Brain plasticity,learning, and developmental disabilities

This is a time of significant gains in methodological development for examining the developing human brain. New efforts are underway to unify the understanding of the development of brain anatomy with physiological, cellular and molecular processes that influence behavioral development. This special issue provides animal models of behavior and brain development, applications of noninvasive imaging and genetic methods to human brain development and behavior, and select reviews of how these models and methods have been applied to the examination of developmental disabilities. This issue reflects a sampling of current approaches to the study of brain plasticity, development and learning in typically and atypically developing humans and animals.     

Neural correlates of establishing, maintaining, and switching brain states

Although the study of brain states is an old one in neuroscience, there has been growing interest in brain state specification owing to MRI studies tracing brain connectivity at rest. In this review, we summarize recent research on three relatively well-described brain states: the resting, alert, and meditation states. We explore the neural correlates of maintaining a state or switching between states, and argue that the anterior cingulate cortex and striatum play a critical role in state maintenance, whereas the insula has a major role in switching between states. Brain state may serve as a predictor of performance in a variety of perceptual, memory, and problem solving tasks. Thus, understanding brain states is critical for understanding human performance.     

Where brain,body, and world collide

The brain fascinates because it is the biological organ of mindfulness itself. It is the inner engine that drives intelligent behavior. Such a depiction provides a worthy antidote to the once-popular vision of the mind as somehow lying outside the natural order. However, it is a vision with a price. For it has concentrated much theoretical attention on an uncomfortably restricted space; the space of the inner neural machine, divorced from the wider world which then enters the story only via the hygienic gateways of perception and action. Recent work in neuroscience, robotics and psychology casts doubt on the effectiveness of such a shrunken perspective. Instead, it stresses the unexpected intimacy of brain, body and world and invites us to attend to the structure and dynamics of extended adaptive systems — ones involving a much wider variety of factors and forces. Whilst it needs to be handled with some caution, I believe there is much to be learnt from this broader vision. The mind itself, if such a vision is correct, is best understood as the activity of an essentially situated brain: a brain at home in its proper bodily, cultural and environmental niche.     

Race, brain size, and intelligence: another reply to Cernovsky

Five sets of observations require explanation. Firstly, within both black and white populations there is a small positive correlation between IQ and brain size whether or not there is control for body size. Secondly, racial differences in average brain size occur such that Mongoloids greater than Caucasoids greater than Negroids especially with control for body size. Thirdly, mammals with larger brains relative to their bodies perform better on learning tasks than mammals with smaller brains relative to their bodies. Fourthly, average racial differences on measures of cognitive performance parallel the differences in average brain size. Fifthly, average racial differences on numerous other traits parallel the differences in intelligence and brain size. It is incumbent on scientists to explain these facts.     

MACHINES, BRAINS, AND PERSONS

Abstract. This paper explores the suggestion that our conscious experience is embodied in, rather than interactive with, our brain activity, and that the distinctive brain correlate of conscious experience lies at the level of global functional organization. To speak of either brains or computers as thinking is categorically inept, but whether stochastic mechanisms using internal experimentation rather than rule-following to determine behavior could embody conscious agency is argued to be an open question, even in light of the Christian doctrine of man. Mechanistic brain science does nothing to discredit Christian experience in dialogue with God or the Christian hope of eternal life.     

Treatment,enhancement, and the ethics of neurotherapeutics

Emerging neurotechnologies, including psychopharmaceuticals, brain stimulation, implantable brain chips, transcranial magnetic stimulation, and brain imaging raise a number of ethical questions. One of the most contentious is the proper role of these technologies in improving or increasing mental and neurological traits and skills in those with no identifiable pathology. The "enhancement" debate centers around a number of concerns and philosophical approaches to the proper role of medicine, therapeutics, and desirable human qualities. Arguements for and against neurological enhancement are reviewed, and historical and social perspectives are offered.     

