Stimulus-response Pairs Research Articles

A compressive sensing approach for inferring cognitive representations with reverse correlation

Uncovering cognitive representations is an elusive goal that is increasingly pursued using the reverse correlation method, wherein human subjects make judgments about ambiguous stimuli. Employing reverse correlation often entails collecting thousands of stimulus-response pairs, which severely limits the breadth of studies that are feasible using the method. Current techniques to improve efficiency bias the outcome. Here we show that this methodological barrier can be diminished using compressive sensing, an advanced signal processing technique designed to improve sampling efficiency. Simulations are performed to demonstrate that compressive sensing can improve the accuracy of reconstructed cognitive representations and dramatically reduce the required number of stimulus-response pairs. Additionally, compressive sensing is used on human subject data from a previous reverse correlation study, demonstrating a dramatic improvement in reconstruction quality. This work concludes by outlining the potential of compressive sensing to improve representation reconstruction throughout the fields of psychology, neuroscience, and beyond.

AMITE: A Novel Polynomial Expansion for Analyzing Neural Network Nonlinearities.

Polynomial expansions are important in the analysis of neural network nonlinearities. They have been applied thereto addressing well-known difficulties in verification, explainability, and security. Existing approaches span classical Taylor and Chebyshev methods, asymptotics, and many numerical approaches. We find that, while these have useful properties individually, such as exact error formulas, adjustable domain, and robustness to undefined derivatives, there are no approaches that provide a consistent method, yielding an expansion with all these properties. To address this, we develop an analytically modified integral transform expansion (AMITE), a novel expansion via integral transforms modified using derived criteria for convergence. We show the general expansion and then demonstrate an application for two popular activation functions: hyperbolic tangent and rectified linear units. Compared with existing expansions (i.e., Chebyshev, Taylor, and numerical) employed to this end, AMITE is the first to provide six previously mutually exclusive desired expansion properties, such as exact formulas for the coefficients and exact expansion errors. We demonstrate the effectiveness of AMITE in two case studies. First, a multivariate polynomial form is efficiently extracted from a single hidden layer black-box multilayer perceptron (MLP) to facilitate equivalence testing from noisy stimulus-response pairs. Second, a variety of feedforward neural network (FFNN) architectures having between three and seven layers are range bounded using Taylor models improved by the AMITE polynomials and error formulas. AMITE presents a new dimension of expansion methods suitable for the analysis/approximation of nonlinearities in neural networks, opening new directions and opportunities for the theoretical analysis and systematic testing of neural networks.

Grounding Mental Representations in a Virtual Multi-Level Functional Framework.

According to the associative theory of learning, reactive behaviors described by stimulus-response pairs result in the progressive wiring of a plastic brain. In contrast, flexible behaviors are supposedly driven by neurologically grounded mental states that involve computations on informational contents. These theories appear complementary, but are generally opposed to each other. The former is favored by neuro-scientists who explore the low-level biological processes supporting cognition, and the later by cognitive psychologists who look for higher-level structures. This situation can be clarified through an analysis that independently defines abstract neurological and informational functionalities, and then relate them through a virtual interface. This framework is validated through a modeling of the first stage of Piaget's cognitive development theory, whose reported end experiments demonstrate the emergence of mental representations of object displacements. The neural correlates grounding this emergence are given in the isomorphic format of an associative memory. As a child's exploration of the world progresses, his mental models will eventually include representations of space, time and causality. Only then epistemological concepts, such as beliefs, will give rise to higher level mental representations in a possibly richer propositional format. This raises the question of which additional neurological functionalities, if any, would be required in order to include these extensions into a comprehensive grounded model. We relay previously expressed views, which in summary hypothesize that the ability to learn has evolved from associative reflexes and memories, to suggest that the functionality of associative memories could well provide the sufficient means for grounding cognitive capacities.

