A new paper from the lab has been published in Chemical Senses today. Free odor identification engages domain-general cognitive abilities in old adults, by Thomas Hörberg, Rohan Raj and Jonas Olofsson (et. al.) and investigates odor identification and cognitive aging.
Find it here: https://doi.org/10.1093/chemse/bjaf049
Our now former PhD Candidate Stephen Pierzchajlo successfully defended his dissertation Smelling Without A Smell: How olfactory-perceptual representations are activated by words.
Abstract:
We spend every day using our senses to interact with the world. Though we use language as a way to understand the sensory world, language might have different roles for different senses. Freely identifying odors in naming tasks is more difficult than with senses like vision, making olfaction an interesting place to study the intersection between language and the senses. While free olfactory identification is poor, word cues strongly increase our ability to identify odors. This has led some to conclude that olfaction is more dependent on supporting information from other senses, and that odors are encoded in a coarse way, so it is particularly dependent on language and sensory cues to function capably. This has further led to debate regarding whether language can activate olfactory-related representations in the brain, or whether odor and language systems are disconnected. The general aim of this thesis was to investigate whether and how word cues can affect olfactory processes and representations.
You can find the dissertation here: https://su.diva-portal.org/
In our most recent publication, Representations of smells: The next frontier for language models?, published in Cognition, we tested language models’ ability to capture olfactory-perceptual and olfactory semantic information.
We trained three generations of language models, using around 200 training configurations and four different text corpora. We then evaluated these models against three different data sets, capturing either olfactory-perceptual or olfactory-semantic information.
Surprisingly, we found classic language models, such as Word2Vec, to best capture olfactory-perceptual content, and state-of-the art models, such as GPT, to excel at olfactory-semantic content. However, the results of Word2Vec depended heavily on the training data, showing much better performance when trained on olfactory-related contexts.
The article can be read here: https://www.sciencedirect.com/science/article/
Authors: Murathan Kurfalı, Pawel Herman, Stephen Pierzchajlo, Jonas Olofsson, Thomas Hörberg
Our new article, Asymmetric cross-sensory interference between spatial memories of sounds and smells revealed in a virtual reality environment was just published in Journal of experimental psychology: Learning, memory, and cognition.
We used virtual reality (VR) technology, together with the VR-compatible olfactometer developed in our lab, to study spatial memory for smells and sounds during active exploration and navigation similar to real life. We investigated whether spatial memory of odors would retroactively interfere with sounds.
Our results shows a decline in spatial memory performance over time and similar retroactive interference effects from smells and sounds. However, exploratory results indicated asymmetric effects in error trials where participants tended to misplace sounds in the vicinity of smells related to the same concepts (e.g., misplacing the sound of a coffee maker at the location of the smell of coffee). This points towards an olfactory dominance at the conceptual level.
The article can be read here: https://doi.org/10.1037/xlm0001493
Authors: Malina Szychowska, Karolina Ersson, and Jonas K. Olofsson
A collaboration with Theresa White of Le Moyne College has been published in Chemical Senses. The systematic review A Cognitive Nose? Evaluating Working Memory Benchmarks in the Olfactory Domain sheds light on the operation of Working memory in olfaction and review research spanning the last 50 years.
Highlights:
According to ChatGPT: ”The study suggests that olfactory memory shares many similarities with working memory in other senses, though there are distinct differences. It emphasizes the need for future research to expand WM theories beyond visual and auditory senses to better understand how our memory interacts with smells.”
Find it here: https://academic.oup.com/chemse/
A new article from the Lab – Evidence from odor similarity judgments suggests a widespread ability to imagine odors – was just published in the Journal of Experimental Psychology: Human Perception and Performance.
In this study, comparisons of similarity judgments between smelled and imagined odors revealed a strong correlation, suggesting that perceptual imagery of odors is possible, with pleasantness serving as a key determinant.
Authors: Stephen Pierzchajlo, Thomas Hörberg, Sandra Challma and Jonas K. Olofsson.
