Psychophysiology of False Memories in a Deese-Roediger-McDermott Paradigm with Visual Scenes

Remembering something that has not in fact been experienced is commonly referred to as false memory. The Deese-Roediger-McDermott (DRM) paradigm is a well-elaborated approach to this phenomenon. This study attempts to investigate the peripheral physiology of false memories induced in a visual DRM paradigm. The main research question is whether false recognition is different from true recognition in terms of accompanying physiological responses

›Nahtoderfahrungen‹. Ein wissenschaftliches Mysterienspiel heute: Interview mit Dieter Vaitl vom 11. November 2017

Dieter Vaitl geht davon aus, dass es sich bei ›Nahtoderfahrungen‹ (NTE) um eine sehr heterogene, begrifflich schwer zu fassende Ansammlung von Phänomenen handelt, die keinesfalls nur in Todesnähe auftreten. Sie sollten deswegen besser innerhalb des wesentlich breiteren Spektrums veränderter Bewusstseinszustände denn als isoliertes Phänomen beschrieben werden. Ihre Komplexität ist vor allem methodologisch eine Herausforderung für die Forschung, die sich dem Thema daher am besten über mehrdimensional angelegte Ansätze widmen sollte. Dieses Potential wurde bislang jedoch noch gar nicht ausgeschöpft. Vaitl sieht daher keinen Grund, aus den bestehenden Erklärungsschwierigkeiten ›Beweisspektakel‹ zugunsten eines Glaubens an jenseitige Wirklichkeiten abzuleiten.In this interview, Dieter Vaitl assumes that ›Near-Death Experience‹ (NDE) is a very heterogeneous collection of phenomena that are difficult to conceptualize and that by no means only occur near death. NDE are therefore better described within the much broader spectrum of altered states of consciousness, rather than as an isolated phenomenon. Their complexity is above all a methodological challenge for research, which should therefore best address the topic using multidimensional approaches. However, this potential has not yet been fully exploited. Vaitl therefore sees no reason to derive from the existing difficulties in explanation an ›evidence spectacle‹ in favor of a belief in otherworldly realities

Influence of contingency awareness on neural, electrodermal and evaluative responses during fear conditioning

In an fMRI study, effects of contingency awareness on conditioned responses were assessed in three groups comprising 118 subjects. A differential fear-conditioning paradigm with visual conditioned stimuli, an electrical unconditioned stimulus and two distractors was applied. The instructed aware group was informed about the contingencies, whereas the distractors prevented contingency detection in the unaware group. The third group (learned aware) was not informed about the contingencies, but learned them despite the distractors. Main effects of contingency awareness on conditioned responses emerged in several brain structures. Post hoc tests revealed differential dorsal anterior cingulate, insula and ventral striatum responses in aware conditioning only, whereas the amygdala was activated independent of contingency awareness. Differential responses of the hippocampus were specifically observed in learned aware subjects, indicating a role in the development of contingency awareness. The orbitofrontal cortex showed varying response patterns: lateral structures showed higher responses in instructed aware than unaware subjects, the opposite was true for medial parts. Conditioned subjective and electrodermal responses emerged only in the two aware groups. These results confirm the independence of conditioned amygdala responses from contingency awareness and indicate specific neural circuits for different aspects of fear acquisition in unaware, learned aware and instructed aware subjects

Differential activation of the lateral premotor cortex during action observation

<p>Abstract</p> <p>Background</p> <p>Action observation leads to neural activation of the human premotor cortex. This study examined how the level of motor expertise (expert vs. novice) in ballroom dancing and the visual viewpoint (internal vs. external viewpoint) influence this activation within different parts of this area of the brain.</p> <p>Results</p> <p>Sixteen dance experts and 16 novices observed ballroom dance videos from internal or external viewpoints while lying in a functional magnetic resonance imaging scanner. A conjunction analysis of all observation conditions showed that action observation activated distinct networks of premotor, parietal, and cerebellar structures. Experts revealed increased activation in the ventral premotor cortex compared to novices. An internal viewpoint led to higher activation of the dorsal premotor cortex.</p> <p>Conclusions</p> <p>The present results suggest that the ventral and dorsal premotor cortex adopt differential roles during action observation depending on the level of motor expertise and the viewpoint.</p

