Ann-Sophie Barwich | Indiana Bloomington (original) (raw)

Books by Ann-Sophie Barwich

Harvard University Press, 2020

Decades of cognition research have shown that external stimuli “spark” neural patterns in particu... more Decades of cognition research have shown that external stimuli “spark” neural patterns in particular regions of the brain. This has fostered a view of the brain as a space that we can map: here the brain responds to faces, there it perceives a sensation in your left hand. But it turns out that the sense of smell—only recently attracting broader attention in neuroscience—doesn’t work this way. A. S. Barwich asks a deceptively simple question: What does the nose tell the brain, and how does the brain understand it?

Barwich interviews experts in neuroscience, psychology, chemistry, and perfumery in an effort to understand the biological mechanics and myriad meanings of odors. She argues that it is time to stop recycling ideas based on the paradigm of vision for the olfactory system. Scents are often fickle and boundless in comparison with visual images, and they do not line up with well-defined neural regions. Although olfaction remains a puzzle, Barwich proposes that what we know suggests the brain acts not only like a map but also as a measuring device, one that senses and processes simple and complex odors.

Accounting for the sense of smell upsets theories of perception philosophers have developed. In their place, Smellosophy articulates a new model for understanding how the brain represents sensory information.

Routledge, 2021

This volume establishes the conceptual foundation for sustained investigation into tool developme... more This volume establishes the conceptual foundation for sustained investigation into tool development in neuroscience. Neuroscience relies on diverse and sophisticated experimental tools, and its ultimate explanatory target—our brains and hence the organ driving our behaviors—catapults the investigation of these research tools into a philosophical spotlight.

The chapters in this volume integrate the currently scattered work on tool development in neuroscience into the broader philosophy of science community. They also present an accessible compendium for neuroscientists interested in the broader theoretical dimensions of their experimental practices. The chapters are divided into five thematic sections. Section 1 discusses the development of revolutionary research tools across neuroscience’s history and argues to various conclusions concerning the relationship between new research tools and theory progress in neuroscience. Section 2 shows how a focus on research tools and their development in neuroscience transforms some traditional epistemological issues and questions about knowledge production in philosophy of science. Section 3 speaks to the most general questions about the way we characterize the nature of the portion of the world that this science addresses. Section 4 discusses hybrid research tools that integrate laboratory and computational methods in exciting new ways. Finally, Section 5 extends research on tool development to the related science of genetics.

The Tools of Neuroscience Experiment will be of interest to philosophers and philosophically minded scientists working at the intersection of philosophy and neuroscience.

Papers by Ann-Sophie Barwich

Review of Philosophy and Psychology, 2024

This paper investigates the spatial dimensions of olfactory perception, challenging philosophical... more This paper investigates the spatial dimensions of olfactory perception, challenging philosophical views that marginalize smell in spatial navigation and cognition compared to visual phenomenology. I argue that both olfactory and visual perception-despite smell often being considered non-spatial or minimally spatial-involve intricate spatial structuring through unconscious cognitive processes. An informationtheoretical approach shows that cognitive inferences turn spatially deficient sensory data into spatialized perceptual content to generate spatial perception across sensory modalities. This challenges the idea that spatial perception is tied to external features. My argument is supported by two lines of evidence: (i) figureground segregation across sensory modalities, suggesting a general mechanism in perceptual processing; (ii) recent neuroscientific evidence demonstrating how spatial information is entailed in olfaction for navigation and environmental 'mapping'. My analysis calls for a reevaluation of assumptions about the non-spatial nature of smell, highlighting significant cognitive and spatial capabilities in olfaction.

European Journal of Neuroscience, 2024

There are many different kinds of models, and they play many different roles in the scientific en... more There are many different kinds of models, and they play many different roles in the scientific endeavour. Neuroscience, and biology more generally, has understandably tended to emphasise empirical models that are grounded in data and make specific, experimentally testable predictions. Meanwhile, strongly idealised or 'toy' models have played a central role in the theoretical development of other sciences such as physics. In this paper, we examine the nature of toy models and their prospects in neuroscience.

Biology & Philosophy, 2024

Machine metaphors abound in life sciences: animals as automata, mitochondria as engines, brains a... more Machine metaphors abound in life sciences: animals as automata, mitochondria as engines, brains as computers. Philosophers have criticized machine metaphors for implying that life functions mechanically, misleading research. This approach misses a crucial point in applying machine metaphors to biological phenomena: their reciprocity. Analogical modeling of machines and biological entities is not a one-way street where our understanding of biology must obey a mechanical conception of machines. While our understanding of biological phenomena undoubtedly has been shaped by machine metaphors, the resulting insights have likewise altered our understanding of what machines are and what they can do.

Proceedings of the 2024 Artificial Life Conference, 2024

This paper investigates respiratory odor navigation with minimal evolutionary robots. We introduc... more This paper investigates respiratory odor navigation with minimal evolutionary robots. We introduce a novel agent tasked with locating a chemical source solely through the use of a respiratory sensor, a challenge inspired by the active sampling strategies observed in a wide variety of animals (e.g., sniffing, whisking). Prevailing hypotheses suggest that odor navigation serves predominantly to gate behaviors in response to information gleaned from different sensory modalities. We analyze the agent's behavior and neural dynamics using dynamical systems theory, demonstrating the possibility of strategies that instead rely solely on the information obtained from their respiratory sensor. Our findings reveal that agents can successfully locate chemical sources through the synchronization of breathing rates with motor outputs, mirroring sensorimotor coupling strategies recently identified in the experimental literature. This research contributes to the theoretical understanding of sensory odor navigation and the role of physiology in agent-environment interactions.

