Comparison of chemosensory, auditory and visual event-related potential amplitudes

To enhance understanding of neuropsychological processing underlying chemosensory event-related potentials (CSERPs), the objective of the present study was to compare CSERPs with auditory (AERPs) and visual event-related potentials (VERPs), and to approach the question of similarities in neuropsychological processing by means of correlation and cluster analyses. A multisensory ERP protocol was used, in which olfactory/chemosomatosensory (pyridine), auditory (1000-Hz tone) and visual (white circle) stimuli were presented in a pseudo-randomized sequence to 18 young, healthy adults. The results show (1) a morphological relation between P2 and P3 components that is different for the chemosensory than for the auditory and visual modalities, (2) a relatively weak association between the chemosensory and auditory/visual modalities for P3 in terms of both correlation and cluster, and (3) a P2/P3 cluster for the chemosensory but not auditory or visual modality. This supports the claim that the chemosensory P2 and P3 components reflect similar neuropsychological processes.     

Expectancy confirmation in spite of disconfirming evidence: The case of price increases due to the introduction of the Euro

People in Germany overwhelmingly believe that the Euro introduction caused an overall price increase, however, no such increase actually took place. To investigate whether this disparity could be based on biased perceptions of the average price trend, four studies were conducted. Participants received two menus from a restaurant (one ‘old’ menu with German Mark (DM) prices and one ‘new’ menu with Euro prices) and were asked to estimate the price trend (in per cent). In all of these studies, price trend judgements were biased towards rising prices. If the prices had in fact been raised, the magnitude of this price increase was overestimated. If the prices had remained stable, significant price increases were perceived. And if the prices had fallen, they were perceived as having remained stable. The bias was systematically related to participants' expectations concerning price increases. A ‘selective outcome correction’ hypothesis proved to best fit the data: incorrect calculation outcomes that are in line with one's expectations are overlooked, whereas incorrect inconsistent outcomes are detected and corrected. The results imply that expectations can influence judgements even when clear disconfirming evidence is available that can be compared with an objective standard, thus leaving no room for interpretation. Copyright © 2004 John Wiley & Sons, Ltd.     

The layers of presence: a bio-cultural approach to understanding presence in natural and mediated environments.

This paper proposes a bio-cultural theory of presence based on four different positions related to the role and structure of presence, as follows. First, presence is a defining feature of self and it is related to the evolution of a key feature of any central nervous system: the embedding of sensory-referred properties into an internal functional space. Without the emergence of the sense of presence it is impossible for the nervous system to experience distal attribution: the referencing of our perception to an external space beyond the limits of the sensory organs themselves. Second, even if the experience of the sense of presence is a unitary feeling, conceptually it can be divided in three different layers, phylogenetically different and strictly related to the three levels of self identified by Damasio. In particular we can make conceptual distinctions between proto presence (self vs. non self), core presence (self vs. present external world), and extended presence (self relative to present external world). Third, given that each layer of presence solves a particular facet of the internal/external world separation, it is characterized by specific properties. Finally, in humans the sense of presence is a direct function of these three layers: the more they are integrated, the more we are present. In the experience of optimal presence, biologically and culturally determined cognitive processes are working in harmony--to focus all levels of the self on a significant situation in the external world, whether this is real or virtual.     

The Role of Group Experiences in the Healing Process of Massive Childhood Holocaust Trauma

This paper proposes that Holocaust child survivors profoundly benefit from participating in a variety of group modalities. From participant observation and interviews we demonstrate that affiliation in organizations, social events, commemorations, rituals, and particular therapeutic groups each contributes to the well-being of Holocaust child survivors. Mourning is enhanced by joining forces with others from a historical event that left many children orphans, bereft of a home, a community, a country, and an identity. Group participants achieve individuation and ego integration, and gain clarity about the complex psychological consequences of surviving the Holocaust. A fragmented identity is restored through the opportunity of interacting with others whose identity has been ruptured by similar cataclysmic events.Senior Research Fellow, Graduate Center of CUNY. Codirector, Psychotherapy with Generations of the Holocaust and Related Traumas, Training Institute for Mental Health. Codirector, Child Development ResearchSenior Member and Faculty, National Psychological Association for Psychoanalysis. Codirector, Child Development Research     

Conformity effects in memory as a function of group size,dissenters and uncertainty

In two experimental studies we investigated how false memory reports provided by anonymous group members affect individuals' recognition. Participants were presented with a series of salient and non‐salient objects and recognition memory was subsequently assessed for presented and non‐presented stimuli. In this recognition test, participants were confronted with (in)correct responses from bogus group members. The findings indicate that the bogus answers influenced memory reports only in the absence of a clear recollection and if the stimulus was not judged to be particularly memorable. Moreover, we found no evidence that motivational influences affected participants' judgements. However, the influence of the bogus group decreased with the presence of dissenters who broke the unanimity of the group, and it increased with higher uncertainty. Copyright © 2002 John Wiley & Sons, Ltd.     

