It is usually taken as given that consciousness involves superior or more elaborate forms of information processing. Contemporary models equate consciousness with global processing, system complexity, or depth or stability of computation. This is in stark contrast with the powerful philosophical intuition that being conscious is more than just having the ability to compute. I argue that it is also incompatible with current empirical findings. I present a model that is free from the strong assumption that consciousness predicts superior performance. (...) The model is based on Bayesian decision theory, of which signal detection theory is a special case. It reflects the fact that the capacity for perceptual decisions is fundamentally limited by the presence and amount of noise in the system. To optimize performance, one therefore needs to set decision criteria that are based on the behaviour, i.e. the probability distributions, of the internal signals. One important realization is that the knowledge of how our internal signals behave statistically has to be learned over time. Essentially, we are doing statistics on our own brain. This ‘higherorder’ learning, however, may err, and this impairs our ability to set and maintain optimal criteria for perceptual decisions, which I argue is central to perception consciousness. I outline three possibilities of how conscious perception might be affected by failures of ‘higher-order’ representation. These all imply that one can have a dissociation between consciousness and performance. This model readily explains blindsight and hallucinations in formal terms, and is beginning to receive direct empirical support. I end by discussing some philosophical implications of the model. (shrink)

This chapter explores a way in which visual processing may involve innate constraints and attempts to show how such processing overcomes one enduring challenge to nativism. In particular, many challenges to nativist theories in other areas of cognitive psychology have focused on the later development of such abilities, and have argued that such development is in conflict with innate origins. Innateness, in these contexts, is seen as antidevelopmental, associated instead with static processes and principles. In contrast, certain perceptual models (...) demonstrate how the very same mental processes can both be innately specified and yet develop richly in response to experience with the environment. This process is entirely unmysterious, as shown in certain formal theories of visual perception, including those that appeal to spontaneous endogenous stimulation and those based on Bayesian inference. (shrink)

There is a certain excitement in vision science concerning the idea of applying the tools of bayesian decision theory to explain our perceptual capacities. Bayesian models are thought to be needed to explain how the inverse problem of perception is solved, and to rescue a certain constructivist and Kantian way of understanding the perceptual process. Anticlimactically, I argue both that bayesian outlooks do not constitute good solutions to the inverse problem, and that they are not constructivist (...) in nature. In explaining how visual systems derive a single percept from underdetermined stimulation, orthodox versions of bayesian accounts encounter a problem. The problem shows that such accounts need to be grounded in Natural Scene Statistics (NSS), an approach that takes seriously the Gibsonian insight that studying perception involves studying the statistical regularities of the environment in which we are situated. Additionally, I argue that bayesian frameworks postulate structures that hardly rescue a constructivist way of understanding perception. Except for percepts, the posits of bayesian theory are not representational in nature. bayesian perceptual inferences are not genuine inferences. They are biased processes that operate over nonrepresentational states. (shrink)

Does natural selection favor veridical percepts—those that accurately depict objective reality? Perceptual and cognitive scientists standardly claim that it does. Here we formalize this claim using the tools of evolutionary game theory and Bayesian decision theory. We state and prove the “Fitness-Beats-Truth Theorem” which shows that the claim is false: If one starts with the assumption that perception involves inference to states of the objective world, then the FBT Theorem shows that a strategy that simply seeks to maximize (...) expected-fitness payoff, with no attempt to estimate the “true” world state, does consistently better. More precisely, the FBT Theorem provides a quantitative measure of the extent to which the fitness-only strategy dominates the truth strategy, and of how this dominance increases with the size of the perceptual space. The FBT Theorem supports the Interface Theory of Perception, which proposes that our perceptual systems have evolved to provide a species-specific interface to guide adaptive behavior, and not to provide a veridical representation of objective reality. (shrink)

