Object decision test (BORB): normative data for the adult Quebec population and performance in Alzheimer’s disease and the semantic variant of primary progressive aphasia

Object decision (OD) test is one subtest of the Birmingham Object Recognition Battery (BORB). It is useful for differential diagnosis among several neurodegenerative diseases. However, normative data provided with this battery count on very few subjects and do not control for the effect of age, which limits interpretability. The purpose of Study 1 was to provide normative data for the OD test of the BORB (version A—hard). The objectives of Study 2 were to establish the diagnostic validity of this task and predictive validity of the normative data in the case of the semantic variant of primary progressive aphasia (svPPA) and Alzheimer’s disease (AD).Based on multiple linear regressions, equations to calculate Z-scores corrected for age were provided for 130 participants aged from 47 to 89 years. Performance of 20 healthy participants was compared to that of 14 individuals with svPPA and 18 with AD. After controlling for confounders, participants with svPPA had a lower total score than controls and AD participants. AD participants had a poorer performance than controls only when chimeric objects were considered. Among those with a deficit on the total score of the test, 94% (17/18, including 12 with svPPA) were correctly identified as having a pathological condition (svPPA or AD). This test could help refine differential diagnosis between svPPA and AD patients, especially before the deficits of episodic memory show up.     

The level of cholinergic nucleus basalis activation controls the specificity of auditory associative memory

Learning involves not only the establishment of memory per se, but also the specific details of its contents. In classical conditioning, the former concerns whether an association was learned while the latter discloses what was learned. The neural bases of associativity have been studied extensively while neural mechanisms of memory specificity have been neglected. Stimulation of the cholinergic nucleus basalis (NBs) paired with a preceding tone induces CS-specific associative memory. As different levels of acetylcholine may be released naturally during different learning situations, we asked whether the level of activation of the cholinergic neuromodulatory system can control the degree of detail that is encoded and retrieved. Adult male rats were tested pre- and post-training for behavioral responses (interruption of ongoing respiration) to tones of various frequencies (1-15 kHz, 70 dB, 2 s). Training consisted of 200 trials/day of tone (8.0 kHz, 70 dB, 2 s) either paired or unpaired with NBs (CS-NBs = 1.8 s) at moderate (65.7+/-9.0 microA, one day) or weak (46.7+/-12.1 microA, three training days) levels of stimulation, under conditions of controlled behavioral state (pre-trial stable respiration rate). Post-training (24 h) responses to tones revealed that moderate activation induced both associative and CS-specific behavioral memory, whereas weak activation produced associative memory lacking frequency specificity. The degree of memory specificity 24 h after training was positively correlated with the magnitude of CS-elicited increase in gamma activity within the EEG during training, but only in the moderate NBs group. Thus, a low level of acetylcholine released by the nucleus basalis during learning is sufficient to induce associativity whereas a higher level of release enables the storage of greater experiential detail. gamma waves, which are thought to reflect the coordinated activity of cortical cells, appear to index the encoding of CS detail. The findings demonstrate that the amount of detail in memory can be directly controlled by neural intervention.     

Relations with Parents and with Peers,Temperament, and Trajectories of Depressed Mood During Early Adolescence

The present study examined (a) whether groups of children can be empirically identified with distinct longitudinal profiles of depressed mood from late childhood through early adolescence, (b) to what extent these different longitudinal depression profiles are predicted by problematic relations with parents, same-sex peers, and other-sex peers, and (c) what role individuals' temperamental characteristics play in this context. Based on a sample of 414 early adolescents (197 girls), four groups were identified with distinct longitudinal profiles of depressed mood between ages 11 and 14: One group with consistently low levels of depressed mood, another with consistently moderate levels of depressed mood, a third group whose depressed mood increased sharply from late childhood through early adolescence, and a fourth group who already showed clinical-range levels of depressed mood during late childhood and whose depressive feelings increased even slightly more thereafter. Subsequent analyses revealed that rejection by same-sex peers was related to the odds of following an increasing trajectory of depressed mood, but only for girls with a highly reactive temperament. A problematic relationship with parents increased the odds of an elevated trajectory of depressed mood regardless of individual temperament. The theoretical and practical implications of these findings are discussed.     

Social Support Mediates the Effects of Dual-Focus Mutual Aid Groups on Abstinence from Substance Use

Background: Specialized 12-step based groups have emerged to address the needs of persons recovering from both substance abuse and psychiatric illness. Objective: This study investigates the role of social support in mediating the association between mutual aid participation and subsequent substance use for dually diagnosed persons. Method: A cohort of Double Trouble in Recovery (DTR) members in New York City were studied prospectively over a two-year period. Findings: Longer DTR participation during the first year of the study was associated with lower substance use in the second year; that effect was partially explained by the maintenance of high level of social support. Conclusion: These findings speak of the enduring influence of 12-step attendance on reducing substance use, and underline the importance of both 12-step attendance and supportive networks for dually diagnosed persons.     

