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One approach to investigate psychophysiological processes occurring in the Concealed Information Test (CIT) is to use a parallel task, which engages specific mental activity in addition to the CIT. In the present study, the influence of an interfering n-back task on the physiological responses in a Concealed Information Test (CIT) was investigated. Forty participants underwent a mock-crime experiment with a modified CIT. In a within-subject design, the CIT was applied in blocks with and without an additional n-back task. Electrodermal activity (EDA), respiration line length (RLL), heart rate (HR), and finger pulse waveform length (FPWL) were registered. Reaction times in the n-back task and the CIT were recorded. The parallel task enhanced the differential EDA response to probe vs. irrelevant items, while it diminished the response differences for RLL and phasic HR. Results shed light upon working-memory-related processes in the CIT. The diverging effects of the interfering mental activity on electrodermal and cardiopulmonary measures, if replicable, might contribute to a better understanding of the psychophysiological responsiveness underlying the CIT.

The study aimed at experimentally investigating whether the human body can anticipate future events under improved methodological conditions. Previous studies have reported contradictory results for the phenomenon typically called presentiment. If the positive findings are accurate, they call into doubt our views about human perception, and if they are inaccurate, a plausible conventional explanation might be based on the experimental design of the previous studies, in which expectation due to item sequences was misinterpreted as presentiment. To address these points, we opted to collect several physiological variables, to test different randomization types and to manipulate subjective significance individually. For the latter, we combined a mock crime scenario, in which participants had to steal specific items, with a concealed information test (CIT), in which the participants had to conceal their knowledge when interrogated about items they had stolen or not stolen. We measured electrodermal activity, respiration, finger pulse, heart rate (HR), and reaction times. The participants (n = 154) were assigned randomly to four different groups. Items presented in the CIT were either drawn with replacement (full) or without replacement (pseudo) and were either presented category-wise (cat) or regardless of categories (nocat). To understand how these item sequences influence expectation and modulate physiological reactions, we compared the groups with respect to effect sizes for stolen vs. not stolen items. Group pseudo_cat yielded the highest effect sizes, and pseudo_nocat yielded the lowest. We could not find any evidence of presentiment but did find evidence of physiological correlates of expectation. Due to the design differing fundamentally from previous studies, these findings do not allow for conclusions on the question whether the expectation bias is being confounded with presentiment.

The question to what extent emotion-related brain activation depends upon the presentation design (block design vs. event-related design) and the stimulus type (scene pictures vs. pictures with facial mimic) has hardly been addressed in previous functional magnetic resonance imaging (fMRI) research. In the present fMRI experiment, 40 right-handed subjects viewed pictures with fear-inducing and disgust-inducing content as well as facial expressions of fear and disgust. Pictures of neutral objects and neutral facial mimic were used as control stimuli. The pictures were presented in a block design for half of the subjects; the other half viewed the same stimuli as singular events in randomized sequence. The participants had been instructed to passively view the pictures. Disgust-evoking scenes provoked activation in the amygdala, the insula and the orbitofrontal cortex (OFC). This applied to the blocked as well as to the event-related design. Fear-relevant scenes were associated with activity in the insula, the OFC and the middle temporal gyri in the event-related design. The presentation in a block design only led to activation in the middle temporal gyri. Facial expressions of disgust and fear did not trigger significant activation neither in the blocked nor event-related design. This surprising outcome may be a result of context and task effects. The face stimuli which were presented together with the more complex scenes in a passive viewing paradigm possibly were not salient enough to trigger emotional processing.

Functional magnetic resonance imaging studies have examined neural correlates of disgust imagery, but have never taken into account the moderating effects of personality traits. Twenty-four women first viewed and subsequently visualized pictures with disgust-inducing and happiness-inducing content. Relative to the picture perception, disgust, and happiness imagery provoked activation of the insula, anterior cingulate cortex, and parietal cortex. Trait disgust was negatively correlated with localized brain activation (e.g. insula, amygdala, parietal cortex, anterior cingulate cortex) during disgust imagery. This study provides first evidence that disgust propensity is associated with brain activation during imagery of repulsive scenes.

