A Comparative Event-Related Potential Study

The phenomenon of social exclusion can be investigated by using a virtual ball-tossing game called Cyberball. In neuroimaging studies, structures have been identified which are activated during social exclusion. But to date the underlying mechanisms are not fully disclosed. In previous electrophysiological studies it was shown that the P3 complex is sensitive to exclusion manipulations in the Cyberball paradigm and that there is a correlation between P3 amplitude and self-reported social pain. Since this posterior event-related potential (ERP) was widely investigated using the oddball paradigm, we directly compared the ERP effects elicited by the target (Cyberball: “ball possession”) and non-target (Cyberball: “ball possession of a co-player) events in both paradigms. Analyses mainly focused on the effect of altered stimulus probabilities of the target and non-target events between two consecutive blocks of the tasks. In the first block, the probability of the target and non-target event was 33% (Cyberball: inclusion), in the second block target probability was reduced to 17%, and accordingly, non-target probability was increased to 66% (Cyberball: exclusion). Our results indicate that ERP amplitude differences between inclusion and exclusion are comparable to ERP amplitude effects in a visual oddball task. We therefore suggest that ERP effects–especially in the P3 range–in the Oddball and Cyberball paradigm rely on similar mechanisms, namely the probability of target and non-target events. Since the simulation of social exclusion (Cyberball) did not trigger a unique ERP response, the idea of an exclusion-specific neural alarm system is not supported. The limitations of an ERP-based approach will be discussed

Are auditory cues special? Evidence from cross-modal distractor-induced blindness

A target that shares features with preceding distractor stimuli is less likely to be detected due to a distractor-driven activation of a negative attentional set. This transient impairment in perceiving the target (distractor-induced blindness/deafness) can be found within vision and audition. Recently, the phenomenon was observed in a cross-modal setting involving an auditory target and additional task-relevant visual information (cross-modal distractor-induced deafness). In the current study, consisting of three behavioral experiments, a visual target, indicated by an auditory cue, had to be detected despite the presence of visual distractors. Multiple distractors consistently led to reduced target detection if cue and target appeared in close temporal proximity, confirming cross-modal distractor-induced blindness. However, the effect on target detection was reduced compared to the effect of cross-modal distractor-induced deafness previously observed for reversed modalities. The physical features defining cue and target could not account for the diminished distractor effect in the current cross-modal task. Instead, this finding may be attributed to the auditory cue acting as an especially efficient release signal of the distractor-induced inhibition. Additionally, a multisensory enhancement of visual target detection by the concurrent auditory signal might have contributed to the reduced distractor effect

Intuitive assessment of spatial navigation beyond episodic memory: Feasibility and proof of concept in middle-aged and elderly individuals

Deficits in spatial navigation in three-dimensional space are prevalent in various neurological disorders and are a sensitive cognitive marker for prodromal Alzheimer’s disease, but are also associated with non-pathological aging. However, standard neuropsychological tests used in clinical settings lack ecological validity to adequately assess spatial navigation. Experimental paradigms, on the other hand, are often too difficult for seniors or patients with cognitive or motor impairments since most require operating a human interface device (HID) or use complex episodic memory tasks. Here, we introduce an intuitive navigation assessment, which is conceptualized using cognitive models of spatial navigation and designed to account for the limited technical experience and diverging impairments of elderly participants and neurological patients. The brief computer paradigm uses videos of hallways filmed with eye tracking glasses, without employing an episodic memory task or requiring participants to operate a HID. Proof of concept data from 34 healthy, middle-aged and elderly participants (56–78 years) provide evidence for the assessment’s feasibility and construct validity as a navigation paradigm. Test performance showed normal distribution and was sensitive to age and education, which needs to be considered when investigating the assessment’s psychometric properties in larger samples and clinical populations. Correlations of the navigation assessment with other neuropsychological tests confirmed its dependence on visuospatial skills rather than visual episodic memory, with age driving the association with working memory. The novel paradigm is suitable for a differentiated investigation of spatial navigation in elderly individuals and promising for experimental research in clinical settings