This book seeks to offer original answers to all the major open questions in epistemology—as indicated by the book’s title. These questions and answers arise organically in the course of a validation of the entire corpus of human knowledge. The book explains how we know what we know, and how well we know it. The author presents a positive theory, motivated and directed at every step not by a need to reply to skeptics or subjectivists, but by the need of (...) a rational individual to know the world. -/- The author draws heavily from Ayn Rand’s theory of concepts as presented in her book, Introduction to Objectivist Epistemology, but departs from her epistemology—especially as explicated by leading exponents of her philosophy—in important ways. Areas of departure include the perception of entities and the role of probability theory in epistemology. -/- A main idea in the book is to begin the validation of the law of causality by identifying that existence causes our consciousness of it. Another key idea is this: The very fact that we perceive entities is the most basic and most extensive evidence that causal forces and causal interactions are regular. -/- Applying Ayn Rand’s principle that characteristics are ranges of measurement, the book offers a philosophical validation of “nonparametric predictive inference,” in turn providing an objective basis for prior probabilities in Bayesian analysis. -/- This book is primarily for a specialized readership—familiar with epistemological ideas and with Ayn Rand’s theory of concepts in particular. The last third of the book uses probability theory and mathematics somewhat beyond basic calculus, but less mathematical explanations are also included to make the general ideas accessible to lay readers. (shrink)

Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause-effect links, or do learners also acquire knowledge about abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that (...) learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre-training can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue-outcome co-occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge. (shrink)

Presented here in a lucid, simple style is an extended defense of a behavioral and direct-realist theory of sense perception. Originally published in 1971. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the (...) rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905. (shrink)

In the early modern period, many authors held that sensation or sensory reception is in some way passive and that perception is in some way active. The notion of a more passive and a more active aspect of perception is already present in Aristotle: the senses receive forms without matter more or less passively, but the “primary sense” also recognizes the salience of present objects. Ibn al-Haytham distinguished “pure sensation” from other aspects of sense perception, achieved by (...) “discernment, inference and recognition,” which included perception of properties such as size and distance as well as similarity, difference, and beauty. Descartes regarded light and color as experiences passively caused in the mind by bodily processes, but he also included distance, perceived through accommodation and convergence, as an immediately caused sensory idea. On the perception side, most theorists held that size and distance perception occurs through unnoticed psychological operations, whether mediated by judgment or associative processes. Association is, in a sense, passive, as it occurs through nonreflective habit formation. But such habits mark a contribution of the subject to perception and are in that way active. The decision of whether sensation and perception are active or passive is highly sensitive to what counts as activity and to what is included as sensation or perception. There is no simple formula, but the generalization that sensation is for the most part passive and perception for the most part active may stand as an imprecise summary of early modern thought on the topic. (shrink)

Presented here in a lucid, simple style is an extended defense of a behavioral and direct-realist theory of sense perception. Originally published in 1971. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to (...) the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905. (shrink)

The goal of the paper is to review existing work on consciousness within the frameworks of Predictive Processing, Active Inference, and Free Energy Principle. The emphasis is put on the role played by the precision and complexity of the internal generative model. In the light of those proposals, these two properties appear to be the minimal necessary components for the emergence of conscious experience—a Minimal Unifying Model of consciousness.

Most contemporary theories of perception, including leading forms of representationalism and naive realism, are monistic: they assume that to consciously perceive is to deploy only one kind of sensory awareness. Here I instead argue for rich pluralism, which says that to consciously perceive is to deploy two very different kinds of sensory awareness in concert: representational awareness of particulars, and non-representational, partly essence-revealing awareness of sensory qualities.

My focus in this paper is on how the basic Bayesian model can be amended to reflect the role of idealizations and approximations in the confirmation or disconfirmation of any hypothesis. I suggest the following as a plausible way of incorporating idealizations and approximations into the Bayesian condition for incremental confirmation: Theory T is confirmed by observation P relative to background knowledge B iff Pr&B) > PrandB), where I is the conjunction of idealizations and approximations used in deriving (...) the prediction PT from T, P. (shrink)

A comparison of disjunctive theories of action and perception. The development of a theory of action that warrants the name, a disjunctive theory. On this theory, there is an exclusive disjunction: either an action or an event (in one sense). It follows that in that sense basic actions do not have events intrinsic to them.

