The relation of learning disabilities to the long-term outcomes of concussion

ObjectiveThis study sought to cross-sectionally evaluate the relation between learning disorders (LD) and long-term concussion outcomes.MethodSeventy-three asymptomatic male university athletes (23 history of concussion with LD; 24 history of concussion no LD; 26 controls) completed the Beck Depression Inventory-2 (BDI-II), the Profile of Mood States (POMS), the Cogstate battery, and an Oddball task during which event-related brain potentials were recorded.ResultsConcussed athletes with LD exhibited greater depressive symptoms (BDI-II), greater total mood disturbance (POMS), decreased accuracy on the One-Card Learning and the N-back task (Cogstate), decreased accuracy on the Oddball task, and reduced ERN amplitude relative to both the concussed athletes without a LD and controls. Concussed athletes with LD also exhibited prolonged P3 latency relative to controls. Irrespective of LD, concussed athletes exhibited increased anger-hostility and decreased Pe amplitudes relative to controls. No differences were observed in P3a amplitude or latency.ConclusionHaving LD may be a significant factor moderating the neurophysiological, cognitive and psycho-affective outcomes of concussion, and may explain a significant portion of the persistent deficits observed by researchers and clinicians.     

The Isolation, Primacy, and Recency Effects Predicted by an Adaptive LTD/LTP Threshold in Postsynaptic Cells

An item that stands out (is isolated) from its context is better remembered than an item consistent with the context. This isolation effect cannot be accounted for by increased attention, because it occurs when the isolated item is presented as the first item, or by impoverished memory of nonisolated items, because the isolated item is better remembered than a control list consisting of equally different items. The isolation effect is seldom experimentally or theoretically related to the primacy or the recency effects—that is, the improved performance on the first few and last items, respectively, on the serial position curve. The primacy effect cannot easily be accounted for by rehearsal in short-term memory because it occurs when rehearsal is eliminated. This article suggests that the primacy, the recency, and the isolation effects can be accounted for by experience-dependent synaptic plasticity in neural cells. Neurological empirical data suggest that the threshold that determines whether cells will show long-term potentiation (LTP) or long-term depression (LTD) varies as a function of recent postsynaptic activity and that synaptic plasticity is bounded. By implementing an adaptive LTP-LTD threshold in an artificial neural network, the various aspects of the isolation, the primacy, and the recency effects are accounted for, whereas none of these phenomena are accounted for if the threshold is constant. This theory suggests a possible link between the cognitive and the neurological levels.     

The mind-brain relationship: the emergent self

This paper explores the mind-brain relationship, using insights from contemporary neuroscience. It seeks to investigate how our brains become who we are, how subjective experience arises. In order to do this some explanation is given of the basic concepts of how the brain produces our subjective mental life. Current neuropsychological and neurobiological understanding of early brain development, memory, emotion and consciousness are explored. There is also an attempt at mapping the mind-brain-self relationship from a uniquely Jungian perspective. Clinical material is included in order to show the relevance of these insights to our work in the consulting room, arguing the value of the affect-regulating, relational aspects of the analytic dyad that forge new neural pathways through emotional connection. Such experience forms the emotional scaffolding necessary for the emergence of reflective function.     

Preference for progressive delays and concurrent physical therapy exercise in an adult with acquired brain injury

The purpose of this study was to increase self-control and engagement in a physical therapy task (head holding) for a man with acquired traumatic brain injury. Once impulsivity was observed (i.e., repeated impulsive choices), an experimental condition was introduced that consisted of choices between a small immediate reinforcer, a large fixed-delay reinforcer, and a large progressive-delay reinforcer. The participant showed a preference for the progressive-delay option, even when the duration of the delay exceeded that of the fixed delay. The results have implications for establishing optimal choice making and teaching life-enhancing skills.     

On aims and methods in the neuroimaging of derived relations

Ingenious and seemingly powerful technologies have been developed recently that enable the visualization in some detail of events in the brain concomitant upon the ongoing behavioral performance of a human participant. Measurement of such brain events offers at the very least a new set of dependent variables in relation to which the independent variables familiarly manipulated in the operant laboratory may be explored. Two related paradigms in which a start has been made in such research concern the derivation of novel or emergent relations from a baseline set of trained relations, and include the phenomenon of transitive inference (TI), observed in studies of stimulus equivalence (SE) and serial learning (SL) or seriation. This paper reviews some published and forthcoming neuroimaging studies of these and related phenomena, and considers how this line of research both demands and represents a welcome synthesis between types of question and levels of explanation in behavioral science that often have been seen as antithetical.     

