Value Of Stimuli Research Articles

A practical comparative investigation of Bruceton and 3POD2.0 statistical testing methods on friction and impact sensitivity testing

ABSTRACT There are multiple different equipment and testing methods to perform sensitivity tests and to determine probabilities and stimulus values for sensitivity of energetic materials. In this study a Bruceton and Three-Phase Optimal Design (3POD2.0), implemented in gonogo software, statistical testing methods were compared in practice by using them to determine impact and friction sensitivity of selected energetic materials. With Bruceton method 50% of the impact sensitivity and 27% of the friction sensitivity test series had to be discarded, due to too high or low s/d ratio. With 3POD2.0 0% of impact and 18% of friction test series had to be discarded, due to an error produced by the gonogo software. The number of individual tests that had to be discarded was much lower with 3POD2.0, since the gonogo software terminates the test process at early phase, while with Bruceton the test series most often must be finished before the validity of results can be assessed. Based on these results and literary reviews it can be concluded that 3POD2.0 is a suitable replacement for Bruceton to determine 50% initiation probability, while additionally gaining the entire sensitivity curve, resulting in fewer futile tests and less wasted resources.

Understanding surprise: Toward a theory of surprise marketing

Surprise marketing is a deliberate strategy involving the introduction of unexpected and/or uncertain elements (e.g., unexpected coupons, mystery box) into the customer shopping journey to evoke strong positive emotions. Despite its widespread use, academic research lacks a comprehensive understanding of its intricacies. This study addresses this gap by delving into four crucial dimensions—what, how, why, and when—to provide a more profound comprehension of surprise marketing, define the concept, and delineate its fundamental characteristics. Building on both theoretical literature and real-world business examples, the authors identify curiosity and attribution as mechanisms that initiate four mediating paths: excitement, anxiety, gratitude, and skepticism. These paths underscore the tensions underlying surprise marketing that also shape marketing outcomes across shopping stages and lead to both favorable and adverse effects. Reflecting these inherent dynamics, this study introduces five managerial moderators—surprise stimulus type, surprise stimulus value, surprise complexity, customer loyalty type, and distribution channel—that can either amplify or reduce the dynamic effects of surprise marketing. These boundaries of its influence reveal managerial pathways to achieve favorable outcomes. This article concludes with managerial implications and research directions to advance pioneering trends in surprise marketing practices.

Positive serial dependence in ratings of food images for appeal and calories

Food is fundamental to survival, and our brains are highly attuned to rapidly process food stimuli. Neural signals show that foods can be discriminated as edible or inedible as early as 85ms after stimulus onset,1 distinguished as processed or unprocessed beginning at 130ms,2 and as high or low density from 165ms.3 Recent evidence revealed specialized processing of food stimuli in the ventral visual pathway,4,5,6 an area that underlies perception of faces and other important objects. For many visual objects, perception can be biased toward recent perceptual history (known as serial dependence7,8). We examined serial dependence for food in two large samples (n>300) who rated sequences of food images for either "appeal" or "calories." Ratings for calories were highly correlated between participants and were similar for males and females. Appeal ratings varied considerably between participants, consistent with the idiosyncratic nature of food preferences, and tended to be higher for males than females. High-calorie ratings were associated with high appeal, especially in males. Importantly, response biases showed clear positive serial dependences: higher stimulus values in the previous trials led to positive biases, and vice versa. The effects were similar for males and females and for calories and appeal ratings and were remarkably consistent across participants. These findings square with recently found food selectively in the visual temporal cortex, reveal a new mechanism influencing food decision-making, and suggest a new sensory-level component that could complement cognitive strategies in diet intervention.

The influence of spatial frequency information on temporal synchrony perception on audiovisual stimuli.

