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Fleming & Michel (F&M) argue that the function of perceptual consciousness is to aid unconscious model-based planning. Unfortunately, unconscious model-based planning probably does not exist. F&M therefore face a dilemma: either perceptual consciousness is for conscious model-based planning or it is for something else. We argue that it is for something else.

Speed of consciousness results may contribute to the popular notion that our consciousness is inefficacious. I argue that Fleming and Michel's claim that consciousness is slow, coupled with their idea that consciousness marks a predictive world model, instead supports a view of agency in which we are consciously engaged with the world as it unfolds, both in perception and response.

Determining the functions of consciousness is difficult, in part because the term "consciousness" subsumes many different sensory modalities and aspects of cognitive processing. Fleming and Michel make an excellent start by forwarding compelling arguments regarding functions for conscious vision. I consider how their picture might generalize beyond vision, by looking at two areas: conscious proprioception and conscious mental imagery.

In consciousness science, theoretical predictions are often untestable, such as claims about phenomenal consciousness in other beings. This evidential underdetermination, in combination with the perceived moral significance of consciousness, puts consciousness science at risk of becoming a marketplace of rationalizations: a field that produces theories that reaffirm social practices and conventions.

Background The principle of double effect is often invoked to interpret clinical intentions in palliative sedation (PS), considering that intended effect may differ from foreseen effect. Despite clarifications, intentions concerning patient consciousness remain ambiguous. Moreover, little is known about how non-palliative care specialists understand and apply these intentions. Methods This study aims to explore physicians' intentions regarding PS, with a particular focus on the relationship between their intentions and patients' consciousness. This qualitative study is based on twelve semi-structured interviews with physicians from a university hospital in France. The methodology combined hierarchical evocation, clinical vignettes, and semi-structured interviews. Results The study reveals considerable heterogeneity in physicians' intentions regarding patient unconsciousness. The distinction between intended and foreseen effects was often poorly understood. References to the doctrine of double effect were rare, whereas the principle of proportionality was more frequently acknowledged. Conclusion This study reveals important discrepancies between specialized frameworks and the conceptual models of clinical reasoning. We particularly highlighted the inadequacy of the principle of double effect to enable an explicit evaluation of the ethical significance of induced unconsciousness and proposed a more integrated approach to palliative sedation, grounded in contemporary evidence, and proportionality.

Impaired consciousness is a common and potentially life-threatening condition that frequently requires admission to intensive care units (ICUs). In sub-Saharan Africa, data on outcomes among critically ill patients with impaired consciousness remain limited, particularly in resource-limited settings. This study aimed to estimate survival and identify factors associated with ICU mortality among adults with impaired consciousness admitted to the ICU of the national referral hospital in Benin. This single-center retrospective cohort study used secondary data from the ICU database covering January 2015 to June 2017. Survival was estimated using the Kaplan-Meier method, and factors associated with ICU mortality were identified using Cox proportional hazards models. Among 416 patients, 279 died, yielding an ICU mortality of 67.1%. The median time to death in the ICU was 5 days. Survival probabilities declined from 77.6% on day 1 to 21.9% on day 15 and 13.7% on day 30. In multivariable analysis, older age and lower Glasgow Coma Scale score showed time-varying associations with ICU mortality. Lower systolic blood pressure, higher body temperature, absence of traumatic brain injury, and absence of oxygen therapy were independently associated with higher ICU mortality. ICU mortality among adults with impaired consciousness admitted to this ICU was very high. This observation is consistent with constraints in essential critical care resources. Simple clinical parameters available at admission may support early risk stratification. Strengthening essential critical care components, particularly basic physiological monitoring and reliable oxygen supply, warrants consideration in sub-Saharan African ICUs.

The sensory horizons hypothesis as an explanation of consciousness depends on visual experience directly affecting neural activity underlying conscious model-based planning. Given that there is no known mechanism for subjective experience to generate action potentials, the sensory horizons hypothesis lacks explanatory insight into the function of consciousness. We contend that a better strategy is to investigate non-causal functions of consciousness.

