The purpose of this research study was to explore the impact of virtual character design on user emotional experience and user behavior in a simulated environment. With simulation training increasing in popularity as a tool for teaching social skills, it is essential that social interactions in virtual environments provide authentic opportunities for practice (Swartout et al., 2006). This study used Interactive Performance Theory (Wirth, 2012) to examine the effect of designing a virtual buddy character with ineffective traits instead of effective or expert traits. The sample population for this study (n = 145) consisted of first year university students enrolled in courses in the fall of 2013 at the University of Central Florida. Data on participant emotional experience and behavior were collected through questionnaires, researcher observations, and physiological signal recording that included participant heart rate and galvanic skin response. Data were analyzed using multivariate analysis of variances (MANOVA), Kruskal-Wallis one-way analysis of variance, and qualitative thematic coding of participant verbal behavior and written responses. Results of the analysis revealed that participants who interacted with an ineffective virtual buddy character had statistically significant higher averages of verbal statements to the antagonist in the simulated environment and statistically significant lower perceptions of antagonist amiability than participants who interacted with an effective virtual buddy. Additionally, participants who interacted with a virtual buddy of the opposite gender gave statistically significant higher ecological validity scores to the simulated environment than participants who interacted with a virtual buddy of the same gender. Qualitative analysis also revealed that participants tended to describe the female buddy character with more ineffective traits than the male buddy character even though effective and ineffective design conditions were equally divided for both groups. Further research should be conducted on the effect of virtual buddy character design in different types of simulation environments and with different target audiences.

Erythema is a hallmark skin response to excessive ultraviolet radiation (UVR) and is associated with cutaneous inflammation. Both are mediated by inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2) and chemoattractants such as 12-hydroxyeicosatetraenoic acid (12-HETE) leading to vasodilation and increased leukocyte infiltration. The erythematous response is more pronounced in individuals with low basal melanin levels or who fail to respond to UVR with a robust up-regulation of melanogenesis. While melanin production is a key function of melanocytes, these cells can also produce NO and PGE2, and are located in close proximity to the dermal vasculature. It has been hypothesized that melanocytes with poor melanogenic capacity may participate in the inflammatory response to UVR. The aim of this project was to investigate the inflammatory response in the skin of individuals with either skin phototype (SPT) 1 or 4 to UVR. Sixteen normal healthy individuals were selected for study (8 SPT-1 & 8 SPT-4). Buttock skin was investigated by immunohistochemistry for leukocyte subtypes, eicosanoid producing enzymes and NO synthases under basal and UVR-stimulated conditions. In addition primary cultures of epidermal melanocytes (EM) were established from 16 individuals (8 SPT-1 & 8 SPT-4) and assessed for the presence of eicosanoid-producing enzymes, melanogenic enzymes and NO synthases, by immunocytochemistry, Polymerase Chain Reaction and Western Blotting and for the production of the main pro-inflammatory eicosanoid PGE2 by ELISA and Mass Spectrometry. Moreover, the fatty acid composition of cultured melanocytes was assessed by Gas Chromatography. Results showed that individuals with SPT-1 had significantly greater neutrophil infiltration into the epidermis than those with SPT-4 at 24 hrs post-UVR. Moreover, CD3+ lymphocyte infiltration into the dermis was significantly greater in individuals with SPT-4 than those with SPT-1 at 24 and 72 hrs post-UVR. NOS-1, NOS-3, 12-LOX and COX-2 expression were significantly increased in SPT-1 skin, while NOS-2 and 15-LOX were significantly increased in SPT-4 skin. As 12-LOX and COX-2 products are chemoattractive (for neutrophils) and pro-inflammatory respectively these data could explain the greater observed neutrophil infiltration in SPT-1. The 15-LOX product (15-HETE) is anti-inflammatory and may suggest that 15-LOX up-regulation in SPT-4 skin may aid resolution of the sunburn response, which in part may be mediated by CD3+ lymphocytes and a class-switch in eicosanoid production from COX to LOX products. Melanocyte primary cultures surprisingly showed that SPT was not correlated with melanin content or melanogenic enzyme expression/activity suggesting that all melanocytes in vitro contained the necessary cellular machinery to produce melanin. This finding may reflect also their equal treatment under these enriched culture conditions, which may or may not be available to these cells in situ. Moreover, all melanocytes expressed the necessary machinery (PLA2, COX-1, cPGES) to produce PGE2. However, only some cultures did so at baseline and in response to UVR, and this was not correlated with SPT. A positive correlation was found however between expression level of dopachrome tautomerase (DCT) and protection against PGE2 production in response to UVR, which may suggest a novel role for DCT unrelated to melanogenesis. In summary this research project has generated data that highlights differences between the skin of individuals with SPT-1 and those with SPT-4, and may provide evidence that the keratinocyte partner contributes significantly to the SPT-associated response. This research may also suggest DCT as a novel therapeutic target to protect EM from participation in the UVR-associated inflammatory response in skin.

