Retrieval per se is not sufficient to trigger reconsolidation of human fear memory

Ample evidence suggests that consolidated memories, upon their retrieval, enter a labile state, in which they might be susceptible to change. It has been proposed that memory labilization allows for the integration of relevant information in the established memory trace (memory updating). Memory labilization and reconsolidation do not necessarily occur when a memory is being reactivated, but only when there is something to be learned during memory retrieval (prediction error). Thus, updating of a fear memory trace should not occur under retrieval conditions in which the outcome is fully predictable (no prediction error). Here, we addressed this issue, using a human differential fear conditioning procedure, by eliminating the very possibility of reinforcement of the reminder cue. A previously established fear memory (picture-shock pairings) was reactivated with shock-electrodes attached (Propranolol group, n=18) or unattached (Propranolol No-Shock Expectation group, n=19). We additionally tested a placebo-control group with the shock-electrodes attached (Placebo group, n=18). Reconsolidation was not triggered when nothing could be learned during the reminder trial, as noradrenergic blockade did not affect expression of the fear memory 24h later in the Propranolol No-Shock Expectation group. Only when the outcome of the retrieval cue was not fully predictable, propranolol, contrary to placebo, reduced the startle fear response and prevented the return of fear (reinstatement) the following day. In line with previous studies, skin conductance response and shock expectancies were not affected by propranolol. Remarkably, a double dissociation emerged between the emotional (startle response) and more cognitive expression (expectancies, SCR) of the fear memory. Our findings have important implications for reconsolidation blockade as treatment strategy for emotional disorders. First, fear reducing procedures that target the emotional component of fear memory do not necessarily affect the cognitive component and vice versa. Second, mere retrieval of the fear memory is not sufficient to induce its labilization and reconsolidation.     

I haven't thought about this for years! Dating recent recalls of vivid memories

In three studies, we examined memories for previous recall. In Studies 1 and 2, undergraduates were asked whether they had vivid memories about various childhood events. After a one‐hour (Study 1) or 2‐week (Study 2) interval, they completed a second questionnaire containing new, but also previously presented childhood items. Participants estimated how recently they had thought about old and new items. A non‐trivial proportion of recent recalls of vivid childhood memories was dated incorrectly. In Study 3, women with recovered and continuous memories of childhood sexual abuse (CSA) completed the childhood events questionnaires used in studies 1 and 2. After a one‐hour interval, they indicated how recently they had thought about new, but also previously presented childhood items. Compared to women with continuous CSA memories, women with recovered memories underestimated their prior remembering. Copyright © 2005 John Wiley & Sons, Ltd.     

Defining body deception and its role in peer based social comparison theories of body dissatisfaction

The purpose of the current study was to operationalize the phenomenon of body deception, describe its theoretical importance, and validate its existence in an experimental paradigm. The definition of body deception includes the intentional misrepresentation of information about appearance to others. The present study examined body deception in a controlled experimental study of male and female same-sex peer groups using a series of hierarchical linear models. Ninety male and 90 female undergraduates were randomized to an experimental same-sex peer group or individual control condition. The results suggested that both men and women used body deception among peers, but men's body deception was muscularity driven whereas women's was thinness driven. Body dissatisfaction was significantly predictive of the degree of body deception used by both genders and it was significantly related to peer group membership. An integrated model for the role of body deception in body image disturbance is proposed.     

Similarity and rules United: similarity- and rule-based processing in a single neural network

A central controversy in cognitive science concerns the roles of rules versus similarity. To gain some leverage on this problem, we propose that rule- versus similarity-based processes can be characterized as extremes in a multidimensional space that is composed of at least two dimensions: the number of features (Pothos, 2005) and the physical presence of features. The transition of similarity- to rule-based processing is conceptualized as a transition in this space. To illustrate this, we show how a neural network model uses input features (and in this sense produces similarity-based responses) when it has a low learning rate or in the early phases of training, but it switches to using self-generated, more abstract features (and in this sense produces rule-based responses) when it has a higher learning rate or is in the later phases of training. Relations with categorization and the psychology of learning are pointed out.     

Coping strategies and quality of life among liver transplantation candidates

The maintenance of self-reported quality of life (QL) among people on the liver transplantation waiting list is one of the priority objectives of transplantation teams. Although there are different determinant factors of QL, results are not conclusive. In our study, the goal was to evaluate both the influence of cirrhosis etiology (ethylic and non-ethylic) and the coping strategies used concerning QL. A sample of 93 patients was selected, divided into two groups: ethylic cirrhosis (EC) and non-ethylic cirrhosis (NEC). QL was evaluated through the SF-36 Health Survey, and coping strategies through the Medical Coping Modes Questionnaire (MCMQ). Our results indicated that subjects with EC obtained similar QL levels to subjects with NEC, on all the SF-36 and MCMQ subscales. Furthermore, negative correlations were found between avoidance and acceptance-resignation coping strategies with the SF-36 components. Consequently, the acceptance-resignation strategy was associated with a worse perception of physical functioning, general and mental health, and vitality and role-emotional. Overall, these results suggest that cirrhosis etiology is not a determinant factor of QL, whereas the acceptance-resignation coping strategy might lead to lower self-perception of QL.     