Proceedings of the 2023 Artificial Life Conference, 2023

In their most abstract form, we can understand tissues as being composed of three general cell ty... more In their most abstract form, we can understand tissues as being composed of three general cell types: stem cells, transitamplifying cells, and differentiated cells. Additionally, we know that these cell types can secrete molecules or regulatory factors that can exert control over other cell populations. Recent work in theoretical biology examined several cell lineage control networks that result in tissue homeostasis. We develop an alternative mass action model that views developmental cell lineages as biological pathways. We demonstrate that three cell lineages are homeostatic irrespective of the implementation and that their control structures exhibit a degeneracy, containing solely negative feedback or negative resistance. We replicate and extend the homeostatic control architectures previously outlined and report on the relevant bifurcations and dynamics of these pathways.

Topics in Cognitive Science , 2023

Representational drift is a phenomenon of increasing interest in the cognitive and neural science... more Representational drift is a phenomenon of increasing interest in the cognitive and neural sciences. While investigations are ongoing for other sensory cortices, recent research has demonstrated the pervasiveness in which it occurs in the piriform cortex for olfaction. This gradual weakening and shifting of stimulus-responsive cells has critical implications for sensory stimulus-response models and perceptual decision-making. While representational drift may complicate traditional sensory processing models, it could be seen as an advantage in olfaction, as animals live in environments with constantly changing and unpredictable chemical information. Non-topographical encoding in the olfactory system may aid in contextualizing reactions to promiscuous odor stimuli, facilitating adaptive animal behavior and survival. This article suggests that traditional models of stimulus-(neural) response mapping in olfaction may need to be reevaluated and instead motivates the use of dynamical systems theory as a methodology and conceptual framework.

Theoretical Perspectives on Smell, 2022

The theme of this chapter is causality. Traditional stimulus-response models have deemed the rece... more The theme of this chapter is causality. Traditional stimulus-response models have deemed the receptors as causally necessary for sensory processing. Nevertheless, they did not sufficiently explicate and specify the scope of their active causal role in bringing about the outcome of perceptual quality in olfaction. In response, Section 8.2 introduces the causal function of the chemical stimulus in the context of different dis- ciplinary contexts in olfaction. Here, we encounter a clear difference in two causal models of stimulus-response relationships: chemistry versus receptor-based explanations. Section 8.3 compares the causal characteristics of these two models and argues that their explanatory difference reveals a contrast in ontology. Section 8.4 links stimulus causality to philosophical interest in odor perception, and contrasts a biological-based view of smell with theories that center on chemistry.
Between a stimulus and its response is a causal space. This chapter focuses on the critical details of the periphery processes that shape this causal space, details that are important for scientific modeling and philosophical theories of perception.

Learning & Behavior, 2023

Recent research suggests that the piriform cortex simultaneously represents spatial and olfactory... more Recent research suggests that the piriform cortex simultaneously represents spatial and olfactory information. These findings may provide further insight into the non-topographic principles of odor coding.

Philosophy Compass, 2022

Theories of perception have traditionally dismissed the sense of smell as a notoriously variable ... more Theories of perception have traditionally dismissed the sense of smell as a notoriously variable and highly subjective sense, mainly because it does not easily fit into accounts of perception based on visual experience. So far, philosophical questions about the objects of olfactory perception have started by considering the nature of olfactory experience. However, there is no philosophically neutral or agreed conception of olfactory experience: it all depends on what one thinks odors are. We examine the existing philosophical methodology for addressing our sense of smell: on the one hand appeals to phenomenology that focus on the experiential dimensions of odor perception and on the other approaches that look at odor sources and their material dimensions. We show that neither strategy provides enough information to account for the human sense of smell and argue that the inclusion of the missing dimension of biology, with its concern for the function (or functions) of olfaction, provides the means to develop a satisfactory and empirically informed philosophy of smell.

Frontiers in Neuroscience, 2022

Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the... more Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the relation between chemical structure and sensory quality with Big Data. These studies advanced computational models of the olfactory stimulus, utilizing artificial intelligence to mine for clear correlations between chemistry and psychophysics. Computational perspectives promised to solve the mystery of olfaction with more data and better data processing tools. None of them succeeded, however, and it matters as to why this is the case. This article argues that we should be deeply skeptical about the trend to black-box the sensory system’s biology in our theories of perception. Instead, we need to ground both stimulus models and psychophysical data on real causal-mechanistic explanations of the olfactory system. The central question is: Would knowledge of biology lead to a better understanding of the stimulus in odor coding than the one utilized in current machine learning models? That is indeed the case. Recent studies about receptor behavior have revealed that the olfactory system operates by principles not captured in current stimulus-response models. This may require a fundamental revision of computational approaches to olfaction, including its psychological effects. To analyze the different research programs in olfaction, we draw on Lloyd’s “Logic of Research Questions,” a philosophical framework which assists scientists in explicating the reasoning, conceptual commitments, and problems of a modeling approach in question.