Thesis (MSc. (Human Physiology, Faculty of Health Sciences))--University of Pretoria, 2008. / Summary in English. Includes bibliographical references.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 5 uppsatser.

Tesis por compendio / [ES] Comprender el comportamiento humano en situaciones de riesgo, cómo los factores individuales y externos influyen en nuestras decisiones y en qué medida es posible influir y modificar nuestros comportamientos, constituye un desafío tanto para los científicos como para la sociedad en general. Desde la perspectiva de la Seguridad y Salud en el Trabajo (SST), así como en numerosos campos como la sociología y las finanzas, este tema tiene importantes implicaciones ya que las situaciones de riesgo son un aspecto común en diversos ámbitos de nuestra vida. La toma de riesgos (TR) es parte del proceso de toma de decisiones en situaciones de incertidumbre, en las que se conoce de antemano la probabilidad de cada consecuencia positiva o negativa. Si bien el concepto de la TR está bien definido en la literatura, se ha abordado desde diferentes perspectivas, por lo que los factores que se han propuesto para explicar o moderar la TR también son muy diversos. Centrándonos en los factores individuales (procesos cognitivos y emocionales) que influyen en la TR, estos pueden afectar la forma en que se abordan las situaciones peligrosas de dos maneras diferentes. En primer lugar, pueden sesgar la percepción de una situación, de modo que no se lleve a cabo una evaluación adecuada y por tanto esto lleve a conductas sesgadas. En segundo lugar, estos factores configuran una cierta propensión general al riesgo en los seres humanos, de modo que pueden o no sentirse atraídos por situaciones potencialmente peligrosas. De la misma manera que la definición de la TR se ha abordado desde diferentes perspectivas, su evaluación también se ha tratado desde diferentes puntos de vista y constituye hoy en día un desafío para investigadores y profesionales, por lo que no se ha encontrado un consenso claro en cuanto a la existencia de una medida validada para la TR. La evaluación de la TR se ha realizado tradicionalmente mediante cuestionarios; sin embargo, se ha demostrado que estas medidas presentan diversas limitaciones que pueden conducir a resultados alterados. Las tareas comportamentales surgen como una solución alternativa capaz de superar algunas de estas barreras. En cambio, su capacidad de transferencia a situaciones de la vida real parece ser limitada. La realidad virtual (RV) permite recrear situaciones reales simuladas para realizar evaluaciones basadas en el desempeño. La RV presenta numerosas ventajas que pueden aportar beneficios para la evaluación de los comportamientos humanos, ya que aporta una mayor inmersión, fidelidad y un mayor nivel de implicación que los métodos de evaluación tradicionales, y numerosos trabajos en el campo de la psicología aplicada y la neurociencia organizacional han avalado su uso para evaluación humana. En esta investigación, proponemos la RV como tecnología capaz de facilitar el estudio de los procesos de la TR, aprovechando sus numerosas posibilidades, que se pueden resumir como: simulación de situaciones de riesgo realistas, interacciones naturales con el entorno virtual, inclusión de medidas implícitas para evaluación oculta y medición fisiológica en tiempo real. Esta tesis proporciona aportaciones a la definición de la TR, particularmente en la identificación de qué factores constituyen este complejo proceso. Además, investiga el uso de la RV inmersiva en la investigación del comportamiento humano, específicamente para la evaluación de la TR, proporcionando premisas de diseño de entornos virtuales para la evaluación de los constructos psicológicos identificados como determinantes para definir la TR. Finalmente, analiza la validez de la RV en combinación con medidas fisiológicas para la evaluación de la TR de forma implícita. / [CA] Comprendre el comportament humà en situacions de risc, com els factors individuals i externs influeixen en les nostres decisions i en quina mesura és possible influir i modificar els nostres comportaments, constitueix un desafiament tant per als científics com per a la societat en general. Des de la perspectiva de la Seguretat i Salut en el Treball (SST), així com en nombrosos camps com la sociologia i les finances, aquest tema té importants implicacions ja que les situacions de risc són un aspecte comú en diversos àmbits de la nostra vida. La presa de riscos (PR) és part del procés de presa de decisions en situacions d'incertesa, en les quals es coneix per endavant la probabilitat de cada conseqüència positiva o negativa. Si bé el concepte de la PR està ben definit en la literatura, s'ha abordat des de diferents