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 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.     

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.     

Separating item-related electrophysiological indices of retrieval effort and retrieval orientation

The relationship between two classes of retrieval process-retrieval orientation and retrieval effort-was investigated using electrophysiological (ERP) and behavioural measures. ERPs were recorded during retrieval phases of exclusion tasks in which participants focused on retrieval of either phonological or semantic associates that were generated in a prior study phase. Participants were separated into two groups on the basis of the relative accuracy of their memory judgments in the retrieval tasks (high vs. low relative difficulty) as a means of assessing retrieval effort. The critical contrasts were between the ERPs evoked by unstudied test items separated according to group and emphasis of the retrieval task (semantic vs. phonological). Reliable differences according to task were evident in the high relative difficulty group only. This finding is consistent with the view that, for this task pair at least, ERPs are sensitive to the processes set in train in pursuit of task relevant information (retrieval orientations) only when relative difficulty is high.     

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.     

Activational and organizational effects of estradiol on male behavioral neuroendocrine function

Evidence is reviewed that establishes an essential role for estradiol, synthesized locally via aromatization of testosterone in the adult as well as the developing male nervous system of rats, ferrets, and mice, in both the organization and adult activation of neural circuits that control appetitive as well as consummatory components of masculine sexual behavior. Evidence is also reviewed suggesting that perinatal estradiol biosynthesis and action in the female's nervous system may contribute to the development of female-typical sexual behavior.     

An ERP study of sensory mismatch expressions in Japanese

Combinations of different sensory words produce mismatch expressions like smooth color and red touch in contrast to normal expressions like red color and smooth touch. Concerning these sensory mismatch expressions, results of three experiments are reported. Experiment 1 revealed that (i) mismatch expressions were less comprehensible than normal expressions, and that (ii) there were two patterns among mismatch expressions: the high-comprehensible mismatch expression (HighCME, e.g., smooth color) and the low-comprehensible mismatch expression (LowCME, e.g., red touch). Experiment 2 revealed that the mismatch expressions produced a significantly greater N400 amplitude than the normal expressions. Experiment 3 implied that the difference between High/LowCME was reflected in a later latency band or in a topographical difference of N400, although the statistical significance was marginal. It is argued that the processes to integrate linguistic elements (e.g., combining adjectives and nouns) are not homogeneous.