Odor Naming Research Articles

Role of verbal encoding in short- and long-term odor recognition.

The role of verbal encoding in odor recognition memory was investigated using odors of low familiarity to subjects before the experiment began. The experimental procedure included two phases--odor learning (first phase) and odor memory testing (second phase)--separated by a delay of 7 days. Five experimental conditions were established: three conditions of odor learning with names (labeling conditions), one condition of odor learning without names (sensory familiarization), and one condition of no learning prior to testing (control conditions). The labeling conditions differed from each other regarding label characteristics. The names were those of odor sources (veridical names), those personally generated by subjects (generated names), or those derived from the chemical names of the odorants (chemical names). Subjects were required to learn 20 fixed associations between odors (targets or distractors) and 20 names during two daily sessions. The learning sessions included two identification tests and ended by a verbal memory test in which subjects recalled odor names. The odor memory test was split into two parts separated by a retention interval of either 20 min (short-term memory) or 24 h (long-term memory). Data showed that olfactory recognition memory was enhanced in subjects who associated veridical or generated names to odors during the learning session. Chemical names were not appropriate to facilitate odor recognition. Similarly, the level of odor identification was higher for veridical and generated names than for chemical names, though the level of verbal memory for chemical names was substantial. Recognition response latencies were systematically longer for a target odor implying a positive response than for a distractor odor implying a negative response. Together, these data suggest that odor recognition and identification are sensitive to the semantic content of labels associated with odors. Odor memory was adversively influenced by time, but this influence was less pronounced when the names were endowed with a rich semantic content.

Primacy and Recency in Recognition of Odours and Recall of Odour Names

This study examined the serial position curve for recognition of odours and recall of odour names, both with and without instructions for verbal elaboration. Participants were allocated to one of two experimental conditions, either with instructions to rehearse verbally the stimuli or with no elaboration instructions. After presentation of 17 odours, either recognition or free recall of the odours was tested immediately after presentation of the last target odour. Recognition showed evidence of primacy for the verbal elaboration condition and recency for both instruction conditions. Recall of odour names showed evidence of primacy for the verbal elaboration conditions and recency for both conditions. Instructions to verbalize did not significantly affect over-all performance for either test condition.

Interference with olfactory memory by visual and verbal tasks.

It has been claimed that olfactory memory is distinct from memory in other modalities. This study investigated the effectiveness of visual and verbal tasks in interfering with olfactory memory and included methodological changes from other recent studies. Subjects were allocated to one of four experimental conditions involving interference tasks [no interference task; visual task; verbal task; visual-plus-verbal task] and presented 15 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Recognition and recall performance both showed effects of interference of visual and verbal tasks but there was no effect for time of testing. While the results may be accommodated within a dual coding framework, further work is indicated to resolve theoretical issues relating to task complexity.

Very Long-Term Memory for Odors: Retention of Odor-Name Associations

The ability to remember odor-name associations for recent odors (those associated with everyday products experienced within the past 2 years) and distant odors (those associated with children's toys not encountered for 3 years or more) was examined in two experiments. In recognition tasks, subjects attempted to match odor names to odors, or odors to odor names. In a recall task, subjects tried to identify odors by name. The results showed that although odor retention was better for recent than distant odors, significant retention remains for odors not experienced since childhood. These results are consistent with other studies that found very slow and gradual loss of odor information in memory. They extend that research by showing that odor information is still available over a much longer period of time.

Memory for odors and odor names: Modalities of elaboration and imagery.

This study examined memory for common odors and odors names that were encoded with visual, verbal, and olfactory elaboration.

Memory for odors and odor names: Modalities of elaboration and imagery.

Memory for odors and odor names: Modalities of elaboration and imagery.

Clinical evaluation of olfaction

An odor identification test and an odor threshold test offered satisfactory quantitative information on olfactory function in patients with chemosensory complaints. The threshold test used various concentrations of butanol presented in an ascending sequence. On each trial, the participant had to choose between stimulus and blank (two-alternative forced-choice procedure). The identification test used common odorous items (e.g., baby powder and ground coffee) and pungent items (e.g., ammonia) to test trigeminal function. A list of odor names and use of corrective feedback during testing overcame word-finding difficulty in odor identification. Each test readily distinguished between patients and control subjects. At present, a score that reflects the combined outcome of the tests is used to indicate five categories of functioning: normal osmesis, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia.

Odor identification by males and females: predictions vs performance

More than 200 males and females estimated the identifiability of 80 common odorous objects (e.g., chocolate, beer, mustard, rubber). The two genders agreed rather closely in their estimates. The groups also agreed closely in their relative judgements of whether males or females could identify the objects better. Both groups anticipated that males would be superior for only a small number of substances, mainly substances that seem stereotypically ‘male’ (e.g., cigar butts, beer, machine oil). The groups anticipated female superiority for not only stereotypically ‘female’ substances (e.g., Ivory soap, Johnson's baby powder, nail polish remover), but also for virtually all foods, including foods presumably consumed equally by both sexes (e.g., potato chips, Juicy Fruit gum, grape drink). The results suggested the existence of a second stereotype, namely that females will be superior at identifying all substances not clearly in the male domain. An experiment that explored the performance of 46 males and females over five sessions revealed general female superiority. The superiority extended to odors considered ‘male’. Males seemed educable and could apparently overcome their disadvantage eventually with merely some help in the retrieval of odor names. Blockage of retrieval seems a strong limiting factor in odor identification for females as well as for males. Irrespective of gender, when persons have the veridical name of a well-known odor made available by one or another means, they exhibit considerable talent at identifying objects by smell.