perspectives, per la qual cosa els factors que s'han proposat per a explicar o moderar la PR també són molt diversos. Centrant-nos en els factors individuals (processos cognitius i emocionals) que influeixen en la PR, aquests poden afectar la forma en què s'aborden les situacions perilloses de dues maneres diferents. En primer lloc, poden esbiaixar la percepció d'una situació, de manera que no es duga a terme una avaluació adequada i per tant això porte a conductes esbiaixades. En segon lloc, aquests factors configuren una certa propensió general al risc en els éssers humans, de manera que poden o no sentir-se atrets per situacions potencialment perilloses. De la mateixa manera que la definició de la PR s'ha abordat des de diferents perspectives, la seua avaluació també s'ha tractat des de diferents punts de vista i constitueix hui dia un desafiament per a investigadors i professionals, per la qual cosa no s'ha trobat un consens clar quant a l'existència d'una mesura validada per a la PR. L'avaluació de la PR s'ha realitzat tradicionalment mitjançant qüestionaris; no obstant això, s'ha demostrat que aquestes mesures presenten diverses limitacions que poden conduir a resultats alterats. Les tasques comportamentals sorgeixen com una solució alternativa capaç de superar algunes d'aquestes barreres. En canvi, la seua capacitat de transferència a situacions de la vida real sembla ser limitada. La realitat virtual (RV) permet recrear situacions reals simulades per a realitzar avaluacions basades en l'acompliment. La RV presenta nombrosos avantatges que poden aportar beneficis per a l'avaluació dels comportaments humans, ja que aporta una major immersió, fidelitat i un major nivell d'implicació que els mètodes d'avaluació tradicionals, i nombrosos treballs en el camp de la psicologia aplicada i la neurociència organitzacional han avalat el seu ús per a avaluació humana. En aquesta investigació, proposem la RV com a tecnologia capaç de facilitar l'estudi dels processos de la PR, aprofitant les seues nombroses possibilitats, que es poden resumir com: simulació de situacions de risc realistes, interaccions naturals amb l'entorn virtual, inclusió de mesures implícites per a avaluació oculta i mesurament fisiològic en temps real. Aquesta tesi proporciona aportacions a la definició de la PR, particularment en la identificació de quins factors constitueixen aquest complex procés. A més, investiga l'ús de la RV immersiva en la investigació del comportament humà, específicament per a l'avaluació de la PR, proporcionant premisses de disseny d'entorns virtuals per a l'avaluació dels constructes psicològics identificats com a determinants per a definir la PR. Finalment, analitza la validesa de la RV en combinació amb mesures fisiològiques per a l'avaluació de la PR de manera implícita. / [EN] Understanding human behaviour in risk situations, how individual and external factors influence our decisions and to what extent it is possible to influence and modify our behaviours, constitutes a challenge both for scientists and for society in general. From the perspective of Occupational Safety and Health (OSH), as well as in numerous fields such as sociology of finance, this topic has important implications since risk situations are a common aspect in various domains of our lives. Risk taking (RT) is part of the decision-making process in uncertain situations, in which the probability of each positive or negative consequence is known in advance. Although the concept of RT is well defined in the literature, it has been approached from different perspectives, so that the factors that have been proposed to explain or moderate RT are also very diverse. Focusing on the individual factors - cognitive and emotional processes - that influence RT, these may affect how hazardous situations are addressed in two different ways. First, they can skew the perception of a situation, so that an adequate evaluation is not carried out and therefore this leads to biased behaviors. Second, these factors shape a certain general propensity towards risk in humans, so that they may or may not be attracted to potentially dangerous situations. In the same way that the definition of RT has been approached from different perspectives, the evaluation of RT has also been treated from different points of view and nowadays constitutes a challenge for researchers and practitioners, so that a clear consensus has not been found regarding the existence of a validated measure for RT. RT evaluation has traditionally been carried out using questionnaires; however, it has been demonstrated that these measures present various limitations that can lead to altered results. Behavioural tasks emerge as an alternative solution capable of overcoming some of these boundaries. Instead, their