially the cornea, have been classified in three functional types: polymodal nociceptors, mechano‐nociceptors and cold thermoreceptors. These sensory nerves are responsible for the conscious sensations evoked in response to ocular surface stimulation as well as for the regulation of tearing and blinking, and they are also involved in the trophic maintenance of the ocular tissues.Depending on the transducing channels they express in their membrane, sensory nerves from the ocular surface respond to different types of stimulus and, after this information is processed by the CNS, different conscious sensations are evoked: corneal mechano‐nociceptors' activation led to pricking pain; polymodal nociceptors evoke burning irritation, and cold thermoreceptors' activation may evoke freshness/cold/dryness/pain depending on the subtype of cold thermoreceptor neuron activated by the stimulus. While reflex blinking and tearing are driven by the activation of polymodal nociceptors as the afferent arm of the reflex, basal blinking and tearing rate are under the control of cold thermoreceptors' activity.During inflammation and after injury (such as UV‐induced keratitis, allergic keratoconjunctivitis, corneal surgery, tear‐deficient dry eye) the activity of corneal sensory nerves is modified in both eyes, even when inflammation or damage affects only one eye. The abnormal corneal sensory nerve activity constitutes the basis for the discomfort, dryness and pain sensations experienced under these conditions. Also, protective mechanisms depending on ocular nerve activity such as blinking and tearing become altered.(Supported by PID2020‐115934RB‐I00 from DOI: MCIN/AEI/10.13039/50110001103, and CIPROM/2021/48 from the Generalitat Valenciana, Spain)

Empathy for the pain of others: Sensitivity to the individual, not to the collective

Groups of people in pain evoke our empathic reactions. Yet how does one empathize with a group? Here, we aim to identify psychological mechanisms that underlie empathic reactions to groups. We theorize that because empathy is an egocentric process routed through the self, people are strongly attuned to the impact on each individual, and less so to the number of individuals affected. In five pre-registered experiments, involving different types of stimuli and valences of the outcomes, we repeatedly find that participants' level of empathy depends on the pain experienced by each individual, but not on the number of individuals in the group. The experiments support our hypothesis. They also add to alternative explanations such as psychophysical numbing and strategic regulation of negative emotions, providing valuable insights into the phenomenon of scope insensitivity. The findings also bear implications for the ongoing debate on the role of empathy in public policy decisions.

Synthesis and Characterization of Novel pH-Responsive Aminated Alginate Derivatives Hydrogels for Tissue Engineering and Drug Delivery.

The aims of this study are to synthesize new derivatives of sodium alginate that improve the inherent properties, such as hydrogel strengthening, and create environmental sensitivity, such as pH sensitivity, for use in drug delivery. Today, hydrogels, due to outstanding properties such as biodegradability, biocompatibility, mechanical properties, and response to stimuli properties, are widely used as harmless biomaterials in various fields in drug delivery, wound dressing, and tissue engineering. Stimulus-sensitive polymers significantly respond to slight changes in their environment. Different types of stimuli are used to influence the properties of polymers, the most important of which are temperature and pH because these are two vital factors in the human body; hence, temperature-sensitive and pHsensitive hydrogels have been extensively studied. The ability to absorb water and swell the hydrogel is due to hydrophilic chains in the hydrogel network, and water absorption by hydrogel can be controlled by response to the stimuli. Since hydrogels mimic human tissue, the ability to retain water in them is essential. As a result, it is considered in many biomedical drug delivery systems. Stimulusresponsive swelling can control diffusion out of and into the hydrogel network, which allows temporal and spatial control of drug release. When a drug is loaded onto a biodegradable and stimulisensitive hydrogel, the drug delivery system has the added advantage of sustained release of the drug, which reduces side effects. In this study, two different hydrocarbons, [1,3-diaminopropane (DAP)] as a short-chain hydrocarbon, and [1,7-diaminoheptane (DAH)] as a long-chain hydrocarbon were grafted onto three types ofsodium alginate (SA), through amide bond linkages. The hydrogel copolymer matrices were compared with sodium alginate (SA) beads. The graft copolymers were characterized using FTIR, 1HNMR, XRD spectroscopy, elemental analysis (CHNS) and thermal analysis (TGA, DTA and DSC). An environmental scanning electron microscope (ESEM) was used to investigate the surface morphology of hydrogels. Effects of variables such as the length of hydrocarbon chains cross-linked to alginate, temperature, pH, and cross-linkers on the properties of hydrogels investigated in the temperature range of 2-70 ˚C and two different pH values (4.4 and 7.4). The results showed that when the hydrocarbon chain length of diamines decreases, the extent of cross-linking and strength of the hydrogels are increased. Other results suggest that the hydrogels obtained from high-viscosity alginate derivatives had positive pH sensitivity. Hydrogels prepared in this study demonstrated good mechanical and swelling ratios that are necessary for wound dressing. DAP-g-SA and DAH-g-SA pH-sensitive hydrogels were successfully synthesized through amide bond linkages. The new synthesis derivatives showed lower swelling levels at low pH (4.4). In contrast, their swelling levels at higher pH (7.4) were significantly enhanced. Higher swelling degree could be obtained at high pH. pH-responsive hydrogels are especially useful for various biological applications due to their unique feature of controlled swelling, biodegradability, biocompatibility, and fluid retention in their network structures. pH-responsive hydrogels, as intelligent systems, can be used in controlled-release drug delivery systems such as insulin delivery.

Timecourse of two-dimensional decision-making to offensive actions.