Previous studies have shown that the spatial frequency (SF) of visual stimuli alters the perceived timing of subjective simultaneity. However, these studies have been limited to the effects of a single SF component. In this study, I measured and compared the points of subjective simultaneity (PSS) for audiovisual stimuli among low, high, and composited SF components. This experiment comprised a dual-presentation timing task and a ternary response format to eliminate response bias. The results indicated that the PSS value of the composition-SF stimuli was more toward visual-lead timing than the low-SF stimuli and did not differ significantly from that of the high-SF stimuli. The correlation coefficients showed that the PSS in composition-SF stimuli marginally approximated that of high-SF stimuli higher than that of low-SF stimuli. Future studies are needed to confirm these findings using visual stimuli with a wider range of SF components and with a modulated contrast.

A Cross-Sectional Study of Circadian Stimulus in Swedish Radiographers' Light Environment.

Background: Timely light exposure is a vital aspect to achieve better sleep and well-being. As there are risks with a disturbed circadian rhythm and benefits with light settings that stimulate the rhythm, the circadian effective light, circadian stimulus (CS), for radiographers was examined. Aim: The aim of the study was to compare radiographers' light environment on the workstations, at a university hospital in Southern Sweden in the form of CS and relate that to recommendations published by the Swedish Environmental Protection Agency. Method: A cross-sectional method has been applied. The measurements for CS were collected in all labs in the radiology department in the middle of January. Result: A total of 804 measures were evenly collected resulting in a median for the 19 labs, where the observed median for all labs was 0.091 CS which is significantly lower than the recommended value of 0.3 CS (p < .001). Comparing work light settings with maximum light levels in the brightest and darkest labs showed a significant difference (p < .001). Conclusion: The CS values in the labs, at the radiology department at a university hospital in Southern Sweden, do not reach the recommended values of circadian stimulus published by the Swedish Environmental Protection Agency when the radiographers themselves set the light. There is a potential for improvement as a significant difference could be seen between the chosen level of light and the maximum possible level of light.

Neural substrate for the engagement of the ventral visual stream in motor control in the macaque monkey.

The present study aimed to describe the cortical connectivity of a sector located in the ventral bank of the superior temporal sulcus in the macaque (intermediate area TEa and TEm [TEa/m]), which appears to represent the major source of output of the ventral visual stream outside the temporal lobe. The retrograde tracer wheat germ agglutinin was injected in the intermediate TEa/m in four macaque monkeys. The results showed that 58-78% of labeled cells were located within ventral visual stream areas other than the TE complex. Outside the ventral visual stream, there were connections with the memory-related medial temporal area 36 and the parahippocampal cortex, orbitofrontal areas involved in encoding subjective values of stimuli for action selection, and eye- or hand-movement related parietal (LIP, AIP, and SII), prefrontal (12r, 45A, and 45B) areas, and a hand-related dysgranular insula field. Altogether these data provide a solid substrate for the engagement of the ventral visual stream in large scale cortical networks for skeletomotor or oculomotor control. Accordingly, the role of the ventral visual stream could go beyond pure perceptual processes and could be also finalized to the neural mechanisms underlying the control of voluntary motor behavior.

Interaction of spatial attention and the associated reward value of audiovisual objects

Reward value and selective attention both enhance the representation of sensory stimuli at the earliest stages of processing. It is still debated whether and how reward-driven and attentional mechanisms interact to influence perception. Here we ask whether the interaction between reward value and selective attention depends on the sensory modality through which the reward information is conveyed. Human participants first learned the reward value of uni-modal visual and auditory stimuli during a conditioning phase. Subsequently, they performed a target detection task on bimodal stimuli containing a previously rewarded stimulus in one, both, or neither of the modalities. Additionally, participants were required to focus their attention on one side and only report targets on the attended side. Our results showed a strong modulation of visual and auditory event-related potentials (ERPs) by spatial attention. We found no main effect of reward value but importantly we found an interaction effect as the strength of attentional modulation of the ERPs was significantly affected by the reward value. When reward effects were examined separately with respect to each modality, auditory value-driven modulation of attention was found to dominate the ERP effects whereas visual reward value on its own led to no effect, likely due to its interference with the target processing. These results inspire a two-stage model where first the salience of a high reward stimulus is enhanced on a local priority map specific to each sensory modality, and at a second stage reward value and top-down attentional mechanisms are integrated across sensory modalities to affect perception.