Introduction to the epistemology of the brain: Indeterminacy,micro-specificity,chaos, and openness

Given that the mind is the brain, as materialists insist, those who would understand the mind must understand the brain. Assuming that arrays of neural firing frequencies are highly salient aspects of brain information processing (the vector functional account), four hurdles to an understanding of the brain are identified and inspected: indeterminacy, micro-specificity, chaos, and openness.My thanks to the editor of this issue and an unnamed referee for many pointed comments and helpful suggestions.     

Race, brain size, and intelligence: a reply to Cernovsky

Cernovsky's 1990 critique of my work on the relation between brain size and IQ inadequately presents my position. I did not address the issue of sex differences in brain size nor did I conclude that "women are less intelligent than men" (p. 337). In the autopsy study cited by Cernovsky, it was concluded that, when body size is controlled, the male-female difference in brain size is removed but the black-white difference in brain size remains. Cernovsky also ignores much additional data, including that Mongoloid populations have larger and heavier brains than Caucasoids. Here, I review evidence on the relation between (a) brain size and race and (b) brain size and intelligence. Data are also tabulated for personality, speed of maturation, and sexuality, on all of which the Caucasoid average consistently falls between those of Mongoloids and Negroids. This ordering may be explained by a gene-based evolutionary theory of r/K reproductive strategies in which Mongoloids are more K-selected than Caucasoids and Caucasoids more than Negroids.     

The need for power,brain norepinephrine turnover,and memory

Subjects were classified according to whether they were high or low in the need for Power and high or low in gain in 3-methoxy-4-hydroxyphenylglycol (MHPG), a putative index of brain norepinephrine (NE) turnover, after engaging in some tasks that involved memory for story content. Subjects who were high inn Power and in the index of brain NE turnover showed better recall of power-related facts than subjects low on both these characteristics, confirming an earlier finding, which suggests that the need for Power is subserved by a noradrenergic reward system in the brain.     

HOMO RELIGIOSUS AND ITS BRAIN: REALITY, IMAGINATION, AND THE FUTURE OF NATURE

Abstract. “Daddy, is God real or is he a part of people's imagination?” The brain constructs reality by bottom-up, genetically programmed mechanisms. Nature selected the human holistic, symbolically thinking, aesthetic brain using a mechanism of brain-language coevolution. Our religious nature and moral capabilities are rooted in this brain, and in the real images it constructs.     

Waves,streams, states,and self: An outline of an integral psychology 1

Abstract

Although far from unanimous, there seems to be a general consensus that neither mind nor brain can be reduced without remainder to the other. This essay argues that indeed both mind and brain need to be included in a nonreductionistic way in any genuinely integral theory of consciousness. In order to facilitate such integration, this essay presents the results of an extensive cross‐cultural literature search on the “mind” side of the equation, suggesting that the mental phenomena that need to be considered in any integral theory include developmental levels or waves of consciousness, developmental lines or streams of consciousness, states of consciousness, and the self (or self‐system). A “master template” of these various phenomena, culled from over one‐hundred psychological systems East and West, is presented. It is suggested that this master template represents a general summary of the “mind” side of the brain‐mind integration. The essay concludes with reflections on the “hard problem,” or how the mind‐side can be integrated with the brain‐side to generate a more integral theory of consciousness.     

Brain catecholamines and memory modulation: effects of footshock, amygdala implantation, and stimulation

The results of previous studies indicate that the extent of a transient decline in brain norepinephrine (NE) levels shortly after training and administration of any of several memory modulating treatments is correlated with later retention performance. The present experiment assessed such changes after one-trial inhibitory (passive) avoidance training and, in addition, measured concentration changes in 3-methoxy-4-hydroxyphenylglycol (MHPG), the major metabolite of brain NE, as well as dopamine (DA) and epinephrine (EPI) levels. The results indicate that the decreases in brain NE after footshock are accompanied by an increase in MHPG, thus providing additional evidence that brain NE is released after training. DA levels were unchanged after training; brainstem EPI levels increased after the training footshock, but forebrain EPI levels were unchanged. A second experiment examined brain catecholamine levels in animals which received post-training electrical stimulation of the amygdala. The findings of this experiment indicate that the amygdala damage which accompanies electrode implantation apparently results in a chronic change in whole brain NE levels and metabolism. After amygdala, NE concentrations in both brainstem and forebrain samples were reduced by 20% and MHPG was increased by 22-34%. Furthermore, NE levels were not responsive to training in implanted animals. Thus, brain NE levels after training were not predictive of retention performance in amygdala-implanted or -stimulated animals. However, the significance of such findings for understanding the possible role of central NE in memory storage is complicated by the severe modification of the dynamics of brain aminergic systems in animals bearing amygdala electrodes.     

