Increased sensitivity to proactive and retroactive interference in amnestic mild cognitive impairment: new insights

Background

Increased sensitivity to proactive (PI) and retroactive (RI) interference has been observed in amnestic mild cognitive impairment (aMCI). PI and RI are often explained as being the result of a response competition mechanism. However, patients with aMCI are supposed to suffer mostly from encoding deficits. We hypothesized that in aMCI interference may occur at encoding and not only at the retrieval stage.

Material and methods

We developed an original paradigm enabling PI and RI to be tested with and without response competitors. Eighteen young controls (YC), 16 elderly controls (EC) and 15 aMCI participated in the study.

Results

The YC and EC groups presented interference effects only in conditions that included a direct response competitor. In contrast, aMCI had interference effects in all conditions including the one without response competitor.

Conclusion

Increased sensitivity to interference in aMCI appears to occur at the encoding/consolidation stage and not only at the retrieval stage, as is the case in healthy subjects. This result is discussed in the context of the associative encoding deficits characterizing aMCI.     

Large-scale brain systems in ADHD: beyond the prefrontal-striatal model

Attention-deficit/hyperactivity disorder (ADHD) has long been thought to reflect dysfunction of prefrontal-striatal circuitry, with involvement of other circuits largely ignored. Recent advances in systems neuroscience-based approaches to brain dysfunction have facilitated the development of models of ADHD pathophysiology that encompass a number of different large-scale resting-state networks. Here we review progress in delineating large-scale neural systems and illustrate their relevance to ADHD. We relate frontoparietal, dorsal attentional, motor, visual and default networks to the ADHD functional and structural literature. Insights emerging from mapping intrinsic brain connectivity networks provide a potentially mechanistic framework for an understanding of aspects of ADHD such as neuropsychological and behavioral inconsistency, and the possible role of primary visual cortex in attentional dysfunction in the disorder.     

Reliability of 2D:4D measurements using a direct method suitable for clinical settings

The second to fourth digit ratio (2D:4D) indicates androgen exposure during early development. Numerous methods are used in the assessment of 2D:4D, however, some are not reliable enough and others are difficult to perform in large epidemiological studies. We assessed the reliability of 2D:4D using a direct method with a caliper, and compared it with a computer-assisted analysis on scanned images. Both methods were moderately correlated, but the scan method produced slightly lower 2D:4D. The main source of variation was differences between subjects (real variation). Reliability was higher among men and among younger participants. All reliability coefficients were higher than 0.8 when three repeated measurements were averaged. Our results suggest that reliability is influenced by participants’ characteristics. Digit ratios determined directly with calipers are reliable when repeated measurements are averaged.     

Testing Target Congruence Theory on Emotional Abuse Victimization Experienced by Heterosexual and LGBQ College Students

Criminological theories traditionally used to explain crime and deviance have now been applied to explain physical intimate partner violence (IPV) experienced by heterosexual and LGBQ victims. Notably missing, however, are studies that test theories that explain why individuals may become victims of emotional abuse by sexual orientation. To this end, we applied target congruence theory to examine the influence of target vulnerability, gratifiability, and antagonism on emotional abuse experienced by college students. Data obtained from two public universities (Heterosexuals=366, LGBQ=113) showed partial support for the theory, with target vulnerability consistently predicting emotional abuse victimization regardless of sexual orientation.     

Emotional responses to a negative emotion induction procedure in Borderline Personality Disorder

The aim of this study was to determine if patients with Borderline Personality Disorder (BPD) present higher emotional response than healthy controls in a laboratory setting. Fifty participants (35 patients with BPD and 15 healthy controls) underwent a negative emotion induction procedure (presentation of standardized unpleasant images). Subjective emotional responses were assessed by means of self-reported questionnaires while biological reactivity during the procedure was measured through levels of salivary cortisol (sCORT) and alphaamylase (sAA). Patients with BPD exhibited significant lower cortisol levels and higher sAA levels compared to controls. Self-reported emotional reactivity did not give rise to differences between groups but participants with BPD did present higher levels of negative emotional intensity at baseline and during the entire procedure. The findings do not give support to the emotional hyperreactivity hypothesis in BPD. However, BPD patients presented heightened negative mood intensity at baseline, which should be considered a hallmark of the disorder. Further studies using more BPD-specific emotion inductions are needed to confirm the trends observed in this study.     

ADAPT: a developmental, asemantic, and procedural model for transcoding from verbal to arabic numerals

This article presents a new model of transcoding numbers from verbal to arabic form. This model, called ADAPT, is developmental, asemantic, and procedural. The authors' main proposal is that the transcoding process shifts from an algorithmic strategy to the direct retrieval from memory of digital forms. Thus, the model is evolutive, adaptive, and particularly suited to account for learning and development. ADAPT, which has been implemented in a computer program, accounts for existing and new developmental data, for new data in adolescents with mild retardation, and for the neuropsychological cases described in the literature.     

Lack of impairment in patients with Parkinson's disease on an object-based negative priming task

12 nondemented patients with Parkinson's disease (M age = 67.3) and 12 normal control participants were administered an object-based attention task that enabled examination of both negative and positive priming. Unlike previous studies in which spatial-based attention tasks were used, results of the present study indicated that the patients displayed negative and positive priming not different from those shown by controls. These results suggest that certain object-based attentional processes may not be impaired in patients with Parkinson's disease.     

Ramadan during a civil war (as reflected in a series of sermons)

In March 1992, the month of Ramadan coincided in Bosnia and Hercegovina with the time between the referendum for the independence of this Yugoslav republic and its recognition by the European Community and the United States. This time was characterized by the transition from a shaky peace into a bloody war. The sermons then given in different mosques in Sarajevo help us to understand better the internal pluralism and evolutions of Bosnian Islam at this time. They also show that some imams used Islam as an impetus to appeasement, and others as an impetus to mobilization. Against the background of extreme tensions between communities, the unanimous perception of Islam as a refuge for the Muslim community encouraged varying re‐Islamization activities.     

Properties of curvilinear vection

Approximately linear relationships were observed between contrast, spatial frequency, temporal frequency, or velocity of stimulation and perceived velocity of curvilinear vection—that is, a visually induced self-motion in a curved path. Similarly, linear relationships were also found between the perceived degree of curvature of curvilinear vection and spatial frequency or velocity of stimulation. Since the perceived velocity of curvilinear vection varies with contrast, spatial frequency, temporal frequency, and angular velocity, and the perceived degree of curvature of curvilinear vection varies only with spatial frequency and angular velocity, peripheral vision is not sufficient for computing accurately the curvilinear component of induced self-motion in a curved path. Concurrently, it was shown that the perceived direction of curvilinear vection is not always unambiguously perceived (Sauvan & Bonnet, 1989). Consequently, it is suggested that two different types of visual processing, which involve the peripheral or the central vision, underlie the processing of curvilinear vection.