Analysis Of Skin Conductance Responses Research Articles

Filtering and model-based analysis independently improve skin-conductance response measures in the fMRI environment: Validation in a sample of women with PTSD

Numerous methods exist for the pre-processing and analysis of skin-conductance response (SCR) data, but there is incomplete consensus on suitability and implementation, particularly with regard to signal filtering in conventional peak score (PS) analysis. This is particularly relevant when SCRs are measured during fMRI, which introduces additional noise and signal variability. Using SCR-fMRI data (n = 65 women) from a fear conditioning experiment, we compare the impact of three nested data processing methods on analysis using conventional PS as well as psychophysiological modeling. To evaluate the different methods, we quantify effect size to recover a benchmark contrast of interest, namely, discriminating SCR magnitude to a conditioned stimulus (CS+) relative to a CS not followed by reinforcement (CS-). Findings suggest that low-pass filtering reduces PS sensitivity (Δd = −20%), while band-pass filtering improves PS sensitivity (Δd = +27%). We also replicate previous findings that a psychophysiological modeling approach yields superior sensitivity to detect contrasts of interest than even the most sensitive PS method (Δd = +110%). Furthermore, we present preliminary evidence that filtering differences may account for a portion of exclusions made on commonly applied metrics, such as below zero discrimination. Despite some limitations of our sample and experimental design, it appears that SCR processing pipelines that include band-pass filtering, ideally with model-based SCR quantification, may increase the validity of SCR response measures, maximize research productivity, and decrease sampling bias by reducing data exclusion.

Detailed analysis of skin conductance responses during a gambling task: Decision, anticipation, and outcomes.

Physiological arousal is considered a key factor of gambling behavior. Hence, to understand gambling behavior it is important to study the arousal responses during gambling. Moreover, crucial mechanisms of action could be uncovered by detailing the situations that produce an arousal response. A gamble, or bet, can be partitioned into three distinct phases: (a) decision phase, during which the information concerning the gamble is presented, outcomes are appraised, and a decision is made on how to gamble; (b) anticipation phase, during which the result of the gamble is awaited; (c) outcome phase, during which the outcome of the gamble is presented. Previous research on arousal responses to gambling have mostly measured tonic changes in arousal, and when phasic responses have been measured, analyses have generally concentrated on one of the gamble phases. The aim of the present study was to map the arousal responses during gambling in more detail by measuring skin conductance responses (SCRs) during all three gamble phases of a simple card game. The anticipation phase was found to produce the largest arousal response, suggesting anticipation to be a major contributor to arousal during gambling behavior. Risk behavior during the gambling task was mirrored in self-reported risk taking in everyday life, and risk-takers displayed smaller SCRs compared to nonrisk-takers during decision making, suggesting this as a possible biomarker for risk-taking individuals.

Automatic credibility assessment screening using discriminate analysis of skin conductance response and photoplethysmograph signals

Automatic credibility assessment screening using discriminate analysis of skin conductance response and photoplethysmograph signals

Analysis of skin conductance response during evaluation of preferences for cosmetic products.

We analyzed skin conductance response (SCR) as a psychophysiological index to evaluate affective aspects of consumer preferences for cosmetic products. To examine the test-retest reliability of association between preferences and SCR, we asked 33 female volunteers to complete two experimental sessions approximately 1 year apart. The participants indicated their preferences in a typical paired comparison task by choosing the better option from a combination of two products among four products. We measured anticipatory SCR prior to expressions of the preferences. We found that the mean amplitude of the SCR elicited by the preferred products was significantly larger than that elicited by the non-preferred products. The participants' preferences and corresponding SCR patterns were well preserved at the second session 1 year later. Our results supported cumulating findings that SCR is a useful index of consumer preferences that has future potential, both in laboratory and marketing settings.