神经颗粒素与脑老化、疾病及应激关系

神经颗粒素是一种神经元特异性、Ca2＋敏感性的鈣调蛋白（CaM）结合蛋白,是蛋白激酶C的突触后底物,与信号传导和长时程增强（LTP）有关。这是一种新发现的脑特异性蛋白质。主要分布在前脑和海马,在皮质、海马CA1-CA3区、齿状回、纹状体和杏仁核中高表达。在大脑发育的不同阶段,神经颗粒素在脑内的含量和分布区域会发生变化,其生物学作用受到国内外学者的关注。近年来国外学者开始对神经颗粒素与脑老化、疾病及应激关系进行考查。该文将着重介绍对神经颗粒素在脑老化、疾病和应激过程中所扮演的角色的研究工作及其新发现,目的是对脑与行为关系的理解及有关的脑机制的研究提供一个新的视点。     

Regional brain catecholamines and memory: effects of footshock, amygdala implantation, and stimulation

Previous findings have revealed a correlation between post-training release of whole brain norepinephrine (NE) and later retention performance. The present experiment examined changes after a training footshock in NE levels, as well as the levels of the major central NE metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), dopamine (DA), and epinephrine (EPI) in eight brain regions. Brain levels of these amines and the metabolite were assessed 10 min after training in a one-trial inhibitory (passive) avoidance task. The results indicate that NE levels decreased significantly in neocortex, neostriatum, hypothalamus, frontal pole, septum, and brainstem, but not in hippocampus or thalamus. The decreases in NE levels were generally accompanied by increases in MHPG; the MHPG/NE ratio increased significantly in all areas in which decreases in NE were observed. DA levels decreased in neostriatum and increased in neocortex and brainstem. Epinephrine levels decreased only in the brainstem sample. Thus, the effects of training on NE are widespread, probably reflecting the release of the amine in most brain regions. Such findings are consistent with the view that posttraining release of brain NE may modulate the storage of new information in many brain regions. One especially potent treatment for modulating memory storage is electrical stimulation of the amygdala. Therefore, we also examined the effects of amygdala implantation and stimulation on brain catecholamine levels to determine whether such changes might be correlated with the effects of amygdala stimulation on memory. The results indicate that electrode implantation into the amygdala results in pervasive changes in NE levels in most brain regions tested. Against this modified baseline, the results of training and electrical stimulation were region specific and very difficult to interpret. The major conclusion which can be derived from this portion of the experiment is that the amygdala damage produced by electrode implantation produces a brain which is substantially different from that of intact animals.     

Ethics,Brain Injuries,and Sports: Prohibition,Reform, and Prudence

Abstract

In this paper, we explore the issue of the elimination of sports, or elements of sports, that present a high risk of brain injury. In particular, we critically examine two elements of Angelo Corlett’s and Pam Sailors’ arguments for the prohibition of football and Nicholas Dixon’s claim for the reformation of boxing to eliminate blows to the head based on (a) the empirical assumption of an essential or causal connection between brain injuries incurred in football and the development of a degenerative brain disease known as chronic traumatic encephalopathy (CTE); and (b) John Stuart Mill’s rejection of consensual domination (ie voluntary enslavement). We present four arguments to contest the validity of Corlett, Dixon’s and Sailor’s positions. Specifically, we argue that (i) certain autonomy-based arguments undermine paternalist arguments for reform; (ii) the nature of the goods people pursue in their lives might justify their foregoing (degrees of) future autonomy; (iii) Mill’s argument against consensual domination draws on ambiguous and arbitrary distinctions; (iv) the lack of consensus and empirical evidence regarding CTE arising from brain injuries in sport underdetermines calls for reform. We conclude that these proposals for reforming or eliminating sports with high risks of brain injuries are not well founded.     

