Characterizing major depressive disorder and substance use disorder using heatmaps and variable interactions: The utility of operant behavior and brain structure relationships.

Background: Rates of depression and addiction have risen drastically over the past decade, but the lack of integrative techniques remains a barrier to accurate diagnoses of these mental illnesses. Changes in reward/aversion behavior and corresponding brain structures have been identified in those with major depressive disorder (MDD) and cocaine-dependence polysubstance abuse disorder (CD). Assessment of statistical interactions between computational behavior and brain structure may quantitatively segregate MDD and CD.

Brain Perfusion Mediates the Relationship Between miRNA Levels and Postural Control.

Transcriptomics, regional cerebral blood flow (rCBF), and a virtual reality-based spatial motor task were integrated using mediation analysis in a novel demonstration of "imaging omics." Data collected in National Collegiate Athletic Association (NCAA) Division I football athletes cleared for play before in-season training showed significant relationships in 1) elevated levels of miR-30d and miR-92a to elevated putamen rCBF, 2) elevated putamen rCBF to compromised Balance scores, and 3) compromised Balance scores to elevated microRNA (miRNA) levels. rCBF acted as a consistent mediator variable (Sobel's test  < 0.

Auditory Feedback Control Mechanisms Do Not Contribute to Cortical Hyperactivity Within the Voice Production Network in Adductor Spasmodic Dysphonia.

Purpose Adductor spasmodic dysphonia (ADSD), the most common form of spasmodic dysphonia, is a debilitating voice disorder characterized by hyperactivity and muscle spasms in the vocal folds during speech. Prior neuroimaging studies have noted excessive brain activity during speech in participants with ADSD compared to controls. Speech involves an auditory feedback control mechanism that generates motor commands aimed at eliminating disparities between desired and actual auditory signals.

Imaging gradual neurodegeneration in a basal ganglia model disease.

Objective: X-linked dystonia-parkinsonism (XDP) is a neurodegenerative disease with adult onset dystonia and subsequent parkinsonism. Postmortem and imaging studies revealed remarkable striatal pathology, with a predominant involvement of the striosomal compartment in the early phase. Here, we aimed to disentangle sequential neurodegeneration in the striatum of XDP patients, provide evidence for preferential loss of distinct striatal areas in the early phase, and investigate whether iron accumulation is present.

White Matter Changes in Cervical Dystonia Relate to Clinical Effectiveness of Botulinum Toxin Treatment.

In a previous report showing white matter microstructural hemispheric asymmetries medial to the pallidum in focal dystonias, we showed preliminary evidence that this abnormality was reduced 4 weeks after botulinum toxin (BTX) injections. In the current study we report the completed treatment study in a full-size cohort of CD patients ( = 14). In addition to showing a shift toward normalization of the hemispheric asymmetry, we evaluated clinical relevance of these findings by relating white matter changes to degree of symptom improvement.

Increased insula-putamen connectivity in X-linked dystonia-parkinsonism.

Preliminary evidence from postmortem studies of X-linked dystonia-parkinsonism (XDP) suggests tissue loss may occur first and/or most severely in the striatal striosome compartment, followed later by cell loss in the matrix compartment. However, little is known about how this relates to pathogenesis and pathophysiology. While MRI cannot visualize these striatal compartments directly in humans, differences in relative gradients of afferent cortical connectivity across compartments (weighted toward paralimbic versus sensorimotor cortex, respectively) can be used to infer potential selective loss in vivo.

Keypress-Based Musical Preference Is Both Individual and Lawful.

Musical preference is highly individualized and is an area of active study to develop methods for its quantification. Recently, preference-based behavior, associated with activity in brain reward circuitry, has been shown to follow lawful, quantifiable patterns, despite broad variation across individuals. These patterns, observed using a keypress paradigm with visual stimuli, form the basis for relative preference theory (RPT).

A Quantitative Relationship between Signal Detection in Attention and Approach/Avoidance Behavior.

This study examines how the domains of reward and attention, which are often studied as independent processes, in fact interact at a systems level. We operationalize divided attention with a continuous performance task and variables from signal detection theory (SDT), and reward/aversion with a keypress task measuring approach/avoidance in the framework of relative preference theory (RPT). Independent experiments with the same subjects showed a significant association between one SDT and two RPT variables, visualized as a three-dimensional structure.

Variable activation in striatal subregions across components of a social influence task in young adult cannabis users.

Introduction: Decades of research have demonstrated the importance of social influence in initiation and maintenance of drug use, but little is known about neural mechanisms underlying social influence in young adults who use recreational drugs.

Methods: To better understand whether the neural and/or behavioral response to social influence differs in young adults using illicit drugs, 20 marijuana-using young adults (MJ) aged 18-25, and 20 controls (CON) performed a decision-making task in the context of social influence, while they underwent functional magnetic resonance imaging scans. A priori analyses focused on the nucleus accumbens (NAc), with post hoc analyses in the rest of the striatum.

Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias.

Background: Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia.

The Commonality of Loss Aversion across Procedures and Stimuli.

Individuals tend to give losses approximately 2-fold the weight that they give gains. Such approximations of loss aversion (LA) are almost always measured in the stimulus domain of money, rather than objects or pictures. Recent work on preference-based decision-making with a schedule-less keypress task (relative preference theory, RPT) has provided a mathematical formulation for LA similar to that in prospect theory (PT), but makes no parametric assumptions in the computation of LA, uses a variable tied to communication theory (i.