Spatial summation of cold and warm detection: Evidence for increased precision when brisk stimuli are delivered over larger area

Cold and warm stimuli delivered over a larger skin area tend to be more easily detected/elicit stronger sensations, a phenomenon referred to as spatial summation. The aim of the present study was to clarify how stimulation area affects thermal detection processes by evaluating whether increasing the stimulation area simply reduces the detection threshold or also reduces the uncertainty of the detection process.Psychometric functions were fitted to the detection performance of 16 healthy subjects. Stimuli (duration: 200 ms; rate of change: 300 °C/s) were delivered to the volar forearm using a Peltier-effect contact thermode and three different stimulation surfaces (23 mm2, 69 mm2, and 116 mm). Stimulation intensities were selected trial-by-trial by the psi marginal method to optimize estimation of slope and threshold parameters of the psychometric function. The raw data (100 stimulus–response pairs per subject per surface and per modality) was used to fit group-level hierarchical models of cold and warm detection, allowing to assess the effect of stimulation surface and account for inter-individual variability.Increasing stimulation area led to a compression of the psychometric function towards baseline skin temperature (reduced threshold and steeper slope), suggesting that spatial summation reflects a change in the precision of the neural representation of the stimulus which in turn influences the ability of the nervous system to distinguish true stimuli from sensory noise. Regardless of area, with the stimulation settings used in this study, cold detection appeared easier than warm detection, possibly because of structural and functional differences between cold- and warm-sensitive afferents.

Visualization of Speech Perception Analysis via Phoneme Alignment: A Pilot Study.

Objective: Speech tests assess the ability of people with hearing loss to comprehend speech with a hearing aid or cochlear implant. The tests are usually at the word or sentence level. However, few tests analyze errors at the phoneme level. So, there is a need for an automated program to visualize in real time the accuracy of phonemes in these tests.Method: The program reads in stimulus-response pairs and obtains their phonemic representations from an open-source digital pronouncing dictionary. The stimulus phonemes are aligned with the response phonemes via a modification of the Levenshtein Minimum Edit Distance algorithm. Alignment is achieved via dynamic programming with modified costs based on phonological features for insertion, deletions and substitutions. The accuracy for each phoneme is based on the F1-score. Accuracy is visualized with respect to place and manner (consonants) or height (vowels). Confusion matrices for the phonemes are used in an information transfer analysis of ten phonological features. A histogram of the information transfer for the features over a frequency-like range is presented as a phonemegram.Results: The program was applied to two datasets. One consisted of test data at the sentence and word levels. Stimulus-response sentence pairs from six volunteers with different degrees of hearing loss and modes of amplification were analyzed. Four volunteers listened to sentences from a mobile auditory training app while two listened to sentences from a clinical speech test. Stimulus-response word pairs from three lists were also analyzed. The other dataset consisted of published stimulus-response pairs from experiments of 31 participants with cochlear implants listening to 400 Basic English Lexicon sentences via different talkers at four different SNR levels. In all cases, visualization was obtained in real time. Analysis of 12,400 actual and random pairs showed that the program was robust to the nature of the pairs.Conclusion: It is possible to automate the alignment of phonemes extracted from stimulus-response pairs from speech tests in real time. The alignment then makes it possible to visualize the accuracy of responses via phonological features in two ways. Such visualization of phoneme alignment and accuracy could aid clinicians and scientists.

Expanding dual-task research by a triple-task

Abstract Multitasking research in the laboratory is dominated by extremely simplistic dual-task paradigms. Although dual-tasks allow for some variations, they do not compare well to more complex everyday task settings. This study expands a classical dual-task paradigm by adding a third task. The dual-tasks and the triple-task always consisted of the same three single tasks. The aim was to investigate the effects of the combinations of the three single-tasks and in which manner response times and costs increased. Stimulus-response pairings were varied either once within participants (E1) or between participants (E2). Our results showed that the increase in response time from dual-tasks to triple-tasks was only 43% of the increase from single-tasks to dual-tasks suggesting a non-linear cost of adding tasks. Moreover, response times in each subtask were higher in triple-task situations compared to single-task or dual-task situations. This is in contrast to classical dual-tasks, in which typically only one of the two responses is delayed. Cognitively, for costs in triple-tasks, unlike in dual-tasks, task coordination seems to play a larger role compared to the classically suggested relationships between stimulus and response in terms of their modality- and ideomotor-compatibility which we will discuss. Overall, the study demonstrates that current multitasking research is limited in its generalizability by focusing only on dual-tasks and would benefit from research with more complex task settings.

Combined Evaluation of Nociceptive Detection Thresholds and Evoked Potentials during Conditioned Pain Modulation: A Feasibility Study.