ability to transference to real life situations appears to be limited. Virtual reality (VR) enables recreating real-simulated situations to carry out performance-based assessments. VR presents numerous advantages that can provide benefits for the evaluation of human behaviours, since it provides greater immersion, fidelity and a higher level of involvement than traditional evaluation methods, and numerous works in the field of applied psychology and organizational neuroscience have endorsed its use for human assessment. In this investigation, we propose VR as technology capable of facilitating the study of RT processes, taking advantage of its numerous possibilities, which can be resumed as: simulation of realistic risk situations, natural interactions with the virtual environment, inclusion of implicit measures for stealth assessment and physiological real-time measurement. This thesis provides novel contributions to the definition of RT, particularly in the identification of which factors constitute this complex process. Moreover, it investigates the use of immersive VR in human behaviour research, specifically for RT assessment, providing design premises of virtual environments for the evaluation of the psychological constructs identified as determinants to define RT. Finally, it analyses the validity of VR in combination with physiological measures for the evaluation of RT in an implicit way. / Contrato predoctoral FPI (BES-2017-079857). Ministerio de Economía, Industria y Competitividad (Madrid, Spain). / Juan Ripoll, CD. (2021). Virtual reality environments for the study of decision-making processes in risky contexts through the use of physiological measures and behavioural responses [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171236 / TESIS / Compendio

Erythema is a hallmark skin response to excessive ultraviolet radiation (UVR) and is associated with cutaneous inflammation. Both are mediated by inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2) and chemoattractants such as 12-hydroxyeicosatetraenoic acid (12-HETE) leading to vasodilation and increased leukocyte infiltration. The erythematous response is more pronounced in individuals with low basal melanin levels or who fail to respond to UVR with a robust up-regulation of melanogenesis. While melanin production is a key function of melanocytes, these cells can also produce NO and PGE2, and are located in close proximity to the dermal vasculature. It has been hypothesized that melanocytes with poor melanogenic capacity may participate in the inflammatory response to UVR. The aim of this project was to investigate the inflammatory response in the skin of individuals with either skin phototype (SPT) 1 or 4 to UVR. Sixteen normal healthy individuals were selected for study (8 SPT-1 & 8 SPT-4). Buttock skin was investigated by immunohistochemistry for leukocyte subtypes, eicosanoid producing enzymes and NO synthases under basal and UVR-stimulated conditions. In addition primary cultures of epidermal melanocytes (EM) were established from 16 individuals (8 SPT-1 & 8 SPT-4) and assessed for the presence of eicosanoid-producing enzymes, melanogenic enzymes and NO synthases, by immunocytochemistry, Polymerase Chain Reaction and Western Blotting and for the production of the main pro-inflammatory eicosanoid PGE2 by ELISA and Mass Spectrometry. Moreover, the fatty acid composition of cultured melanocytes was assessed by Gas Chromatography. Results showed that individuals with SPT-1 had significantly greater neutrophil infiltration into the epidermis than those with SPT-4 at 24 hrs post-UVR. Moreover, CD3+ lymphocyte infiltration into the dermis was significantly greater in individuals with SPT-4 than those with SPT-1 at 24 and 72 hrs post-UVR. NOS-1, NOS-3, 12-LOX and COX-2 expression were significantly increased in SPT-1 skin, while NOS-2 and 15-LOX were significantly increased in SPT-4 skin. As 12-LOX and COX-2 products are chemoattractive (for neutrophils) and pro-inflammatory respectively these data could explain the greater observed neutrophil infiltration in SPT-1. The 15-LOX product (15-HETE) is anti-inflammatory and may suggest that 15-LOX up-regulation in SPT-4 skin may aid resolution of the sunburn response, which in part may be mediated by CD3+ lymphocytes and a class-switch in eicosanoid production from COX to LOX products. Melanocyte primary cultures surprisingly showed that SPT was not correlated with melanin content or melanogenic enzyme expression/activity suggesting that all melanocytes in vitro contained the necessary cellular machinery to produce melanin. This finding may reflect also their equal treatment under these enriched culture conditions, which may or may not be available to these cells in