Vision science combines ideas from physics, biology, and psychology. The language and ideas of mathematics help scientists communicate and provide an initial framing for understanding the visual system. Mathematics combined with computational modeling adds important realism to the formulations. Together, mathematics and computational tools provide a realistic estimate of the initial signals the brain analyzes to render visual judgments (e.g., motion, depth, and color). This chapter first traces calculations from the representation of the light signal, to how that signal is transformed by the lens to the retinal image, and then how the image is converted into cone photoreceptor excitations. The central steps in the initial encoding rely heavily on linear systems theory and the mathematics of signal-dependent noise. We then describe computational methods that add more realism to the description of how light is encoded by cone excitations. Finally, we describe the mathematical formulation of the ideal observer using all the encoded information to perform a visual discrimination task, and Bayesian methods that combine prior information and sensory data to estimate the light input. These tools help us reason about the information present in the neural representation, what information is lost, and types of neural circuits for extracting information.

Focusing on the Middle English poem, Pearl (with evidence from other literary works), this essay considers how the initial situation of the Dreamer explores a half-dozen principles for literary invention that are distinctively medieval, including personal displacement and feelings of anxiety, bewilderment and marvelling. These qualities define the initial state of mind which enables the Dreamer’s visions to occur and develop. Aristotle wrote in his Metaphysics (I. 2) that philosophising begins with wondering and questioning, a principle revered throughout the Middle Ages. Though all these elements of what we now call ‘creativity’ have their roots in practices of invention and argumentation described in ancient philosophy and rhetoric, the particular shapes that these classical principles assume by the late Middle Ages derive from long-established traditions of monastic meditation and contemplative envisioning more than from academic rhetoric and logic. Bonaventure’s opening to his Itinerarium mentis ad Deum recounts the marvel of Francis of Assisi’s seraphic vision, adapting it as a general method for meditation; Chaucer’s Squire’s Tale turns the marvels of the flying horse and visionary mirror into problems in optics and engineering. Pearl turns the dreamer’s initial wondering within a brilliant fantasy to the means for understanding his own human condition.

This chapter argues that thinking about Roberto Bolaño in the context of journalism and mass culture means recognizing how mainstays of globalized twentieth-century journalistic communication – photographic realism, reportage with a pretension of objectivity, investigative journalism – as well as discourses about literature, have circulated differently in Latin America, Europe, and the United States. Explores in particular the convergences and divergences between Latin American and Spanish crónicas and North American New Journalism in Bolaño’s fiction and in his own newspaper writing, the essay argues that Bolaño’s portrayal of the daily cultural and political contexts one confronts in the newspaper reflects his suggestion that readers are always exiles, and that they produce a commentary on seeing as both a journalistic practice and a metaphor for social understanding. Bolaño draws on, but also rewrites, the history of literary journalism in a wider Atlantic world, even as he comments on the superficiality of mass media and culture. Discussing Bolaño’s engagement with cronistas such as Rubén Darío, Enrique Gómez Carrillo, Carlos Monsiváis, and Pedro Lemebel, the chapter includes discussions of 2666, Los detectives salvajes, Bolaño’s short stories, and articles he wrote for newspapers and magazines in Spain and Chile.

This brief epilogue closes the circle. If the story opened with a solemn view of the Great Hall of Justice, it ends in the quiet of a living room on the other side of The Hague. Sophie and Norma get a final chance to chat about the events of the past three years. What was Sophie thinking when she joined the international judiciary? Where is the vision that was promised to her when she graduated from university? Norma does her best to cheer up her girlfriend. A 19th century novel, an orchestral piece by Ennio Morricone, and a glass of red wine do the trick.

None of us can really remember anything about our lives before the age of two years. How much of what makes us what we are has been set by that time? We challenge the widely-accepted idea that what we are is ‘determined’ by inherited genes and we start to explore how interaction with parents/carers establishes our behaviour. We use examples drawn from fiction and the real world to explore how the brain learns from the conditions in early life. We explain why this adaptability underpins development of our senses, our behaviour and our self-control. This introduces control as one of the themes of the book – how much we are in control of our bodies and how control develops based on environmental cues. We question what effect today’s exposure to digital media may have on the developing brain, and explore new ideas about the development of defence mechanisms, from immunity to the gut microbiome. Through the quote from JM Barrie, author of ‘Peter Pan’: ‘You always know after you are two. Two is the beginning of the end’, we ask whether age two is the beginning of the end or the end of the beginning of development.

Samuel Johnson’s lifelong interest in travel and travel writing aligns neatly, in many ways, with his empiricist metaphysics. When we travel, we compare our assumptions and preconceptions against the real world and track the inevitable incongruities. But Johnson’s enduring interest in travel also reveals a more complex engagement with the material world – and Lockean empiricism more broadly – than we often recognize, and his attitude toward the genre is more complicated, more critical and probing, than we might expect. With reference primarily to Rasselas and A Journey to the Western Islands of Scotland, this chapter examines how Johnson leverages travel to combat habituation; enable comparative knowledge, which produces meaning and value; and assess our bodies and minds as we perceive, digest, and retain knowledge. Facilitating a comparative intellectual paradigm, and foregrounding epistemology, travel is, for Johnson, a critical posture that underpins his thinking far beyond his travel texts.