Deficient top-down inhibitory control via diffuse noxious inhibitory control (DNIC) is a mechanism known to be responsible for the maintenance and development in several chronic pain syndromes. Experimentally, DNIC is often induced by conditioned pain modulation (CPM) paradigms such as a Cold Pressor Test (CPT). Recently, a method called the NDT-EP method has been developed with the aim to evaluate the nociceptive function, which it does via simultaneous tracking of nociceptive detection thresholds (NDT) and evoked potentials (EP). It remains to be investigated whether we can evaluate DNIC via the NDT-EP method. In this study, we take the first step to investigate this by evaluating the feasibility to combine the NDT-EP method with a 7 minutes CPT. In total 20 participants of a wide age-range were measured before, during, and after a CPT. All except 1 participant were able to complete the protocol, and enough stimulus-response pairs could be obtained for psychophysical as well as electrophysiological evaluation. Preliminary analysis of the NDT's and EP's showed results in line with earlier research such as a higher threshold for nociceptive stimuli and a lower EP amplitudes. Several NDT's of mostly elderly people (59±16 years), however, exceeded the maximum applicable stimulus strength during (7/20) or after (9/20) CPT and consequently had to be excluded from the analysis. To what extent this is a consequence of the CPT or other factors such as strong habituation associated more with elderly people, is subject to further investigation. In conclusion, the results of this study show that with the present protocol, it is feasible to combine the NDT-EP method with a CPM paradigm in almost all subjects, but that the NDT data of mostly older subjects could not be properly analyzed. Further directions for research and improvements are outlined.

Multiplicative priming of the correct response can explain the interaction between Simon and flanker congruency.

In the Simon task, participants perform a decision on non-spatial features (e.g., stimulus color) by responding with a left or right key-press to a stimulus presented on the left or right side of the screen. In the flanker task, they classify the central character while ignoring the flanking characters. In each task, there is a conflict between the response-relevant features and the response-irrelevant features (i.e., the location on the screen for the Simon task, and the flankers for the flanker task). Thus, in both tasks, resolving conflict requires to inhibit irrelevant features and to focus on relevant features. When both tasks were combined within the same trial (e.g., when the row of characters was presented on the left or right side of the screen), most previous research has shown an interaction. In the present study, we investigated whether this interaction is affected by a multiplicative priming of the correct response occurring when both Simon and flanker irrelevant features co-activate the correct response (Exp. 1), a spatial overlap between Simon and flanker features (Exp. 2), and the learning of stimulus-response pairings (Exp. 3). The results only show an impact of multiplicative priming.

Vicarious Value Learning: Knowledge transfer through affective processing on a social differential outcomes task

The findings of differential outcomes training procedures in controlled stimulus-response learning settings have been explained through theorizing two processes of response control. These processes concern: i) a stimulus-response route, and, ii) an outcome expectancy route through which valuations of stimuli (typically auditory or visual) may be represented. Critically, under certain contingencies of learning, the interaction of these two processes enables a transfer of knowledge. Transfer is hypothesized to occur via implicit inference for response selection given novel stimulus-response pairings. In this article, we test this transfer of knowledge, previously only examined in individual settings, in novel social settings. We find that participants are able to achieve transfer of knowledge and suggest they achieve this through vicariously learning the differential valuations of stimuli made by the (confederate) ‘other’ involved in the task. We test this effect under two experimental conditions through manipulation of the information made available to participants observing the confederate other's choices. The results of EEG recordings are, additionally, evaluated and discussed in the context of social signalling and emotional and cognitive empathy. We also consider implications for clinical and technological social learning settings.

No evidence for automatic response activation with target onset in the avatar-compatibility task

When people take the perspective of an avatar and perform a stimulus-response compatibility task, they generally show the same compatibility effects that are expected from the avatar’s position instead of their own. In this study, we investigated if these effects are caused by automatic response activation, a concept featured in dual-route models of stimulus-response compatibility. In two experiments we asked 24 participants each to perform a compatibility task from an avatar’s point of view. We introduced a delay between the presentation of the target and the avatar in half of the trials so that the participants had to wait until the avatar appeared to select the correct response. Because the automatic response activation is known to decay quickly, its influence is eliminated in this condition. In contrast to the prediction by the automatic response activation account, we observed a larger compatibility effect in the delayed condition with orthogonal (Experiment 1) and parallel (Experiment 2) stimulus-response pairings. Additionally, distributional analyses of the compatibility effects did not support the automaticity predictions. We conclude that these results call into question the role of automatic response activation for spatial compatibility in general and perspective-based compatibility effects in particular.

Task representation affects the boundaries of behavioral slowing following an error.

