Neuroimaging Methods for Nursing Science.

BACKGROUND: Since the inception of magnetic resonance imaging, thousands of studies have appeared in the literature reporting on multiple imaging techniques. However, there is a paucity of neuroimaging research programs developed by nurse scientists. OBJECTIVES: The purpose of this article is to introduce the nurse scientist to complex neuroimaging methods with the ultimate goal of creating impetus for future use of brain imaging in nursing research. METHODS: This article reviews common neuroimaging methods, presents vocabulary frequently used in neuroimaging work, provides information on access to resources in neuroimaging education, and discusses considerations for use of neuroimaging in research. RESULTS: Ten imaging modalities are reviewed, including structural and functional magnetic resonance imaging, computed tomography, positron emission tomography, and encephalography. DISCUSSION: Choosing an imaging modality for research depends on the nature of the research question, needs of the patient population of interest, and resources available to the novice and seasoned nurse scientist. Neuroimaging has the potential to innovate the study of symptom science and encourage interdisciplinary collaboration in research.

Remembering all that and then some: recollection of autobiographical memories after a 1-year delay.

We have previously shown that repeated retrievals of remote autobiographical memories over the course of one month led to an overall increase in reported detail (Nadel, Campbell, & Ryan, 2007). The current study examined the retrieval of those same memories 1 year later in order to determine whether the level of detail remained stable or whether the memories returned to their original state. Participants reported even more details than they had recalled at least 1 year earlier, including new details that were reported for the first time. This finding was consistent across both multiple and single retrieval conditions, suggesting that the critical factor leading to the increase in recall was the passage of time. These findings provide evidence for long-term effects of repeated retrieval on memory content.

Neural Mechanisms of Acceptance and Commitment Therapy for Chronic Pain: A Network-Based fMRI Approach.

Over 100 million Americans suffer from chronic pain (CP), which causes more disability than any other medical condition in the United States at a cost of $560-$635 billion per year (Institute of Medicine, 2011). Opioid analgesics are frequently used to treat CP. However, long term use of opioids can cause brain changes such as opioid-induced hyperalgesia that, over time, increase pain sensation. Also, opioids fail to treat complex psychological factors that worsen pain-related disability, including beliefs about and emotional responses to pain. Cognitive behavioral therapy (CBT) can be efficacious for CP. However, CBT generally does not focus on important factors needed for long-term functional improvement, including attainment of personal goals and the psychological flexibility to choose responses to pain. Acceptance and Commitment Therapy (ACT) has been recognized as an effective, non-pharmacologic treatment for a variety of CP conditions (Gutierrez et al., 2004). However, little is known about the neurologic mechanisms underlying ACT. We conducted an ACT intervention in women (n = 9) with chronic musculoskeletal pain. Functional magnetic resonance imaging (fMRI) data were collected pre- and post-ACT, and changes in functional connectivity (FC) were measured using Network-Based Statistics (NBS). Behavioral outcomes were measured using validated assessments such as the Acceptance and Action Questionnaire (AAQ-II), the Chronic Pain Acceptance Questionnaire (CPAQ), the Center for Epidemiologic Studies Depression Scale (CES-D), and the NIH Toolbox Neuro-QoLTM (Quality of Life in Neurological Disorders) scales. Results suggest that, following the 4-week ACT intervention, participants exhibited reductions in brain activation within and between key networks including self-reflection (default mode, DMN), emotion (salience, SN), and cognitive control (frontal parietal, FPN). These changes in connectivity strength were correlated with changes in behavioral outcomes including decreased depression and pain interference, and increased participation in social roles. This study is one of the first to demonstrate that improved function across the DMN, SN, and FPN may drive the positive outcomes associated with ACT. This study contributes to the emerging evidence supporting the use of neurophysiological indices to characterize treatment effects of alternative and complementary mind-body therapies.

Improvements in Speech of Children with Apraxia: The Efficacy of Treatment for Establishing Motor Program Organization (TEMPOSM).