Latent inhibition and autonomic respones: A psychophysiological approach

Latent inhibition, retarded learning after preexposure to the to-be- conditioned stimulus, has been implied as a tool for the investigation of attentional deficits in schizophrenia and related disorders. The present paper reviews research that used Pavlovian conditioning as indexed by autonomic responses (electrodermal, vasomotor, cardiac) to investigate latent inhibition in adult humans. Latent inhibition has been demonstrated repeatedly in healthy subjects in absence of a masking task that is required in other latent inhibition paradigms. Moreover, latent inhibition of Pavlovian conditioning is stimulus-specific and increases with an increased number of preexposure trials which mirrors results from research in animals. A reduction of latent inhibition has been shown in healthy subjects who score high on questionnaire measures of psychosis proneness and in unmedicated schizophrenic patients. The latter result was obtained in a within-subject paradigm that holds promise for research with patient samples.</p

An interfering Go/No-go task does not affect accuracy in a Concealed Information Test

Following the idea that response inhibition processes play a central role in concealing information, the present study investigated the influence of a Go/No-go task as an interfering mental activity, performed parallel to the Concealed Information Test (CIT), on the detectability of concealed information. 40 undergraduate students participated in a mock-crime experiment and simultaneously performed a CIT and a Go/No-go task. Electrodermal activity (EDA), respiration line length (RLL), heart rate (HR) and finger pulse waveform length (FPWL) were registered. Reaction times were recorded as behavioral measures in the Go/No-go task as well as in the CIT. As a within-subject control condition, the CIT was also applied without an additional task. The parallel task did not influence the mean differences of the physiological measures of the mock-crime-related probe and the irrelevant items. This finding might possibly be due to the fact that the applied parallel task induced a tonic rather than a phasic mental activity, which did not influence differential responding to CIT items. No physiological evidence for an interaction between the parallel task and sub-processes of deception (e.g. inhibition) was found. Subjects' performance in the Go/No-go parallel task did not contribute to the detection of concealed information. Generalizability needs further investigations of different variations of the parallel task

Neuroimaging of emotion : empirical effects of proportional global signal scaling in fMRI data analysis

Global variations of BOLD-fMRI signal are often considered as nuisance effects. This unwanted source of variance is commonly eliminated using proportional global signal scaling (PGSS). However, application of PGSS relies on the assumption that global variations of BOLD signal and experimental conditions are uncorrelated. It has been shown for cognitive tasks that the unjustified application of PGSS might greatly distort statistical results. The present study examined this issue in the domain of emotion research. Specifically, fMRI data were obtained in a block-design, while 21 subjects passively viewed high and low emotionally arousing pleasant, unpleasant, and neutral pictures. Violations of the orthogonality assumption were found for analyses of emotional pictures high in arousal, causing dramatically different outcomes when compared to analyses performed without PGSS. Application of PGSS was associated with attenuated emotional activation in visual cortical areas, insensitivity to emotional activations in limbic and paralimbic regions, and widely distributed artificial deactivations. In contrast, the orthogonality assumption was not violated for low arousing emotional materials. Thus, the validity of using PGSS varied as a function of the emotional arousal of the stimuli. Taken together, the unwarranted use of PGSS might contribute to conflicting results in affective neuroscience fMRI studies, in particular with respect to limbic and paralimbic structures

Neural Responses to Smoking Stimuli Are Influenced by Smokers' Attitudes towards Their Own Smoking Behaviour

An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users) whereas others are discontent (dissonant users). Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli) and stimuli associated with the terminal stage (END-smoking-stimuli) of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula) in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex) compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli) are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli) seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant smokers experience difficulties in translating their attitudes into an actual behavior change

The Concealed Information Test is Susceptible to Misleading Information

An approach toward detecting hidden knowledge is the Concealed Information Test (CIT). It relies on the memory of crime‐relevant information. This study investigated whether its validity is susceptible to memory distortion by misleading information. A misleading information paradigm was employed to distort memory prior to an interrogation with a CIT. Forty‐one participants watched a video with specific crime‐related information. After a 1‐week retention interval, misleading information was introduced. Afterward, a CIT was performed, followed by a threefold memory test. When misleading information was presented, memory performance was reduced, and no physiological response differences between crime‐relevant and crime‐irrelevant information were found. Without presenting misleading information, physiological responses differed between responses to crime‐relevant and crime‐irrelevant information. However, responses in all physiological measures also differed between misleading and irrelevant information. The results indicate that the CIT is susceptible to misleading information, which reduces its validity in specific constellations