Rowman & Littlefield, 2022

Can we use light switches and, at the same time, believe in myths? This question resonates with o... more Can we use light switches and, at the same time, believe in myths? This question resonates with ongoing disputes about the authority of science versus non-scientific ways of thinking. Recently, concerns regarding an overreach of scientific authority in human culture renewed momentum to pseudoscientific ideas originating in anti-science sentiments. This chapter sets out to rethink the currently prevailing image of science in light of its role as a facilitator of cognitive evolution to counter these potentially harmful conjectures. My argument unfolds in three steps. It first touches on the specific role of science in human cultural development. Drawing on ideas by Bultmann of the Marburg school, I suggest distinguishing between cosmological and existentialist questions in our engagement with the world. This distinction forms the backdrop against which we can understand the current popularization and rise of speculative metaphysics. Second, I examine a specific example: the recent revival of panpsychism as an example of an increasing conflation of existentialist with cosmological questions. Of particular concern in this context is that current support for panpsychism is fueled by a science-skepticism that draws on arguments from the philosophy of science. In a third step, this chapter warns that these arguments used to back science-skepticism build on a misleading image of science, which portrays science as an unchanging cognitive practice with varying knowledge outputs. However, I contend that science is not principally in the business of accumulating facts; rather, it is a cognitive activity in the pursuit of more sophisticated questions for understanding the world. Such shift in the image of science results in a change of its explanatory target by focusing on cognitive participation in its processes instead of centering analysis on its products like knowledge and technologies. Linking to recent theories of cultural evolution in cognitive science, analysis of science is best framed via the evolutionary development of cognitive gadgets or mental mechanisms through cultural transmission. Such a revised image of science then offers new avenues of collaboration with the humanities in the twenty-first century.

Routledge, 2022

Since the 1990s, molecular and cellular cognition (MCC) has elucidated critical causal mechanisms... more Since the 1990s, molecular and cellular cognition (MCC) has elucidated critical causal mechanisms behind higher level processes of perception and cognition. New intervention techniques, including genetic tracers and fluorescent visualization, have facilitated targeted access and manipulation of molecular pathways to investigate their precise roles in cognition and links to behavior. Insights from MCC have transformed central ideas of cognition, especially memory. This chapter introduces key developments in late 20th-century neuroscience that explain how the discovery of the molecular mechanisms modified theoretical understanding of memory as a cognitive function. It also looks at contemporary innovations in optical imaging microscopy that further exemplify the central argument that technological innovations in the study of cellular processes constitute fundamental also of high-level cognitive theories.

The Tools of Neuroscience Experiment, 2022

Barwich and Xu present a first-hand account of Xu’s recent application of a new tool, SCAPE micro... more Barwich and Xu present a first-hand account of Xu’s recent application of a new tool, SCAPE microscopy, which uncovered a new mechanism of mixture coding at the olfactory periphery. SCAPE (Swept, Confocally-Aligned Planar Excitation) microscopy allows for fast three-dimensional, high- resolution imaging of entire small organisms (e.g., larvae) or large intact tissue sections (e.g., in mice). Barwich and Xu illustrate how technologies facilitate a broader and different theoretical perspective by being an integral part of the thinking process itself and by co-creating mental structures.

Perspectives on Science, 2021

In 1991, Linda Buck and Richard Axel identified the multigene family expressing odor receptors. T... more In 1991, Linda Buck and Richard Axel identified the multigene family expressing odor receptors. Their discovery transformed research on olfaction overnight, and Buck and Axel were awarded the 2004 Nobel Prize in Physiology or Medicine. Behind this success lies another, less visible study about the methodological ingenuity of Buck. This hidden tale holds the key to answering a fundamental question in discovery analysis: What makes specific discovery tools fit their tasks? Why do some strategies turn out to be more fruitful than others? The fit of a method with an experimental system often establishes the success of a discovery. However, the underlying reasoning of discovery is hard to codify. These difficulties point toward an element of discovery analysis routinely sidelined as a mere biographical element in the philosophical analysis of science: the individual discoverer's role. I argue that the individual researcher is not a replaceable epistemic element in discovery analysis. This article draws on contemporary oral history, including interviews with Buck and other actors key to developments in late 1980s olfaction.

Journal of Theoretical Biology, 2021

Should theories of “higher-level” cognitive effects originate in “lower-level” molecular mechanis... more Should theories of “higher-level” cognitive effects originate in “lower-level” molecular mechanisms? This paper supports reductionist explanations of sensory perception via molecular mechanisms in neurobiology. It shows that molecular and cellular mechanisms must constitute the material foundation to derive better theories and models for neuroscience. In support of “bottom-up theorizing”, we explore the recent application of a new real-time molecular imaging technique (SCAPE microscopy) to mixture coding in olfaction. Seemingly emergent “higher level” psychological effects in odor perception, irreducible to the physical stimulus, are linked back to underlying molecular mechanisms at the receptor level. Critical to understanding the importance of the SCAPE study is its notable theoretical impact. It proves a possible answer to the neurocomputational challenge in olfaction from combinatorial coding at the periphery: how does the brain discriminate different complex mixtures from widespread and overlapping receptor activation? The failure of previous reductionist structure-odor explanations is shown to reside in misconceptualizations of the critical causal elements involved. Causally fundamental features are not of parts independently of a mechanism. Components and their relevant features are units via their causal role within a mechanism. Here, new technologies allow revisiting our understanding of the ontology and levels of organization of a system.

Cell and Tissue Research , 2021

Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret ... more Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret and navigate their environments. Odor detection starts with the activation of odorant receptors (ORs), expressed in mature olfactory sensory neurons (OSNs) populating the olfactory mucosa. Different odorants, or different concentrations of the same odorant, activate unique ensembles of ORs. This mechanism of combinatorial receptor coding provided a possible explanation as to why different odorants are perceived as having distinct odors. Aided by new technologies, several recent studies have found that antagonist interactions also play an important role in the formation of the combinatorial receptor code. These findings mark the start of a new era in the study of odorant-receptor interactions and add a new level of complexity to odor coding in mammals.