Decision-making is an important component in the perception-action coupling required for athletes to achieve fine performance. Signal detection theory (SDT) provides a means of quantifying athletes' decision-making processes, based on their ability to discriminate between different types of stimuli (sensitivity) and the locations of their response criteria along a decision axis in a given situation. Studies have shown differences in these two indices between athletes and less-experienced counterparts, although these studies were limited to unidimensional decision-making problems. In the present study, SDT analysis was applied to two-dimensional decision-making by volleyball players regarding their opponents' attacks, using a four-alternative forced-choice task combining judgments of the type (spike or tip) and direction (cross-court or down-the-line) of attacks. Furthermore, a temporal occlusion task was used to reveal the timecourses of changes in sensitivity and the location of response criteria relating to judgments of attack type and direction. There were three groups of participants, eight top-league players, ten collegiate players, and ten novices. The results showed clear effects of expertise and distinct timecourses for the two types of judgment. For the attack type judgments, the sensitivities of the top-league players were relatively low at the early occlusion points, and their response criteria were biased toward judging attacking actions as spikes. At the late occlusion points, their sensitivity peaked, and there was no bias in their response criteria. For the directional judgments, the sensitivity of the three groups improved as the occlusion point advanced, while their response criteria tended to become more similar, which was not the case for the attack type judgments. These results are discussed together with previous studies of volleyball players' decision-making and judgments regarding deceptive actions in sports.

Cortical Neurons Adjust the Action Potential Onset Features as a Function of Stimulus Type

Pyramidal neurons and interneurons play critical roles in regulating the neuronal activities in the mammalian cortex, where they exhibit different firing patterns. Pyramidal neurons mainly exhibit regular-spiking firing patterns, while interneurons have fast-spiking firing patterns. Cortical neurons have distinct action potential onset dynamics, in which the evoked action potential is rapid and highly variable. However, it is still unclear how cortical regular-spiking and fast-spiking neurons discriminate between different types of stimuli by changing their action potential onset parameters. Thus, we used intracellular recordings of regular-spiking and fast-spiking neurons, taken from layer 2/3 in the somatosensory cortex of adult mice, to investigate changes in the action potential waveform in response to two distinct stimulation protocols: the conventional step-and-hold and frozen noise. The results show that the frozen noise stimulation paradigm evoked more rapid action potential with lower threshold potential in both neuron types. Nevertheless, the difference in the action potential rapidity in response to different stimuli was significant in regular-spiking pyramidal neurons while insignificant in fast-spiking interneurons. Furthermore, the threshold variation was significantly higher for regular-spiking neurons than for fast-spiking neurons. Our findings demonstrate that different types of cortical neurons exhibit various onset dynamics of the action potentials, implying that different mechanisms govern the initiation of action potentials across cortical neuron subtypes.

Identifying and naming number digits in Setswana

This study experimentally tested how well Setswana native speakers know numbers in their language, and whether they can articulate numbers of varying complexities in Setswana. To this end, we present results from a computerbased number transcoding task on how Setswana speakers identify and articulate number digits in Setswana. We measured participants’ (N = 104, 48 males and 55 females, 18–35 years old) response times and accuracy scores to four different types of stimuli: single, double, triple, and quadruple digits. Results confirm the study hypothesis that simple numbers are easier to identify and name in Setswana than more complex digits. Both reaction times and accuracy scores show that less complex numbers have shorter reaction times and high accuracy scores, while more complex quadruple numbers take longer to identify and name in Setswana, and attract low correctness scores. Results have various implications and reflect how numeracy skills are taught, and how Setswana speakers generally use numbers.

Symmetry Detection in Autistic Adults Benefits from Local Processing in a Contour Integration Task.

Symmetry studies in autism are inconclusive possibly due to different types of stimuli used which depend on either local or global cues. Therefore, this study compared symmetry detection between 20 autistic and 18 non-autistic adults matched on age, IQ, gender and handedness, using contour integration tasks containing open and closed contours that rely more on local or global processing respectively. Results showed that the autistic group performed equally well with both stimuli and outperformed the non-autistic group only for the open contours, possibly due to a different strategy used in detecting symmetry. However, there were no group differences for the closed contour. Results explain discrepant findings in previous symmetry studies suggesting that symmetry tasks that favour a local strategy may be advantageous for autistic individuals. Implications of the findings towards understanding visual sensory issues in this group are discussed.

Light-controlled growth of DNA organelles in synthetic cells.

Living cells regulate many of their vital functions through dynamic, membraneless compartments that phase separate (condense) in response to different types of stimuli. In synthetic cells, responsive condensates could similarly play a crucial role in sustaining their operations. Here we use DNA nanotechnology to design and characterize artificial condensates that respond to light. These condensates form via the programmable interactions of star-shaped DNA subunits (nanostars), which are engineered to include photo-responsive protection domains. In the absence of UV irradiation, the nanostar interactions are not conducive to the formation of condensates. UV irradiation cleaves the protection domains, increases the nanostar valency and enables condensation. We demonstrate that this approach makes it possible to tune precisely the kinetics of condensate formation by dosing UV exposure time. Our experimental observations are complemented by a computational model that characterizes phase transitions of mixtures of particles of different valency, under changes in the mixture composition and bond interaction energy. In addition, we illustrate how UV activation is a useful tool to control the formation and size of DNA condensates in emulsion droplets, as a prototype organelle in a synthetic cell. This research expands our capacity to remotely control the dynamics of DNA-based components via physical stimuli and is particularly relevant to the development of minimal artificial cells and responsive biomaterials.