Matthew J. Kmiecik

23andMe · Research

Relational thinking involves comparing abstract relationships between mental representations that vary in complexity; however, this complexity is rarely made explicit during everyday comparisons. This study explored how people naturally navigate relational complexity and interference using a novel relational match-to-sample (RMTS) task with both mi...

Increased sensory sensitivity across non-nociceptive modalities is a common symptom of chronic pain conditions and is associated with chronic pain development. Providing a better understanding of the brain-behavior relationships that underlie multimodal hypersensitivity (MMH) may clarify the role of MMH in the development of chronic pain. We studie...

Multimodal hypersensitivity (MMH)—greater sensitivity across multiple sensory modalities (eg, light, sound, temperature, pressure)—is associated with the development of chronic pain. However, previous MMH studies are restricted given their reliance on self-reported questionnaires, narrow use of multimodal sensory testing, or limited follow-up. We c...

The LRRK2 G2019S variant is the most common cause of monogenic Parkinson’s disease (PD); however, questions remain regarding the penetrance, clinical phenotype and natural history of carriers. We performed a 3.5-year prospective longitudinal online study in a large number of 1286 genotyped LRRK2 G2019S carriers and 109 154 controls, with and withou...

Importance: The lack of information on progression, phenoconversion, and risk of dementia in a large genotyped sample impedes reliable enrichment for early interventional trials in Parkinson's disease (PD). Objective: To investigate PD penetrance, risk, motor/non-motor phenotypes, and APOE allele effects in LRRK2 G2019S and GBA N370S carriers. Desi...

Background: Early detection of Parkinson's disease (PD), a neurodegenerative disease with central and peripheral nerve involvement, ensures timely treatment access. Microbes influence nervous system health and are altered in PD. Methods: We examined gut and mouth microbiomes from recently diagnosed patients in a geographically diverse, matched c...

Introduction Puberty encompasses a multitude of physical, hormonal, and psychological changes. Additionally, adolescents also experience a delay in circadian rhythm, increasing their vulnerability to insufficient sleep. Even though puberty and sleep share a strong association, few studies have explored the shift in sleep after the onset of menstrua...

Introduction Adolescence is marked by shifts in sleep, both in terms of timing and quality. Little is known about how these disruptions in sleep relate to pain and executive functioning (EF) following the onset of menstruation (e.g., menarche) in females. This study examines the relations between 1) sleep disturbances and pain, 2) sleep disturbance...

Early detection of Parkinson’s disease (PD), a neurodegenerative disease with central and peripheral nerve involvement, ensures timely treatment access. Microbes influence nervous system health and are altered in PD. We examined gut and mouth microbiomes from recently diagnosed patients in a geographically diverse, matched case-control, metagenomic...

The LRRK2 G2019S variant is the most common cause of monogenic Parkinson's Disease (PD); however, questions remain regarding the penetrance, clinical phenotype, and natural history of carriers. We performed a 3.5 year prospective longitudinal online study in a large number of 1,286 genotyped LRRK2 G2019S carriers and 109,154 controls, with and with...

Background: Although dysmenorrhea is a highly prevalent risk factor for irritable bowel syndrome (IBS), the factors underlying this risk are not fully understood. Prior studies support a hypothesis that repeated distressing menstrual pain promotes cross-organ pelvic sensitization with heightened visceral sensitivity. Aims: To further explore cro...

Better understanding of the mechanisms underlying perceived unpleasantness in response to a stimulus are critically needed to improve the treatment of sensory disorders such as migraine and chronic pain. We previously found that generally healthy, young adult women with preclinical evidence of pelvic hypersensitivity reported greater visual unpleas...

Background and Aims: Multimodal hypersensitivity (MMH) is a hallmark symptom associated with chronic pain conditions [3–5,8,10,12,14] and mechanisms responsible for MMH may be a key reason why individuals develop chronic pain [2,7] or a determinant of treatment response [6,9]. MMH is increased sensitivity across multiple sensory modalities (e.g., l...

Multimodal hypersensitivity (MMH)---greater sensitivity across multiple sensory modalities (e.g., light, sound, temperature, pressure)---is a mechanism hypothesized to be responsible for the development of chronic pain and pelvic pain. However, previous studies of MMH are restricted given their reliance on biased self-report questionnaires, limited...

Prior studies of A:B::C:D verbal analogies have identified several factors that affect performance, including the semantic similarity between source and target domains (semantic distance), the semantic association between the C-term and incorrect answers (distracter salience), and the type of relations between word pairs. However, it is unclear how...