Ber. Wissenschaftsgesch., 2020

Perfumes embody a chemical record of style and technology. Blurring the boundary between what cou... more Perfumes embody a chemical record of style and technology. Blurring the boundary between what counts as natural and artificial in both a material and a perceptual sense, perfumery presents us with a domain of multiple disciplinary identities relevant to social studies: art, craft, and techno-science. Despite its profound impact as a cultural practice, perfume has seldom featured in historical scholarship. The reason for this neglect is its inherently qualitative dimension: perfume cannot be understood via codified representation but requires direct acquaintance with its sensory and material basis. The historical study of perfumery thus necessitates an experimental approach that comes not without challenge. This article looks at contemporary recreations of old perfumes to identify the difficulties involved in the experimental recreation of fragrances as sensory and performative artifacts. We highlight the need for a reconceptualization of methodology for inconcrete objects of study as part of the broader interest in experimental approaches to the humanities.

Cell, 2020

In 1991, Buck and Axel published a landmark study in Cell for work that was awarded the 2004 Nobe... more In 1991, Buck and Axel published a landmark study in Cell for work that was awarded the 2004 Nobel Prize. The identification of the olfactory receptors as the largest family of GPCRs catapulted olfaction into mainstream neurobiology. This BenchMark revisits Buck’s experimental innovation and its surprising success at the time.

Harvard University Press, 2020

Decades of cognition research have shown that external stimuli “spark” neural patterns in particu... more Decades of cognition research have shown that external stimuli “spark” neural patterns in particular regions of the brain. This has fostered a view of the brain as a space that we can map: here the brain responds to faces, there it perceives a sensation in your left hand. But it turns out that the sense of smell—only recently attracting broader attention in neuroscience—doesn’t work this way. A. S. Barwich asks a deceptively simple question: What does the nose tell the brain, and how does the brain understand it?

Barwich interviews experts in neuroscience, psychology, chemistry, and perfumery in an effort to understand the biological mechanics and myriad meanings of odors. She argues that it is time to stop recycling ideas based on the paradigm of vision for the olfactory system. Scents are often fickle and boundless in comparison with visual images, and they do not line up with well-defined neural regions. Although olfaction remains a puzzle, Barwich proposes that what we know suggests the brain acts not only like a map but also as a measuring device, one that senses and processes simple and complex odors.

Accounting for the sense of smell upsets theories of perception philosophers have developed. In their place, Smellosophy articulates a new model for understanding how the brain represents sensory information.

Routledge, 2021

This volume establishes the conceptual foundation for sustained investigation into tool developme... more This volume establishes the conceptual foundation for sustained investigation into tool development in neuroscience. Neuroscience relies on diverse and sophisticated experimental tools, and its ultimate explanatory target—our brains and hence the organ driving our behaviors—catapults the investigation of these research tools into a philosophical spotlight.

The chapters in this volume integrate the currently scattered work on tool development in neuroscience into the broader philosophy of science community. They also present an accessible compendium for neuroscientists interested in the broader theoretical dimensions of their experimental practices. The chapters are divided into five thematic sections. Section 1 discusses the development of revolutionary research tools across neuroscience’s history and argues to various conclusions concerning the relationship between new research tools and theory progress in neuroscience. Section 2 shows how a focus on research tools and their development in neuroscience transforms some traditional epistemological issues and questions about knowledge production in philosophy of science. Section 3 speaks to the most general questions about the way we characterize the nature of the portion of the world that this science addresses. Section 4 discusses hybrid research tools that integrate laboratory and computational methods in exciting new ways. Finally, Section 5 extends research on tool development to the related science of genetics.

The Tools of Neuroscience Experiment will be of interest to philosophers and philosophically minded scientists working at the intersection of philosophy and neuroscience.

Review of Philosophy and Psychology, 2024

This paper investigates the spatial dimensions of olfactory perception, challenging philosophical... more This paper investigates the spatial dimensions of olfactory perception, challenging philosophical views that marginalize smell in spatial navigation and cognition compared to visual phenomenology. I argue that both olfactory and visual perception-despite smell often being considered non-spatial or minimally spatial-involve intricate spatial structuring through unconscious cognitive processes. An informationtheoretical approach shows that cognitive inferences turn spatially deficient sensory data into spatialized perceptual content to generate spatial perception across sensory modalities. This challenges the idea that spatial perception is tied to external features. My argument is supported by two lines of evidence: (i) figureground segregation across sensory modalities, suggesting a general mechanism in perceptual processing; (ii) recent neuroscientific evidence demonstrating how spatial information is entailed in olfaction for navigation and environmental 'mapping'. My analysis calls for a reevaluation of assumptions about the non-spatial nature of smell, highlighting significant cognitive and spatial capabilities in olfaction.

European Journal of Neuroscience, 2024

There are many different kinds of models, and they play many different roles in the scientific en... more There are many different kinds of models, and they play many different roles in the scientific endeavour. Neuroscience, and biology more generally, has understandably tended to emphasise empirical models that are grounded in data and make specific, experimentally testable predictions. Meanwhile, strongly idealised or 'toy' models have played a central role in the theoretical development of other sciences such as physics. In this paper, we examine the nature of toy models and their prospects in neuroscience.

