Towards a functional neural systems model of developmental stuttering

This paper overviews recent developments in an ongoing program of brain imaging research on developmental stuttering that is being conducted at the University of Texas Health Science Center, San Antonio. This program has primarily used H₂¹⁵O PET imaging of different speaking tasks by right-handed adult male and female persistent stutterers, recovered stutterers and controls in order to isolate the neural regions that are functionally associated with stuttered speech. The principal findings have emerged from studies using condition contrasts and performance correlation techniques. The emerging findings from these studies are reviewed and referenced to a neural model of normal speech production recently proposed by Jürgens [Neurosci. Biobehav. Rev. 26 (2002) 235]. This paper will report (1) the reconfiguration of previous findings within the Jürgens Model; (2) preliminary findings of an investigation with late recovered stutterers; (3) an investigation of neural activations during a treatment procedure designed to produce a sustained improvement in fluency; and (4) an across-studies comparison that seeks to isolate neural regions within the Jürgens Model that are consistently associated with stuttering. Two regions appear to meet this criterion: right anterior insula (activated) and anterior middle and superior temporal gyri (deactivated) mainly in right hemisphere. The implications of these findings and the direction of future imaging investigations are discussed.

Educational objectives: The reader will learn about (1) recent uses of H₂¹⁵O PET imaging in stuttering research; (2) the use of a new neurological model of speech production in imaging research on stuttering; and (3) initial findings from PET imaging investigations of treated and recovered stutterers.     

STIMULUS FADING AS TREATMENT FOR OBSCENITY IN A BRAIN-INJURED ADULT

Obscene verbalizations of a person with traumatic brain injury were treated using stimulus fading as the singular form of intervention. Results of a functional assessment revealed that obscenity was maintained by negative reinforcement. Stimulus fading (initial elimination of instructional demands followed by their gradual reintroduction) produced immediate and substantial reductions in obscenity that were maintained as the frequency of demands increased to baseline levels. Potential applications of the use of antecedent treatment strategies are discussed.     

Synergistic effects of ethanol and cocaine on brain stimulation reward.

The effects of two widely abused drugs, ethanol and cocaine, were examined alone and in combination on intracranial reward processes. In agreement with previous research, higher doses of both cocaine and ethanol alone produced facilitation of behavior maintained by brain stimulation reward. Low intraperitoneal doses of ethanol and cocaine, which alone did not affect performance, were found to reduce stimulation reward threshold and modestly increase response rate. The enhancement of brain stimulation reward by the combination of ethanol and cocaine suggests that both drugs may produce their rewarding effects through common neuronal substrates and that they may potentiate the abuse of each other.     

A GROUP-ORIENTED CONTINGENCY TO INCREASE LEISURE ACTIVITIES OF ADULTS WITH TRAUMATIC BRAIN INJURY

An interdependent group-oriented contingency and graphic feedback were used to increase the activity levels of residents of a group home for persons with traumatic brain injury. Results showed that the intervention was effective for 4 of the 6 subjects. Individual performances must be examined when implementing group contingencies because all subjects may not respond.     

Involvement of reactive oxygen species in emotional stress: A hypothesis based on the immobilization stress-induced oxidative damage and antioxidant defense changes in rat brain,and the effect of antioxidant treatment with reduced glutathione

We examined the oxidative damage and antioxidant defense changes with immobilization-induced emotional stress in the rat brain. Though superoxide dismutase activity remained unchanged, brain peroxidation was significantly accelerated by the immobilization stress. Membrane fluidity study with spin labeling in brain cortical membrane showed that immobilization stress induced an increase in microviscosity of membrane layer near the surface and in the ordering of membrane proteins but a decrease in microviscosity at the core of the membrane bilayer. The Na, K-ATPase activity decreased whereas the levels of some monoamines and their metabolites increased along with their metabolic rate. The administration of reduced glutathione showed a protective effect on the immobilization stress-induced stomach bleeding, oxidative damage and abnormal changes in the brain antioxidant defenses. Based on these results and on previous reports, we hypothesize that immobilization stress may induce the formation of reactive oxygen species which weakens the brain antioxidant defenses and induces oxidative damage. The antioxidant administration of reduced glutathione provides further evidence to support the above hypothesis, and also may provide clues in the search for a rational therapy to emotional stress. A possible correlation of emotional stress to aging is also discussed.     