Colour difference detection algorithm for warp‐knitted fabric based on image colour appearance model

AbstractDetecting colour differences in warp‐knitting fabric is essential to ensure its quality. Machine vision algorithms are commonly used for automatic colour difference detection. However, the current algorithm directly extracts RGB (red, green, blue) colour stimulus values from the image without considering the image's colour attributes, leading to a significant error in colour difference detection. To solve this issue, a colour appearance model is introduced into the field of colour difference detection for warp‐knitted fabric. Initially, a colour appearance model based on CAM16 is established, and the critical parameters are calculated to obtain the colour appearance attribute of the fabric. The colour difference calculation formula is then constructed in the uniform colour space of CAM16‐UCS. A template selection algorithm based on principal component analysis was designed to select warp‐knitted cloth images with standard colours. Subsequently, a cloth colour difference detection algorithm was developed using the cloth colour profile model. The performance of the colour difference formula based on the colour profile model was evaluated using the PF/3 method. To compare the CIELab, CMC(2:1), and CIEDE2000 colour difference formulas, standardised residual sum of squares was used. The results indicated that the colour difference formula based on the colour‐appearance model is about 5.32% different from the visual colour difference perceived by the human eye. However, it can perform as well as the CMC(2:1) colour difference formula, which is widely used in the textile industry.

Simulation research of the influence of different representative wavelengths on colorimetric temperature measurement accuracy

Abstract Colorimetric temperature measurement can achieve greater accuracy by obtaining data on the spectral radiance at two representative wavelengths. As color CCD cameras have three pairs of color combinations, the research would explore the accuracy of these three combinations in temperature measurement by simulation research. The stimulation values of the CCD camera for the three primary colors often differ from the three primary color wavelengths specified by the CIE. Therefore, through conducting comparative temperature measurement experiments on simulated objects, the research assesses the accuracy of color temperature measurement by comparing the performance of the CIE-specified wavelengths for the three primary colors with the stimulus values of a color CCD camera. Additionally, this research would also investigate the impact of differences in representative wavelengths on the accuracy of non-grey body temperature measurements.

Coupling Relationships between the Brain and the Central Pattern Generator Based on a Fractional-Order Extended Hindmarsh-Rose Model.

The states of the central nervous system (CNS) can be classified into subcritical, critical, and supercritical states that endow the system with information capacity, transmission capabilities, and dynamic range. A further investigation of the relationship between the CNS and the central pattern generators (CPG) is warranted to provide insight into the mechanisms that govern the locomotion system. In this study, we established a fractional-order CPG model based on an extended Hindmarsh-Rose model with time delay. A CNS model was further established using a recurrent excitation-inhibition neuronal network. Coupling between these CNS and CPG models was then explored, demonstrating a potential means by which oscillations generated by a neural network respond to periodic stimuli. These simulations yielded two key sets of findings. First, frequency sliding was observed when the CPG was sent to the CNS in the subcritical, critical, and supercritical states with different external stimulus and fractional-order index values, indicating that frequency sliding regulates brain function on multiple spatiotemporal scales when the CPG and CNS are coupled together. The main frequency range for these simulations was observed in the gamma band. Second, with increasing external inputs the coherence index for the CNS decreases, demonstrating that strong external inputs introduce neuronal stochasticity. Neural network synchronization is then reduced, triggering irregular neuronal firing. Together these results provide novel insight into the potential mechanisms that may underlie the locomotion system.