Biology & Philosophy, 2024

Machine metaphors abound in life sciences: animals as automata, mitochondria as engines, brains a... more Machine metaphors abound in life sciences: animals as automata, mitochondria as engines, brains as computers. Philosophers have criticized machine metaphors for implying that life functions mechanically, misleading research. This approach misses a crucial point in applying machine metaphors to biological phenomena: their reciprocity. Analogical modeling of machines and biological entities is not a one-way street where our understanding of biology must obey a mechanical conception of machines. While our understanding of biological phenomena undoubtedly has been shaped by machine metaphors, the resulting insights have likewise altered our understanding of what machines are and what they can do.

Proceedings of the 2024 Artificial Life Conference, 2024

This paper investigates respiratory odor navigation with minimal evolutionary robots. We introduc... more This paper investigates respiratory odor navigation with minimal evolutionary robots. We introduce a novel agent tasked with locating a chemical source solely through the use of a respiratory sensor, a challenge inspired by the active sampling strategies observed in a wide variety of animals (e.g., sniffing, whisking). Prevailing hypotheses suggest that odor navigation serves predominantly to gate behaviors in response to information gleaned from different sensory modalities. We analyze the agent's behavior and neural dynamics using dynamical systems theory, demonstrating the possibility of strategies that instead rely solely on the information obtained from their respiratory sensor. Our findings reveal that agents can successfully locate chemical sources through the synchronization of breathing rates with motor outputs, mirroring sensorimotor coupling strategies recently identified in the experimental literature. This research contributes to the theoretical understanding of sensory odor navigation and the role of physiology in agent-environment interactions.

Proceedings of the 2023 Artificial Life Conference, 2023

In their most abstract form, we can understand tissues as being composed of three general cell ty... more In their most abstract form, we can understand tissues as being composed of three general cell types: stem cells, transitamplifying cells, and differentiated cells. Additionally, we know that these cell types can secrete molecules or regulatory factors that can exert control over other cell populations. Recent work in theoretical biology examined several cell lineage control networks that result in tissue homeostasis. We develop an alternative mass action model that views developmental cell lineages as biological pathways. We demonstrate that three cell lineages are homeostatic irrespective of the implementation and that their control structures exhibit a degeneracy, containing solely negative feedback or negative resistance. We replicate and extend the homeostatic control architectures previously outlined and report on the relevant bifurcations and dynamics of these pathways.

Topics in Cognitive Science , 2023

Representational drift is a phenomenon of increasing interest in the cognitive and neural science... more Representational drift is a phenomenon of increasing interest in the cognitive and neural sciences. While investigations are ongoing for other sensory cortices, recent research has demonstrated the pervasiveness in which it occurs in the piriform cortex for olfaction. This gradual weakening and shifting of stimulus-responsive cells has critical implications for sensory stimulus-response models and perceptual decision-making. While representational drift may complicate traditional sensory processing models, it could be seen as an advantage in olfaction, as animals live in environments with constantly changing and unpredictable chemical information. Non-topographical encoding in the olfactory system may aid in contextualizing reactions to promiscuous odor stimuli, facilitating adaptive animal behavior and survival. This article suggests that traditional models of stimulus-(neural) response mapping in olfaction may need to be reevaluated and instead motivates the use of dynamical systems theory as a methodology and conceptual framework.

Theoretical Perspectives on Smell, 2022

The theme of this chapter is causality. Traditional stimulus-response models have deemed the rece... more The theme of this chapter is causality. Traditional stimulus-response models have deemed the receptors as causally necessary for sensory processing. Nevertheless, they did not sufficiently explicate and specify the scope of their active causal role in bringing about the outcome of perceptual quality in olfaction. In response, Section 8.2 introduces the causal function of the chemical stimulus in the context of different dis- ciplinary contexts in olfaction. Here, we encounter a clear difference in two causal models of stimulus-response relationships: chemistry versus receptor-based explanations. Section 8.3 compares the causal characteristics of these two models and argues that their explanatory difference reveals a contrast in ontology. Section 8.4 links stimulus causality to philosophical interest in odor perception, and contrasts a biological-based view of smell with theories that center on chemistry.
Between a stimulus and its response is a causal space. This chapter focuses on the critical details of the periphery processes that shape this causal space, details that are important for scientific modeling and philosophical theories of perception.

Learning & Behavior, 2023

Recent research suggests that the piriform cortex simultaneously represents spatial and olfactory... more Recent research suggests that the piriform cortex simultaneously represents spatial and olfactory information. These findings may provide further insight into the non-topographic principles of odor coding.

Philosophy Compass, 2022

Theories of perception have traditionally dismissed the sense of smell as a notoriously variable ... more Theories of perception have traditionally dismissed the sense of smell as a notoriously variable and highly subjective sense, mainly because it does not easily fit into accounts of perception based on visual experience. So far, philosophical questions about the objects of olfactory perception have started by considering the nature of olfactory experience. However, there is no philosophically neutral or agreed conception of olfactory experience: it all depends on what one thinks odors are. We examine the existing philosophical methodology for addressing our sense of smell: on the one hand appeals to phenomenology that focus on the experiential dimensions of odor perception and on the other approaches that look at odor sources and their material dimensions. We show that neither strategy provides enough information to account for the human sense of smell and argue that the inclusion of the missing dimension of biology, with its concern for the function (or functions) of olfaction, provides the means to develop a satisfactory and empirically informed philosophy of smell.

