Frontoparietal cortical networks for directing attention and the eye to visual locations: Identical, independent, or overlapping neural systems?

Functional anatomical and single-unit recording studies indicate that a set of neural signals in parietal and frontal cortex mediates the covert allocation of attention to visual locations, as originally proposed by psychological studies. This frontoparietal network is the source of a location bias that interacts with extrastriate regions of the ventral visual system during object analysis to enhance visual processing. The frontoparietal network is not exclusively related to visual attention, but may coincide or overlap with regions involved in oculomotor processing. The relationship between attention and eye movement processes is discussed at the psychological, functional anatomical, and cellular level of analysis.

Selective attention to stimulus location modulates the steady-state visual evoked potential.

Steady-state visual evoked potentials (SSVEPs) were recorded from the scalp of human subjects who were cued to attend to a rapid sequence of alphanumeric characters presented to one visual half-field while ignoring a concurrent sequence of characters in the opposite half-field. These two-character sequences were each superimposed upon a small square background that was flickered at a rate of 8.6 Hz in one half-field and 12 Hz in the other half-field. The amplitude of the frequency-coded SSVEP elicited by either of the task-irrelevant flickering backgrounds was significantly enlarged when attention was focused upon the character sequence at the same location. This amplitude enhancement with attention was most prominent over occipital-temporal scalp areas of the right cerebral hemisphere regardless of the visual field of stimulation. These findings indicate that the SSVEP reflects an enhancement of neural responses to all stimuli that fall within the "spotlight" of spatial attention, whether or not the stimuli are task-relevant. Recordings of the SSVEP provide a new approach for studying the neural mechanisms and functional properties of selective attention to multi-element visual displays.

The resource consumption principle: attention and memory in volumes of neural tissue.

In the cerebral cortex, the small volume of the extracellular space in relation to the volume enclosed by synapses suggests an important functional role for this relationship. It is well known that there are atoms and molecules in the extracellular space that are absolutely necessary for synapses to function (e.g., calcium). I propose here the hypothesis that the rapid shift of these atoms and molecules from extracellular to intrasynaptic compartments represents the consumption of a shared, limited resource available to local volumes of neural tissue. Such consumption results in a dramatic competition among synapses for resources necessary for their function. In this paper, I explore a theory in which this resource consumption plays a critical role in the way local volumes of neural tissue operate. On short time scales, this principle of resource consumption permits a tissue volume to choose those synapses that function in a particular context and thereby helps to integrate the many neural signals that impinge on a tissue volume at any given moment. On longer time scales, the same principle aids in the stable storage and recall of information. The theory provides one framework for understanding how cerebral cortical tissue volumes integrate, attend to, store, and recall information. In this account, the capacity of neural tissue to attend to stimuli is intimately tied to the way tissue volumes are organized at fine spatial scales.

Visual attention to surfaces in three-dimensional space.

Although attention plays a significant role in vision, its spatial deployment and spread in the third dimension is not well understood. In visual search experiments we show that we cannot easily focus attention across isodepth loci unless they are part of a well-formed surface with locally coplanar elements. Yet we can easily spread our attention selectively across well-formed surfaces that span an extreme range of stereoscopic depths. In cueing experiments, we show that this spread of attention is, in part, obligatory. Attentional selectivity is reduced when targets and distractors are coplanar with or rest on a common receding stereoscopic plane. We conclude that attention cannot be efficiently allocated to arbitrary depths and extents in space but is linked to and spreads automatically across perceived surfaces.