Dissociable effects of hunger, exposure and sensory overlap on flavour liking

The hedonic value of a flavour stimulus is shaped by familiarity with the combination of its sensory components and the perceiver’s metabolic state. While the relationship between these processes has important implications for understanding food acceptance, interactions between them and their potential specificity to the specific sensory features of the food consumed remain to be defined. In two preregistered experiments, we combined a sensory dilution series with a metabolic state modulation to examine whether hunger affected perceived flavour pleasantness across different levels of sensory concordance. Both experiments consisted of two sessions, whereby healthy participants evaluated the pleasantness of olfactory-gustatory stimuli – once while sated from a standardised meal and once while hungry. Experiment I demonstrated that perceived congruence of odour and taste strongly predicted flavour pleasantness, with no significant additive or interactive hunger effects. Experiment II replicated these results with a larger sample and found no sensory specific modulation of pleasantness. Importantly, exploratory analyses on data from Experiment II indicated that hunger effects were partially counteracted by interactions with prior exposure, where pleasantness enhancement through hunger was stronger for initial exposure under sated conditions. Pre-registered confirmatory analyses replicated this effect on the independent dataset from Experiment I. No interactions between sensory concordance and metabolic state were observed. Our findings demonstrate a robust effect of sensory concordance on pleasantness across metabolic states. Additive pleasantness enhancement by hunger is vulnerable to learning by prior exposure. Synergies between these determinants of hedonic value provide novel insights into strategies for dietary change which merit further investigation.

RLPeri: Accelerating Visual Perimetry Test with Reinforcement Learning and Convolutional Feature Extraction

Visual perimetry is an important eye examination that helps detect vision problems caused by ocular or neurological conditions. During the test, a patient's gaze is fixed at a specific location while light stimuli of varying intensities are presented in central and peripheral vision. Based on the patient's responses to the stimuli, the visual field mapping and sensitivity are determined. However, maintaining high levels of concentration throughout the test can be challenging for patients, leading to increased examination times and decreased accuracy. In this work, we present RLPeri, a reinforcement learning-based approach to optimize visual perimetry testing. By determining the optimal sequence of locations and initial stimulus values, we aim to reduce the examination time without compromising accuracy. Additionally, we incorporate reward shaping techniques to further improve the testing performance. To monitor the patient's responses over time during testing, we represent the test's state as a pair of 3D matrices. We apply two different convolutional kernels to extract spatial features across locations as well as features across different stimulus values for each location. Through experiments, we demonstrate that our approach results in a 10-20% reduction in examination time while maintaining the accuracy as compared to state-of-the-art methods. With the presented approach, we aim to make visual perimetry testing more efficient and patient-friendly, while still providing accurate results.

Correction to: Love evolution algorithm: a stimulus–value–role theory-inspired evolutionary algorithm for global optimization

Correction to: Love evolution algorithm: a stimulus–value–role theory-inspired evolutionary algorithm for global optimization

Decoding of auditory surprise in adult magnetoencephalography data using Bayesian models

BackgroundThe Bayesian brain framework has been proposed to explain how the brain processes and interprets sensory information. Magnetoencephalography (MEG) and electroencephalography (EEG) are two neuroimaging techniques commonly used with decoding models to study neural responses to auditory, visual and somatosensory stimuli. Our study aims to investigate neural responses to auditory stimuli using MEG data and to determine which temporal components in MEG data are sufficient for decoding surprise based on Bayesian models. MethodMEG data acquired from 18 subjects during an auditory binary oddball task was used. The data were pre-processed, and features were selected from different time windows. Five Bayesian learning models were applied to the experimental task stimuli, and each single trial's surprise value was calculated. The relationship between the extracted features in MEG data and the surprise regressors was investigated using linear regression and 5-fold cross-validation. ResultsThe results showed that the middle and late components of the MEG evoked potentials were significantly more informative than the early components. The results indicated that the Dirichlet-Categorical model outperformed the other model's decoding performance as demonstrated by higher R-squared values and lower MSE and BIC values. ConclusionsThe findings of this study provide evidence for the existence of a neural network that generates surprise in the human brain and highlight the importance of the middle and late components of the MEG evoked potentials for decoding the surprise value of auditory stimuli.