Age-related striatal BOLD changes without changes in behavioral loss aversion.

Loss aversion (LA), the idea that negative valuations have a higher psychological impact than positive ones, is considered an important variable in consumer research. The literature on aging and behavior suggests older individuals may show more LA, although it is not clear if this is an effect of aging in general (as in the continuum from age 20 and 50 years), or of the state of older age (e.g.

Redefining neuromarketing as an integrated science of influence.

Multiple transformative forces target marketing, many of which derive from new technologies that allow us to sample thinking in real time (i.e., brain imaging), or to look at large aggregations of decisions (i.

The relationship between self-report of depression and media usage.

Depression is a debilitating condition that adversely affects many aspects of a person's life and general health. Earlier work has supported the idea that there may be a relationship between the use of certain media and depression. In this study, we tested if self-report of depression (SRD), which is not a clinically based diagnosis, was associated with increased internet, television, and social media usage by using data collected in the Media Behavior and Influence Study (MBIS) database (N = 19,776 subjects).

Cannabis use is quantitatively associated with nucleus accumbens and amygdala abnormalities in young adult recreational users.

Marijuana is the most commonly used illicit drug in the United States, but little is known about its effects on the human brain, particularly on reward/aversion regions implicated in addiction, such as the nucleus accumbens and amygdala. Animal studies show structural changes in brain regions such as the nucleus accumbens after exposure to Δ9-tetrahydrocannabinol, but less is known about cannabis use and brain morphometry in these regions in humans. We collected high-resolution MRI scans on young adult recreational marijuana users and nonusing controls and conducted three independent analyses of morphometry in these structures: (1) gray matter density using voxel-based morphometry, (2) volume (total brain and regional volumes), and (3) shape (surface morphometry).

Imaging studies in focal dystonias: a systems level approach to studying a systems level disorder.

Focal dystonias are dystonias that affect one part of the body, and are sometimes task-specific. Brain imaging and transcranial magnetic stimulation techniques have been valuable in defining the pathophysiology of dystonias in general, and are particularly amenable to studying focal dystonias. Over the past few years, several common themes have emerged in the imaging literature, and this review summarizes these findings and suggests some ways in which these distinct themes might all point to one common systems-level mechanism for dystonia.

Evidence for altered basal ganglia-brainstem connections in cervical dystonia.

Background: There has been increasing interest in the interaction of the basal ganglia with the cerebellum and the brainstem in motor control and movement disorders. In addition, it has been suggested that these subcortical connections with the basal ganglia may help to coordinate a network of regions involved in mediating posture and stabilization. While studies in animal models support a role for this circuitry in the pathophysiology of the movement disorder dystonia, thus far, there is only indirect evidence for this in humans with dystonia.

Microstructural abnormalities in subcortical reward circuitry of subjects with major depressive disorder.

Background: Previous studies of major depressive disorder (MDD) have focused on abnormalities in the prefrontal cortex and medial temporal regions. There has been little investigation in MDD of midbrain and subcortical regions central to reward/aversion function, such as the ventral tegmental area/substantia nigra (VTA/SN), and medial forebrain bundle (MFB).

Methodology/principal Findings: We investigated the microstructural integrity of this circuitry using diffusion tensor imaging (DTI) in 22 MDD subjects and compared them with 22 matched healthy control subjects.

Recurrent, robust and scalable patterns underlie human approach and avoidance.

Background: Approach and avoidance behavior provide a means for assessing the rewarding or aversive value of stimuli, and can be quantified by a keypress procedure whereby subjects work to increase (approach), decrease (avoid), or do nothing about time of exposure to a rewarding/aversive stimulus. To investigate whether approach/avoidance behavior might be governed by quantitative principles that meet engineering criteria for lawfulness and that encode known features of reward/aversion function, we evaluated whether keypress responses toward pictures with potential motivational value produced any regular patterns, such as a trade-off between approach and avoidance, or recurrent lawful patterns as observed with prospect theory.

Methodology/principal Findings: Three sets of experiments employed this task with beautiful face images, a standardized set of affective photographs, and pictures of food during controlled states of hunger and satiety.

New hypotheses about postural control support the notion that all dystonias are manifestations of excessive brain postural function.

This paper postulates that all forms of the neurological movement disorder, dystonia, can be argued to reflect excessive function of one or more components of the brain postural system. This is based on four central arguments. First, because some forms of postural control are already known to be dynamic, rather than static, it is suggested that hyperkinetic dystonias reflect excessive function of dynamic postures, rather than abnormal movements.

Cortical thickness abnormalities in cocaine addiction--a reflection of both drug use and a pre-existing disposition to drug abuse?

The structural effects of cocaine on neural systems mediating cognition and motivation are not well known. By comparing the thickness of neocortical and paralimbic brain regions between cocaine-dependent and matched control subjects, we found that four of 18 a priori regions involved with executive regulation of reward and attention were significantly thinner in addicts. Correlations were significant between thinner prefrontal cortex and reduced keypresses during judgment and decision making of relative preference in addicts, suggesting one basis for restricted behavioral repertoires in drug dependence.