Developmental differences in memory for cross‐modal associations

Associative learning is critical to normal cognitive development in children. However, young adults typically outperform children on paired‐associate tasks involving visual, verbal and spatial location stimuli. The present experiment investigated cross‐modal odour–place associative memory in children (7–10 years) and young adults (18–24 years). During the study phase, six odours were individually presented and paired with one of 12 spatial locations on a board. During the test phase, participants were presented with the six stimuli individually and were asked to place each stimulus on the correct spatial location. Children committed significantly more errors on the odour–place task than did young adults. However, item recognition memory for the odours or spatial locations involved in the odour–place associative memory task was similar between children and young adults. Therefore, poor odour–place associative memory in children did not result from impaired memory for the individual odours or spatial locations involved in the associations. The results suggest that cross‐modal associative memory is not fully developed in children.     

Discriminating between strong and weak structures in three‐mode principal component analysis

Recently, a number of model selection heuristics (i.e. DIFFIT, CORCONDIA, the numerical convex hull based heuristic) have been proposed for choosing among Parafac and/or Tucker3 solutions of different complexity for a given three‐way three‐mode data set. Such heuristics are often validated by means of extensive simulation studies. However, these simulation studies are unrealistic in that it is assumed that the variance in real three‐way data can be split into two parts: structural variance, due to a true underlying Parafac or Tucker3 model of low complexity, and random noise. In this paper, we start from the much more reasonable assumption that the variance in any real three‐way data set is due to three different sources: (1) a strong Parafac or Tucker3 structure of low complexity, accounting for a considerable amount of variance, (2) a weak Tucker3 structure, capturing less prominent data aspects, and (3) random noise. As such, Parafac and Tucker3 simulation studies are run in which the data are generated by adding a weak Tucker3 structure to a strong Parafac or Tucker3 one and perturbing the resulting data with random noise. The design of these studies is based on the reanalysis of real data sets. In these studies, the performance of the numerical convex hull based model selection method is evaluated with respect to its capability of discriminating strong from weak underlying structures. The results show that in about two‐thirds of the simulated cases, the hull heuristic yields a model of the same complexity as the strong underlying structure and thus succeeds in disentangling strong and weak underlying structures. In the vast majority of the remaining third, this heuristic selects a solution that combines the strong structure and (part of) the weak structure.     

Subtle Bias Against Muslim Job Applicants in Personnel Decisions1

Contemporary theories of prejudice suggest that racism still exists in society, but is expressed in subtle and justifiable manners. Employing such theoretical frameworks, the present study examined subtle ways in which social category information is used differentially in personnel decisions. Participants (managers or undergraduates) were presented with background information and a résumé (with a typical Muslim or European American name) for a hypothetical job applicant. After reviewing the résumés, participants judged the applicant on hirability, salary assignment, and other job‐related characteristics. Results showed that the Muslim applicant, relative to the American, was unfavorably judged in salary assignment and job‐related characteristics in the presence of negative information. Both managers and undergraduates exhibited the same bias. Implications of the findings are discussed.     

Problem Solvers Adjust Cognitive Offloading Based on Performance Goals

When incorporating the environment into mental processing (cf., cognitive offloading), one creates novel cognitive strategies that have the potential to improve task performance. Improved performance can, for example, mean faster problem solving, more accurate solutions, or even higher grades at university.¹ Although cognitive offloading has frequently been associated with improved performance, it is yet unclear how flexible problem solvers are at matching their offloading habits with their current performance goals (can people improve goal‐related instead of generic performance, e.g., when being in a hurry and aiming for a “quick and dirty” solution?). Here, we asked participants to solve a cognitive task, provided them with different goals—maximizing speed (SPD) or accuracy (ACC), respectively—and measured how frequently (Experiment 1) and how proficiently (Experiment 2) they made use of a novel external resource to support their cognitive processing. Experiment 1 showed that offloading behavior varied with goals: Participants offloaded less in the SPD than in the ACC condition. Experiment 2 showed that this differential offloading behavior was associated with high goal‐related performance: fast answers in the SPD, accurate answers in the ACC condition. Simultaneously, goal‐unrelated performance was sacrificed: inaccurate answers in the SPD, slow answers in the ACC condition. The findings support the notion of humans as canny offloaders who are able to successfully incorporate their environment in pursuit of their current cognitive goals. Future efforts should be focused on the finding's generalizability, for example, to settings without feedback or with high mental workload.