This study investigated whether bulimia nervosa (BN) and binge-eating disorder (BED) are associated with structural brain abnormalities. Both disorders share the main symptom binge-eating, but are considered differential diagnoses. We attempted to identify alterations in grey matter volume (GMV) that are present in both psychopathologies as well as disorder-specific GMV characteristics. Such information can help to improve neurobiological models of eating disorders and their classification. A total of 50 participants (patients suffering from BN (purge type), BED, and normal-weight controls) underwent structural MRI scanning. GMV for specific brain regions involved in food/reinforcement processing was analyzed by means of voxel-based morphometry. Both patient groups were characterized by greater volumes of the medial orbitofrontal cortex (OFC) compared to healthy controls. In BN patients, who had increased ventral striatum volumes, body mass index and purging severity were correlated with striatal grey matter volume. Altogether, our data implicate a crucial role of the medial OFC in the studied eating disorders. The structural abnormality might be associated with dysfunctions in food reward processing and/or self-regulation. The bulimia-specific volume enlargement of the ventral striatum is discussed in the framework of negative reinforcement through purging and associated weight regulation.

The magnitude of the startle eyeblink response is diminished when the startle-eliciting probe is shortly preceded by another stimulus. This so called prepulse inhibition is interpreted as an automatic sensorimotor gating mechanism. There is substantial support for prepulse inhibition deficits in subjects suffering from schizophrenia spectrum disorders and in psychosis-prone normals as well. Thus, prepulse inhibition deficits may reflect vulnerability on the hypothesized psychopathological continuum from “normal” to “schizophrenia.” The present experiment investigated the amount of prepulse inhibition in a sample selected for “belief in extraordinary phenomena,” an attitude related to measures of psychosis-proneness. Believers and skeptics were tested in an acoustic prepulse-inhibition paradigm. As expected, presentation of prepulses clearly diminished magnitude of startle response, with greatest inhibition effects gained by lead intervals of 60 and 120 msec. Patterns of response were identical for believers and skeptics, i.e., attitude towards extraordinary phenomena did not seem to be related to functional information-processing deficits as has been observed in psychosis-prone normals.

Physiological responses in the Concealed Information Test (CIT) are known to depend on the depth of encoding critical items; CIT questions commonly refer to knowledge about critical items. It is unclear to what extent (1) different modes of item handling in a mock-crime, and (2) alternative questioning formats, e.g. asking about participants' particular actions with the critical items, influence the physiological responses. In the presented mock-crime study with fifty-three participants, two questioning formats, i.e. "Did you see …?" (viewing questioning) and "Did you steal …?" (stealing questioning), were compared between subjects. The mode of encoding, stealing vs. merely viewing the critical objects, was varied within subject. Skin conductance, electrocardiogram, respiration, and finger pulse were recorded. For both questioning formats and each physiological measure, physiological responses to stolen as well as merely viewed objects differed from those to irrelevant objects. Considering viewing questioning, responses to stolen and merely viewed objects did not differ, with the exception of greater phasic decreases of heart rate for stolen objects. Considering stealing questioning, responses to stolen objects exceeded those to merely viewed objects with each physiological measure. The statistically proven interaction between mode of encoding a particular object and questioning format sheds light on the factors influencing the physiological responses in a CIT. The level of subjective significance of a particular item might emerge interactively from the mode of item handling and the questioning format.