Researchers have recognized the role that task representation plays in our behavior for many years. However, the specific influence that the structure of one's task representation has on executive functioning has only recently been investigated. Prior research suggests that adjustments of cognitive control are affected by subtle manipulations of aspects of the stimulus-response pairs within and across task sets. This work has focused on examples of cognitive control such as response preparation, dual-task performance, and the congruency sequence effect. The current study investigates the effect of task representation on another example of control, post-error slowing. To determine if factors that influence how people represent a task affect how behavior is adjusted after an error, an adaptive attention-shifting task was developed with multiple task delimiting features. Participants were randomly assigned to a separate task set (two task sets) or an integrated task set (one task set) group. For the separate set group, the task sets switched after each trial. Results showed that only the integrated set group exhibited post-error slowing. This suggests that task representation influences the boundaries of cognitive control adjustments and has implications for our understanding of how control is organized when adjusting to errors in performance.

Dual-task interference and response strategies in simulated car driving: impact of first-task characteristics on the psychological refractory period effect.

Presentation of a task T1 typically delays the response to a subsequent task T2, more so with high temporal task overlap than with low temporal overlap. This so-called "psychological refractory period effect" (PRP effect) has been observed even if T1 required not a choice between distinct stimulus-response pairs, but rather between a given stimulus-response pair occurring once or twice. We explored which response strategy participants use for responding to such an unusual type of T1 and how such a T1 interacts with T2 performance. In a driving simulator, participants followed a lead car and had to honk when that car's rear window changed color (T1). In condition "pure", the color always changed once and required a single honk; in condition "mixed", the color changed once and required a single honk on some trials, but on other trials, it changed twice 200ms apart and required a double honk. Participants also had to brake when the lead car braked (T2). On dual-task trials, T1 preceded T2 with a varying stimulus onset asynchrony (SOA) of 50-1200ms. Reaction time to the first T1 stimulus was similar in "pure" and "mixed" and it was comparable with the reaction time to the second T1 stimulus. Reaction time to the T2 stimulus increased as SOA decreased from 350 to 50ms, confirming the existence of a PRP effect. Furthermore, reaction time to the T2 stimulus was similar in "pure" and in "mixed" with one T1 stimulus, but was higher in "mixed" with two T1 stimuli. This pattern of findings is compatible with the view that presentation of the first T1 stimulus triggers a single response, which is amended into a double response, if a second T1 stimulus is displayed. The amendment does not need to wait until central processing of the original response is completed, and it therefore begins with no delay beyond the regular reaction time. Our findings further suggest that the mere possibility of a second T1 stimulus being presented does not increase the PRP effect on T2, probably because response amendments are not equivalent to classical response choices. However, the actual presentation of a second T1 stimulus indeed does increase the PRP effect on T2, probably because amendments start 200ms later than the original response, and therefore prolong central processing of T1.

Separation of Tasks Into Distinct Domains, Not Set-Level Compatibility, Minimizes Dual-Task Interference.

Dual-task costs are often significantly reduced or eliminated when both tasks use compatible stimulus-response (S-R) pairs. Either by design or unintentionally, S-R pairs used in dual-task experiments that produce small dual-task costs typically have two properties that may reduce dual-task interference. One property is that they are easy to keep separate; specifically, one task is often visual-spatial and contains little verbal information and the other task is primarily auditory-verbal and has no significant spatial component. The other property is that the two sets of S-R pairs are often compatible at the set-level; specifically, the collection of stimuli for each task is strongly related to the collection of responses for that task, even if there is no direct correspondence between the individual items in the sets. In this paper, we directly test which of these two properties is driving the absence of large dual-task costs. We used stimuli (images of hands and auditory words) that when previously been paired with responses (button presses and vocal utterances) produced minimal dual-task costs, but we manipulated the shape of the hands in the images and the auditory words. If set-level compatibility is driving efficient performance, then these changes should not affect dual-task costs. However, we found large changes in the dual-task costs depending on the specific stimuli and responses. We conclude that set-level compatibility is not sufficient to minimize dual-task costs. We connect these findings to divisions within the working memory system and discuss implications for understanding dual-task performance more broadly.

Dissociation of binding and learning processes.