Estimating thresholds with the adaptive scan method of psychophysical testing

We previously introduced an adaptive psychophysical method called the adaptive scan (AS) that is readily available in the digital app PART. AS presents multiple progressive tracks (e.g., “scans”) each of which comprises a range of stimulus values whose positioning adapts based on a listener´s performance. Each scan is intended to contain trials above and below a listener´s detection or discrimination threshold for an auditory cue, which is anticipated to increase familiarity with the tested cues. Previously, AS was validated against other known adaptive psychophysical methods (e.g., up-down staircases) and the method of constant stimulus using the QUEST algorithm. QUEST allowed for targeting the same point in the psychometric function (e.g., 80% threshold) in all methods tested. However, the QUEST procedure is parametric, requires many trials, and is not easily applied to the diversity of psychophysical tests that AS can be useful for. Here, we examine a variety of alternative approaches to estimate threshold from the AS procedure. This work adds to the usability of AS in particular and psychophysical testing in general.

Click SP/AP Area Ratio Vesrus Tone Burst SP Amplitude to Diagnose Ménière's Disease Using Electrocochleography.

To evaluate the sensitivity and the specificity of summating potential (SP)/action potential (AP) area under the curve (AUC) ratio by a transtympanic electrode and a click stimulus (TT-CS), SP/AP AUC ratio by an extratympanic electrode and a click stimulus (ET-CS) and SP amplitude value by a transtympanic electrode and tone burst stimulus (TT-TBS) in regard of Ménière's disease (MD) diagnosis. This is the first study that compares SP amplitude value performed by a TT-TBS and the SP/AP AUC ratio performed by a TT-CS. Retrospective comparative study. Ninety-five patients met the inclusion criteria for electrocochleography (ECochG) testing in a tertiary care center. The sensitivity and specificity of our different ECochG protocols were calculated in regardof the diagnosis of MD. The patients' mean age was 54 years old (female predominance). The sensitivity and the specificity of SP/AP area ratio by a TT-CS were 88.5% and 70.0%, respectively. On the other hand, the sensitivity and specificity for the SP amplitude value by a TT-TBS were 60.0% and 55.6%, respectively. SP/AP area ratio by TT-CS was statistically better than SP amplitude value by TT-TBS to detect MD disease (P = .016). However, no difference was identified between SP/AP area ratio by ET-CS and SP amplitude value by a TT-TBS (P = .573). SP/AP area ratio by click stimulation has higher sensitivity and specificity to detect MD compared to SP amplitude value by tone burst stimulation. ECochG would be extremely useful in the diagnosis of MD if we use the SP/AP area ratio (sensitivity: 88.5%); therefore, it changes the bad reputation of ECochG sensitivity using SP/AP amplitude ratio (sensitivity: 51.7%) for the diagnosis of MD.

The Neural Correlates of Individual Differences in Reinforcement Learning during Pain Avoidance and Reward Seeking.

Organisms learn to gain reward and avoid punishment through action-outcome associations. Reinforcement learning (RL) offers a critical framework to understand individual differences in this associative learning by assessing learning rate, action bias, pavlovian factor (i.e., the extent to which action values are influenced by stimulus values), and subjective impact of outcomes (i.e., motivation to seek reward and avoid punishment). Nevertheless, how these individual-level metrics are represented in the brain remains unclear. The current study leveraged fMRI in healthy humans and a probabilistic learning go/no-go task to characterize the neural correlates involved in learning to seek reward and avoid pain. Behaviorally, participants showed a higher learning rate during pain avoidance relative to reward seeking. Additionally, the subjective impact of outcomes was greater for reward trials and associated with lower response randomness. Our imaging findings showed that individual differences in learning rate and performance accuracy during avoidance learning were positively associated with activities of the dorsal anterior cingulate cortex, midcingulate cortex, and postcentral gyrus. In contrast, the pavlovian factor was represented in the precentral gyrus and superior frontal gyrus (SFG) during pain avoidance and reward seeking, respectively. Individual variation of the subjective impact of outcomes was positively predicted by activation of the left posterior cingulate cortex. Finally, action bias was represented by the supplementary motor area (SMA) and pre-SMA whereas the SFG played a role in restraining this action tendency. Together, these findings highlight for the first time the neural substrates of individual differences in the computational processes during RL.

