Christian de Weerd (Universität Erlangen-Nürnberg, Germany): Sentience Gaps as an Obstacle for Non-human Sentience Research 

Non-human sentience researchers typically understand sentience as valenced conscious experience, conscious states that feel good or bad such as joy or pain (Browning & Birch, 2022). Finding ways to infer the presence of sentience in non-human systems is widely taken to be of central concern in non-human consciousness and welfare research (Browning & Veit, 2022). Unsurprisingly, much work focusses on understanding, and developing indicators for, non-human sentience (Crump et al., 2022; Sneddon et al., 2014; Gibbons et al., 2022; Elwood & Adams, 2015; Feinberg & Mallat, 2017; see Browning & Birch, 2022).  

However, sentience indicators should be sensitive to valency and consciousness. Valency can be understood as a physical/functional property which distinguishes paradigmatic valenced states (e.g. pain) from paradigmatically non-valenced conscious states (e.g. visual perception). For instance, according to Carruthers (2018) valency is a first-order indicative representation of value, a property that all paradigmatically valenced conscious states share. Most valency accounts allow for unconscious valenced states, which is sometimes taken to be a desideratum for any valency theory (Carruthers, 2018). One worry, then, is that sentience indicators are primarily sensitive to valenced states as such, leaving it unclear whether these states are also conscious (Dawkins, 2012; 2017; 2021).  

To avoid these concerns, it’s been suggested that insights on non-human valency should be supplemented with insights on non-human consciousness (Browning & Birch, 2021; Shevlin, manuscript; Browning & Veit, 2023). This leads to a natural, and often (implicitly) endorsed, view that to infer the presence of sentience we can simply combine the most plausible consciousness and valency indicators (see e.g., Browning & Birch, 2022; Shevlin, manuscript; Browning & Veit, 2023). I call this the combinatorial approach.  

However, in this paper I will argue that this combinatorial approach faces an obstacle in the form of what I call sentience gaps. Sentience gaps occur when a non-human target system has (the capacity for) conscious states and (the capacity for) valenced states yet lacks sentience. In such systems, (i.e. perceptually) conscious states and valenced states exist, and are processed, independently from one another. In such cases, one might correctly infer, using consciousness indicators, that a system is conscious, and correctly infer, using valency indicators, that a system has valenced states, yet one might wrongly conclude that therefore the system is also sentient.  

Sentience gaps are problematic because we currently have no way to determine whether non-human systems with conscious and valenced states also have a sentience gap. Thus, our ability to make inferences about on-human sentience is impaired by not knowing how widespread sentience gaps are. I will analyze the underlying views that give rise to sentience gaps and argue how they give rise to sentience gaps. Finally, I will sketch and analyze the following three strategies to move beyond sentience gaps. The first strategy is to develop experimental paradigms to directly disentangle conscious from unconscious valency. The second strategy is to put additional constraints on the combinatorial approach. The third strategy is to reject the assumption that perceptual and valenced consciousness are dissociated.    

 References 

Browning, H., & Birch, J. (2022). Animal Sentience. Philosophy Compass, 17(5).  https://doi.org/10.1111/phc3.12822 

Browning, H., & Veit, W. (2022). The sentience shift in animal research. The New  Bioethics, 28(4), 299-314. http://www.doi.org/10.1080/205002877.2022.2077681 

Browning, H., & Veit, W. (2023). Studying Animal Feelings: Integrating Sentience Research  and Welfare Science. Journal of Consciousness Studies, 30(7), 196-222. 

Carruthers, P. (2018). Valence and Value. Philosophy and Phenomenological Research, 97(3),  658-680. https://doi.org/10.1111/phpr.12395 

Crump, A., Browning, H., Schnell, A., Burn, C., & Birch, J. (2022). Sentience in decapod  crustaceans: A general framework and review of the evidence. Animal Sentience, 32(1). https://www.doi.org/10.51291/2377-7478.1691 

Dawkins, M. S. (2012). Why animals matter: Animal consciousness, animal welfare and  human well-being. Oxford University Press. 

Dawkins, M. S. (2017). Animal welfare with and without consciousness. Journal of Zoology,  301, 1-10. https://doi.org/10.1111/ jzo.12434 

Dawkins, M. S. (2021). The science of animal welfare: Understanding what animals want.  Oxford University Press. 

Elwood, R. W., & Adams, L. (2015). Electric shock causes physiological stress responses in  shore crabs, consistent with prediction of pain. Biology letters, 11(11), 20150800.  https://doi.org/10.1098/rsbl.2015.0800 

Feinberg, T. E., & Mallatt, J. M. (2016). The ancient origins of consciousness: How the brain created experience. MIT Press. 

Gibbons, M., Crump, A., Barrett, M., Sarlak, S., Birch, J., & Chittka, L. (2022). Can insects  feel pain? A review of the neural and behavioural evidence. In: Jurenka, Russel, (ed.)  Advances in Insect Physiology. Academic Press, pp. 155-229. 

Shevlin, H. (manuscript). Animal suffering and felt unpleasantness: a sensory-motivational  account. https://henryshevlin.com/wp-content/uploads/2015/04/Animal-suffering-and- felt-unpleasantness.pdf 

Sneddon, L. U., Elwood, R. W., Adamo, S. A., & Leach, M. C. (2014). Defining and  assessing animal pain. Animal Behaviour, 97, 201–212.  https://doi.org/10.1016/j.anbehav.2014.09.007