Histological data: Hollard and Davison (1971)

As Mogenson and Cioé (1977) have assumed that our electrodes aimed at the ectostriatum (Hollard and Davison, 1971) were actually located there, we feel that a presentation of the histological data is necessary. Following termination of further experiments (Hollard, 1974) the pigeons, numbered 93, 95, and 119, were sacrificed and perfused with saline followed by 10% formalin. Sections, 50 microns thick, were cut on a freezing microtome. Prints were made by mounting each unstained section of a microscope slide and placing them in a standard photographic enlarger. The electrode tips of Pigeons 93 and 119 were located in the paleostriatal complex. The sections of Pigeon 95 were damaged and precise localization was not possible. Further work in this laboratory has also found that, using the same coordinates, electrode tips tend to fall in the paleostriatum, rather than in the more dorsal ectostriatum at which they are aimed. The paleostriatal placements tended to sustain self-stimulation, whereas others located in the ectostriatum sustained relatively low or unstable rates.     

IDENTITY AND THE BRAIN: THE BIOLOGICAL BASIS OF OUR SELF

This article reviews the neuroscientific understanding of the self and personal identity, focusing on various elements of inclusivity and exclusivity as well as engaging religious and spiritual perspectives. We will also consider how the identity is comprised of biological, social, and ideological or spiritual aspects, and how they are interconnected. We will consider how the brain helps us to construct and maintain our representation of the self and what happens when we have self-transcendent experiences. Such an evaluation will have implications for understanding the intersection between consciousness and the self. This information will be helpful from both the psychological and spiritual perspective for understanding human identity.     

Psychobiological Treatment Response to a Two-Week Posttraumatic Stress Disorder and Mild Traumatic Brain Injury Integrated Treatment Program: A Case Report

Posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) demonstrate high prevalence and comorbidity among post-9/11 veterans. Veterans with this comorbidity often present with multiple co-occurring healthcare needs and increased clinical complexity. The current case report describes the clinical presentation of a veteran with mild TBI and PTSD, both before, during, and after treatment within a multidisciplinary 2-week intensive outpatient program involving prolonged exposure, evidence-based PTSD treatment, and Cognitive Symptom Management and Rehabilitation Therapy, evidence-based treatment for postconcussive symptoms. Mr. A was a 25-year-old White, transgender male who presented with a complex mental health history. At intake, presenting complaints included anxiety, panic attacks, nightmares, and depression secondary to military sexual trauma, as well as reported cognitive difficulties secondary to a concussion. He met current criteria for PTSD as well as panic disorder with agoraphobia. Head injury history consisted of a motor vehicle collision with less than 30 seconds loss of consciousness, brief posttraumatic amnesia, and alterations of consciousness. Mr. A demonstrated habituation during individual exposure sessions as assessed via skin conductance during imaginal exposures and decreased subjective ratings during in vivo exposures, as well as a decrease in trauma-potentiated startle response to trauma cues. Posttreatment data indicates significant reduction in neurobehavioral, posttraumatic stress, and depression symptoms and significant improvement in subjective cognitive functioning. The current findings support the feasibility and efficacy of short-term integrated treatment for complex clinical presentations and the need for larger scale research investigating combined PTSD and TBI intervention.     

Is sexual-aggressive vocal communication related to asymmetric mechanisms in the brain?

In Mongolian gerbil males, a reliable asymmetric relationship has been discovered between a stereotyped ultrasonic vocalizattion and the volume of a discrete nucleus within the preoptic-anterior hypothalamic area, the sexually dimorphic area, pars compacta (SDApc). The steroid-sensitive ultrasonic, emitted at high levels during courtship interactions, is associated with the absence of aggressive encounters and appears to be necessary for the formation and maintenance of pair-bonds with females. Interactions between unfamilliar, non-pair-bonded adult male and estrous female gerbils result in male aggression, reduction of male ultrasonic calling, and disruption of normal female dartmale follow sociosexual sequences. Castration further reduces ultrasonic calling, inhibits normal sociosexual sequences, and increses aggression in interaction between unfamiliar compared to pair-bonded individuals. Bothg brain structure and lateralization of vocal function in males depend on the action of sex steroids during sexual differentiation and in adulthood. Thus, the gerbil provides a new model to study steroid-dependent lateralization of brain mechanisms of vocal behavior mediating aggressive-sexual relationships. © 1994 Wiley-Liss, Inc.     

Traumatic Brain Injury in School-Age Children Academic and Social Outcome

School-aged children with a traumatic brain injury (TBI) require extraordinary effort and energy from individuals in their school, home, and community. The purpose of this study was to examine the academic, behavioral, and social outcomes of a cohort of children and adolescents following TBI. A comprehensive assessment of cognitive functioning, achievement, and adaptive behavior was administered to 43 school-aged children 2 years after their TBI. Premorbid functioning for each participant was obtained from state-mandated test scores assessed prior to the TBI. The predictive utility of premorbid functioning, TBI severity, and age at injury were examined. Findings revealed that premorbid functions were significant predictors of reading and spelling achievement and adaptive functioning. Severity of injury was predictive of adaptive functioning. Implications of findings include program development, reintegration into school, and educating parents and teachers.