Purpose: This study investigated the efficacy of Treatment for Establishing Motor Program Organization (TEMPOSM) in childhood apraxia of speech (CAS).Method: A mixed between- and within-participant design with multiple baselines across participants and behaviors was used to examine acquisition, generalization, and maintenance of skills. TEMPOSM was administered in four one-hour sessions a week over a four-week period for eleven participants (ages 5 to 8), allocated to either an immediate treatment group or a wait-list control group. Acoustic and perceptual variables were measured at baseline, immediate post-treatment, and one-month post-treatment.Results: Children demonstrated significant improvements in specific acoustic measures of segmentation and lexical stress, as well as perceptual measures of fluency, lexical stress, and speech-sound accuracy. Treatment and generalization effects were maintained one-month post-treatment with generalization to untreated stimuli.Conclusion: TEMPOSM was efficacious in improving segmental and suprasegmental impairments in the speech of children with CAS.

Network Alterations in Comorbid Chronic Pain and Opioid Addiction: An Exploratory Approach.

The comorbidity of chronic pain and opioid addiction is a serious problem that has been growing with the practice of prescribing opioids for chronic pain. Neuroimaging research has shown that chronic pain and opioid dependence both affect brain structure and function, but this is the first study to evaluate the neurophysiological alterations in patients with comorbid chronic pain and addiction. Eighteen participants with chronic low back pain and opioid addiction were compared with eighteen age- and sex-matched healthy individuals in a pain-induction fMRI task. Unified structural equation modeling (SEM) with Lagrange multiplier (LM) testing yielded a network model of pain processing for patient and control groups based on 19 a priori defined regions. Tests of differences between groups on specific regression parameters were determined on a path-by-path basis using z-tests corrected for the number of comparisons. Patients with the chronic pain and addiction comorbidity had increased connection strengths; many of these connections were interhemispheric and spanned regions involved in sensory, affective, and cognitive processes. The affected regions included those that are commonly altered in chronic pain or addiction alone, indicating that this comorbidity manifests with neurological symptoms of both disorders. Understanding the neural mechanisms involved in the comorbidity is crucial to finding a comprehensive treatment, rather than treating the symptoms individually.

Autobiographical memory retrieval and hippocampal activation as a function of repetition and the passage of time.

Multiple trace theory (MTT) predicts that hippocampal memory traces expand and strengthen as a function of repeated memory retrievals. We tested this hypothesis utilizing fMRI, comparing the effect of memory retrieval versus the mere passage of time on hippocampal activation. While undergoing fMRI scanning, participants retrieved remote autobiographical memories that had been previously retrieved either one month earlier, two days earlier, or multiple times during the preceding month. Behavioral analyses revealed that the number and consistency of memory details retrieved increased with multiple retrievals but not with the passage of time. While all three retrieval conditions activated a similar set of brain regions normally associated with autobiographical memory retrieval including medial temporal lobe structures, hippocampal activation did not change as a function of either multiple retrievals or the passage of time. However, activation in other brain regions, including the precuneus, lateral prefrontal cortex, parietal cortex, lateral temporal lobe, and perirhinal cortex increased after multiple retrievals, but was not influenced by the passage of time. These results have important implications for existing theories of long-term memory consolidation.

A novel dual-color bifocal imaging system for single-molecule studies.

In this paper, we report the design and implementation of a dual-color bifocal imaging (DBI) system that is capable of acquiring two spectrally distinct, spatially registered images of objects located in either same or two distinct focal planes. We achieve this by separating an image into two channels with distinct chromatic properties and independently focusing both images onto a single CCD camera. The two channels in our device are registered with subpixel accuracy, and long-term stability of the registered images with nanometer-precision was accomplished by reducing the drift of the images to ∼5 nm. We demonstrate the capabilities of our DBI system by imaging biomolecules labeled with spectrally distinct dyes and micro- and nano-sized spheres located in different focal planes.