Here Dante, not yet dead, is in Paradise. His participation premortem in the knowledge and love of Heaven, and so in its community, is experienced as the “mystical,” which, earthbound, points to the reality that transcends the earth. And if Paradiso is by way of its narrative the articulation of Dante’s mystical theology it is so in a style that seems to owe much to that of St. Bonaventure, a distinctive feature of which is that he brings together all the steps on the way to a mystical union from the lowest “purgative” disciplines of the senses and through the reform of intellect, memory, and will, into the final vision of God. This theological epistemology allows Dante to conceive of Paradise as holding together the two dimensions of Heaven as at once an eternal journey of learning, an ultimate paideia, and a vision finally achieved.

Sensory information enters the cerebral cortex through separate thalamocortical pathways that originate in different senses. One of these pathways links the dorsal lateral geniculate nucleus of the thalamus to the primary visual cortex and is crucial for mammalian vision. Over the past decades, there has been tremendous progress in understanding its functional organization, and new tools are allowing us to isolate, with increasing precision, its different components. Just as different senses remain segregated on their way to the cerebral cortex, the different properties of the visual stimulus also reach the primary visual cortex through separate geniculocortical pathways. On the one hand, these separate pathways underlie the parallel processing of stimulus position, eye of origin, light–dark polarity, and temporal dynamics, a strategy that is well preserved across species. On the other hand, the convergence of the different geniculocortical pathways in the visual cortex enables cortical neurons to extract features of the visual world that are not encoded by any geniculocortical pathway individually. This chapter reviews the current knowledge on the functional organization of this prominent thalamocortical pathway and concludes by raising key questions to be addressed in the future.

Decreased vision in the aged population poses significant morbidity and decreases quality of life. At least one third of the American population over age 65 has significant vision compromise due to ophthalmic disease. Decreased vision limits independence and poses significant economic and societal burdens. Ophthalmic disease in the elderly poses significant challenges to patients and providers due to the vast and diverse spectrum of ophthalmic conditions, and therefore requires specialized care by optometrists and ophthalmologists.

Ophthalmic diseases are seen at a higher frequency in aged patients and include structural changes, malignancies, and infections of the eyelids and orbit. In addition, diseases such as cataracts, age-related macular degeneration (ARMD), glaucoma, and ischemic optic neuropathy are seen at a significantly higher incidence in elderly patients and can result in severe vision loss. Routine ophthalmic care is required to identify, manage, and treat such diseases in order to prevent sequelae, optimize independence, and preserve vision. Medical therapies, surgical intervention, low-vision aids, and social support systems can be utilized to aid in treatment.

Your vision statement for your group, presented both orally and in writing, is one of your most important and memorable acts as a leader. It should be given a great deal of advance thought and planning ahead of time, and you should be sure to vet it with a number of people who will give you good and frank advice. Although they can be intimidating, vision statements are usually full of positivity and forward thinking, are a great source of inspiration to your group, and serve as the ultimate frame of reference. This chapter describes difference between “mission” and “vision,” and how to develop both types of statements. It discusses the three “pillars” of academic medicine – clinical, research, and education – but also additional pillars worth considering as you develop your mission and vision statements. It goes into how to set goals, metrics, and milestones for your vision statement, as well timelines for achieving them. It then describes how to get your group to fully understand your vision and rally behind it, and concludes with a discussion of how to periodically reassess and recalibrate your vision.

The chapter deals with Galen’s attack on the pulse-classification of the first-century CE Pneumatist doctor Archigenes, and examines Galen’s reasons for replacing Archigenes’ theory with his own. Galen claims that Archigenes has no idea of the proper method of determining the real species of pulse, and he castigates him for terminological failings as well. But it turns out on close analysis that Archigenes’ actual classification is very close to Galen’s own; and the terminological cavils seem fairly trivial and pedantic. So what is the real substance of Galen’s attack? The chapter suggests that the point at issue is partly simply a matter of professional rivalry, but partly also a consequence of Galen’s insistence on adhering to the properly philosophical method of conducting divisions.

This paper is detective work. I aim to show that the brilliant Pythagorean mathematician Archytas of Tarentum was the founder of ancient Greek mathematical optics. The evidence is indirect. (1) A fragment of Aristotle preserved in Iamblichus is one of two doxographical notices to mention Pythagorean work in optics. (2) Apuleius credits Archytas with a theory of visual rays which saves the principle that the angle of reflection is equal to the angle of incidence. I argue that the source from which Apuleius got this information was the Catoptrics of Archimedes, the genuineness of which I defend against Knorr’s hypothesis that it is the Euclidean Catoptrics, which had been misattributed to Archimedes. (3) The omission of optics from the mathematical curriculum in Plato’s Republic, and the Timaeus’ wholly physical account of mirror images, can be explained as polemical, for it is well attested that optics was practised in the Academy. The reason Plato does not mention optics is that he objected to Archytas using mathematics to understand the physical world rather than to transcend it.

What does Aquinas mean when he speaks of ‘spiritual’ change in explaining sense perception? This chapter is partly exegesis of that notion, partly explication of the author’s own previous invocation of ‘spiritual’ change to characterise the way perception for Aristotle takes on sensible form without matter, and partly explanation of why in philosophy since Descartes it is so difficult to understand how for Aristotle and Aquinas perception is both physical and mental. For both thinkers, it is an ‘unordinary’ physical alteration. That does not make it a ‘mental’ event in any sense that contrasts with ‘physical’. In sight the eye is coloured by the sensible form of red conceived not as a natural form, but as what Aquinas calls an intentio. The notion of intentio here expresses the idea of cognitive awareness, or of sensible form causing knowledge in a being which has the power of cognition. Aquinas calls sight the ‘most spiritual’ of the senses because, whereas with the operation of the other senses ordinary natural processes are required either as causal antecedents or concomitant effects, in sight there is no similar natural change at all. In its power of cognition alone we reach the end of explanation.