Maturation of EEG power spectra in early adolescence: a longitudinal study

This study investigated the fine-grained development of the EEG power spectra in early adolescence, and the extent to which it is reflected in changes in peak frequency. It also sought to determine whether sex differences in the EEG power spectra reflect differential patterns of maturation. A group of 56 adolescents were tested at age 10 years and then at two further time-points approximately 18 months apart. The EEG was recorded during both eyes-closed and eyes-open conditions and Fourier transformed to provide estimates of absolute and relative spectral power at 0.5 Hz intervals from 0.5 to 40 Hz. The peak alpha frequency for each individual at each time-point was also determined for relative spectral power. Partial Least Squares (PLS) analysis was used to determine the combination of electrodes and frequencies that showed developmental change, or differed between the sexes. As a function of age, absolute delta and theta frequencies power decreased, and relative alpha2 and beta frequencies increased, replicating the standard findings of a decrease in lower, and increase in higher, frequencies with age. A small but significant increase in peak alpha frequency with age was detected. Moreover PLS analysis performed with individual alpha frequencies aligned to 10 Hz suggested that the age-related increase seen in alpha2 relative power was driven by changes in the peak frequency. Although males demonstrated higher alpha power than females, there were no sex differences in peak frequency, suggesting that there may be more to sex differences in EEG power than simply different rates of maturation between the two sexes.     

Executive Functioning Characteristics Associated with ADHD Comorbidity in Adolescents with Disruptive Behavior Disorders

The nature of executive dysfunction in youth with disruptive behavior disorders (DBD) remains unclear, despite extensive research in samples of children with attention-deficit hyperactivity disorder (ADHD). To determine the relationship between DBD, ADHD, and executive function deficits in aggressive teens, adolescents with DBD and comorbid ADHD (DBD + ADHD; n = 25), DBD without ADHD (DBD-ADHD; n = 23), and healthy controls (HC; n = 25) were compared on neurocognitive tests and questionnaires measuring executive functioning. Teens with DBD + ADHD performed worse on both neurocognitive and questionnaire measures of executive function than the DBD-ADHD and HC groups. Results suggest that subgroups of DBD may exist depending on the presence or absence of comorbid ADHD, which may have implications for the selection and efficacy of treatment strategies.     

Orthographic redundancy in letter recognition: Orthographic neighbourhood or orthographic context?

Abstract

In explaining the word-superiority effect (i.e. the better detection of a letter in a word than in a nonword), the Interactive Activation Model (IAM) of McClelland and Rumelhart (1981) and the Fuzzy Logical Model of Perception (FLMP) of Massaro (1979) emphasise the importance of orthographic redundancy (i.e. the regularities of letters within words) in different ways. In the IAM, orthographic redundancy is defined by the number of “friends”; that is, words sharing the same letters except one with the word containing the target letter. Such friends constitute the orthographic “neighbourhood”. FLMP stresses the orthographic “context”; that is, the similarity of the word with a representation in the lexicon. The orthographic neighbourhood and context are manipulated independently in Experiment 1, and the findings are better understood in terms of the orthographic neighbourhood. By increasing the number of friends in nonwords, better letter detection is also obtained in nonwords as compared with letter detection in random letter strings (Experiment 2). These findings, together with the position effects obtained, are more clearly in agreement with the IAM than with the FLMP.     

Lukasiewicz's Many-valued Logic and Neoplatonic Scalar Modality

This paper examines the role of ‘situations’ in John Dewey's philosophy of logic. To do this properly it is necessary to contrast Dewey's conception of experience and mentality with views characteristic of modern epistemology. The primary difference is that, rather than treat experience as peripheral and or external to mental functions (reason, etc.), we should treat experience as a field in and as a part of which thinking takes place. Experience in this broad sense subsumes theory and fact, hypothesis and evidence, reason and observation, thought and perception. Logic in this view is a formal study of the generic features of all possible kinds of experience in this broad (thick, deep, wide, multifaceted) sense. The goal of this paper is to explain what Dewey thinks a situation is in the context of this view of experience, and to argue for the fundamental importance of that idea for logic and philosophy in general.