Aversive social learning experiences might play a significant role in the aetiology of social anxiety disorder. Therefore, we investigated emotional learning and unlearning processes in healthy humans using a social conditioning paradigm. Forty-nine healthy subjects participated in a 2-day fMRI differential conditioning protocol. Acquisition and extinction were conducted on Day 1 and extinction recall on Day 2. BOLD responses, ratings and skin conductance responses were collected. Our data indicate successful conditioning and extinction on the neural and subjective level. As a main result, we observed a positive correlation of social anxiety and conditioning responses on the subjective level (valence and fear) as well as on the neural level with significant CS(+)/CS(-) differentiation in the left amygdala and the left hippocampus. Further, significant CS(+)/CS(-) differentiation in the left amygdala was found during extinction and was associated with lower scores in social anxiety. During extinction recall, we found a tendentially negative correlation of social anxiety and CS(+)/CS(-) differentiation in the vmPFC. In sum, we were able to show that social anxiety is related to conditionability with socially threatening stimuli. This could point to an important aspect in the aetiology of social anxiety disorder.

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.Sixty subjects participated in the experiment, which included a study phase with visual scenes each showing a group of interrelated items in social contexts. Subjects were divided into an experimental group undergoing a classical DRM design and a control group without DRM manipulation. The control group was implemented in order to statistically control for possible biases produced by memorability differences between stimulus types. After a short retention interval, a pictorial recognition phase was conducted in the manner of a Concealed Information Test. Simultaneous recordings of electrodermal activity, respiration line length, phasic heart rate, and finger pulse waveform length were used. Results yielded a significant Group by Item Type interaction, showing that true recognition is accompanied by greater electrodermal activity than false recognition.Results are discussed in the light of Sokolov's Orienting Reflex, the Preliminary Process Theory and the Concealed Information Test. Implications and restrictions of the introduced design features are critically discussed. This study demonstrates the applicability of measures of peripheral physiology to the field of false memory research.

Attentional, intentional, and motivational factors are known to influence the physiological responses in a Concealed Information Test (CIT). Although concealing information is essentially a social action closely related to motivation, CIT studies typically rely on testing participants in an environment lacking of social stimuli: subjects interact with a computer while sitting alone in an experimental room. To address this gap, we examined the influence of social stimuli on the physiological responses in a CIT. Seventy-one participants underwent a mock-crime experiment with a modified CIT. In a between-subjects design, subjects were either questioned acoustically by a pre-recorded male voice presented together with a virtual male experimenter's uniform face or by a text field on the screen, which displayed the question devoid of face and voice. Electrodermal activity (EDA), respiration line length (RLL), phasic heart rate (pHR), and finger pulse waveform length (FPWL) were registered. The Psychopathic Personality Inventory - Revised (PPI-R) was administered in addition. The differential responses of RLL, pHR, and FPWL to probe vs. irrelevant items were greater in the condition with social stimuli than in the text condition; interestingly, the differential responses of EDA did not differ between conditions. No modulatory influence of the PPI-R sum or subscale scores was found. The results emphasize the relevance of social aspects in the process of concealing information and in its detection. Attentional demands as well as the participants' motivation to avoid detection might be the important links between social stimuli and physiological responses in the CIT.

The Concealed Information Test (CIT) is a valid method to detect hidden knowledge by means of psychophysiological measures. Concealing information is always a social behavior; yet, the role of social aspects has barely been investigated in recent CIT research favoring standardized, computer-based experiments. Evaluative observation is known to influence social behavior as well as physiological measures; examining the impact of evaluative observation on physiological responding in a CIT is the aim of this study. Sixty-three students completed a mock-crime and then underwent a CIT. In a between-subjects manipulation, half of the participants were observed through a camera and were faced with the real-time video of the experimenter watching them while completing the CIT. The other half completed the CIT without observation and video. Electrodermal activity, respiration line length, phasic heart rate, and finger pulse waveform length were registered. A specific questionnaire captured the individual fear of negative evaluation. Typical differential CIT responses occurred in both groups and with each measure. Contrary to expectations, differential CIT responses did not differ between groups. No modulatory influence of the fear questionnaire score on physiological responding was found. A ceiling effect, involving high attention and high motivation to avoid detection as well as high arousal in both groups due to the CIT procedure per se is discussed as explanation for these results, while the independence of the orienting reflex of social and motivational influence appears less likely in the light of previous literature.

