Scientific publications

Modulation of Higher-Order Olfaction Components on Executive Functions in Humans

Jun 17, 2015 | Magazine: PloS One

Fagundo AB (1), Jiménez-Murcia S (2), Giner-Bartolomé C (1), Islam MA (1), de la Torre R (3), Pastor A (4) Casanueva FF (5), Crujeiras AB (5), Granero R (6), Baños R (7(, Botella C (8), Fernández-Real JM (9), Frühbeck G (10), Gómez-Ambrosi J (10), Menchón JM (11), Tinahones FJ (12), Fernández-Aranda F (2).
(1) Department of Psychiatry, University Hospital of Bellvitge-IDIBELL, Barcelona, Spain; CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain.
(2) Department of Psychiatry, University Hospital of Bellvitge-IDIBELL, Barcelona, Spain; CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Department of Clinical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain.
(3) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Integrative Pharmacology and Systems Neuroscience Research Group, Neuroscience Research Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
(4) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Integrative Pharmacology and Systems Neuroscience Research Group, Neuroscience Research Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; Department of Pharmacology, School of Medicine, Universitat Autònoma de Barcelona, Spain.
(5) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Endocrine Division, Complejo Hospitalario U. de Santiago, Santiago de Compostela University, Santiago de Compostela, Spain.
(6) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Departament de Psicobiologia i Metodologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
(7) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Department of Personality, Evaluation and Psychological Treatment of the University of Valencia, Valencia, Spain.
(8) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Department of Basic Psychology, Clinic and Psychobiology of the University Jaume I, Castelló, Spain.
(9) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdlBGi) Hospital Dr Josep Trueta, Girona, Spain.
(10) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Metabolic Research Laboratory, Clínica Universidad de Navarra, University of Navarra, IdiSNA, Pamplona, Spain.
(11) Department of Psychiatry, University Hospital of Bellvitge-IDIBELL, Barcelona, Spain; Department of Clinical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain; CIBER Salud Mental (CIBERsam), Instituto Salud Carlos III, Barcelona, Spain.
(12) CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain; Department of Endocrinology and Nutrition, Hospital Clínico Universitario Virgen de Victoria, Málaga, Spain. 


ABSTRACT

The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both executive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans.

The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used.

One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test-WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia.

Olfactory abilities were assessed using the ''Sniffin' Sticks'' test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All participants were female, aged between 18 and 60.

Results showed that participants with hyposmia displayed worse performance in decision making (IGT; Cohen's-d = 0.91) and cognitive flexibility (WCST; Cohen's-d between 0.54 and 0.68) compared to those with normosmia.

Multiple regression adjusted by the covariates participants' age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance.

Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive measures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders.

CITATION  PLoS One. 2015 Jun 17;10(6):e0130319. doi: 10.1371/journal.pone.0130319. eCollection 2015