situ. Moreover, all melanocytes expressed the necessary machinery (PLA2, COX-1, cPGES) to produce PGE2. However, only some cultures did so at baseline and in response to UVR, and this was not correlated with SPT. A positive correlation was found however between expression level of dopachrome tautomerase (DCT) and protection against PGE2 production in response to UVR, which may suggest a novel role for DCT unrelated to melanogenesis. In summary this research project has generated data that highlights differences between the skin of individuals with SPT-1 and those with SPT-4, and may provide evidence that the keratinocyte partner contributes significantly to the SPT-associated response. This research may also suggest DCT as a novel therapeutic target to protect EM from participation in the UVR-associated inflammatory response in skin. / Wellcome Trust

Hansen and Hansen (1988) found that angry targets in happy crowds were found more quickly and accurately than happy targets in angry crowds. This finding, they dubbed the Face-in-the-Crowd effect. Gilboa-Schechtman and colleagues (1999) found that high anxious participants show a greater enhancement of detecting angry versus happy targets. The purpose of the current studies was to replicate these findings, and to determine whether Rational and Experiential decision-making styles play a role in target detection (Study One) and crowd searching (Study Two), and if these decision-making styles interact with affective predisposition for both reaction time and galvanic skin response in the face-in-the-crowd task. In Study One, I replicated the anger superiority effect and the Anxiety x Target interaction. I also found that the Rational Group tended to be faster than the Experiential Group overall. I found that the High Trait Anxious group had higher GSR than the Low Trait Anxious group averaged over both target conditions. The Rational group had higher GSR when presented with happy targets than when presented with angry targets whereas the Experiential group did not show this difference. In Study Two, I failed to replicate the anger inferiority effect of crowd searching, but I did find that the Rational group tended to be faster than the Experiential group, especially for angry crowd searching. I also found that the Low-State-Anxious-Rational group had lower galvanic skin responses than all other groups across all analyses. The most exciting finding of these two studies was that he Rational Group demonstrated a facility for the face-in-the-crowd task, validating decision-making style as an important dimension to be considered in future face-in-the-crowd research. The research also provided support for network theories and it is hoped that future studies might endeavor to explore facial processing with this theoretical framework in mind.

Hansen and Hansen (1988) found that angry targets in happy crowds were found more quickly and accurately than happy targets in angry crowds. This finding, they dubbed the Face-in-the-Crowd effect. Gilboa-Schechtman and colleagues (1999) found that high anxious participants show a greater enhancement of detecting angry versus happy targets. The purpose of the current studies was to replicate these findings, and to determine whether Rational and Experiential decision-making styles play a role in target detection (Study One) and crowd searching (Study Two), and if these decision-making styles interact with affective predisposition for both reaction time and galvanic skin response in the face-in-the-crowd task. In Study One, I replicated the anger superiority effect and the Anxiety x Target interaction. I also found that the Rational Group tended to be faster than the Experiential Group overall. I found that the High Trait Anxious group had higher GSR than the Low Trait Anxious group averaged over both target conditions. The Rational group had higher GSR when presented with happy targets than when presented with angry targets whereas the Experiential group did not show this difference. In Study Two, I failed to replicate the anger inferiority effect of crowd searching, but I did find that the Rational group tended to be faster than the Experiential group, especially for angry crowd searching. I also found that the Low-State-Anxious-Rational group had lower galvanic skin responses than all other groups across all analyses. The most exciting finding of these two studies was that he Rational Group demonstrated a facility for the face-in-the-crowd task, validating decision-making style as an important dimension to be considered in future face-in-the-crowd research. The research also provided support for network theories and it is hoped that future studies might endeavor to explore facial processing with this theoretical framework in mind.