The article can be found here: https://psycnet.apa.org/
In a new study, published in Human Brain Mapping, SCI-lab members Georgios Menelaou and Jonas Olofsson teamed up with researchers from Harvard University, Northwestern University and Karolinska Institute to understand how the smell brain regions are connected to deeper brain networks – the so-called Default-Mode Network (DMN) – which is thought to be responsible for concepts and meaning. The connections were measured with resting-state fMRI using a stepwise connectivity method. They found that the sense of smell was different from other senses by having a closer connective pathway to the DMN. They also found that the olfactory regions reached the DMN via two distinct pathways in the brain. The research gives insights into how the sense of smell connects to other parts of the brain in unique ways. The work was sponsored by the Swedish Research Council and the Wallenberg Foundations.
Another study from the lab is published in Food Quality & Preference! On the basis of natural language in product reviews, this study compares and maps the semantic spaces of the chemosensory vocabularies of the wine, perfume and food product domains.
Thomas Hörberg and Murathan Kurfali have spearheaded this study. Find it here: https://doi.org/10.1016/j.foodqual.2024.105357
A new article from the Lab has been published in Cognitive Science! The article’s full title is ”A Rose by Another Name? Odor Misnaming is Associated with Linguistic Properties” and is about the work lead by Thomas Hörberg and Murathan Kurfali.
Abstract:
Naming common odors is a surprisingly difficult task: Odors are frequently misnamed. Little is known about the linguistic properties of odor misnamings. We test whether odor misnamings of old adults carry information about olfactory perception and its connection to lexical-semantic processing. We analyze the olfactory–semantic content of odor source naming failures in a large sample of older adults in Sweden (n = 2479; age 58–100 years). We investigate whether linguistic factors and semantic proximity to the target odor name predict how odors are misnamed, and how these factors relate to overall odor identification performance. We also explore the primary semantic dimensions along which misnamings are distributed. We find that odor misnamings consist of surprisingly many vague and unspecific terms, such as category names (e.g., fruit) or abstract or evaluative terms (e.g., sweet). Odor misnamings are often strongly associated with the correct name, capturing properties such as its category or other abstract features. People are also biased toward misnaming odors with high-frequency terms that are associated with olfaction or gustation. Linguistic properties of odor misnamings and their semantic proximity to the target odor name predict odor identification performance, suggesting that linguistic processing facilitates odor identification. Further, odor misnamings constitute an olfactory–semantic space that is similar to the olfactory vocabulary of English. This space is primarily differentiated along pleasantness, edibility, and concreteness dimensions. Odor naming failures thus contain plenty of information about semantic odor knowledge.
The article can be found at https://doi.org/10.1111/cogs.70003.
Our article Olfactory categorization is shaped by a transmodal cortical network for evaluating perceptual predictions has been early released in JNeuroSci!
Abstract:
Creating and evaluating predictions are considered important features in sensory perception. Little is known about processing differences between the senses and their cortical substrates. Here, we tested the hypothesis that olfaction, the sense of smell, would be highly dependent on (non-olfactory) object-predictive cues and involve distinct cortical processing features. We developed a novel paradigm to compare prediction error processing across senses. Participants listened to spoken word cues (e.g. “lilac”) and determined whether target stimuli (odors or pictures) matched the word cue or not. In two behavioral experiments (total n = 113; 72 female), the disparity between congruent and incongruent response-times was exaggerated for olfactory relative to visual targets, indicating a greater dependency on predictive verbal cues to process olfactory targets. A pre-registered fMRI study (n = 30; 19 female) revealed the anterior cingulate cortex (a region central for error detection) being more activated by incongruent olfactory targets, indicating a role for olfactory predictive error processing. Additionally, both the primary olfactory and visual cortices were significantly activated for incongruent olfactory targets, suggesting olfactory prediction errors are dependent on cross-sensory processing resources, whereas visual prediction errors are not. We propose that olfaction is characterized by a strong dependency on predictive (non-olfactory) cues, and that odors are evaluated in the context of such predictions by a designated transmodal cortical network. Our results indicate differences in how predictive cues are used by different senses in rapid decision-making.
Stephen Pierzchajlo, PhD student, is the main author and with this release is the culmination of 4 years of work.
Fine the paper here: https://www.jneurosci.org/content/early/2024/03/29/JNEUROSCI.1232-23.2024
Stephen Pierzchajlo