Ian Phillips

How is it that individuals who deny experiencing visual imagery nonetheless perform normally on tasks which seem to require it? This puzzle of aphantasia has perplexed philosophers and scientists since the late nineteenth century. Contemporary responses include: (i) idiosyncratic reporting, (ii) faulty introspection, (iii) unconscious imagery, and (iv) complete lack of imagery combined with the use of alternative strategies. None offers a satisfying explanation of the full range of first‐person, behavioural and physiological data. Here, I diagnose the puzzle of aphantasia as arising from the mistaken assumption that variation in imagery is well‐captured by a single ‘vividness’ scale. Breaking with this assumption, I defend an alternative account which elegantly accommodates all the data. Crucial to this account is a fundamental distinction between visual‐object and spatial imagery. Armed with this distinction, I argue that subjective reports and objective measures only testify to the absence of visual‐object imagery, whereas imagery task performance is explained by preserved spatial imagery which goes unreported on standard ‘vividness’ questionnaires. More generally, I propose that aphantasia be thought of on analogy with agnosia, as a generic label for a range of imagery deficits with corresponding sparing.

This chapter develops a view of shadows as _pure visibilia_: objects constitutively and exhaustively connected in nature, existence and qualities to our experience of them. It takes as its stalking horse Sorensen’s very different view, arguing that, contrary to his intended purpose, the hypothesis that shadows are pure visibilia provides a more satisfying account of his striking cases of shadow movement. The claim that shadows are pure visibilia is further motivated by drawing on considerations from aesthetics and vision science. The chapter ends with a puzzle: if shadows do not strictly represent independent elements of our environments, why do we perceive them at all? A speculative answer is tendered. Shadows are visual artefacts: creatures of the light world, carved by our visual systems in the service of the better detection and discrimination of ordinary material objects.

The relation between attention, perception, and awareness is among the most fundamental problems in the science of the mind. One of the most striking and well-known phenomena bearing on this question is inattentional blindness (IB). In IB, naive observers fail to report clearly visible stimuli when their attention is otherwise engaged—famously missing a gorilla parading before their eyes. IB carries tremendous significance, both as evidence that awareness requires attention and as a tool in seeking the neural correlates of consciousness. However, such implications rest on a notoriously biased measure: asking participants whether they noticed anything unusual (and interpreting negative answers as reflecting a complete lack of perception). Here, in the largest ever set of IB studies, we show that, as a group, inattentionally blind participants can successfully report the location, color, and shape of stimuli they deny noticing, demonstrating that perceptual information remains accessible in IB. By introducing absent trials, we further show that observers are collectively biased to report not noticing in IB—essentially ‘playing it safe’ in reporting their sensitivity. These data provide the strongest evidence to date of significant residual visual sensitivity in IB. They also challenge the use of inattentional blindness to argue that awareness requires attention.

Objects and events are fundamental units of perception: Objects structure our experience of space, and events structure our experience of time. A striking and counterintuitive finding about object representation is that it can warp perceived space, such that stimuli within an object appear farther apart than stimuli in empty space. Might events influence perceived time in the same way objects influence perceived space? Here, five experiments (N=500 adults) show that they do: Just as stimuli within an object are perceived as farther apart in space, stimuli within an event are perceived as further apart in time. Such “Event-based Warping” is elicited both by events characterized by sound (E1), as well as events characterized by silence (E2). Moreover, these effects cannot be explained by surprise, distraction or attentional-cueing (E3 and E4), and also arise cross-modally (from audition to vision; E5). We suggest that object-based warping and event-based warping are both instances of a more general phenomenon in which representations of structure — whether in space or in time — generate powerful and analogous relative perceptual distortions.

How is it that individuals who deny experiencing visual imagery nonetheless perform normally on tasks which seem to require it? This puzzle of aphantasia has perplexed philosophers and scientists since the late nineteenth century. Contemporary responses include: (i) idiosyncratic reporting, (ii) faulty introspection, (iii) unconscious imagery, and (iv) complete lack of imagery combined with the use of alternative strategies. None offers a satisfying explanation of the full range of first-person, behavioural and physiological data. Here, I diagnose the puzzle of aphantasia as arising from the mistaken assumption that variation in imagery is well-captured by a single ‘vividness’ scale. Breaking with this assumption, I defend an alternative account which elegantly accommodates all the data. Crucial to this account is a fundamental distinction between visual-object and spatial imagery. Armed with this distinction, I argue that subjective reports and objective measures only testify to the absence of visual-object imagery, whereas imagery task performance is explained by preserved spatial imagery which goes unreported on standard ‘vividness’ questionnaires. More generally, I propose that aphantasia be thought of on analogy with agnosia, as a generic label for a range of imagery deficits with corresponding sparing.

Science begins with mystery. What causes lightning? How did this mold stop bacterial growth? Why do we age? Arguably, the two greatest mysteries are the cosmos and consciousness—the vast world out there and the vibrant world within. Scientists captivated by one can be called to study the other, seduced by the thought that these mysteries are connected. Science writer George Musser’s book Putting Ourselves Back in the Equation reviews their progress: Can physics unlock the mystery of consciousness? Does consciousness underlie fundamental physics?

