Disentangling Fear and Anxiety in Self–reported Responses to Situational Scripts

With decreasing threat ambiguity and increasing threat imminence, human psychophysiological responses can be mapped onto a defensive continuum that distinguishes between the states of general anxiety, cued anxiety, and fear. The present study aimed to investigate whether self–reported physiological, cognitive, behavioral and attentional responses can also distinguish between cued anxiety and fear. Healthy participants (N=141) received 9 situational scripts (3 prototypical scripts per phase of the defensive continuum) each followed by 22 responses. They indicated how likely they would display each response in the described situation. The results of an INDCLAS–analysis indicated that the distinction between "cued anxiety" and "fear" can be made on the basis of self–reported responses. Responses typical for fear situations were "fear of dying", "breathing faster", and "feeling of choking". Cued anxiety situations evoked "accelerated heart rate", "to startle", "sharpened senses", "tense muscles" and "sweating". This finding may contribute to constructing an easy tool to distinguish cued anxiety and fear in both clinical and experimental contexts

Unpaired shocks during extinction weaken the contextual renewal of a conditioned discrimination

Extinction is generally more fragile than conditioning, as illustrated by the contextual renewal effect. The traditional extinction procedure entails isolated presentations of the conditioned stimulus. Extinction may be boosted by adding isolated presentations of the unconditioned stimulus, as this should augment breaking the contingency between the two stimuli. In a human conditioning experiment with on-line expectancy ratings and electrodermal responding as dependent variables, 32 participants were differentially conditioned to two neutral figures using electric shock. After a change of context, one group received normal extinction treatment whereas another group received explicitly unpaired presentations of the figures and shock. At test, the two figures were presented in the original context again. For both measures, only the group that received normal extinction showed renewal of the conditioned discrimination. These results suggest that unpaired shocks during extinction strengthen the extinction learning. © 2009 Elsevier Inc. All rights reserved.status: publishe

Instruction and Experience Based Belief Construction and Revision

In this paper we discuss the difference between instruction and experience induced belief construction and its resistance to conflicting evidence. Experiment 1 is a succesful replication of the renewal effect with experience induced belief acquisition. In Experiment 2, it is shown that the level of belief acquisition that is obtained through experience is also obtained through instruction. Nevertheless, the absence of a renewal effect in this experiment shows that both learning methods differ in their underlying cognitive structure

Fear generalization in humans: Impact of verbal instructions

Fear generalization lies at the heart of many anxiety problems, but little is known about the factors that can influence this phenomenon. The present study investigated whether verbal instructions about specific stimulus features can influence conditioned fear generalization. All participants were fear conditioned to a yellow triangle, using an electric shock. Participants had received pre-experimental instructions saying that the shapes (or colours) of the stimuli were informative for the occurrence of shock (group Shape and group Colour, respectively). Next, generalization was tested to presentations of a blue triangle (same shape) as well as a yellow square (same colour). Fear reactions were measured through skin conductance and online ratings of shock-expectancy. The results showed strongest generalization to the same shape stimulus in group Shape, versus the same colour stimulus in group Colour. Hence, the same learning experience can have opposite effects in terms of fear generalization, depending on verbally transmitted information about the relative importance of individual stimulus features.status: publishe

Extinction in fear conditioning : effects on startle modulation and evaluative self-reports

A basic feature of human evaluative conditioning is that the reported acquired valence of a previously neutral conditioned stimulus (CS) that has been paired with a valenced unconditioned stimulus (US), is resistant to extinction. The present study investigated whether startle modulation, sometimes presented as an index of acquired valence, reflected this basic feature. In a differential fear conditioning paradigm (n = 38) with an electrocutaneous stimulus as the US, a strong extinction manipulation was conducted by removing the US-electrodes and by extended extinction trials. At the end of extinction, the results corroborated previous findings of evaluative conditioning in that the reported valence for CS+ was still more negative than for CS-, despite disappearance of the differential skin conductance responses. However, startle modulation did not show resistance-to-extinction. Results were discussed in terms of recent conceptualizations of extinction

El efecto de la (im)predictabilidad en el miedo contextual: una réplica de hallazgos básicos

<p>El objetivo de este estudio fue investigar el rol de la (im)predictabilidad en el paradigma de condicionamiento de miedo, al analizar las diferencias tanto en el condicionamiento específico (cue) como en el contextual. Por consiguiente, se manipuló la presentación del estímulo incondicionado (EI) utilizando dos condiciones: una presentación apareada del EI con el estímulo condicionado —EC en adelante— (predecible) y una presentación no apareada del EI (impredecible). Se manipuló el contexto utilizando la luz central del cuarto experimental: condiciones de oscuridad y claridad. Las variables independientes fueron la respuesta de conductancia de la piel y la medición de la respuesta de sobresalto. Los participantes fueron 65 alumnos de primer año de psicología. Los resultados muestran más condicionamiento contextual en el bloque no apareado (impredecible) comparado con el apareado, y condicionamiento específico en el bloque apareado (predecible).</p><p>---</p><p>The aim of this experiment was to study the role of (un)predictability in a fear conditioning paradigm: analyzing the differences in both cue and context conditioning. For this reason, we manipulated the presentation of the unconditional stimulus (US) using two conditions:a paired presentation of the US-CS (predictable) and an unpaired presentationof the US (unpredictable). We manipulated the context using the lightning of the experimental room: dark and light conditions. Our dependent variables were the skin conductance response (SCR) and the startle reflex measurement. Participants were 65 students from the Universityof Leuven. Results showed more context conditioning in the unpaired block (unpredictable) compared to the paired one and cue conditioning in the paired block (predictable).</p

Optimization of a contextual conditioning protocol for rats using combined measurements of startle and freezing

status: publishe