Training the brain: practical applications of neural plasticity from the intersection of cognitive neuroscience, developmental psychology, and prevention science

Prior researchers have shown that the brain has a remarkable ability for adapting to environmental changes. The positive effects of such neural plasticity include enhanced functioning in specific cognitive domains and shifts in cortical representation following naturally occurring cases of sensory deprivation; however, maladaptive changes in brain function and development owing to early developmental adversity and stress have also been well documented. Researchers examining enriched rearing environments in animals have revealed the potential for inducing positive brain plasticity effects and have helped to popularize methods for training the brain to reverse early brain deficits or to boost normal cognitive functioning. In this article, two classes of empirically based methods of brain training in children are reviewed and critiqued: laboratory-based, mental process training paradigms and ecological interventions based upon neurocognitive conceptual models. Given the susceptibility of executive function disruption, special attention is paid to training programs that emphasize executive function enhancement. In addition, a third approach to brain training, aimed at tapping into compensatory processes, is postulated. Study results showing the effectiveness of this strategy in the field of neurorehabilitation and in terms of naturally occurring compensatory processing in human aging lend credence to the potential of this approach. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Age-dependent consequences of seizures: relationship to seizure frequency, brain damage, and circuitry reorganization

Seizures in the developing brain pose a challenge to the clinician. In addition to the acute effects of the seizure, there are questions regarding the impact of severe or recurrent seizures on the developing brain. Whether provoked seizures cause brain damage, synaptic reorganization, or epilepsy is of paramount importance to patients and physicians. Such questions are especially relevant in the decision to treat or not treat febrile seizures, a common occurrence in childhood. These clinical questions have been addressed using clinical and animal research. The largest prospective studies do not find a causal connection between febrile seizures and later temporal lobe epilepsy. The immature brain seems relatively resistant to the seizure-induced neuronal loss and new synapse formation seen in the mature brain. Laboratory investigations using a developmental rat model corresponding to human febrile seizures find that even though structural changes do not result from hyperthermic seizures, synaptic function may be chronically altered. The increased understanding of the cellular and synaptic mechanisms of seizure-induced damage may benefit patients and clinicians in the form of improved therapies to attenuate damage and changes induced by seizures and to prevent the development of epilepsy.     

Structural brain variation,age, and response time

Response time (RT) generally slows with aging, but the contribution of structural brain changes to this slowing is unknown. We used voxel-based morphometry (VBM) to determine gray matter (GM) and white matter (WM) brain volumes in 9 middle-aged adults (38–58 years old) and 9 seniors (66–82 years old). We correlated brain volumes with RT assessed in both a simple visual stimulus-response task and a visual continuous recognition memory task. No GM correlations with simple RT were significant; there was one WM correlation in the right fusiform gyrus. In the memory task, faster RT was correlated (p<.05, corrected) with less GM in the globus pallidus, the parahippocampus, and the thalamus for both groups. Several Brodmann areas (BA) differed between the groups such that in each area, less GM was correlated with slower RTs in the middle-aged group but with faster RTs in the senior group (BAs 19, 37, 46, 9, 8, 6, 13, 10, 41, and 7). The results suggest that individual differences in specific brain structure volumes should be considered as potential moderating factors in cognitive brain imaging studies.     

A few thoughts about the mind,the brain,and a child with early deprivation

Infant brain research is having an increasing impact on child psychotherapy and our understanding of the neurobiological effects of trauma and neglect. This paper outlines the 'experience-dependent' nature of brain development in infancy and the concept of critical periods in such development. The effects of deprivation on child development are illustrated and case material from a child who was institutionalized during his second year is used as a basis for posing questions about the nature of the mind and the brain. In spite of his deprivation, he was able to communicate imaginatively. Schore's proposal for the use of early interventions is put forward to counter discouragement that can be engendered by work with severely deprived children.