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A specialized odor memory buffer in primary olfactory cortex.

Zelano C, Montag J, Khan R, Sobel N - PLoS ONE (2009)

Bottom Line: The neural substrates of olfactory working memory are unknown.We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes.These findings suggest a novel dedicated mechanism in primary olfactory cortex, where odor information is maintained in temporary storage to subserve ongoing tasks.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel. czelano@gmail.com

ABSTRACT

Background: The neural substrates of olfactory working memory are unknown. We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes.

Methodology/principal findings: We used functional magnetic resonance imaging to measure activity in the brains of subjects who were remembering either nameable or unnameable odorants. We found a double dissociation whereby remembering nameable odorants was reflected in sustained activity in prefrontal language areas, and remembering unnameable odorants was reflected in sustained activity in primary olfactory cortex.

Conclusions/significance: These findings suggest a novel dedicated mechanism in primary olfactory cortex, where odor information is maintained in temporary storage to subserve ongoing tasks.

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Related in: MedlinePlus

Sniff size across conditions.Participants sniffed equally during nameable and unnameable conditions. The left panel shows the mean sniff, in liters per minute, for nameable and unnameable conditions. The center panel shows sniff duration, in liters per minute, for nameable and unnameable conditions. The right panel shows sniff maximum, in liters per minute, for nameable and unnameable conditions.
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pone-0004965-g003: Sniff size across conditions.Participants sniffed equally during nameable and unnameable conditions. The left panel shows the mean sniff, in liters per minute, for nameable and unnameable conditions. The center panel shows sniff duration, in liters per minute, for nameable and unnameable conditions. The right panel shows sniff maximum, in liters per minute, for nameable and unnameable conditions.

Mentions: Odorants classified as unnameable and nameable were rated as equally intense (t(9) = 0.76, p<.45) and pleasant (t(9) = 0.38, p<.7) yet significantly more difficult to name (t(9) = 9.6, p<.0001) (figure 2a). Subjects' performance on the delayed match to sample task was better for the five second delay conditions than for the ten second delay conditions (F(1,9) = 7.04, p<.02), but did not differ between the nameable and unnameable conditions (F(1,9) = 3.2, p<.11) (figure 2b). Sniffs of nameable odorants did not differ in duration (F(1,9) = 0.08, p<.7853), max flow (F(1,9) = 2.14, p<.1745) or mean flow (F(1,9) = 2.15, p<.1769) from sniffs of unnameable odorants (figure 3). Upon completion of all scans, each subject answered a multiple choice survey questionnaire regarding his/her strategy of remembering the odorants they could or could not name (figure S1). Subjects reported that when they could easily name the odorant, they remembered the word describing it. However, when the odorant was difficult to name, subjects attempted to hold the smell in mind during the delay.


A specialized odor memory buffer in primary olfactory cortex.

Zelano C, Montag J, Khan R, Sobel N - PLoS ONE (2009)

Sniff size across conditions.Participants sniffed equally during nameable and unnameable conditions. The left panel shows the mean sniff, in liters per minute, for nameable and unnameable conditions. The center panel shows sniff duration, in liters per minute, for nameable and unnameable conditions. The right panel shows sniff maximum, in liters per minute, for nameable and unnameable conditions.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2654926&req=5

pone-0004965-g003: Sniff size across conditions.Participants sniffed equally during nameable and unnameable conditions. The left panel shows the mean sniff, in liters per minute, for nameable and unnameable conditions. The center panel shows sniff duration, in liters per minute, for nameable and unnameable conditions. The right panel shows sniff maximum, in liters per minute, for nameable and unnameable conditions.
Mentions: Odorants classified as unnameable and nameable were rated as equally intense (t(9) = 0.76, p<.45) and pleasant (t(9) = 0.38, p<.7) yet significantly more difficult to name (t(9) = 9.6, p<.0001) (figure 2a). Subjects' performance on the delayed match to sample task was better for the five second delay conditions than for the ten second delay conditions (F(1,9) = 7.04, p<.02), but did not differ between the nameable and unnameable conditions (F(1,9) = 3.2, p<.11) (figure 2b). Sniffs of nameable odorants did not differ in duration (F(1,9) = 0.08, p<.7853), max flow (F(1,9) = 2.14, p<.1745) or mean flow (F(1,9) = 2.15, p<.1769) from sniffs of unnameable odorants (figure 3). Upon completion of all scans, each subject answered a multiple choice survey questionnaire regarding his/her strategy of remembering the odorants they could or could not name (figure S1). Subjects reported that when they could easily name the odorant, they remembered the word describing it. However, when the odorant was difficult to name, subjects attempted to hold the smell in mind during the delay.

Bottom Line: The neural substrates of olfactory working memory are unknown.We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes.These findings suggest a novel dedicated mechanism in primary olfactory cortex, where odor information is maintained in temporary storage to subserve ongoing tasks.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel. czelano@gmail.com

ABSTRACT

Background: The neural substrates of olfactory working memory are unknown. We addressed the questions of whether olfactory working memory involves a verbal representation of the odor, or a sensory image of the odor, or both, and the location of the neural substrates of these processes.

Methodology/principal findings: We used functional magnetic resonance imaging to measure activity in the brains of subjects who were remembering either nameable or unnameable odorants. We found a double dissociation whereby remembering nameable odorants was reflected in sustained activity in prefrontal language areas, and remembering unnameable odorants was reflected in sustained activity in primary olfactory cortex.

Conclusions/significance: These findings suggest a novel dedicated mechanism in primary olfactory cortex, where odor information is maintained in temporary storage to subserve ongoing tasks.

Show MeSH
Related in: MedlinePlus