Assessing the motivational value of infant video clips on chimpanzees through discrimination learning task.

The motivational value of visual infant stimuli in humans is considered to encourage parental behavior. To explore the evolutionary roots of this preference for infants, we examined the reward value of conspecific infant videos compared to adult ones in nine chimpanzees. We employed a novel approach, a simultaneous discrimination task with differential sensory reinforcement. In Experiments 1 and 2, we tested if watching conspecific infant videos is more rewarding than watching adult ones. Participants were required to discriminate between two visual stimuli by a touch panel task. In video reward trials, a video clip featuring a chimpanzee infant followed a correct choice, while one featuring an adult followed an incorrect choice. However, the percentage of correct choices did not significantly differ from chance except in one chimpanzee, indicating that chimpanzees did not exhibit a preference for watching infant videos over those of adult. In Experiment 3, we tested if chimpanzees prefer conspecific videos over a blank screen; however, we did not find evidence either at a group level. These results suggest that the incentive salience of infant stimuli may not be universally compelling across species. Additionally, we discuss the limitations of the task using sensory reinforcement.

Brain state-dependent responses of midbrain dopaminergic neurons to footshock under urethane anaesthesia.

For a long time, it has been assumed that dopaminergic (DA) neurons in both the ventral tegmental area (VTA) and the substantia nigra pars compacta (SNc) uniformly respond to rewarding and aversive stimuli by either increasing or decreasing their activity, respectively. This response was believed to signal information about the perceived stimuli's values. The identification of VTA&SNc DA neurons that are excited by both rewarding and aversive stimuli has led to the categorisation of VTA&SNc DA neurons into two subpopulations: one signalling the value and the other signalling the salience of the stimuli. It has been shown that the general state of the brain can modulate the electrical activity of VTA&SNc DA neurons, but it remains unknown whether this factor may also influence responses to aversive stimuli, such as a footshock (FS). To address this question, we have recorded the responses of VTA&SNc DA neurons to FSs across cortical activation and slow wave activity brain states in urethane-anaesthetised rats. Adding to the knowledge of aversion signalling by midbrain DA neurons, we report that significant proportion of VTA&SNc DA neurons can change their responses to an aversive stimulus in a brain state-dependent manner. The majority of these neurons decreased their activity in response to FS during cortical activation but switched to increasing it during slow wave activity. It can be hypothesised that this subpopulation of DA neurons may be involved in the 'dual signalling' of both the value and the salience of the stimuli, depending on the general state of the brain.

Range adaptive value representations in schizophrenia and major depression

Anhedonia and amotivation are core symptoms of schizophrenia (SCZ) and major depressive disorder (MDD). Reward processing involves constructing and contrasting the representations for expected value (EV) and outcome value (OV) of a given stimulus, a phenomenon termed range adaptation. Impaired range adaptation can lead to anhedonia and amotivation. This study aimed to examine range adaptation in SCZ patients and MDD patients. Fifty SCZ, 46 MDD patients and 56 controls completed the Effort-based Pleasure Experience Task to measure EV and OV adaptation. SCZ and MDD patients showed altered range adaptation, albeit in different patterns. SCZ patients exhibited over-adaptation to OV and reduced adaptation to EV. By contrast, MDD patients exhibited diminished OV adaptation but intact EV adaptation. Both OV and EV adaptation were correlated with anhedonia and amotivation in SCZ and MDD. Taken together, our findings suggest that range adaptation is altered in both SCZ and MDD patients. Associations of OV and EV adaptation with anhedonia and amotivation were consistently found in SCZ and MDD patients. Impaired range adaptation in SCZ and MDD patients may be putative neural mechanisms and potential intervention targets for anhedonia and amotivation.