Decreased olfactory discrimination is associated with impulsivity in healthy volunteers

Abstract

In clinical populations, olfactory abilities parallel executive function, implicating shared neuroanatomical substrates within the ventral prefrontal cortex. In healthy individuals, the relationship between olfaction and personality traits or certain cognitive and behavioural characteristics remains unexplored. We therefore tested if olfactory function is associated with trait and behavioural impulsivity in nonclinical individuals. Eighty-three healthy volunteers (50 females) underwent quantitative assessment of olfactory function (odour detection threshold, discrimination, and identification). Each participant was rated for trait impulsivity index using the Barratt Impulsiveness Scale and performed a battery of tasks to assess behavioural impulsivity (Stop Signal Task, SST; Information Sampling Task, IST; Delay Discounting). Lower odour discrimination predicted high ratings in non-planning impulsivity (Barratt Non-Planning impulsivity subscale); both, lower odour discrimination and detection threshold predicted low inhibitory control (SST; increased motor impulsivity). These findings extend clinical observations to support the hypothesis that deficits in olfactory ability are linked to impulsive tendencies within the healthy population. In particular, the relationship between olfactory abilities and behavioural inhibitory control (in the SST) reinforces evidence for functional overlap between neural networks involved in both processes. These findings may usefully inform the stratification of people at risk of impulse-control-related problems and support planning early clinical interventions.

Mid-Luteal Olfactory Abilities Reveal Healthy Women’s Emotional and Cognitive Functions

“…A recent study on a healthy population reported that better olfactory discrimination and worse olfactory threshold abilities predicted a shorter SSRT in a standard stop-signal task (Herman et al, 2018). However, we did not find a significant correlation between olfactory abilities and the SSRT estimation in the current study.…”

“…Studies on patients with psychiatric (e.g., schizophrenia and depression) and neurodegenerative (e.g., Parkinson's disease and Alzheimer's disease) disorders have discovered that hyposmia often accompanies emotional symptoms (Martzke et al, 1997;Croy et al, 2014;Kohli et al, 2016;Croy and Hummel, 2017) and cognitive decline (Masala et al, 2018;Sanna et al, 2021). Although olfactory identification and recognition performances were reported to be comparable between patients with mild or moderate depressive disorder and healthy controls (Zucco and Bollini, 2011), decreased odor discrimination ability was associated with a more impulsive tendency even within the non-clinical population (Herman et al, 2018). Recent studies further reveal the indicative role of olfaction in humans.…”

Neurological and Neuropsychiatric Disorders in Relation to Olfactory Dysfunction

“…It has been attributed to impaired olfactory processing [112]. Within the healthy population, impulsive tendencies exhibit some link to olfactory defects [113]. Narcolepsy is associated with hypocretin deficiency of the limbic system.…”

BrainNET: Inference of Brain Network Topology Using Machine Learning

“…Increased NSPL was found in the right olfactory region in ADHD-I compared with ADHD-C, suggesting lesser integration. Deficits in olfactory ability have been linked to impulsive tendencies within the healthy population and have discriminatory features in identifying people at risk of impulse-controlrelated problems, supporting the planning of early clinical interventions (Herman et al, 2018). Further studies are required to investigate whether the functional network topology can be used as a biological marker for early diagnosis, treatment, and prognosis of ADHD.…”