This chapter seeks to recover an approach to consciousness from a general theory of brain function, namely the prediction error minimization theory. The way this theory applies to mental and developmental disorder demonstrates its relevance to consciousness. The resulting view is discussed in relation to a contemporary theory of consciousness, namely the idea that conscious perception depends on Bayesian metacognition; this theory is also supported by considerations of psychopathology. This Bayesian theory is first disconnected from the higher-order (...) thought theory, and then, via a prediction error conception of action, connected instead to the global neuronal workspace theory. Considerations of mental and developmental disorder therefore show that a very general theory of brain function is relevant to explaining the structure of conscious perception; furthermore, this theory can subsume and unify two contemporary approaches to consciousness, in a move that seeks to elucidate the fundamental mechanism for selection of representational content into consciousness. (shrink)

Summary An attempt is made in this book to expound the Buddhist theory of perception as conceived by Dinnaga and Dharmkirti, especially as presented in Pramanavarttika of the latter. The study is divided into nine chapters. The first chapter deals with the Dinaga-Dharmakirti logico-epistemological sub-system within the overall system of Buddhist philosophy. The second chapter brings out the unique contribution of Pramanavarttika as a commentary to Pramanasamuccaya of Dinnaga. The third and fourth chapters are focused on the pre-Dinnaga and (...) non-Buddhist theories of perception. The fifth chapter deals with Dharmkirti’s well- reasoned addition of the term ‘non-illusive” to the definition of perception as given by Dinnaga. The sixth chapter is devoted to the main theme freedom from conceptual construction or kalpnapodham as the definiens of the term pratyaksha. The seventh chapter is about the four kinds of perception. The eighth chapter deals with the nature of the object of perception, the criteria of valid perception along with a discussion on illusion. The ninth chapter sums up the relevance of Pramanavarttika’ s contribution to Buddhist philosophy. (shrink)

In recent years, the rich tradition of various philosophical theories of perception has been increasingly studied by scholars of the history of philosophy of ...

_Phenomenology of Perception: Theories and Experimental Evidence_ presents an interpretation of phenomenology as a set of commitments to discover the immanent grammar of perception by reviewing arguments and experimental results that are still important today for psychology and the cognitive sciences.

The title refers to theories that require a certain sort of relation between X and an experience of S in order that S perceive X. The relation might be causal, counterfactual, doxastic, or otherwise. It is argued against such theories that there are possible cases in which X stands in the required relation to an experience of S and S does not perceive X and cases in which X is perceived though it does not stand in the required (...) relation. (shrink)

In this essay Elizabeth de Freitas follows Tim Ingold's groundbreaking anthropological work on lines and their cultural and material significance to argue that the line is the engine of theory, be it the drawn line of inscription or mathematical measure, the exclusionary line of delineation, or the undulating generative line of flight. De Freitas focuses on contemporary theories of perception that deploy the line — and mobilize the force of theory — so as to encode and reconfigure the (...) student's body. She draws on the work of Gilles Deleuze to develop a topological approach to the line, and argues that such an approach aligns with current philosophical approaches to social interaction that might be termed “topo-philosophy.”. (shrink)