Age-Specific Effects of Visual Feature Binding

Temporary binding of visual features enables objects to be stored and maintained in the visual working memory as a singular structure, irrespective of its inherent complexity. Although working memory capacity is reduced in aging, previous behavioral studies suggest that binding is preserved. Using event-related brain potentials (ERPs), we tested whether stimulus encoding is different in younger (N = 26, mean age = 28.5) and older (N = 22; mean age = 67.4) participants in a change detection task. The processing costs of binding were defined by the difference between feature-alone (color or shape) and feature-binding (color–shape) conditions. The behavioral data revealed that discrimination ability was reduced in the feature-binding condition, and that this effect was more attenuated in older participants. A corresponding ERP effect was not found in early components related to visual feature detection and processing (posterior N1 and frontal P2). However, the late positive complex (LPC) was more often expressed in the feature-binding condition, and the increase in amplitude was more pronounced in older participants. The LPC can be related to attentional allocation processes which might support the maintenance of the more complex stimulus representation in the binding task. However, the selective neural overactivation in the encoding phase observed in older participants does not prevent swap errors in the subsequent retrieval phase

Behavioral and ERP effects in the Cyberball paradigm

Social participation can be examined using the Cyberball paradigm, a virtual balltossing game. Reducing the involvement of the participant is supposed to activate a neural alarm system, and to threaten fundamental social needs. Our previous findings indicate that the latter process can be linked to an enhancement of the centro-parietal P3 amplitude, signaling a modulation of the subjective expectancy of involvement. A preceding more frontal ERP component, the P2, does not depend of the probability of involvement, but reflects the appraisal of social reward. In this experiment, we examined whether overinclusion of participants enhances the satisfaction of social needs, reduces the P3 amplitude correspondingly, and affects central reward processing. In the control condition, participants (n = 40) were included (two co-player, ball Possession 33%), and overincluded (ball possession 46%) in the experimental condition. In a counterbalanced design, we also controlled for the order of conditions. As predicted, overinclusion increased the satisfaction of social needs, with exception of “self esteem”, and reduced the P3 amplitude. As for the frontal P2, overinclusion only enhanced the amplitudes if the less frequent involvement (condition: inclusion) was experienced previously. The behavioral and P3 data suggest that the feelings of social belonging, meaningful existence, and control are related to the subjective expectancy of social involvement, and can be described in terms of a linear continuum ranging from exclusion to overinclusion. In contrast, appraisal of social rewards does not depend on the probability of involvement

Loss of control as a violation of expectations: Testing the predictions of a common inconsistency compensation approach in an inclusionary cyberball game

Personal control relies on the expectation that events are contingent upon one’s own behavior. A common ‘inconsistency compensation approach’ posits that a violation of expectancies in social interaction triggers aversive arousal and compensatory effort. Following this approach, we tested the hypothesis that interventions affecting participants' decisions violate the expected personal control. In a modified version of the established cyberball paradigm, participants were not excluded, but consistently included. However, their decisions regarding the recipient of a ball throw in the virtual game were occasionally overruled (expectancy violation). We hypothesized that this intervention will trigger a P3 response in event-related brain potentials (ERP). Since this component is related to subjective expectancies, its amplitude was assumed to depend on the frequency of interventions (independent factor: loss of control). Further, we manipulated the vertical position of the participants’ avatar on the computer screen (independent factor: verticality). Building on research showing that verticality is related to the self-assigned power and influences the expected level of control, we hypothesized that the ERP effects of intervention should be more pronounced for participants with avatars in superior position. As predicted, both experimental factors interactively affected the expression of the ERP response: In case of low intervention frequency, P3 amplitudes were significantly pronounced if the participants’ avatar was positioned above as compared to below co-players (high > low self-assigned power). The effect of verticality could be traced back to a lack of adaptation of P3 amplitudes to recurring aversive events. By demonstrating that loss of control triggers ERP effects corresponding to those triggered by social exclusion, this study provides further evidence for a common cognitive mechanism in reactions to aversive events based on an inconsistency in expectancy states

