Chronic Pain in Older Adults: A Neuroscience-Based Psychological Assessment and Treatment Approach.

Chronic pain remains a serious healthcare challenge, particularly for older adults who suffer substantial disability and are susceptible to serious risks from pain medications and invasive procedures. Psychotherapy is a promising option for older adults with chronic pain, since it does not contribute to medical or surgical risks. However, standard psychotherapies for chronic pain, including cognitive-behavioral therapy (CBT), acceptance and commitment therapy, and mindfulness-based interventions, produce only modest and time-limited benefits for older adults. In this article, we describe a novel, evidence-based psychological assessment and treatment approach for older adults with chronic pain, including a detailed case example. The approach begins with reviewing patients' pain, psychosocial, and medical histories to elicit evidence of a subtype of chronic pain called centralized (primary, nociplastic, or psychophysiologic) pain, which is highly influenced and may even be caused by life stress, emotions, and alterations in brain function. Patients then undertake a novel psychotherapy approach called emotional awareness and expression therapy (EAET) that aims to reduce or eliminate centralized pain by resolving trauma and emotional conflicts and learning healthy communication of adaptive emotions. Our published preliminary clinical trial (n = 53) indicated that EAET produced statistically significant and large effect size advantages over CBT in pain reduction and marginally greater improvements in pain interference than CBT for older adults with chronic musculoskeletal pain. Geriatric mental healthcare providers may learn this assessment and treatment approach to benefit many of their patients with chronic pain.

Characteristics of Spontaneous Square-Wave Jerks in the Healthy Macaque Monkey during Visual Fixation.

Saccadic intrusions (SIs), predominantly horizontal saccades that interrupt accurate fixation, include square-wave jerks (SWJs; the most common type of SI), which consist of an initial saccade away from the fixation target followed, after a short delay, by a return saccade that brings the eye back onto target. SWJs are present in most human subjects, but are prominent by their increased frequency and size in certain parkinsonian disorders and in recessive, hereditary spinocerebellar ataxias. SWJs have been also documented in monkeys with tectal and cerebellar etiologies, but no studies to date have investigated the occurrence of SWJs in healthy nonhuman primates. Here we set out to determine the characteristics of SWJs in healthy rhesus macaques (Macaca mulatta) during attempted fixation of a small visual target. Our results indicate that SWJs are common in healthy nonhuman primates. We moreover found primate SWJs to share many characteristics with human SWJs, including the relationship between the size of a saccade and its likelihood to be part of a SWJ. One main discrepancy between monkey and human SWJs was that monkey SWJs tended to be more vertical than horizontal, whereas human SWJs have a strong horizontal preference. Yet, our combined data indicate that primate and human SWJs play a similar role in fixation correction, suggesting that they share a comparable coupling mechanism at the oculomotor generation level. These findings constrain the potential brain areas and mechanisms underlying the generation of fixational saccades in human and nonhuman primates.

The effects of fixation target size and luminance on microsaccades and square-wave jerks.

A large amount of classic and contemporary vision studies require subjects to fixate a target. Target fixation serves as a normalizing factor across studies, promoting the field's ability to compare and contrast experiments. Yet, fixation target parameters, including luminance, contrast, size, shape and color, vary across studies, potentially affecting the interpretation of results. Previous research on the effects of fixation target size and luminance on the control of fixation position rendered conflicting results, and no study has examined the effects of fixation target characteristics on square-wave jerks, the most common type of saccadic intrusion. Here we set out to determine the effects of fixation target size and luminance on the characteristics of microsaccades and square-wave jerks, over a large range of stimulus parameters. Human subjects fixated a circular target with varying luminance and size while we recorded their eye movements with an infrared video tracker (EyeLink 1000, SR Research). We detected microsaccades and SWJs automatically with objective algorithms developed previously. Microsaccade rates decreased linearly and microsaccade magnitudes increased linearly with target size. The percent of microsaccades forming part of SWJs decreased, and the time from the end of the initial SWJ saccade to the beginning of the second SWJ saccade (SWJ inter-saccadic interval; ISI) increased with target size. The microsaccadic preference for horizontal direction also decreased moderately with target size . Target luminance did not affect significantly microsaccades or SWJs, however. In the absence of a fixation target, microsaccades became scarcer and larger, while SWJ prevalence decreased and SWJ ISIs increased. Thus, the choice of fixation target can affect experimental outcomes, especially in human factors and in visual and oculomotor studies. These results have implications for previous and future research conducted under fixation conditions, and should encourage forthcoming studies to report the size of fixation targets to aid the interpretation and replication of their results.