Action is a means of acquiring perceptual information about the environment. Turning around, for example, alters your spatial relations to surrounding objects and, hence, which of their properties you visually perceive. Moving your hand over an object’s surface enables you to feel its shape, temperature, and texture. Sniffing and walking around a room enables you to track down the source of an unpleasant smell. Active or passive movements of the body can also generate useful sources of perceptual information (Gibson 1966, (...) 1979). The pattern of optic flow in the retinal image produced by forward locomotion, for example, contains information about the direction in which you are heading, while motion parallax is a “cue” used by the visual system to estimate the relative distances of objects in your field of view. In these uncontroversial ways and others, perception is instrumentally dependent on action. According to an explanatory framework that Susan Hurley (1998) dubs the “Input-Output Picture”, the dependence of perception on action is purely instrumental: "Movement can alter sensory inputs and so result in different perceptions… changes in output are merely a means to changes in input, on which perception depends directly" (1998: 342). -/- The action-based theories of perception, reviewed in this entry, challenge the Input-Output Picture. They maintain that perception can also depend in a noninstrumental or constitutive way on action (or, more generally, on capacities for object-directed motor control). This position has taken many different forms in the history of philosophy and psychology. Most action-based theories of perception in the last 300 years, however, have looked to action in order to explain how vision, in particular, acquires either all or some of its spatial representational content. Accordingly, these are the theories on which we shall focus here. -/- We begin in Section 1 by discussing George Berkeley’s Towards a New Theory of Vision (1709), the historical locus classicus of action-based theories of perception, and one of the most influential texts on vision ever written. Berkeley argues that the basic or “proper” deliverance of vision is not an arrangement of voluminous objects in three-dimensional space, but rather a two-dimensional manifold of light and color. We then turn to a discussion of Lotze, Helmholtz, and the local sign doctrine. The “local signs” were felt cues for the mind to know what sort of spatial content to imbue visual experience with. For Lotze, these cues were “inflowing” kinaesthetic feelings that result from actually moving the eyes, while, for Helmholtz, they were “outflowing” motor commands sent to move the eyes. -/- In Section 2, we discuss sensorimotor contingency theories, which became prominent in the 20thcentury. These views maintain that an ability to predict the sensory consequences of self-initiated actions is necessary for perception. Among the motivations for this family of theories is the problem of visual direction constancy—why do objects appear to be stationary even though the locations on the retina to which they reflect light change with every eye movement?—as well as experiments on adaptation to optical rearrangement devices (ORDs) and sensory substitution. -/- Section 3 examines two other important 20th century theories. According to what we shall call the motor component theory, efference copies generated in the oculomotor system and/or proprioceptive feedback from eye-movements are used together with incoming sensory inputs to determine the spatial attributes of perceived objects. Efferent readiness theories, by contrast, look to the particular ways in which perceptual states prepare the observer to move and act in relation to the environment. The modest readiness theory, as we shall call it, claims that the way an object’s spatial attributes are represented in visual experience can be modulated by one or another form of covert action planning. The bold readiness theory argues for the stronger claim that perception just is covert readiness for action. -/- In Section 4, we move to the disposition theory, most influentially articulated by Gareth Evans (1982, 1985), but more recently defended by Rick Grush (2000, 2007). Evans’ theory is, at its core, very similar to the bold efferent readiness theory. There are some notable differences, though. Evans’ account is more finely articulated in some philosophical respects. It also does not posit a reduction of perception to behavioral dispositions, but rather posits that certain complicated relations between perceptual input and behavioral provide spatial content. Grush proposes a very specific theory that is like Evans’ in that it does not posit a reduction, but unlike Evans’ view, does not put behavioral dispositions and sensory input on an undifferentiated footing. (shrink)

In this paper I wish to propose and defend a form of the Representative Theory of Perception. According to this version of the theory, when a subject perceives some object x to be in a state P1 he does so by being aware of some modfication M1 of some object E. The subject's way of perceiving any one of a range of objects x,y,z, … is that of being aware of some modification of E. It will be a necessary (...) condition of someone's perceiving x to have property P1 that E be modified in some way. And in order for the modifications of E to be representations, a given property P1 will need to be causally related, characteristically, to one or more specific modifications, M1,M2, … Mn, of E. symbolized by ‘X'.). (shrink)

A survey of work on the philosophy of perception, mind, and mental representation by Berkeley and his early modern predecessors, notably Descartes, Hobbes, Malebranche, and Locke.