A methodological note on nonlinear time series analysis: is the open- and closed-loop model of Collins and De Luca (1993) a statistical artifact?

The authors reexamined, theoretically and empirically, the method proposed by J. J. Collins and C. D. De Luca (1993) for the analysis of center-of-pressure trajectories. The main argument in this article is that Collins and De Luca's approach is not adapted to the analysis of bounded time series and leads to statistical artifacts such as underestimation of the diffusion process for long-term intervals. The open- and closed-loop model developed by Collins and De Luca is a direct consequence of those statistical problems. Applying more classical methods, such as rescaled range analysis or detrended fluctuation analysis, the authors show that center-of-pressure trajectories can be modeled as continuous, antipersistent fractional Brownian motion. More specifically, those trajectories behave like 1/f noise, a ubiquitous feature in adaptive biological systems.     

Low-ball and compliance to a request: an application in a field setting

The low-ball refers to a compliance technique in which a demand of someone to agree to a request is followed by telling the person the real cost of the request. The number of people who maintain their first decision is larger than the number in the condition in which the real cost of the request is stated prior to the initial compliance. Researches in this paradigm traditionally included a request addressed by a professor to students but was never tested between strangers. So, an experiment was carried out in which people were solicited to keep a dog (8 kg) on a lead until a male confederate returned from a visit to someone in a hospital. In low-ball condition, the confederate told the subject who agreed to the request that it would take 30 min., whereas in the control condition the confederate gave this information when stating his request. Analysis showed that low-ball technique leads people to maintain their first decision.     

Multisensory spatial representations in eye-centered coordinates for reaching

Humans can reach for objects with their hands whether the objects are seen, heard or touched. Thus, the position of objects is recoded in a joint-centered frame of reference regardless of the sensory modality involved. Our study indicates that this frame of reference is not the only one shared across sensory modalities. The location of reaching targets is also encoded in eye-centered coordinates, whether the targets are visual, auditory, proprioceptive or imaginary. Furthermore, the remembered eye-centered location is updated after each eye and head movement. This is quite surprising since, in principle, a reaching motor command can be computed from any non-visual modality without ever recovering the eye-centered location of the stimulus. This finding may reflect the predominant role of vision in human spatial perception.     

Affective personality differences in neural processing efficiency confirmed using fMRI

To test for a relation between individual differences in personality and neural-processing efficiency, we used functional magnetic resonance imaging (fMRI) to assess brain activity within regions associated with cognitive control during a demanding working memory task. Fifty-three participants completed both the self-report behavioral inhibition sensitivity (BIS) and behavioral approach sensitivity (BAS) personality scales and a standard measure of fluid intelligence (Raven’s Advanced Progressive Matrices). They were then scanned as they performed a three-back working memory task. A mixed blocked/ event-related fMRI design enabled us to identify both sustained and transient neural activity. Higher BAS was negatively related to event-related activity in the dorsal anterior cingulate, the lateral prefrontal cortex, and parietal areas in regions of interest identified in previous work. These relationships were not explained by differences in either behavioral performance or fluid intelligence, consistent with greater neural efficiency. The results reveal the high specificity of the relationships among personality, cognition, and brain activity. The data confirm that affective dimensions of personality are independent of intelligence, yet also suggest that they might be interrelated in subtle ways, because they modulate activity in overlapping brain regions that appear to be critical for task performance.     

Dual commitment to organization and supervisor: A person-centered approach

A recent trend in commitment research has been to use person-centered analytic strategies to identify homogeneous subgroups with varying configurations of commitment mindsets (affective, normative, continuance) or targets (e.g., organization, supervisor, team). A person-centered approach takes a more holistic perspective than the traditional variable-centered approach and can reflect potentially complex interactions among commitment mindsets and/or targets. We extend application of the person-centered approach to investigate profiles of commitment to two interrelated targets, the organization and supervisor, in two studies (Ns = 481 and 264) involving Belgian university graduates. Using latent profile analyses, we found that a similar 5-profile model fit best in both studies. The mindset pattern for the two targets was similar for some profile groups, but differed for others. The groups differed on perceived organizational and supervisory support and voluntary turnover largely as expected from commitment and support theory. Implications for future research and management practice are discussed.