Frontiers in Neuroscience, 2022

Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the... more Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the relation between chemical structure and sensory quality with Big Data. These studies advanced computational models of the olfactory stimulus, utilizing artificial intelligence to mine for clear correlations between chemistry and psychophysics. Computational perspectives promised to solve the mystery of olfaction with more data and better data processing tools. None of them succeeded, however, and it matters as to why this is the case. This article argues that we should be deeply skeptical about the trend to black-box the sensory system’s biology in our theories of perception. Instead, we need to ground both stimulus models and psychophysical data on real causal-mechanistic explanations of the olfactory system. The central question is: Would knowledge of biology lead to a better understanding of the stimulus in odor coding than the one utilized in current machine learning models? That is indeed the case. Recent studies about receptor behavior have revealed that the olfactory system operates by principles not captured in current stimulus-response models. This may require a fundamental revision of computational approaches to olfaction, including its psychological effects. To analyze the different research programs in olfaction, we draw on Lloyd’s “Logic of Research Questions,” a philosophical framework which assists scientists in explicating the reasoning, conceptual commitments, and problems of a modeling approach in question.

Rowman & Littlefield, 2022

Can we use light switches and, at the same time, believe in myths? This question resonates with o... more Can we use light switches and, at the same time, believe in myths? This question resonates with ongoing disputes about the authority of science versus non-scientific ways of thinking. Recently, concerns regarding an overreach of scientific authority in human culture renewed momentum to pseudoscientific ideas originating in anti-science sentiments. This chapter sets out to rethink the currently prevailing image of science in light of its role as a facilitator of cognitive evolution to counter these potentially harmful conjectures. My argument unfolds in three steps. It first touches on the specific role of science in human cultural development. Drawing on ideas by Bultmann of the Marburg school, I suggest distinguishing between cosmological and existentialist questions in our engagement with the world. This distinction forms the backdrop against which we can understand the current popularization and rise of speculative metaphysics. Second, I examine a specific example: the recent revival of panpsychism as an example of an increasing conflation of existentialist with cosmological questions. Of particular concern in this context is that current support for panpsychism is fueled by a science-skepticism that draws on arguments from the philosophy of science. In a third step, this chapter warns that these arguments used to back science-skepticism build on a misleading image of science, which portrays science as an unchanging cognitive practice with varying knowledge outputs. However, I contend that science is not principally in the business of accumulating facts; rather, it is a cognitive activity in the pursuit of more sophisticated questions for understanding the world. Such shift in the image of science results in a change of its explanatory target by focusing on cognitive participation in its processes instead of centering analysis on its products like knowledge and technologies. Linking to recent theories of cultural evolution in cognitive science, analysis of science is best framed via the evolutionary development of cognitive gadgets or mental mechanisms through cultural transmission. Such a revised image of science then offers new avenues of collaboration with the humanities in the twenty-first century.

Routledge, 2022

Since the 1990s, molecular and cellular cognition (MCC) has elucidated critical causal mechanisms... more Since the 1990s, molecular and cellular cognition (MCC) has elucidated critical causal mechanisms behind higher level processes of perception and cognition. New intervention techniques, including genetic tracers and fluorescent visualization, have facilitated targeted access and manipulation of molecular pathways to investigate their precise roles in cognition and links to behavior. Insights from MCC have transformed central ideas of cognition, especially memory. This chapter introduces key developments in late 20th-century neuroscience that explain how the discovery of the molecular mechanisms modified theoretical understanding of memory as a cognitive function. It also looks at contemporary innovations in optical imaging microscopy that further exemplify the central argument that technological innovations in the study of cellular processes constitute fundamental also of high-level cognitive theories.

The Tools of Neuroscience Experiment, 2022

Barwich and Xu present a first-hand account of Xu’s recent application of a new tool, SCAPE micro... more Barwich and Xu present a first-hand account of Xu’s recent application of a new tool, SCAPE microscopy, which uncovered a new mechanism of mixture coding at the olfactory periphery. SCAPE (Swept, Confocally-Aligned Planar Excitation) microscopy allows for fast three-dimensional, high- resolution imaging of entire small organisms (e.g., larvae) or large intact tissue sections (e.g., in mice). Barwich and Xu illustrate how technologies facilitate a broader and different theoretical perspective by being an integral part of the thinking process itself and by co-creating mental structures.

Perspectives on Science, 2021

In 1991, Linda Buck and Richard Axel identified the multigene family expressing odor receptors. T... more In 1991, Linda Buck and Richard Axel identified the multigene family expressing odor receptors. Their discovery transformed research on olfaction overnight, and Buck and Axel were awarded the 2004 Nobel Prize in Physiology or Medicine. Behind this success lies another, less visible study about the methodological ingenuity of Buck. This hidden tale holds the key to answering a fundamental question in discovery analysis: What makes specific discovery tools fit their tasks? Why do some strategies turn out to be more fruitful than others? The fit of a method with an experimental system often establishes the success of a discovery. However, the underlying reasoning of discovery is hard to codify. These difficulties point toward an element of discovery analysis routinely sidelined as a mere biographical element in the philosophical analysis of science: the individual discoverer's role. I argue that the individual researcher is not a replaceable epistemic element in discovery analysis. This article draws on contemporary oral history, including interviews with Buck and other actors key to developments in late 1980s olfaction.