A single encounter of a stimulus together with a response can result in a short-lived association between the stimulus and the response [sometimes called an event file, see Hommel, Müsseler, Aschersleben, & Prinz, (2001) Behavioral and Brain Sciences, 24, 910-926]. The repetition of stimulus-response pairings typically results in longer lasting learning effects indicating stimulus-response associations (e.g., Logan & Etherton, (1994) Journal of Experimental Psychology: Learning, Memory, and Cognition, 20, 1022-1050]. An important question is whether or not what has been described as stimulus-response binding in action control research is actually identical with an early stage of incidental learning (e.g., binding might be seen as single-trial learning). Here, we present evidence that short-lived binding effects can be distinguished from learning of longer lasting stimulus-response associations. In two experiments, participants always responded to centrally presented target letters that were flanked by response irrelevant distractor letters. Experiment 1 varied whether distractors flanked targets on the horizontal or vertical axis. Binding effects were larger for a horizontal than for a vertical distractor-target configuration, while stimulus configuration did not influence incidental learning of longer lasting stimulus-response associations. In Experiment 2, the duration of the interval between response n - 1 and presentation of display n (500 ms vs. 2000 ms) had opposing influences on binding and learning effects. Both experiments indicate that modulating factors influence stimulus-response binding and incidental learning effects in different ways. We conclude that distinct underlying processes should be assumed for binding and incidental learning effects.

Pre-transplant mental health disorders and non-adherence and post-transplant outcomes in kidney transplant recipients

The findings of differential outcomes training procedures in controlled stimulus-response learning settings have been explained through theorizing two processes of response control. These processes concern: i) a stimulus-response route, and, ii) an outcome expectancy route through which valuations of stimuli (typically auditory or visual) may be represented. Critically, under certain contingencies of learning, the interaction of these two processes enables a transfer of knowledge. Transfer is hypothesized to occur via implicit inference for response selection given novel stimulus-response pairings. In this article, we test this transfer of knowledge, previously only examined in individual settings, in novel social settings. We find that participants are able to achieve transfer of knowledge and suggest they achieve this through vicariously learning the differential valuations of stimuli made by the (confederate) ‘other’ involved in the task. We test this effect under two experimental conditions through manipulation of the information made available to participants observing the confederate other's choices. The results of EEG recordings are, additionally, evaluated and discussed in the context of social signalling and emotional and cognitive empathy. We also consider implications for clinical and technological social learning settings.

Extracting multidimensional stimulus-response correlations using hybrid encoding-decoding of neural activity

In neuroscience, stimulus-response relationships have traditionally been analyzed using either encoding or decoding models. Here we propose a hybrid approach that decomposes neural activity into multiple components, each representing a portion of the stimulus. The technique is implemented via canonical correlation analysis (CCA) by temporally filtering the stimulus (encoding) and spatially filtering the neural responses (decoding) such that the resulting components are maximally correlated. In contrast to existing methods, this approach recovers multiple correlated stimulus-response pairs, and thus affords a richer, multidimensional analysis of neural representations. We first validated the technique’s ability to recover multiple stimulus-driven components using electroencephalographic (EEG) data simulated with a finite element model of the head. We then applied the technique to real EEG responses to auditory and audiovisual narratives experienced identically across subjects, as well as uniquely experienced video game play. During narratives, both auditory and visual stimulus-response correlations (SRC) were modulated by attention and tracked inter-subject correlations. During video game play, SRC varied with game difficulty and the presence of a dual task. Interestingly, the strongest component extracted for visual and auditory features of film clips had nearly identical spatial distributions, suggesting that the predominant encephalographic response to naturalistic stimuli is supramodal. The diversity of these findings demonstrates the utility of measuring multidimensional SRC via hybrid encoding-decoding.

Chrysippus's pigeon: Exclusion-based responding in an avian model.

Inference by exclusion can be exhibited by deductively responding to new stimuli that are presented in the context of familiar stimuli. We investigated exclusion-based responding in pigeons using a 2-alternative forced-choice discrimination task. In Phase 1, pigeons learned to associate 2 stimuli (A and B) with Response 1 and 2 stimuli (C and D) with Response 2. Following successful acquisition of these stimulus-response pairings, pigeons advanced to Phase 2, in which stimuli A and B were now reassigned to Response 2. Based on their Phase 1 training, pigeons should initially choose Response 1 when presented with A and B in Phase 2 (this response is now incorrect, but the birds would not yet have had the opportunity to learn the new stimulus-response associations). Also, in Phase 2, stimuli E and F-new stimuli replacing stimuli C and D-were concurrently presented and assigned to Response 1. Without prior training, pigeons' initial responding to E and F in Phase 2 should be at chance. However, if the pigeons were to apply an exclusion rule (stimuli E and F stand in opposition to stimuli A and B), then they might initially choose Response 2 for new stimuli E and F because they are concurrently choosing Response 1 for stimuli A and B. If that is the case, then choice accuracy for stimuli E and F should also be below chance. Indeed, our pigeons responded at reliably below chance levels to stimuli E and F, consistent with their exhibiting an exclusion rule-based strategy, which could actually arise from a more mechanical underlying process such as acquired equivalence formation. (PsycINFO Database Record