Simulation-based training has gained widespread attention recently as a response to drawbacks associated with traditional training approaches, such as high training costs (instructors, equipment, etc.), high risks (e.g. pilot training), and ethical issues (e.g. medical training), as well as a lack of availability of certain training environments (e.g. space exploration). Apart from their target training domains, many of aspects of simulations differ, such as their degree of physical realism (fidelity), scenarios (e.g. story), and pedagogical aspects (e.g. after-action reviews and collaborative learning). Among those aspects, designers have mostly focused on developing high-fidelity simulations with the expectation of increasing the effectiveness of training. However, some authors suggest that the above belief is a myth as researchers have failed to identify a linear relationship between the (physical) fidelity and training effectiveness of simulations.  Most researchers have therefore evaluated the correspondence between the behaviours of trainees in both real world and simulated contexts, however, the existing methods of simulation validation using behavioural measures have a number of drawbacks, such as the fact that they do not address certain complex phenomena of skills acquisition. Bridging the above knowledge gap, this research reports on empirical investigations using an improved methodology for validating training simulations. This research includes an investigation of the user experience of trainees, with respect to the acceptance of virtual scenarios provoking a similar psychophysiological response as in real world scenarios, and the training potential of simulations with respect to the positive transfer of training from a simulator to real world operational contexts. The most prominent features of the proposed methodology include the use of psychophysiological measures in addition to traditional behavioural measures and the use of natural (quasi-) experiments. Moreover, its conceptual framework was influenced by contemporary theories in cognitive science (e.g. constructivism and embodied cognition). The results of this research have several important theoretical and methodological implications, involving, for example, the dependency of the effectiveness of simulations on the perceived realism of trainees, which is more embodied than has been predicted by previous researchers, and the requirement of several different types/levels of adaptive training experience, depending on the type of trainee. / Träning i simulatorer har på senare år fått ökad uppmärksamhet som en respons på problem och svårigheter förknippade med traditionella träningsansatser, såsom höga kostnader (instruktörer och utrustning, etc.), hög risk (t.ex. träning av piloter), och etiska aspekter (t.ex. träning av kirurger), likaväl som avsaknaden av träningsmöjligheter och miljöer (t.ex. forskning om rymden). Bortsett från vad som specifikt tränas så skiljer sig simuleringar åt i ett flertal olika aspekter såsom fysisk realism (eng. fidelity), scenarier (handling) och pedagogiska aspekter (t.ex. genomgång efter övning och kollaborativt lärande).  Bland dessa aspekter så har designers ofta fokuserat att utveckla simuleringar med hög realism med förväntningen att detta ska göra träningen mer effektiv. Litteraturen antyder dock att denna föreställning inte stämmer och att de flesta simuleringar med hög realism inte har lyckats uppnå denna målsättning. En slutsats är därför att det finns ett behov av metoder som kan validera potentialen hos simuleringar avsedda att stödja träning – redan innan dessa används. Enligt litteraturen så är utbildningspotentialen hos en simulering starkt kopplad till hur väl den psykologiska effekten en simulering har, stämmer överens med en verklig upplevelse. Forskning har emellertid identifierat ett flertal svagheter hos existerande ansatser för att validera simuleringar; de är oftast baserade på prestations- och/eller subjektiva