Uncovering mnestic problems in help-seeking individuals reporting subjective cognitive complaints

In individuals with subjective cognitive impairments (SCI) the risk for the development of a neurodegenerative disease is assumed to be increased. However, it is not clear which factors contribute to the expression of SCI: Is it related to the cognitive resources already challenged, or is the psycho-affective state of more relevance? Using a novel online assessment combining self-report questionnaires and neuropsychological psychometric tests, significant predictors for the level of complaints were identified in two samples of elderly individuals: Help-seekers (HS, n = 48) consulting a memory clinic and a matched sample of non-help-seekers (nHS, n = 48). Based on the results of the online assessment, the SCI level was found to be significantly determined by the psycho-affective state (depressive mood) in the nHS group, whereas cognitive performance (cued recall) was the main predictor in the HS group. The predictive value of recall performance, however, is more-strongly expressed in memory tests which reduce the impact of compensatory strategies (face–name-association vs. word lists). Our results indicate that the problem-focused behavior of help-seeking individuals is also associated with a higher sensitivity for cognitive deficits—which can be uncovered with an appropriate psychometric test. Considering these factors, the conversion risk in individuals with SCI can probably be determined more reliably

Processing of increased frequency of social interaction in social anxiety disorder and borderline personality disorder

We investigated how patients with social anxiety disorder (SAD) and patients with borderline personality disorder (BPD) process an increase in the frequency of social interaction. We used an EEG-compatible version of the online ball-tossing game Cyberball to induce an increase in the frequency of social interaction. In the first condition, each player received the ball equally often (inclusion: 33% ball reception). In the following condition, the frequency of the ball reception was increased (overinclusion: 45% ball reception). The main outcome variable was the event-related potential P2, an indicator for social reward processing. Moreover, positive emotions were assessed. Twenty-eight patients with SAD, 29 patients with BPD and 28 healthy controls (HCs) participated. As expected, HCs and patients with BPD, but not patients with SAD, showed an increase in the P2 amplitude from the inclusion to the overinclusion condition. Contrary to our expectations, positive emotions did not change from the inclusion to the overinclusion condition. EEG results provide preliminary evidence that patients with BPD and HCs, but not patients with SAD, process an increase in the frequency of social interaction as rewarding

Phenotypic Variability in Autosomal Dominant Familial Alzheimer Disease due to the S170F Mutation of Presenilin-1

Background: In rare cases, patients with Alzheimer disease (AD) present at an early age and with a family history suggestive of an autosomal dominant mode of inheritance. Mutations of the presenilin-1 (PSEN1) gene are the most common causes of dementia in these patients. Early-onset and particularly familial AD patients frequently present with variable non-amnestic cognitive symptoms such as visual, language or behavioural changes as well as non-cognitive, e.g. motor, symptoms. Objective: To investigate the phenotypic variability in carriers of the PSEN1 S170F mutation. Methods: We report a family with 4 patients carrying the S170F mutation of whom 2 underwent detailed clinical examinations. We discuss our current findings in the context of previously reported S170F cases. Results: The clinical phenotype was consistent regarding initial memory impairment and early onset in the late twenties found in all S170F patients. There were frequent non-amnestic cognitive changes and, at early stages of the disease, indications of a more pronounced disturbance of visuospatial abilities as compared to face and object recognition. Non-cognitive symptoms most often included myoclonus and cerebellar ataxia. A review of the available case reports indicates some phenotypic variability associated with the S170F mutation including different constellations of symptoms such as parkinsonism and delusions. Conclusion: The variable clinical findings associated with the S170F mutation highlight the relevance of atypical phenotypes in the context of research and under a clinical perspective. CSF sampling and detection of Ap species may be essential to indicate AD pathology in unclear cases presenting with cognitive and motor symptoms at a younger age