Several studies investigating psychophysiological correlates of false memories suggest that psychophysiology may provide incremental information to subjectively reported memory. Based on previous findings in a Deese-Roediger-McDermott paradigm, we examined three components of event-related EEG potentials of memory in a misleading information paradigm. 39 participants watched a video that included eight randomized details (e.g., the color of an envelope). After a retention interval of one week, four out of eight details were replaced by misleading details in a narrative text. Afterward, EEG was derived during a recognition test. First, we found that the amplitude at parietal electrodes did not differ between true and false memories. Instead, parietal positivity was more pronounced during yes- compared to no-responses, indicating parietal positivity reflects subjectively reported memory. Second, we found more positive frontal amplitudes associated with false compared to true memories in late time windows. Consequently, our findings indicate that false memories differ from true memories with respect to late frontal activation. In conclusion, we assume that parietal positivity reflects subjectively experienced memory, whereas late frontal activation holds incremental information to the subjectively experienced and reported memory.

Functional magnetic resonance imaging (fMRI) studies consistently demonstrate an enhanced activation of the visual cortex in reaction to emotionally salient visual stimuli. This increase of activation is probably modulated by top-down processes, that are initiated in emotion processing structures, specifically the amygdala and the orbitofrontal cortex. In the present fMRI study, a differential fear conditioning paradigm was applied to investigate this assumed modulation. Hemodynamic responses towards a neutral visual stimulus (CS+) predicting an electrical stimulation (UCS) were compared with responses towards a neutral and unpaired stimulus (CS-). Thereby, particularly the time courses of neural responses were considered. Skin conductance measures were concurrently recorded. Our results show that the differentiation between CS+ and CS- within the amygdala and the extended visual cortex was accomplished during a late acquisition phase. In the orbitofrontal cortex the differentiation occurred at an earlier stage and was then sustained throughout acquisition. It is suggested that these altering activation patterns are reflecting different phases of learning, integrating the analyzed regions to varying degrees. Additionally, the results indicate that statistical analyses comprising a temporal variation of hemodynamic responses are more likely to detect amygdala activation.

This study investigates the effect of awareness of stimulus contingencies on BOLD responses within the amygdala, the orbitofrontal, and the occipital cortex, and on differential skin conductance responses (SCRs) during fear conditioning. Of two geometric figures, the paired conditioned stimulus (CS+) predicted an electrical stimulus (unconditioned stimulus = UCS), whereas the unpaired conditioned stimulus (CS-) was not followed by the UCS. Awareness of stimulus contingencies was manipulated experimentally, creating an aware and an unaware group: a distracter figure and a working memory task were introduced to conceal the stimulus contingencies of the conditioning paradigm, hence preventing contingency detection in the unaware group. The aware group was informed beforehand about the relation between CS+, CS-, and UCS. Differential SCRs were only obtained in the aware but not in the unaware group. Conversely, we observed enhanced responses of the amygdala, the orbitofrontal, and the occipital cortex to the CS+ in the unaware group only. Thus, we found a dissociation of SCR differentiation and the activation of a neural fear network depending on the presence or absence of awareness. These results support a model of fear conditioning that distinguishes between a more cognitive level of learning, reflected in contingency awareness and differential SCRs, and the awareness independent activation of a fear network.

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.