Molecular Genetic Basis of Opposite Gene by Environment Interactions in Reading Disability and Attention Deficit/Hyperactivity Disorder

The goal of this study is to better understand the genetic basis of Reading Disability (RD) and Attention Deficit Hyperactivity Disorder (ADHD) by examining molecular G x E interactions with parental education for each disorder. Research indicates that despite sharing genetic risk factors, RD and ADHD are influenced by different types of G x E interactions with parental education - a diathesis stress interaction in the case of ADHD and a bioecological interaction in RD. In order to resolve this apparent paradox, we conducted a preliminary study using behavioral genetic methods to test for G x E interactions in RD and the inattentive subtype of ADHD (ADHD-I) in the same sample of monozygotic and dizygotic Colorado Learning Disabilities Research Center same-sex twin pairs (DeFries et al., 1997), and our findings were consistent with the literature. We posited a genetic hypothesis for this opposite pattern of interactions, which suggests that only genes specific to each disorder enter into these opposite interactions, not the shared genes underlying their comorbidity. This study sought to further investigate this paradox using molecular genetics methods. We examined multiple candidate genes identified for RD or related language phenotypes and those identified for ADHD for G x E interactions with parental education. The specific aims of this study were as follows: 1) partition known risk alleles for RD and/or related language phenotypes and ADHD-I into those which are pleiotropic and non-pleiotropic by testing each risk allele for association with both RD and ADHD-I, 2) explore the main effects of parental education on both RD and ADHD-I, 3) address G-E correlations, and 4) conduct exploratory G x E interaction analyses in order to test the genetic hypothesis. Analyses suggested a number of pleiotropic genes that influence both RD and ADHD; however, results did not remain after correcting for multiple comparisons. Although exploratory G x E interaction findings were not significant after multiple comparison correction, results suggested a G x E interaction in the bioecological direction with KIAA0319, parental education, and ADHD-I. Given the limited power in the current study, replication of these findings with larger samples is necessary.

Relationship Maintenance in Couples with a Partner Who Has Attention Deficit Hyperactivity Disorder

The body of research on the relationship functioning of adults with attention deficit hyperactivity disorder (ADHD) is relatively small; the aim of the present study is to advance our understanding of this topic. It has been estimated that three to ten percent of children and one to five percent of adults have impairing symptoms of ADHD, which is a total of 4 million children and 4-5 million adults in the U.S. (Wender, 2000). A recent prevalence study found that approximately 4.4% of adults in the U.S. meet the criteria for a diagnosis of ADHD (Kessler et al., 2006). Children with ADHD show innate temperamental characteristics, usually inattentiveness, distractibility, impulsivity, restlessness, demandingness, hyperreactivity, low tolerance for frustration, temperoutbursts, bossiness and stubbornness, and mood lability, along with an innate proclivity for academic underachievement. It has been estimated that one- to two-thirds of children with ADHD have symptoms that continue into adulthood, and for 40-50% of these adults, these symptoms are serious enough to cause impairment in functioning (Everett & Everett, 1999; Wender, 2000). Research suggests that the majority of cases are transmitted genetically, but some may be due to exposure to environmental toxins such as lead. Consumption of excess sugar or allergies to food may exacerbate or mimic ADHD symptoms in some children, but they are not a cause of ADHD (Wender, 2000). One hypothesized cause of the symptoms associated with ADHD is a deficit in the brain's executive functioning (Barkley & Gordon, 2002). Executive functioning can be conceptualized as the ability to inhibit, organize, and plan behaviors. Barkley and Gordon (2002) define it as the abilityto self-direct and regulate behaviors toward future goals, including social behaviors and goals. Other research suggests that executive functioning consists of inhibition, control of interference, verbal and nonverbal working memory, emotional regulation, attention, verbal fluency, visual scanning, and processing speed. Studies have shown impairments in these areas among adults with ADHD (Barkley & Gordon, 2002; Barkley, Murphy & Kwasnik, 1996; Goldstein, 2002).