A head-to-head comparison of SCRalyze and Ledalab, two model-based methods for skin conductance analysis

Model-based analysis of skin conductance responses (SCR) can furnish less noisy estimates of sympathetic arousal (SA) than operational peak scoring approaches, as shown in previous work. Here, I compare two model-based methods for analysis of evoked (stimulus-locked) SCR, implemented in two software packages, SCRalyze and Ledalab, with respect to their sensitivity in recovering SA. Four datasets are analysed to compare predictive validity, i.e. the sensitivity to distinguish pairs of SA states that are known to be different. SCRalyze was significantly better able than Ledalab to recover this known difference in four out of five tested contrasts and comparable in the remaining one. SCRalyze performed significantly better than conventional analysis in all contrasts. I conclude that the model-based method engendered in SCRalyze is currently the best available approach to provide robust and sensitive estimates of sympathetic arousal.

Problem gamblers are hyposensitive to wins: An analysis of skin conductance responses during actual gambling on electronic gaming machines

Physiological arousal is purportedly a key determinant in the development and maintenance of gambling behaviors, with problem gambling conceptualized in terms of abnormal autonomic responses. Theoretical conceptualizations of problem gambling are discordant regarding the nature of deficit in this disorder; some accounts posit that problem gamblers are hypersensitive to reward, and others that they are hyposensitive to reward and/or punishment. Previous research examining phasic electrodermal responses in gamblers has been limited to laboratory settings, and reactions to real gaming situations need to be examined. Skin conductance responses (SCRs) to losses, wins, and losses disguised as wins (LDWs) were recorded from 15 problem gamblers (PGs) and 15 nonproblem gamblers (NPGs) while they wagered their own money during electronic gaming machine play. PGs demonstrated significantly reduced SCRs to reward. SCRs to losses and LDWs did not differ for either PGs or NPGs. This hyposensitivity to wins may reflect abnormalities in incentive processing, and may represent a potential biological marker for problem gambling.

Model‐based analysis of skin conductance responses: Towards causal models in psychophysiology

The empirical investigation of unobservable psychological processes usually rests on operational definitions. As an alternative, we propose the use of explicit causal models. This is particularly useful in psychophysiology, where formal models can be expressed mathematically, exploiting biophysical constraints, and inverted to yield estimates of unobservable processes. In psychophysiology, recent advances have been made in causal modeling for skin conductance responses, which we discuss to exemplify the development of such models. Empirical evidence suggests that these methods have a greater validity compared to operational approaches. This review concludes by considering the theoretical implications for the field of psychophysiology and benefits for practical data analysis.

Modelling event-related skin conductance responses

Analytic tools for psychophysiological signals often make implicit assumptions that are unspecified. In developing a mathematical framework for analysis of skin conductance responses [SCRs], we formalise our assumptions by positing that SCRs can be regarded as the output of a linear time-invariant filter. Here, we provide an empirical test of these assumptions. Our findings indicate that a large component of the variance in SCRs can be explained by one response function per individual. We note that baseline variance (i.e. variance in the absence of evoked responses) is higher than variance that could not be explained by a linear time-invariant model of evoked responses. Furthermore, there was no evidence for nonlinear interactions among evoked responses that depended on their temporal overlap. We develop a canonical response function and show that it can be used for signals from different recording sites. We discuss the implications of these observations for model-based analysis of SCRs.

Physiologic correlates of direct and averted gaze

The present study was designed to explore the effects of reciprocated and unreciprocated gaze upon skin conductance and heart rate response. A paradigm used previously to investigate maternal response to infant gaze was selected which allowed us to consider possible order effects, sex differences and differential rates of habituation in response to direct and averted gaze. Twenty-four males and 24 females were shown 10 sec silent images of an adult face on a videotape monitor of an adult face. In one condition, the en face position offered eye contact; in the other condition, eye contact was not possible. Each subject viewed a sequence of six identical episodes of one condition followed by six episodes of the other condition. Analysis of skin conductance response revealed a significant effect of stimulus sex ( p < 0.05) with the male stimulus figures eliciting the greater skin conductance response. HR responses to the two conditions varied not only as a function of stimulus sex but also as a function of the viewer's sex. The most distinctive data came from a male viewing another male. For this group alone, responding was consistent to unreciprocated gaze viewed first ( p < 0.01) and viewed second ( p < 0.05); and for this group alone responding to reciprocated gaze viewed first habituated ( p < 0.05).