For over a century and certainly since single-unit recordings in the 1960s the theory of perception that has dominated thinking and research, with implications for the understanding of all other cognitive domains, entails a neocortical process of progressive assembly from V-1 to V-4 leading to object-construction and secondary spatial updating and recognition. In recent years, however, difficulties with the theory have emerged in neurophysiological research though a compelling alternative has not been forcefully argued. It is the purpose of this (...) paper to review the main features of the microgenetic account of perception, which inverts standard theory 180 degrees, and aligns the perceptual process with patterns of evolutionary growth. This theory developed on clinical study, and perhaps for this reason has not received sufficient attention, in mainstream cognitive and affective neuroscience, though it provides an account not only of perception but of stages in memory, imagery, the present moment, and the mind/brain state. (shrink)

Anthony J. Lisska presents a new analysis of Thomas Aquinas's theory of perception. While much work has been undertaken on Aquinas's texts, little has been devoted principally to his theory of perception and less still on a discussion of inner sense. The thesis of intentionality serves as the philosophical backdrop of this analysis while incorporating insights from Brentano and from recent scholarship. The principal thrust is on the importance of inner sense, a much-overlooked area of Aquinas's philosophy of (...) mind, with special reference to the vis cogitativa. Approaching the texts of Aquinas from contemporary analytic philosophy, Lisska suggests a modest 'innate' or 'structured' interpretation for the role of this inner sense faculty. He argues that were it not for the vis cogitativa, Aquinas would be unable to account for an awareness of the principal ontological category in his metaphysics. (shrink)

Comparisons are drawn between two theories of visual perception and two modes of information processing. Characteristics delineating dorsal and ventral visual systems lack internal consistency, probably because they are not completely separable. Mechanism is inherent when distinguishing these systems, and becomes more apparent with different processing domains. What is lacking is a more explicit means of linking these theories.

My aim in this paper is to offer a systematic analysis of a feature of Kant’s theory of perception that tends to be overlooked, viz., his account of how the imagination forms images in perception. Although Kant emphasizes the centrality of this feature of perception, indeed, calling it a ‘necessary ingredient’ of perception, commentators have instead focused primarily on his account of sensibility and intuitions on the one hand, and understanding and concepts on the other. However, (...) I show that careful attention to what he says about the nature of images, their connection to the imagination, and their role in perception in his Metaphysics Lectures, as well as in the Deduction and Schematism chapters of the first Critique reveals that Kant is working with a richer, more nuanced framework for perception than is often attributed to him. I contend that it is only once we have a revised framework for Kant’s theory of perception in place that we will be able to make further headway in debates, e.g., about whether or not he is a conceptualist about perception. (shrink)

A survey of work on perception, mind, and mental representation by 18th century philosophers after Berkeley, notably Robert Smith, William Porterfield, David Hume, Etienne de Condillac, and Thomas Reid.

In this paper I wish to propose and defend a form of the Representative Theory of Perception. According to this version of the theory, when a subject perceives some object x to be in a state P1 he does so by being aware of some modfication M1 of some object E. The subject's way of perceiving any one of a range of objects x,y,z, … is that of being aware of some modification of E. It will be a necessary (...) condition of someone's perceiving x to have property P1 that E be modified in some way. And in order for the modifications of E to be representations, a given property P1 will need to be causally related, characteristically, to one or more specific modifications, M1,M2, … Mn, of E. symbolized by ‘X'.). (shrink)

Second-order uncertainty, also known as model uncertainty and Knightian uncertainty, arises when decision-makers can (partly) model the parameters of their decision problems. It is widely believed that subjective probability, and more generally Bayesian theory, are ill-suited to represent a number of interesting second-order uncertainty features, especially “ignorance” and “ambiguity”. This failure is sometimes taken as an argument for the rejection of the whole Bayesian approach, triggering a Bayes vs anti-Bayes debate which is in many ways analogous to what (...) the classical vs non-classical debate used to be in logic. This paper attempts to unfold this analogy and suggests that the development of non-standard logics offers very useful lessons on the contextualisation of justified norms of rationality. By putting those lessons to work I will flesh out an epistemological framework suitable for extending the expressive power of standard Bayesian norms of rationality to second- order uncertainty in a way which is both formally and foundationally conservative. Contents. (shrink)