Three Dichotomies in Lawyers’ Ethics (With Particular Attention to the Corporation as Client)

Three usually unexpressed, and too often unnoticed, conceptual dichotomies underlie our perception and understanding of lawyers’ ethics. First, the existence of a special body of professional ethics and professional regulation presupposes some special need or risk. Criminal and civil law are apparently insufficient. Ordinary day-to-day morality and ordinary ethics, likewise, are not considered to be enough. What is the risk entailed by the notion of a profession that is special; who needs protection, and from what? Two quite different possible answers to this question provide the first of the three dichotomies examined in this article: one can understand the risk as primarily to a vulnerable client from a powerful professional; or, to the contrary, from a powerful client-lawyer combination toward vulnerable others. Second, what is the foundational orientation of lawyers? Are lawyers serving primarily their particular clients, and those clients’ preferences, choices and autonomy? Or is the primary allegiance of lawyers to some community or collective goal or interest distinct from the particular goals or interests of the client? The third dichotomy concerns not the substance of the risk, or the primary orientation, but the appropriate means of responding to that risk or that fundamental obligation. Should professional ethics be implemented primarily through rules? Or, should we rely on character and the discretion of lawyers to make a thought out, all things considered, decision? Each of these three presents a fundamental difference in how we perceive and address issues of lawyers’ ethics. Each affects our understanding and analysis on multiple levels, from (1) determining the appropriate or requisite conduct in a particular situation, to (2) framing a specific rule or approach for a particular category of situations, to (3) more general or abstract theory or policy. A person’s inclinations in regard to the dichotomies affects the conclusions that person will reach on each of those levels of analysis, yet those inclinations and assumptions are frequently unexamined and unarticulated. One’s position on each of the dichotomies tends to structure the approach and outcome without the issues and choice having been explicitly addressed or possibly even noticed. This article is an effort to ameliorate that problem. Part I addresses the question of what is the risk in the work of lawyers, or the function of lawyers, for which professional ethics is the answer. The concluding section focuses on the particular problem of the corporation as client. Part II then asks the related and possibly consequent question of what is the foundational orientation or allegiance of the lawyer? Is it to the individual client? Or is it to some larger community interest? Again, the concluding section focuses on the corporation. Part III turns to the means or method for addressing the obligations and possible problems of the professional ethics of lawyers. Should lawyers’ ethics guide and confine the conduct of lawyers primarily through rules? Or should it function primarily through reliance on the knowledge, judgment and character of lawyers? If the latter were the guide, ethical decisions would be made on a situation by situation basis under the discretion of each lawyer. Toward the end of each discussion possibilities for bridging the dichotomy are considered (and with such bridges each dichotomy may come to look more like a spectrum or continuum.). At several points after its introduction in Parts I and II, the special problem of the corporation as client is revisited and possible solutions suggested. Illustrating the usefulness of keeping the dichotomies in view, Part IV applies them to several exemplary situations of ethical difficulty in actual lawyer practice. For readers finding it difficult to envision the consequences of these distinctions, turning ahead to Part IV may be useful in making the discussion more concrete. Some commonalities across the dichotomies and connections among them are then developed in the concluding section, Part V.

Examining the relationship among genes, attention bias to emotion, and depression in youth

The investigation of biologically initiated pathways to psychological disorder is critical to advance our understanding of mental illness. Research has suggested that attention bias to emotion may be an intermediate trait for depression associated with biologically plausible candidate genes, such as the serotonin transporter (5-HTTLPR) and catechol-o-methyl-transferase (COMT) genes, yet there have been mixed findings in regards to the precise direction of effects. The experience of recent stressful life events (SLEs) may be an important, yet currently unstudied, moderator of the relationship between genes and attention bias as SLEs have been associated with both gene expression and attention to emotion. Additionally, although attention biases to emotion have been studied as a possible intermediate trait associated with depression, no study has examined whether attention biases within the context of measured genetic risk lead to increased risk for clinical depressive episodes over time. Therefore, this research investigated both whether SLEs moderate the link between genetic risk (5-HTTLPR and COMT) and attention bias to emotion and whether 5-HTTLPR and COMT moderated the relationship between attention biases to emotional faces and clinical depression onset prospectively across 18 months within a large community sample of youth (n= 467). Analyses revealed a differential effect of gene. Youth who were homozygous for the low expressing allele of 5-HTTLPR (S/S) and had experienced more recent SLEs within the last three months demonstrated preferential attention toward negative emotional faces (angry and sad). However, youth who were homozygous for the high expressing COMT genotype (Val/Val) and had experienced more recent SLEs showed attentional avoidance of positive facial expressions (happy). Additionally, youth who avoided negative emotion (i.e., anger) and were homozygous for the S allele of the 5-HTTLPR gene were at greater risk for prospective depressive episode onset. Increased risk for depression onset was specific to the 5-HTTLPR gene and was not found when examining moderation by COMT. These findings highlight the importance of examining risk for depression across multiple levels of analysis, such as combined genetic, environmental, and cognitive risk, and is the first study to demonstrate clear evidence of attention biases to emotion functioning as an intermediate trait predicting depression.