ターゲットに対する反応回数は遂行成績並びに視覚的注意に影響するのか

Visual attention refers to cognitive functions for selecting task-relevant information and filtering out task-irrelevant information. Psychological research on visual attention has utilized congruency effects observed in Stimulus-Response compatibility paradigms, such as the Stroop task, the Flanker task, and the Simon task as the benchmark for investigating cognitive control. A number of studies (e.g., Egner, 2007) have demonstrated that the congruency effect is larger when congruent trials appear frequently within a given block than when they appear infrequently. This phenomenon is termed the proportion congruency (PC) effect, which is considered to reflect fluctuations in visual selectivity. Recently, however, a number of researchers have challenged the view that the PC effect reflects the modulation of visual selectivity. Schmidt (2013) for example argued that the PC effect is driven by performance improvements based on learning predictive relationships between stimuli and responses, rather than by the modulation of visual selectivity. It is notably unclear whether performance improvements are caused by increased contingency of a specific stimulus-response, or high response frequency resulting from the increased contingency in a block. This study was designed to examine the effect of response frequency on Simon task performance by manipulating the number of responses (pushing response buttons) to a target in the Simon task. More specifically, right-handed undergraduate and graduate students (N = 16) were requested to press a key once for a specific target (e.g., red circle) and press the key twice for the other target (e.g., green circle). Our results demonstrated that reaction times and error rates were not dependent on the number of reactions. This finding suggests that performance improvement is caused by contingency learning of stimulus-response pairs and not by the high response frequency.

Automatized smoking-related action schemata are reflected by reduced fMRI activity in sensorimotor brain regions of smokers.

In the later stages of addiction, automatized processes play a prominent role in guiding drug-seeking and drug-taking behavior. However, little is known about the neural correlates of automatized drug-taking skills and drug-related action knowledge in humans. We employed functional magnetic resonance imaging (fMRI) while smokers and non-smokers performed an orientation affordance task, where compatibility between the hand used for a behavioral response and the spatial orientation of a priming stimulus leads to shorter reaction times resulting from activation of the corresponding motor representations. While non-smokers exhibited this behavioral effect only for control objects, smokers showed the affordance effect for both control and smoking-related objects. Furthermore, smokers exhibited reduced fMRI activation for smoking-related as compared to control objects for compatible stimulus-response pairings in a sensorimotor brain network consisting of the right primary motor cortex, supplementary motor area, middle occipital gyrus, left fusiform gyrus and bilateral cingulate gyrus. In the incompatible condition, we found higher fMRI activation in smokers for smoking-related as compared to control objects in the right primary motor cortex, cingulate gyrus, and left fusiform gyrus. This suggests that the activation and performance of deeply embedded, automatized drug-taking schemata employ less brain resources. This might reduce the threshold for relapsing in individuals trying to abstain from smoking. In contrast, the interruption or modification of already triggered automatized action representations require increased neural resources.

Estimation and Identifiability of Model Parameters in Human Nociceptive Processing Using Yes-No Detection Responses to Electrocutaneous Stimulation.

Healthy or pathological states of nociceptive subsystems determine different stimulus-response relations measured from quantitative sensory testing. In turn, stimulus-response measurements may be used to assess these states. In a recently developed computational model, six model parameters characterize activation of nerve endings and spinal neurons. However, both model nonlinearity and limited information in yes-no detection responses to electrocutaneous stimuli challenge to estimate model parameters. Here, we address the question whether and how one can overcome these difficulties for reliable parameter estimation. First, we fit the computational model to experimental stimulus-response pairs by maximizing the likelihood. To evaluate the balance between model fit and complexity, i.e., the number of model parameters, we evaluate the Bayesian Information Criterion. We find that the computational model is better than a conventional logistic model regarding the balance. Second, our theoretical analysis suggests to vary the pulse width among applied stimuli as a necessary condition to prevent structural non-identifiability. In addition, the numerically implemented profile likelihood approach reveals structural and practical non-identifiability. Our model-based approach with integration of psychophysical measurements can be useful for a reliable assessment of states of the nociceptive system.