Olfactory function in psychotic disorders: Insights from neuroimaging studies

Table 2 Olfactory studies

Ref.	AuthorsPassive smelling	Year	Modality	Subject group(s)	Finding
[46]	Zatorre et al	1992	PET	Healthy subjects	Piri (B) and OFC (RH)
[53]	Levy et al	1997	FMRI	Healthy subjects	P and UP: piri, amyg, hippocam, cing and post inf front cortex (laterality not specified)
[43]	Sobel et al	1998	FMRI	Healthy subjects	Passive smelling, lat OFC; Sniffing-piri (B) and post OFC (B)
[48]	Savic et al	2000	PET	Healthy subjects	OFC (RH), amyg/piri (RH), thal (RH), insula (LH), ant cing
[49]	Gottfried et al	2002	FMRI	Healthy subjects	P and UP: Amyg (B), post OFC (B), post piri (B), insula (RH)
[45]	Royet et al	2003	FMRI	Healthy subjects	UP and P odorants-piri/amyg, hypothal, sup temp, insula and OFC, ant cing
[44]	Kareken et al	2004	PET	Healthy subjects	Piri (B), amyg (B), insula (B); sniffing lateral OFC (B)
[47]	Kjelvik et al	2012	FMRI	Healthy subjects	Piri (B), amyg (B), OFC (B) and thal (B) cing (RH), insula (LH)
[25]	Plailly et al	2006	PET	Psychosis patients	HC > SZ Piri (LH) and inf front (LH)
					SZ > HC insula (RH)
	Good et al	Under review	FMRI	Psychosis patients	HC > SZ thal (RH), caud (B), ant cing, OFC (B only midly greater), mid temp gyrus (B)
	Hedonics (Valence)
[55]	Zald et al	1997	PET	Healthy subjects	Aversive odorant- amyg and OFC; less aversive- only OFC (LH)
[56]	Fulbright et al	1998	FMRI	Healthy subjects	Pleasant- BA 46/9 (RH), 32 (LH), 8 (B) 6 (RH) and insula (B); Unpleasant- 46/9 (RH), 32 (LH), 6 (B), insula (RH)
[57]	Royet et al	2000	PET	Healthy subjects	Hedonic judgement- ant cing, OFC (LH), sup front (LH), midd front gyrus (LH), inf midd temporal (LH)
[49]	Gottfried et al	2002	FMRI	Healthy subjects	UP: insula (RH), lat hypothal (LH), amyg (RH), post OFC (L); P: piri (RH), insula (RH), post OFC (RH)
[45]	Royet et al	2003	FMRI	Healthy subjects	Hedonic valence -UP > P: piri (LH), amyg (LH); P > U: cing (LH)
[58]	Rolls et al	2003	FMRI	Healthy subjects	P: med OFC; ant cing
[54]	Anderson et al	2003	FMRI	Healthy subjects
[72]	Crespo-Facorro et al	2001	PET	Psychosis patients	HC > SZ P vs UP: insula (LH), para hipp (LH), sup temp gyrus (LH), accumbens (RH), lingual gyrus (B), cb. vermis (LH) SZ > HC Med OFC (B), DLPFC (B), med front (LH), lat front (RH), lat front (LH), front operculum (LH), parahipp (RH), post cing (LH)
[25]	Plailly et al	2006	PET	Psychosis patients	HC > SZ Insula (LH) and Inf front (LH)
[27]	Schneider et al	2007	FMRI	Psychosis patients	HC > SZ UP: Midd temp gyrus (RH) Midd front gyrus (RH) Insula; P: thal (L) SZ > HC UP: Midd front (RH) ant cing (RH)
	Intensity
[54]	Anderson et al	2003	FMRI	Healthy subjects	Amyg (B)
[63]	Winsto et al	2005	FMRI	Healthy subjects	Amyg, (but only at the extremes of valence), OFC and piri
	Familiarity
[60]	Royet et al	1999	PET	Healthy subjects	Med frontal (RH), inf front (LH), sup front(LH) cingulate (B)
[57]	Royet et al	2000	PET	Healthy subjects	OFC (B), ant cing, sup front (LH) midd front (RH)
[25]	Plailly et al	2006	PET	Psychosis patients	HC > SZ piri (LH), sup temp gyrus(LH), gyrus rectus(RH), OFC (LH), inf OFC (LH)
	Identification
[47]	Kjelvik et al	2012	FMRI	Healthy subjects	Correctly identified entorhinal cortex (LH), Hippocam (RH), parahippocam gyrus (B), OFC and piriform cortices Incorrectly identified: OFC and piri cortices
[73]	Clark et al	1991	PET	Psychosis patients	HC > SZ front (B) parietal (B); Norm > Micro thal (RH) and basal ganglia
[33]	Malaspina et al	1998	SPECT	Psychosis patients	HC > SZ inf. Front (RH), sup temp (RH) supramarg/angular gyrus (RH) HC (but not SZ) hippocam(B), fusiform(RH)
	Genetic Trait
[27]	Schneider et al	2007	FMRI	Psychosis patients	HC > FDR UP: mid front gyrus(RH) FDR > HC P: ant cing(LH)

FMRI: Functional magnetic resonance imaging; PET: Positron emission tomography; SPECT: Single photon emission computed tomography; HC: Healthy controls; SZ: Schizophrenia patients; FDR: First-degree relatives; UP: Unpleasant; P: Pleasant; B: Bilateral; LH: Left hemisphere; RH: Right hemisphere; ant: Anterior; post: Posterior; lat: LAteral; inf: Interior; sup: Superior; midd: Middle; temp: Temporal; front: Frontal; Amyg: Amygdala; piri: Piriform cortex; hippocam: Hippocampus; OFC: Orbitofrontal cortex; ant cing: Anterior cingulate; thal: Thalamus; hypothal: Hypothalamus; parahippocam: Parahippocampal; DLPFC: Dorsolateral prefrontal cortex.