Journal of Theoretical Biology, 2021

Should theories of “higher-level” cognitive effects originate in “lower-level” molecular mechanis... more Should theories of “higher-level” cognitive effects originate in “lower-level” molecular mechanisms? This paper supports reductionist explanations of sensory perception via molecular mechanisms in neurobiology. It shows that molecular and cellular mechanisms must constitute the material foundation to derive better theories and models for neuroscience. In support of “bottom-up theorizing”, we explore the recent application of a new real-time molecular imaging technique (SCAPE microscopy) to mixture coding in olfaction. Seemingly emergent “higher level” psychological effects in odor perception, irreducible to the physical stimulus, are linked back to underlying molecular mechanisms at the receptor level. Critical to understanding the importance of the SCAPE study is its notable theoretical impact. It proves a possible answer to the neurocomputational challenge in olfaction from combinatorial coding at the periphery: how does the brain discriminate different complex mixtures from widespread and overlapping receptor activation? The failure of previous reductionist structure-odor explanations is shown to reside in misconceptualizations of the critical causal elements involved. Causally fundamental features are not of parts independently of a mechanism. Components and their relevant features are units via their causal role within a mechanism. Here, new technologies allow revisiting our understanding of the ontology and levels of organization of a system.

Cell and Tissue Research , 2021

Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret ... more Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret and navigate their environments. Odor detection starts with the activation of odorant receptors (ORs), expressed in mature olfactory sensory neurons (OSNs) populating the olfactory mucosa. Different odorants, or different concentrations of the same odorant, activate unique ensembles of ORs. This mechanism of combinatorial receptor coding provided a possible explanation as to why different odorants are perceived as having distinct odors. Aided by new technologies, several recent studies have found that antagonist interactions also play an important role in the formation of the combinatorial receptor code. These findings mark the start of a new era in the study of odorant-receptor interactions and add a new level of complexity to odor coding in mammals.

Ber. Wissenschaftsgesch., 2020

Perfumes embody a chemical record of style and technology. Blurring the boundary between what cou... more Perfumes embody a chemical record of style and technology. Blurring the boundary between what counts as natural and artificial in both a material and a perceptual sense, perfumery presents us with a domain of multiple disciplinary identities relevant to social studies: art, craft, and techno-science. Despite its profound impact as a cultural practice, perfume has seldom featured in historical scholarship. The reason for this neglect is its inherently qualitative dimension: perfume cannot be understood via codified representation but requires direct acquaintance with its sensory and material basis. The historical study of perfumery thus necessitates an experimental approach that comes not without challenge. This article looks at contemporary recreations of old perfumes to identify the difficulties involved in the experimental recreation of fragrances as sensory and performative artifacts. We highlight the need for a reconceptualization of methodology for inconcrete objects of study as part of the broader interest in experimental approaches to the humanities.

Cell, 2020

In 1991, Buck and Axel published a landmark study in Cell for work that was awarded the 2004 Nobe... more In 1991, Buck and Axel published a landmark study in Cell for work that was awarded the 2004 Nobel Prize. The identification of the olfactory receptors as the largest family of GPCRs catapulted olfaction into mainstream neurobiology. This BenchMark revisits Buck’s experimental innovation and its surprising success at the time.

Frontiers in Neuroscience, 2019

The annals of science are filled with successes. In footnotes do we hear about the failures, the ... more The annals of science are filled with successes. In footnotes do we hear about the failures, the cul-de-sacs, and the forgotten ideas. Failure is how research advances. Yet it hardly features in theoretical perspectives on science. That is a mistake. Failures, whether clear-cut or ambiguous, are heuristically fruitful in their own right. Thinking about failure questions our measures of success, including the conceptual foundations of current practice, that can only be transient in an experimental context. This article advances the heuristics of failure analysis, meaning the explicit treatment of certain ideas or models as failures. The value of failures qua being a failure is illustrated with the example of grandmother cells; the contested idea of a hypothetical neuron that encodes a highly specific but complex stimulus, such as the image of one’s grandmother. Repeatedly evoked in popular science and maintained in textbooks, there is sufficient reason to critically review the theoretical and empirical background of this idea.

Frontiers in Psychology, 2019

Does the sense of smell involve the perception of odor objects? General discussion of perceptual ... more Does the sense of smell involve the perception of odor objects? General discussion of perceptual objecthood centers on three criteria: stimulus representation; perceptual constancy; and figure-ground segregation. These criteria, derived from theories of vision, have been applied to olfaction in recent philosophical debates about psychology. An inherent problem with such framing of olfactory objecthood is that philosophers explicitly ignore the constitutive factors of the sensory systems that underpin the implementation of these criteria. The biological basis of odor coding is fundamentally different from the coding principles of the visual system. This article analyzes the three measures of perceptual objecthood against the biological background of the olfactory system. It contrasts the coding principles in olfaction with the visual system to show why these criteria of objecthood fail to be instantiated in odor perception. The argument demonstrates that olfaction affords perceptual categorization without the need to form odor objects.

Neo.Life, 2020

Becoming an expert in anything, whether it’s wine tasting or mathematics, changes the way you per... more Becoming an expert in anything, whether it’s wine tasting or mathematics, changes the way you perceive the world.

Neo.Life, 2020

Short piece on the effect of smell training on the brain and neural plasticity for Neo.Life

STAT news, 2020

First Opinion Piece for STAT news.

On Episode 48, Nick chats with Ann-Sophie Barwich, Visiting Professor in the Cognitive Science Pr... more On Episode 48, Nick chats with Ann-Sophie Barwich, Visiting Professor in the Cognitive Science Program at Indiana University Bloomington, about growing up studying literature in East Germany, finding her voice as a researcher, and the importance of thinking about the sense of smell as a model for neuroscience and the senses.

