Representation of olfactory information in the primate orbitofrontal cortex

Rolls, Edmund T.; Critchley, Hugo; Treves, Alessandro

doi:10.1152/jn.1996.75.5.1982

Cited by 129 publications

(89 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus this measure is useful in analysing encoding. A feature of the single cell information theoretic analyses that we have performed is that rigorous corrections have been made for the finite sampling effect, that is, that the number of trials of data is limited (Rolls, Critchley, & Treves, 1996;Rolls et al, 1997b;Tovee, Rolls, Treves, & Bellis, 1993). Figure 5 shows the stimulus-specific information I(s,R) available in the neuronal response about each of 20 face stimuli calculated for the neuron (am242) whose firing rate response profile to the set of 68 stimuli is shown in Fig.…”

Section: Single Cell Informationmentioning

confidence: 99%

Cortical coding

Rolls

2016

Language, Cognition and Neuroscience

View full text Add to dashboard Cite

SummaryThe encoding of information in the primate inferior temporal visual cortex, hippocampus, orbitofrontal cortex, and insula, is described. All these areas investigated have sparse distributed graded firing rate representations. The firing rate probability distribution is close to exponential. The information increases approximately linearly with the number of neurons. Consistent with this relative independence, there is little extra information that is available because of stimulus-dependent synchrony, and little redundancy. The code can be read very fast, in 20-50 ms, by dot-product, biologically plausible decoding. The advantages of this code include high capacity, generalization, graceful degradation, and rapid read-out of the information by biologically plausible dot-product decoding. None of these are properties of local or 'grandmother-cell' representations. Consistent evidence is becoming available for humans. Thus the evidence indicates that information is encoded in many cortical areas by sparse distributed graded firing rate representations, and this type of representation has major computational advantages for the brain including for language that are not met by local or 'grandmother-cell' representations.

show abstract

Section: Single Cell Informationmentioning

confidence: 99%

Cortical coding

Rolls

2016

Language, Cognition and Neuroscience

View full text Add to dashboard Cite

show abstract

“…1) (17,(45)(46)(47)(48) . Visual inputs also become associated by learning in the OFC with the taste of food to represent the sight of food and contribute to flavour (49,50) .…”

Section: The Secondary Taste Cortexmentioning

confidence: 99%

Taste, olfactory and food texture reward processing in the brain and the control of appetite

Rolls

2012

Proc. Nutr. Soc.

106

View full text Add to dashboard Cite

Complementary neuronal recordings and functional neuroimaging in human subjects show that the primary taste cortex in the anterior insula provides separate and combined representations of the taste, temperature and texture (including fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex (OFC), these sensory inputs are for some neurons combined by learning with olfactory and visual inputs, and these neurons encode food reward in that they only respond to food when hungry, and in that activations correlate with subjective pleasantness. Cognitive factors, including word-level descriptions, and attention modulate the representation of the reward value of food in the OFC and a region to which it projects, the anterior cingulate cortex. Further, there are individual differences in the representation of the reward value of food in the OFC. It is argued that over-eating and obesity are related in many cases to an increased reward value of the sensory inputs produced by foods, and their modulation by cognition and attention that over-ride existing satiety signals. It is proposed that control of all rather than one or several of these factors that influence food reward and eating may be important in the prevention and treatment of overeating and obesity.

show abstract

“…This type of population coding has been proposed as a mechanism for signal processing in the OB and olfactory and visional cortices (32)(33)(34)(35) and it should be particularly useful for determining solutions in closed form because of the finite number of glomeruli. The large dimensionality in glomerular space has the advantage of being quantified.…”

Section: Modification Of Saps With Prolonged Exposurementioning

confidence: 99%

Assessment and discrimination of odor stimuli in rat olfactory bulb by dynamic functional MRI

Kida²,

Hyder³

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

118

View full text Add to dashboard Cite

Dynamic blood oxygenation level-dependent functional MRI was applied at 7 T in the rat olfactory bulb (OB) with pulsed delivery of iso-amyl acetate (IAA) and limonene. Acquisition times for singleslice and whole OB data were 8 and 32 s, respectively, with spatial resolution of 220 ؋ 220 ؋ 250 m. On an intrasubject basis, short IAA exposures of 0.6 min separated by 3.5-min intervals induced reproducible spatial activity patterns (SAPs) in the olfactory nerve layer, glomerular layer, and external plexiform layer. During long exposures (Ϸ10 min), the initially dominant dorsal SAPs declined in intensity and area, whereas in some OB regions, the initially weak ventral͞lateral SAPs increased first and then decreased. The SAPs of different concentrations were topologically similar, which implies that whereas an odor at various concentrations activates the same subsets of receptor cells, different concentrations are assessed and discriminated by variable magnitudes of laminarspecific activations. IAA and limonene reproducibly activated different subsets of receptor cells with some overlaps. Whereas qualitative topographical agreement was observed with results from other methods, the current dynamic blood oxygenation level-dependent functional MRI results can provide quantitative SAPs of the entire OB.blood oxygenation level-dependent ͉ functional mapping ͉ olfactory bulb I n mammals, olfactory behaviors such as determination of food palatability and searching require accurate assessment and discrimination of different odor types, concentrations, and exposure duration (1). Distinctions between these behavioral tasks are believed to rely on a spatial-encoding mechanism in which different odor and concentrations evoke spatial activity patterns (SAPs) in the olfactory bulb (OB). The SAPs are derived from functionally induced activity in olfactory receptor neurons that synapse at specific glomeruli (2).Insights into the coding of olfactory information have been partially inferred from SAPs in the OB, where the data can be obtained by various methods: 2-deoxyglucose autoradiography (3), electrophysiology (4), c-fos expression (5), functional MRI (fMRI) (6), and optical imaging of voltage-sensitive dyes (7) or intrinsic signals (8). Experimental limitations of each method affect data interpretations because each method maps a specific signal. Certain experimental criteria have to be met for olfactory perception to be systematically and ideally derived from the functional architecture revealed by the SAPs: (i) the neuroanatomy of the whole OB has to be mapped; (ii) the dynamic nature of SAPs in the whole OB has to be mapped with both high spatial and temporal resolutions; (iii) laminar-specific activations in the different layers have to be quantitated; and (iv) reproducibility of SAPs has to be established in a quantitative manner such that the effects of stimulus parameters (e.g., odor type, concentration, and exposure duration) can be easily identified and separated. If each criterion is met on an intrasubject basis by a par...

show abstract

Representation of olfactory information in the primate orbitofrontal cortex

Cited by 129 publications

References 37 publications

Cortical coding

Cortical coding

Taste, olfactory and food texture reward processing in the brain and the control of appetite

Assessment and discrimination of odor stimuli in rat olfactory bulb by dynamic functional MRI

Contact Info

Product

Resources

About