Introduction: Increased sensory sensitivity across non-nociceptive modalities is a common symptom of chronic pain conditions and has been shown in individuals with chronic pelvic pain (CPP); however, the neural mechanisms underlying this hypersensitivity are unknown. Understanding the brain-behavior relationships that explain multimodal hypersensit...

Multisensory hypersensitivity (MSH), which refers to persistent discomfort across sensory modalities, is a risk factor for chronic pain. Developing a better understanding of the neural contributions of disparate sensory systems to MSH may clarify its role in the development of chronic pain. We recruited a cohort of women (n=147) enriched with parti...

This poster presents preliminary data from this study that was presented at the Cognitive Neuroscience Annual Meeting 2020 (virtual conference).

Mechanistic theories of the N400 event-related potential—a neural correlate indexing semantic processing in the brain—implicate the roles of prediction, priming, and bottom-up sensory integration in language comprehension; however, mechanisms explaining volitional aspects of semantic meaning construction are not fully understood. To explore this, p...

The locus coeruleus - norepinephrine system (LC-NE) – a primary dispenser of norepinephrine in the brain – modulates allocation of attention used in executive functioning and reasoning through connection tracts to the prefrontal cortex (PFC); however, the changes of norepinephrine related to decision-making when affected by transcranial direct curr...

Traumatic brain injuries (TBIs) occur when we receive a harmful blow to the head that results in disruptions to normal brain functioning. TBIs often cause cognitive deficits that include difficulties in concentration (e.g., mental fog), planning, and setting/achieving goals. These cognitive abilities are often classified more broadly as executive f...

Background: Some individuals who sustain traumatic brain injuries (TBIs) continue to experience significant cognitive impairments chronically (months to years post injury). Many tests of executive function are insensitive to these executive function impairments, as such impairments may only appear during complex daily life conditions. Daily life o...

Analogical reasoning—our ability to abstract relational similarities between situations despite surface-level differences—varies between individuals; however, current analogy tasks are often not difficult enough to capture variability in performance across healthy and clinical populations. To address this challenge, we developed a scene analogy ass...

Performing relational comparisons is considered among the most intelligent cognitive capacities. Animal studies have demonstrated that chimpanzees and crows are capable of relational reasoning with second-order relationships (e.g., analogies); however, it has been hypothesized that only humans are capable of reasoning with third-order relationships...

Background: Some individuals who sustain traumatic brain injuries (TBIs) continue to experience significant cognitive impairments chronically (months-to-years post-injury). Many tests of executive function are insensitive to these executive function impairments, as such impairments may only appear during complex daily life conditions. Daily life of...

Our ability to integrate increasingly complex relationships underlies human reasoning (Holyoak & Thagard, 1995), relies on the prefrontal cortex (e.g., Christoff et al., 2001; Waltz et al., 1999), and correlates with intelligence (Marshalek, Lohman, & Snow, 1983). Kroger, Holyoak, and Hummel (2004) demonstrated that comparing increasingly complex r...

Clinical investigations of individuals with chronic stage traumatic brain injury (TBI) showing mild-to-moderate levels of residual impairment largely use standardized neuropsychological assessments to measure executive functioning. The Hayling Sentence Completion Test (HSCT) relies upon several executive functions but detects cognitive impairments...

Poster to be presented at the annual American Congress of Rehabilitation Medicine (ACRM) in Chicago, IL. Presents a partial least squares correlation analysis of the relationships between BOLD response and white matter microstructure in adults with chronic mild-moderate traumatic brain injury (TBI). Note: the currently published abstract in the Arc...

In multivariate analyses, data are typically structured with observations (i.e., participants) on the rows and measurements (i.e., variables) on the columns. These data structure types are commonly analyzed with methods such as principal components analysis (PCA) or factor analyses (FA). However, PCA, FA, and related techniques are not always suita...

Analogical reasoning—the ability to understand and utilize relational similarities between entities despite surface-level differences—helps individuals solve problems and navigate through novel situations. This ability varies across healthy and clinical populations, yet current analogical reasoning tasks often fail to capture subtle performance var...

Media violence exposure causes increased aggression and decreased prosocial behavior, suggesting that media violence desensitizes people to the emotional experience of others. Alterations in emotional face processing following exposure to media violence may result in desensitization to others' emotional states. This study used scalp electroencephal...

Developmental, neuropsychological, and computational studies have suggested the importance of both relational knowledge and working memory in analogical reasoning. In this study, we investigated the extent to which individual differences in working memory (WM) and crystallized knowledge (Gc) predicted accuracies on a visual analogy verification tas...

Computational accounts have traditionally focused on mapping between structured representations as fundamental to analogical processing. However, a recent connectionist model has been used to argue that structured representations may not be necessary to solve verbal analogies. Green and colleagues (2010) have shown that brain areas associated with...