The authors make common assumptions that I reject: that consciousness has functions distinct from those of the brain processes on which it depends, that there is a moment at which consciousness happens, and that consciousness itself can be measured. This leads to Cartesian materialism and asking such unanswerable questions as when and why consciousness evolved. An alternative view is proposed.

Action may indeed rely on unconscious sensory processing, but that may not be true of perceptual recognition in aquatic species, which in mammals relies on brain circuits that are paradigmatically associated with conscious processing. Perhaps limited sensory horizons even make model-based conscious processing especially important for finding prey and mates, avoiding predators, and navigating underwater environments.

Our response to commentaries further clarifies the links between visual postdictive phenomena, conscious experience, reality monitoring, and planning. We also engage with suggestions about the limits and generality of our conclusions for other sensory modalities and visually guided behavior in aquatic organisms. We conclude that the role of sensory horizons in visual consciousness offers powerful constraints on theory and generates novel testable hypotheses for consciousness science.

In a vision-first story, conscious vision evolved before other kinds of conscious experience. This can be contrasted with an olfaction-first story, in which conscious vision co-opted integrative mechanisms that first evolved for modeling the causes of olfactory stimuli. An olfaction-first story makes good sense of the connection between consciousness and holistic integration across temporal windows in the ∼400ms range.

A central plank of Fleming and Michel's thought-provoking paper is that postdiction reveals a lower bound for the speed of consciousness, showing that perceptual awareness is slow and motivating their perceptual reality monitoring theory of consciousness. The plank cannot bear the weight: Postdiction neither demonstrates a lower bound for the speed of consciousness nor shows that awareness is slow.

Fleming and Michel convincingly argue that the water-to-land transition put evolutionary pressure on the temporal structure of conscious vision. But their interpretation of postdictive effects, which leads them to conclude that conscious vision is slow, suffers from conceptual issues and inadvertently leads them to an overly discrete and serial model of temporal consciousness.

The authors make a timely argument that the temporal profile of consciousness is an under-exploited constraint on theories of consciousness. However, the exact timing matters for the evolutionary hypothesis. A rival hypothesis is that in aquatic environments, it already had the function of representing distal objects, with a time-delay to consciousness in the 100-200ms range.

Fleming and Michel propose that conscious perception is "slow", with a delay of 350-450ms. But this claim is premature. Here, we will show that the speed of conscious perception remains unresolved. Examining evidence from vision and language research, we will explore how this fundamental question may ultimately be answered to test the validity of this foundational claim.

A strict lower limit of 400 ms is suggested for the formation of conscious vision. This processing delay could result from the need to create a unified percept over visual features processed with different time constants, and even longer intentional visual processes. Given the flexibility of these processing times, we question the need for a strict lower limit for conscious vision.

We challenge Fleming and Michel's arguments that aquatic animals do not have conscious vision. Focusing on fish, we suggest - on the basis of what we know about their cognition and evolution - that most fish are likely to have conscious vision, which evolved well before the transition to a largely terrestrial habitat. We end by clarifying the difference between our model-based, learning-driven view of the evolution of animal consciousness and Fleming and Michel's view.

Fleming and Michel's hypothesis about the origins of consciousness not only faces multiple challenges but also overlooks phenomenal experience-the very phenomenon that needs explaining. Although we are in broad agreement with the authors' overall perspective, we highlight challenges and suggest that consciousness evolved to attribute subjective value, enabling organisms to care about and act upon what they sense.

Arthropods, such as jumping spiders, depend on vision over a distance when hunting. Their tactics suggest planning. Experimental evidence indicates that they use representations acquired from one location when acting in another. These tiny creatures should, therefore, depend upon reality-monitoring and be conscious. Is this necessarily the case? Could we know what sort of consciousness they might possess?