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©The Author(s) 2015.
World J Psychiatr. Jun 22, 2015; 5(2): 210-221
Published online Jun 22, 2015. doi: 10.5498/wjp.v5.i2.210
Published online Jun 22, 2015. doi: 10.5498/wjp.v5.i2.210
Table 1 Description of the olfactory methods used to examine different olfactory domains
Olfactory domain | Methods by which this domain is assessed |
Passive smelling | Odorant is presented passively to the subject. Imaging done without response or overt cognitive appreciation |
Olfactory detection | Similar to passive smelling, however, the subject must press a button to signal the onset of the odorant perception |
Odour “sniffing” | Subjects are given instructions to inhale the odorant during presentation |
Olfactory intensity | Rating the odorant as to its perceived strength. Can be done by a button press (Is the odour “strong”?) |
Intensity may be assessed by ratings of odorants (e.g., VAS) outside of the scanner and presenting odours that have been rated on opposite ends of the continuum (very strong vs very weak) | |
Olfactory familiarity | Recollect prior exposure without the exact autobiographical context and also without naming. Button press if odour is “familiar” |
Olfactory hedonics (valence) | The determination of pleasantness of the odorant. |
Button press to rate whether an odorant is pleasant | |
Pleasant/Unpleasant odorant rated (e.g., VAS) outside of the scanner and presenting odours that have been rated on opposite ends of the continuum (very unpleasant to very pleasant) | |
Olfactory identification | Correct identification- those items that are correctly labeled vs those for which label is incorrect |
Olfactory identification test score used to capture most impaired, compared with normal sense of smell | |
Forced choice odour naming during scanning |
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) |
- Citation: Good KP, Sullivan RL. Olfactory function in psychotic disorders: Insights from neuroimaging studies. World J Psychiatr 2015; 5(2): 210-221
- URL: https://www.wjgnet.com/2220-3206/full/v5/i2/210.htm
- DOI: https://dx.doi.org/10.5498/wjp.v5.i2.210