Current models of attention describe attention not as a homogenous entity but as a set of neural networks whose measurement yields a set of three endophenotypes-alerting, orienting, and executive control. Previous findings revealed different neuroanatomical regions for these subsystems, and data from twin studies indicate differences in their heritability. The present study investigated the molecular genetic basis of attention in a sample of 100 healthy subjects. Attention performance was assessed with the attention network test that distinguishes alerting, orienting, and executive control (conflict) using a simple reaction time paradigm with different cues and congruent and incongruent flankers. Two gene loci on candidate genes for cognitive functioning, the functional catechol-O-methyltransferase (COMT) VAL158MET and the tryptophan hydroxylase 2 (TPH2) -703 G/T promoter polymorphism, were tested for possible associations with attention. COMT is involved in the catabolism of dopamine, and TPH is the rate-limiting enzyme for serotonin synthesis. Results showed no effect of the COMT polymorphism on attention performance. However, the TT genotype of TPH2 -03 G/T was significantly associated with more errors (a possible indicator of impaired impulse control; p = .001) and with decreased performance in executive control (p = .001). This single-nucleotide polymorphism on the TPH2 gene explained more than 10% of the variance in both indicators of attention stressing the role of the serotonergic system for cognitive functions.

The Concealed Information Test (CIT) requires the examinee to deceptively deny recognition of known stimuli and to truthfully deny recognition of unknown stimuli. Because deception and orienting are typically coupled, it is unclear how exactly these sub-processes affect the physiological responses measured in the CIT. The present study aimed at separating the effects of deception from those of orienting. In a mock-crime study, using a modified CIT, thirty-six of seventy-two subjects answered truthfully ('truth group'), whereas the other thirty-six concealed their knowledge ('lie group'). Answering was delayed for 4 s after item presentation. Electrodermal activity (EDA), respiration (RLL), and phasic heart rate (HR) were recorded. A decomposition of EDA responses revealed two response components; the response in the first interval was expected to indicate orienting, stimulus evaluation, and answer preparation, whereas the response in the second interval was assumed to reflect answer-related processes. Inconclusively, both EDA components differentiated between 'probe' and 'irrelevant' items in both groups. Phasic HR and RLL differed between item classes only in the 'lie' group, thus reflecting answer-related processes, possibly deception, rather than merely orienting responses. The findings further support the notion that psychophysiological measures elicited by a modified CIT may reflect different mental processes involved in orienting and deception.

The simulation concept suggested by Jeannerod (Neuroimage 14:S103-S109, 2001) defines the S-states of action observation and mental simulation of action as action-related mental states lacking overt execution. Within this framework, similarities and neural overlap between S-states and overt execution are interpreted as providing the common basis for the motor representations implemented within the motor system. The present brain imaging study compared activation overlap and differential activation during mental simulation (motor imagery) with that while observing gymnastic movements. The fMRI conjunction analysis revealed overlapping activation for both S-states in primary motor cortex, premotor cortex, and the supplementary motor area as well as in the intraparietal sulcus, cerebellar hemispheres, and parts of the basal ganglia. A direct contrast between the motor imagery and observation conditions revealed stronger activation for imagery in the posterior insula and the anterior cingulate gyrus. The hippocampus, the superior parietal lobe, and the cerebellar areas were differentially activated in the observation condition. In general, these data corroborate the concept of action-related S-states because of the high overlap in core motor as well as in motor-related areas. We argue that differential activity between S-states relates to task-specific and modal information processing.

This functional magnetic resonance imaging study investigated long-term effects of cognitive behavior therapy (CBT) in individuals suffering from spider phobia. Ten female patients who had shown positive immediate CBT effects were invited to take part in a 6-month follow-up investigation. Here, the patients, along with eight non-phobic females, were presented with the same pictures depicting spiders, generally disgust-inducing, generally fear-inducing and neutral content, which they had viewed 6 months earlier. Patients' self-report and overt behavior indicated a positive long-term clinical improvement. Related hemodynamic changes included an increase in medial orbitofrontal cortex (OFC) activity. As the medial OFC is involved in emotion-related learning, especially in the representation of positive stimulus-outcome associations, we conclude that the medial OFC effect constitutes the neuronal basis of the lasting positive CBT outcome. Activity to disorder-irrelevant pictures decreased across the sessions in the lateral OFC and in the insula, which most likely reflects general habituation.