top of page
Uvic JK_edited.jpg

Jamie Knight

PhD

  • Facebook
  • Twitter
  • LinkedIn
  • Instagram

Hello

Here's who I am & what I do

My passion for olfactory health began during my graduate studies where my research focused on identifying early signs of dementia. I learned about the strong connection between the sense of smell and memory and began to use smells to study for my exams. After completing my PhD, I decided to create Olfactory Health, a service dedicated to helping people improve and regain their sense of smell.

​

Exploring Cognitive Health through an Olfactory Health Lens

At the intersection of neuropsychology and chemosensory science, my research interests are driven by a profound desire to understand the early stages of cognitive decline and dementia. With a focus on how olfactory (smell) testing can detect early signs of these conditions, my research delves into the intricate relationship between sensory function and cognitive health.

A Lifespan Perspective on Cognitive Health

My work encompasses a broad spectrum, examining neuropsychological and chemosensory functioning across different stages of life. This approach is crucial in unraveling the complexities of age-related cognitive decline and neurodegenerative diseases. By analyzing patterns and changes over time, I aim to contribute to a deeper understanding of how these diseases evolve and impact individuals differently. My focus lies in understanding the key markers of successful aging (social engagement, physical activity and olfactory health) and developing plans that will lead to a longer healthspan.

The Potential of Olfactory Training

One of my core areas of interest is the potential role of olfactory training in enhancing brain health. The research clearly shows that targeted sensory training can have a positive impact on olfactory performance and the potential impacts this training can have on the brain offers a promising avenue for both preventative strategies and interventions. My research is dedicated to exploring this possibility, seeking innovative ways to harness the power of our senses in maintaining and improving cognitive function.

Commitment to Advancing Brain Health

Through my research and collaborations, I am committed to advancing our understanding of brain health. By bridging the gap between scientific discovery and practical applications, I aspire to contribute meaningfully to the field and make a difference in the lives of those affected by cognitive decline and neurodegenerative diseases. I have focused on ehealth and digital health technologies to use emerging technology to support individuals both preemptively and throughout the progression of cognitive decline.  I have a further interest in specifically women’s brain health and the implications of hormone replacement therapy during menopause and how lack of estrogen and HRT access can potentially translate to an increased risk of dementia for women.

Abstract

Background

The existing literature suggests that impaired olfaction may be an early marker for cognitive decline. Tracking the earliest stages of the progression to dementia is paramount, and yet the importance of olfactory ability throughout cognitive states and death remains unclear.

Methods

Drawing data from the Rush Memory and Aging Project (N = 1 501; 74% female), olfactory ability was assessed using the Brief Smell Identification Test (range = 0–16), while cognitive states (unimpaired, mild cognitive impairment [MCI], and dementia) were determined using a 3-step neuropsychological diagnostic protocol at up to 15 annual occasions. Multistate survival models simultaneously estimated the association of olfactory ability on transitions through cognitive states and death, while multinomial regression models estimated cognitively unimpaired and total life expectancies.

Results

Higher olfactory scores were associated with a reduced risk of transitioning from unimpaired cognition to MCI (hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.82–0.88) and from MCI to dementia (HR = 0.89, 95% CI = 0.86–0.93), indicating that 1-unit increase in olfactory scores was associated with an approximate 14% and 11% reduction in risk, respectively. Additionally, higher olfactory scores were associated with a greater likelihood of transitioning backward from MCI to unimpaired cognition (HR = 1.07, 95% CI = 1.02–1.12). Furthermore, higher baseline olfactory scores were associated with more years of longevity without cognitive impairment. However, olfaction was not associated with the transition to death when accounting for transitions through cognitive states.

Conclusions

Findings suggest that higher olfactory identification scores are associated with a decreased risk of transitioning to impaired cognitive states and that associations between olfaction and mortality may occur primarily through the pathway of neurodegeneration.

Abstract

Objectives

To determine whether assessment-to-assessment fluctuations in episodic memory (EM) reflect fluctuations in olfaction over time.

Methods

Within-person coupled variation in EM and the Brief Smell Identification Test (BSIT) was examined in 565 participants aged 58–106 with autopsy data from the Rush Memory and Aging Project. A growth model for up to 15 years of EM data, with BSIT as time-varying covariate, was estimated accounting for main effects of sex, education, ε4 allele, and Alzheimer’s disease (AD) pathology, BSIT and time-varying BSIT, as well as the interaction between AD pathology and time-varying BSIT.

Results

Individuals with higher BSIT scores (b = .01, standard error [SE] = .004, p = .009) had slower declines in EM. High AD pathology (b = −.06, SE = .02, p = .001) was associated with more rapid declines in EM. The association between time-specific fluctuations in EM and BSIT differed by level of AD pathology (b = .08, SE = .034, p = .028), with a higher EM–BSIT association at higher levels of pathology.

Discussion

BSIT and EM fluctuate together over measurement occasions, particularly for individuals with AD pathology. Repeated intraindividual measurements provide information that could lead to early detection and inexpensive monitoring of accumulating AD pathology.

bottom of page