20 Minute talk presenting the fruits and labor of my three year postdoctoral research as a Presid... more 20 Minute talk presenting the fruits and labor of my three year postdoctoral research as a Presidential Scholar at the Center for Science and Society, Columbia University.

Three open challenges discussed in this talk:
(1) What's so special about smell - regarding its perception and neural basis?
(2) Philosophy of Science as part of Scientific collaborations: Where does Philosophy fail, can/should we do something new... and is that still Philosophy?
(3) Buzzword aside: Is interdisciplinarity more than being fluent (and potentially mediocre) in two fields?

(Thanks belongs to Stuart Firestein & Lab, the PSSN program headed by Pamela Smith, and all the scientists who have lent me their time.)

Things we learn this week: dogs aren’t so great at sniffing, men aren’t so lazy, and New York doe... more Things we learn this week: dogs aren’t so great at sniffing, men aren’t so lazy, and New York doesn’t smell so bad (anymore). Gail Simmons (Top Chef) is co-host; Jon Batiste plays his melodica for us; the live fact-checker is Mike Maughan.

Post for Auxiliary Hypotheses, the Blog of the British Journal for the Philosophy of Science

Imperfect Cognitions, 2017

Video of my talk at MIT, Center for Bits and Atoms (Andreas Mershin's lab), 9 December 2015: http... more Video of my talk at MIT, Center for Bits and Atoms (Andreas Mershin's lab), 9 December 2015: https://www.youtube.com/watch?v=ej45lyl3rzA

Research on olfaction is on the rise. The discovery of the olfactory receptor genes by Linda Buck and Richard Axel in 1991 catapulted olfaction from eccentricity into core neurobiological research. With the identification of the receptors as G-protein coupled receptors olfactory research became affiliated with a wide range of cell signaling studies. While a lot of fundamental questions about olfactory processing are still open to dispute, the consensus is that the olfactory pathway will facilitate a greater neurobiological understanding of signal processing. One of the open questions that attracted greater attention over the past ten years is the longstanding problem of how the brain ‘maps’ smells. My postdoc project centers on olfaction to analyze theoretical and experimental breakthroughs through scientific methodology. Its current dynamics and susceptibility to the revision of its core premises makes olfactory research an excellent example to study the ambiguity of determining what is a reliable research strategy. One of the key reasons for the historical marginalization of olfaction was the experimental difficulty of conducting research into olfaction: How do you ‘materialize’ odors and by what criteria do you make them comparable? Part of the contemporary significance of research in olfaction is its potential for methodological innovations: How do you overcome the persistent difficulties in modeling transmembrane receptors and how should the organization of activation patterns in the cortex be modeled? By tracing the emergence, success, decline and failure of standard lab routines in past and present research on the sense of smell, I want to understand the uncertainties and the ‘missing knowledge’ that drive contemporary (neuro)scientific research.

Talk has three parts: quick general philosophy intro, odorant receptors and GPCRs, olfactory cortex mapping.
(Correction: Linda Buck tried 3 not 8 years finding the receptors.)

Philosophia, 2019

Review of Conscious Experience by Anil Gupta for Philosophia. What is the role of conscious ex... more Review of Conscious Experience by Anil Gupta for Philosophia.

What is the role of conscious experience in rational perceptual judgment? Anil Gupta’s book does something daring; it sets out to answer this question without a definition of conscious experience. It thereby avoids “the hard problem,” it avoids “the easy problem,” and it also avoids the practical problem of fixing a most elusive notion...

Isis, Dec 2015

Review of Astrid Schwarz "Experiments in Practice" (History and Philosophy of Technoscience, 2.) ... more Review of Astrid Schwarz "Experiments in Practice" (History and Philosophy of Technoscience, 2.) vii 􏰀 257 pp., illus., maps, table, bibl., index. London: Pickering & Chatto, 2014. £60 (cloth). In: Isis - A Journal for the History of Science Society

In this interview, Ann-Sophie Barwich, Assistant Professor at Indiana University Bloomington, tal... more In this interview, Ann-Sophie Barwich, Assistant Professor at Indiana University Bloomington, talks about being baptized in protest in East Germany, acting, poetry, Faust, Die Toten Hosen, Demian, an early interest in drama and art, dabbling in literary studies in college, and then philosophy and science, dealing with loss, working with John Dupré, the problem with armchair philosophy, Hedwig Dohm and feminism, models and the practice turn in philosophy of science, starting a dissertation on Leibniz and ending up with a dissertation on the history and philosophy of the science of smell, Stuart Firestein, language and philosophy, The Rusty Bike, sexism, petrichor, her new book on the philosophy and science of smell, Ambergris, dogs, beer and Indiana, Gestalt switches, Martha Nussbaum, EEG, the Churchlands and John Bickle, The Philosopher Queens, Lost in Translation, Blondie, Leonard Cohen, Pollock, Death in Venice, Kandinski, Murder She Wrote, Tesla, and her last meal…

Biological Theory, Mar 2013

The European Advanced Seminars in the Philosophy of the Life Sciences (EASPLS) are biennial sympo... more The European Advanced Seminars in the Philosophy of the Life Sciences (EASPLS) are biennial symposia organized by members from six leading European institutions in the philosophy of the life sciences-the

Biological Theory, Jun 2011