Three Dichotomies in Lawyers’ Ethics (With Particular Attention to the Corporation as Client)

Three usually unexpressed, and too often unnoticed, conceptual dichotomies underlie our perception and understanding of lawyers’ ethics. First, the existence of a special body of professional ethics and professional regulation presupposes some special need or risk. Criminal and civil law are apparently insufficient. Ordinary day-to-day morality and ordinary ethics, likewise, are not considered to be enough. What is the risk entailed by the notion of a profession that is special; who needs protection, and from what? Two quite different possible answers to this question provide the first of the three dichotomies examined in this article: one can understand the risk as primarily to a vulnerable client from a powerful professional; or, to the contrary, from a powerful client-lawyer combination toward vulnerable others. Second, what is the foundational orientation of lawyers? Are lawyers serving primarily their particular clients, and those clients’ preferences, choices and autonomy? Or is the primary allegiance of lawyers to some community or collective goal or interest distinct from the particular goals or interests of the client? The third dichotomy concerns not the substance of therisk, or the primary orientation, but the appropriate means of responding to that risk or that fundamental obligation. Should professional ethics be implemented primarily through rules? Or, should we rely on character and the discretion of lawyers to make a thought out, all things considered, decision? Each of these three presents a fundamental difference in how we perceive and address issues of lawyers’ ethics. Each affects our understanding and analysis on multiple levels, from (1) determining the appropriate or requisite conduct in aparticular situation, to (2) framing a specific rule or approach for a particular category of situations, to (3) more general or abstract theory or policy. A person’s inclinations in regard to the dichotomies affects the conclusions that person will reach on each of those levels of analysis, yet those inclinations and assumptions are frequently unexamined and unarticulated. One’s position on each of the dichotomies tends to structure the approach and outcome without the issues and choice having been explicitly addressed or possibly even noticed. This article is an effort to ameliorate that problem. Part I addresses the question of what is the risk in the work of lawyers, or the function of lawyers, for which professional ethics is the answer. The concluding section focuses on the particular problem of the corporation as client. Part II then asks the related and possibly consequent question of what is the foundational orientation or allegiance of the lawyer? Is it to the individual client? Or is it to some larger community interest? Again, the concluding section focuses on thecorporation. Part III turns to the means or method for addressing the obligations and possible problems of the professional ethics of lawyers. Should lawyers’ ethics guide and confine the conduct of lawyers primarily through rules? Or should it function primarily through reliance on the knowledge, judgment and character of lawyers? If the latter were the guide, ethical decisions would be made on a situation by situation basis under the discretion of each lawyer. Toward the end of each discussion possibilities for bridging the dichotomy are considered (and with such bridges each dichotomy may come to look more like a spectrum or continuum.). At several points after its introduction in Parts I and II, the special problem of the corporation as client is revisited and possible solutions suggested. Illustrating the usefulness of keeping the dichotomies in view, Part IV applies them to several exemplary situations of ethical difficulty in actual lawyer practice. For readers finding it difficult to envision the consequences of these distinctions, turning ahead to Part IV may be useful in making the discussion more concrete. Some commonalities across the dichotomies and connections among them are then developed in the concluding section, Part V.

Nouveaux memoires touchant le Mexique ou la Nouvelle Espagne: recueillis sur les lieux avec une attention particulière par Mr. de Montségur, capitaine de vaisseaux du roy catolique pendant les annees 1707 et 1708 : manuscript, [17--]

Manuscript, in an unidentified hand, with revisions and corrections in a different hand [Monségur?].