It is widely held that episodic memory is constitutively connected with space and time. In particular, many contend that episodic memory constitutively has spatial and/or temporal content: for instance, necessarily representing a spatial scene, or when a given event occurred, or at the very minimum that it occurred in the past. Here, I critically assess such claims. I begin with some preparatory remarks on the nature of episodic memory. I then ask: How, if at all, is episodic memory constitutively spatial? And, how, if at all, is episodic memory constitutively temporal? In answer, I argue that episodic memory need not have any spatial content, nor (in any substantial sense) need it represent when its events occur, nor even that they occur in the past. Instead, only a relatively modest connection holds between episodic memory and time in virtue of the temporal structure of its objects. Finally, I critically assess whether considerations concerning the organization and encoding of episodic memory in creatures like us provide stronger reason to posit a constitutive link between our episodic memories and space or time.

Auditory perception is traditionally conceived as the perception of sounds — a friend’s voice, a clap of thunder, a minor chord. However, daily life also seems to present us with experiences characterized by the absence of sound — a moment of silence, a gap between thunderclaps, the hush after a musical performance. In these cases, do we positively hear silence? Or do we just fail to hear, and merely judge or infer that it is silent? This longstanding question remains controversial in both the philosophy and science of perception, with prominent theories holding that sounds are the only objects of auditory experience and thus that our encounter with silence is cognitive, not perceptual. However, this debate has largely remained theoretical, without a key empirical test. Here, we introduce a novel empirical approach, presenting experimental evidence that silence can be genuinely perceived (not just cognitively inferred). We ask whether silences can ‘substitute’ for sounds in event-based auditory illusions — empirical signatures of auditory event representation in which auditory events distort perceived duration. Seven experiments introduce three new ‘silence illusions’ — the one-silence-is-more illusion, silence-based warping, and the oddball-silence illusion — each adapted from a prominent perceptual illusion previously thought to arise only from sounds. Subjects were immersed in ambient noise interrupted by silences structurally identical to the sounds in the original illusions. In all cases, silences elicited temporal distortions perfectly analogous to the illusions produced by sounds. Our results suggest that silence is truly heard, not merely inferred, introducing a general approach for studying absence perception.

Berger and Mylopoulos (2019) critique recent scepticism about unconscious perception, focusing on experimental work from Peters and Lau, and theoretical work of my own. Central to their wide-ranging discussion is the claim that unconscious perception occupies a default status within both experimental and folk psychology. Here, I argue to the contrary that a conscious-perception-only model should be our default. Along the way, I offer my own analysis of Peters and Lau's study, assess the folk psychological status of unconscious perception, discuss vision-for-action, and confront an important dilemma which Berger and Mylopoulos raise for the sceptic concerning the existence of unconscious mentality in general.

Many contemporary theorists charge that naïve realists are incapable of accounting for illusions. Various sophisticated proposals have been ventured to meet this charge. Here, we take a different approach and dispute whether the naïve realist owes any distinctive account of illusion. To this end, we begin with a simple, naïve account of veridical perception. We then examine the case that this account cannot be extended to illusions. By reconstructing an explicit version of this argument, we show that it depends critically on the contention that perceptual experience is diaphanous, or more minimally and precisely, that there can be no difference in phenomenal properties between two experiences without a difference in the scenes presented in those experiences. Finding no good reason to accept this claim, we develop and defend a simple, naïve account of both veridical perception and illusion, here dubbed Simple, Austere Naïve Realism.

A wealth of cases – most notably blindsight and priming under inattention or suppression – have convinced philosophers and scientists alike that perception occurs outside awareness. In recent work (Phillips 2016a, 2018; Phillips and Block 2017, Peters et al. 2017), I dispute this consensus, arguing that any putative case of unconscious perception faces a dilemma. The dilemma divides over how absence of awareness is established. If subjective reports are used, we face the problem of the criterion: the concern that such reports underestimate conscious experience (Eriksen 1960, Holender 1986, Peters and Lau 2015). If objective measures are used, we face the problem of attribution: the concern that the case does not involve genuine individual-level perception. Quilty-Dunn (2019) presents an apparently compelling example of unconscious perception due to Mitroff et al. (2005) which, he contends, evades this dilemma. The case is fascinating. However, as I here argue, it does not escape the dilemma’s clutches.

Most contemporary theorists regard the traditional thesis that perception is essentially conscious as just another armchair edict to be abandoned in the wake of empirical discovery. Here I reconsider this dramatic departure from tradition. My aim is not to recapture our prelapsarian confidence that perception is inevitably conscious (though much I say might be recruited to that cause). Instead, I want to problematize the now ubiquitous belief in unconscious perception. The paper divides into two parts. Part One is more purely philosophical. It explains how standard arguments for unconscious perception rely on contentious background assumptions concerning the relation between ordinary perception and the explanatory constructs of scientific psychology. Part Two, in contrast, offers detailed engagement with relevant empirical work. It exposes how, even setting aside the concerns identified in Part One, a dilemma confronts the believer in unconscious perception. This dilemma arises because ordinary perception is an individual-level state or occurrence, yet criteria sufficiently stringent to guarantee that a putatively perceptual state is unconscious vitiate the grounds for its attribution to the individual. The dilemma foments a hypothesis, namely that the conditions for genuine, individual-level perception are sufficient conditions for perceptual consciousness. The viability of this hypothesis should unnerve anyone who thinks unconscious perception is simply an empirical given.