Hintikka has criticized psychologists for "hasty epistemologizing," which he takes to be an unwarranted transfer of ideas from psychology (a discipline dealing with questions of fact) into epistemology (a discipline dealing with questions of method and theory). Hamlyn argues, following Hintikka, that Gibson's theory of perception is an example of such an inappropriate transfer, especially insofar as Hamlyn feels Gibson does not answer several important questions. However, Gibson's theory does answer the relevant questions, albeit in a new and radical (...) way, which suggests that the alleged distinction between psychology and epistemology is suspect. In fact, contrary to Hintikka and Hamlyn's claims, Gibson's theory of perception appears to be a valuable source of epistemological as well as psychological ideas. (shrink)

This is a very selective survey of developments in epistemology, concentrating on work from the past twenty years that is of interest to philosophers of science. The selection is organized around interesting connections between distinct themes. I first connect issues about skepticism to issues about the reliability of belief-acquiring processes. Next I connect discussions of the defeasibility of reasons for belief to accounts of the theory-independence of evidence. Then I connect doubts about Bayesian epistemology to issues about the content (...) of perception. The last detailed connection is between considerations of the finiteness of cognition and epistemic virtues. To connect the connections I end by briefly discussing the pressure that consideration of social roles in the transmission of belief puts on the purposes of epistemology. (shrink)

Perceptual experiences are often divided into the following three broad categories: veridical perceptions, illusions, and hallucinations. For example, when one has a visual experience as of a red object, it may be that one is really seeing an object and its red colour (veridical perception), that one is seeing a green object (illusion), or that one is not seeing an object at all (hallucination). Many maintain that the same account should be given of the nature of the conscious experience (...) that occurs in each of these three cases. Those who hold a disjunctive theory of perception deny this. Disjunctivists typically reject the claim that the same kind of experience is common to all three cases because they hold views about the nature of veridical perception that are inconsistent with it. (shrink)

A philosphical exploration of perception explores Wittgenstein's work on visual meaning and his analysis of the concept of "seeing.".

Nichols offers the first comprehensive interpretation of the eighteenth-century Scottish philosopher Thomas Reid's theory of perception - by far the most important feature of his philosophical system. Nichols's consummate knowledge of Reid's texts, lively examples, and plainspoken style make this book especially readable. It will be the definitive analysis for a long time to come.

This chapter argues that Merleau-Ponty’s account of perception should be understood, not as a theory of perception in the usual sense, but as belonging squarely to transcendental philosophy. Contra the interpretation of Phenomenology of Perception as essentially a work in the philosophy of psychology, and the associated naturalistic construal of his ideas, it is suggested that Merleau-Ponty must be seen in the light of the history of transcendental philosophy and that an original form of idealism lies at (...) the heart of his philosophical project. The transcendental turn is presupposed by Merleau-Ponty’s claims regarding perception, and his key notion of ambiguity is a transcendental descendant of Kant’s strategy of establishing idealism by way of antinomy. (shrink)

The chapter deals with misconceptions in perception theory that are based on the idea of slicing the nature of perception along the joints of physics and on corresponding ill-conceived ʹpurposesʹ and ʹgoalsʹ of the perceptual system. It argues that the conceptual structure underlying the percept cannot be inferentially attained from the sensory input. The output of the perceptual system, namely meaningful categories, is evidently vastly underdetermined by the sensory input, namely physico-geometric energy patterns. Thus, the core task of (...) perception theory is to understand the internal conceptual structure with which our perceptual system is endowed. The conceptual structure underlying the semantic distinctions that characterise the output of the perceptual system can, by conceptual necessity, only be expressed by a logical language that is strictly more powerful than the logical language by which sensory notions can be expressed. Consequently, the internal structure underlying perceptual meaning – including core notions such as ‘Gestalt’ or ‘perceptual object’ – cannot be derived, by whatever kind of general inductive machinery, from the sensory input, or, more generally, from experience. (shrink)