mätningar; de har fokuserat en eller ett fåtal psykologiska aspekter; och de bygger på traditionella teorier. Baserat på resultat från studier av en kör-simulator presenteras och föreslås i denna avhandling ett förbättrat ramverk för utvärdering. De mest centrala egenskaperna hos det föreslagna ramverket inbegriper användandet av psyko-fysiologiska mått tillsammans med mer traditionella mått; det konceptuella ramverket bygger på samtida teoretiska ansatser (tex konstruktivism och kroppslig kognition); samt användandet av fält (kvasi-) experiment. Utöver uppnåendet av uppsatta mål för forskningen så har resultaten ett flertal teoretiska och metodologiska implikationer. Bland dessa återfinns beroendet mellan effektiviteten hos en simulering och den upplevelse av realitet som de tränade har, vilken är mer grundläggande än vad som rapporterats i tidigare forskning, samt kravet på flera och olika typer av anpassning av träningsupplevelse för den tränade för att förhöja potentialen hos träningssimulatorer. / SIDA Funded National e-Learning Centre Project at the University of Colombo School of Computing, Sri Lanka

Η σύγχρονη μελέτη της κεντρικής και αυτόνομης δραστηριότητας θεωρούνται χρήσιμες στην ανάδειξη της σχέσης των δύο συστημάτων και της φυγόκεντρου ανατροφοδότησης των περιφερικών αλλαγών. Στην εργασία αυτή διερευνώνται οι πιθανές σχέσεις μεταξύ κεντρικών και αυτόνομων απαντήσεων σε σωματαισθητικούς ερεθισμούς. Η ηλεκτροδερμική δραστηριότητα (ΗΔΑ) είναι δείκτης της αυτόνομης δραστηριότητας. Προκλητά δυναμικά και ΗΔΑ καταγράφονταν ταυτόχρονα έπειτα από μια σειρά ερεθισμών του μέσου νεύρου ,με τρείς διαφορετικές εντάσεις, σε έξι φυσιολογικά άτομα. Η χαμηλότερη ένταση ερεθισμού ρυθμίζονταν έτσι ώστε να μη γίνεται αντιληπτή από το άτομα. Τα επάρματα P40, P100, N200 και P300 των προκλητών δυναμικών εξήχθησαν από το καταγεγραμμένο σήμα. Μελετήσαμε το πλάτος και τον λανθάνοντα χρόνο και διερευνήσαμε την πιθανή συσχέτιση των μεγεθών αυτών της ΗΔΑ. Χρησιμοποιήσαμε την συνηθισμένη μέθοδο της μεσοποίησης (average), καθώς και την προσέγγιση των μοναδιαίων απαντήσεων, εξάγωντας τις απαντήσεις με την χρήση χωρικού φίλτρου. Το συμπαθητικό νευρικό σύστημα φαινόταν να απαντά ακόμα και σε ερεθισμούς μη αντιληπτούς από το υποκείμενο. Η φλοιική επεξεργασία των αντιληπτών και μη ερεθισμάτων όπως αποτυπώνονταν με τα επάρματα των προκλητών δυναμικών, φαίνεται να είναι όμοια και στις δύο περιπτώσεις κατά τη διάρκεια των πρώτων 40ms έπειτα από τον ερεθισμό, ενώ τα μακρά κύματα ήταν απόνατ στους μη αντιληπτούς ερεθισμούς. Τα πλάτη της ΗΔΑ και του P300 με την προσέγγιση των μοναδιαίων απαντήσεων παρουσίαζαν μια σημαντική θετική συσχέτιση. / Concurrent studies of central and autonomic activity are considered useful in elucidating the relationship between the two systems and indicating the centripetal feedback of peripheral changes. The SSR (sympathetic skin response) is one index of autonomic arousal. In our study we examine the possible relationships between central and autonomic responses to somatosensory stimuli. EPs (evoked potentials) and SSRs were simultaneously recorded during a series of electrical stimuli of median nerve in six normal adults using three different intensities of stimuli. The weakest of them was unperceived by subject. The P40, P100, N200 and P300 waves of EPs were extracted and their latencies and amplitudes were analysed in order to find correlations with those of the SSRs. We used the conventional method of signal averaging and the single trial (ST) approach, as the EP waves were subtracted by spatial filtering. Interestingly, sympathetic nervous system seemed to react even to stimuli unperceived by the subject. The cortical processing of consciously perceived and unperceived somatosensory stimuli as it was expressed by the evoked potentials seems to be identical during the first 40ms after the stimulus onset while later waves were absent for unperceived stimuli. SSR and P300 amplitude at the ST level had a positive correlation.