Mindfulness,learning and the brain

I have tried to sketch an approach to the complex phenomena that go by the name of ‘mindfulness’ that both does justice to this complexity and depth, and also offers a way of thinking about mindfulness in evolutionary, ecosocial and neural terms: terms that enable us to ask questions like: where did mindfulness come from? What kind of consciousness is it? What was it for, before it was co-opted by spiritual and therapeutic kinds of discourse and practice? And how do brains do it? In essence, I am suggesting that human brains seem to have developed, for good evolutionary reasons, a degree of facility with imaginative empathy and as-if identification; and that mindfulness capitalises on this to create what is probably a uniquely human form of learning—or rather unlearning.     

Examining the Role of Social Network Intervention as an Integral Component of Community-Based,Family-Focused Practice

Social network intervention aimed at bolstering the informal supports of high risk families is recognized as a common element of community-based, family-focused practice models, such as intensive family preservation services (IFPS), multisystemic therapy (MST), and the wraparound process. The empirical research basis for these practice models is examined, with an eye toward discerning the extent to which network intervention is identified as a critical component of comprehensive service. Results reveal that few studies make clear the degree to which treatment adhered to a focus on natural network enhancement or the development of informal resources. Those that did, suggest that relatively few families received this form of ecologically-oriented intervention. Consequently, this body of practice research offers insufficient evidence of the benefits or limitations associated with network facilitation with multi-need families. Explanations for these findings are explored and directions for future research are recommended.     

Disclosure of HIV-Positive Status to Latino Gay Men's Social Networks

This study explored disclosure of serostatus in a sample of 155 HIV-positive Latino gay men from New York City and Washington, DC. We examined rates of disclosure to different members of the social network: mothers, fathers, close friends, and primary sexual partners. There were high rates of disclosure of HIV-positive serostatus to main partners and closest friends and lower rates to fathers and mothers. We examined the role of 3 contextual target-dependent factors (emotional closeness to target, anticipated reactions from target, and target's knowledge of sexual orientation), as well as acculturation and time since diagnosis. Three separate logistic regression models were performed to predict disclosure of HIV-positive status to 3 targets: mothers, fathers, and closest friends. We found that disclosure was not a generalized tendency, but rather different factors were influential depending on the target. Whether the target was aware of participant's sexual orientation was associated with disclosure in all 3 models. Greater emotional closeness also predicted disclosure to mother and father; greater U.S. acculturation was associated with disclosure to father and marginally to mother. A longer time since diagnosis was associated with disclosure to the closest friend. These findings highlight the importance of taking into account roles and relationships, and their effect on disclosure.     

The scaling of postural adjustments during bimanual load-lifting in traumatic brain-injured adults

Previous postural studies of traumatic brain injury (TBI) patients have been limited to identifying deficits in static and quasi-dynamic postural control tasks such as weight shifting. In this study, we examined whether or not patients with TBI are able to scale adequately their postural adjustments during the performance of the dynamic task of bimanual load-lifting. An age matched group of healthy adults served as controls. We used the Tetrax posturography system that calculates a stability score (ST) based on fluctuations in vertical ground reaction forces, normalized for body weight. During quiet standing, the ST scores of the TBI group were significantly higher than the control group. Forward weight shift and percentage change in the vertical ground reaction forces (lift postural adjustment (LPA) and post-lift postural adjustment (PLPA) scores) linearly increased with increasing load weight in both healthy and TBI subjects. Group differences were found in the magnitude of forward weight shift but not in the relative increase of the LPA and PLPA scores during the lifting and post-lifting phases respectively. The forward weight shift of the TBI group was lower-than-normal and asymmetrical--there was significantly less forward weight shift on the more affected than on the less affected limb. In addition, a significant amplitude coupling was found between the scaling of the weight shift of the heel and forefoot of each limb. However, no coupling was found between the weight shift amplitudes of homologous parts of both limbs in the TBI group. The results showed that scaling based on prior experience was preserved in the TBI group, though some TBI subjects demonstrated absent scaling in either the more affected or less affected heel or forefoot. The differences between the normal and TBI groups in postural adjustments are not necessarily a sign of pathology; rather they may represent a deliberate choice of the central nervous system to counteract predictable disturbances.     

Depression After Traumatic Brain Injury: A Review of Evidence for Clinical Heterogeneity

Depression represents a major source of disability among individuals who have suffered a traumatic brain injury (TBI), with estimates of prevalence in this population ranging over 50%. In comparison with other sequelae of TBI, depression is often poorly conceptualized and treated among acute care and rehabilitation professionals. One reason for this is the lack of clear etiological models for the development of depression following TBI. This paper argues that post-TBI depression actually represents a heterogeneous category, with multiple etiologic pathways and clinical implications. The literature in this area is reviewed, with an emphasis on an appreciation of the diversity within this clinical population. Conclusions focus on suggestions for differential diagnosis and treatment options.