Experiences	of	duration	and	cognitive penetrability Carrie	Figdor (Forthcoming	in	Brogaard	and	Gatzia,	eds.,	The	Rational	Roles	of Perceptual	Experience:	Beyond	Vision	(Oxford)) Please	contact	the	author	for	use	or	citation	of	material	in	this draft. Abstract.	This	paper	considers	the	cognitive	penetrability	of	our	experiences	of	the	durations	of	everyday	events.	I	defend	an	account	of	subjective	duration	based	in	contemporary	psychological	and	neurobiological research. I show its philosophical adequacy by demonstrating its utility	in	explaining	the	phenomenology	of	duration	experiences.	I	then consider	whether	cognitive	penetrability	is	a	problem	for	these	experiences.	I	argue	that,	to	the	contrary,	the	problem	presupposes	a	relationship	between	perception and	belief that	duration	perceptions	and	beliefs	do	not	exhibit.	Instead,	the	assignment	of	epistemic	features	to	particular processing stages appears to answer to pragmatic needs, not psychological facts. 1 Introduction While "everyday life consists	of	picnics	and	meetings just as it consists	of chairs	and	birds"	(Zacks	et al. 2007:	23), events have	been	given	relatively	short	shrift	in	perception	research.	Similarly,	problems in	the	epistemology	of	perception	are framed	almost	exclusively in terms	of	objects	and	their	properties, in	particular	those	perceived	visually.	This	paper	extends	the	philosophical	debates	to	include	the	epistemology	of	event	perception.	The main phenomenologically accessible difference between object and	event	perception	is	the	experience	of	temporal	information	in the	latter.	Although	temporal	experience	includes	temporal	order, simultaneity,	and	duration,	I	focus	on	our	experiences	of	duration, and consider mainly their relation to the problem of cognitive penetrability. 1 Is the perception of the temporal unfolding of events cognitively	penetrated? If so, is this cognitive	penetration epistemically	pernicious? In	Sec.	1,	I	present	the	problem	of	the	experience	of	duration	from	a	philosophical	perspective.	I	then	offer	an	empiricallybased account of	how	we	perceive durations. I focus on perceptions	of	everyday	events	occurring	within	timescales	of	seconds	to minutes	to	hours.	This is the range	of interval timing,	which lies between	millisecond timing (involved in speech perception and motor control) and circadian timing (regulating the 24-hour sleep-wake	cycle).	On	this	account,	such	experiences	are	a	consequence	of	event	segmentation	and	interval	timing	processes.	This account	provides insight into	the	philosophical	problem	of	duration,	and	shows	how	experiences	of	the	now	are	derived	from	experiences	of	durations. In	Sec.	2,	I	consider	the	problem	of	cognitive	penetrability and its implications for the justification of perceptual beliefs about	duration.	I	argue	that	duration	experiences	and	beliefs	can't 1	I	will	use	"perception"	throughout	to	mean	"conscious	perception",	which	is standard	usage.	An	exception is	Raftopoulos	2000,	who	uses	"perception" (in the	case	of	vision)	as	processing	up	to	Marr's	2.5D	sketch	and	"observation"	for perceptual	experience. 2 be	divided into the stages required	to formulate the	problem. In interval processing, stored temporal information is combined with nonstored nontemporal information to produce both duration	experiences	and	beliefs.	The	problem	of	cognitive	penetrability requires	belief to influence	perception,	whereas interval	processing	yields	both	belief	and	perception. An independent philosophical debate regarding temporal experience, which I will set aside, concerns the metaphysics of time. This is the debate between the	Aand	Btheories	of time. They	agree	that	time	exists,	but	differ	on	the	nature	of	tense.	An	Atheorist	holds	that	the	present	(the	"now"	or	"specious	present") is	ontologically	special,	and	that	the	past	and	future	do	not	exist. The	B-theorist	holds	that	past,	present,	and	future	are	all	equally real,	and	that	the	present	is	not	ontologically	special	(although	it may	be	special	for	psychological	reasons;	of	course,	it	can	also	be psychologically	special	for	A-theorists).	Temporal	experiences	can be veridical if there is a past, present, and future that	we track, whether	the	A-theory	or	B-theory	of	time	is	correct,	although	not if time itself is	an illusion.	So	aside from	global	skepticism	about the reality of time, this debate does not affect the question of whether	event	percepts	justify	event	beliefs.2 For	the	same	reason,	I	also	set	aside	background	issues	in the	metaphysics of events.	While events seem to be perennially suspect from an ontological perspective, arguments from parsimony for denying ontological commitment to events cut both ways.	Four-dimensionalists	hold	that	objects	are	very	slow	events, and	process	metaphysicians	hold	that	processes	are	fundamental. Everyday perception is consistent with a four-dimensionalist metaphysics	as	well	as	one	that	downgrades	events	to	properties of or relations between objects. The prevailing contemporary view	is	that	events	are	particulars,	not	universals	(Casati	and	Var- 2	Callender	(2010)	summarizes	the	contemporary	debate	in	physics	about	the existence of time as a fundamental physical magnitude. This debate leaves open its existence as an emergent	magnitude, in relation to	which temporal experiences can be veridical or illusory. I will assume time is (at least) an emergent	property. 3 zi	2005).	Even	so, there	are	sharply	different	ways	of individuating	them	(Quine	1985;	Davidson	1967;	Kim	1973).	I	will	assume the	coarse-grained	view	of	individuation	adopted	explicitly	or	implicitly in the	empirical literature	on	event	perception.	A coarsegrained view entails that the same token event might have changed in certain	ways, including in its	duration, and remained the same event. This is plausible because there are modalityspecific	limits	below	which	we	cannot	distinguish	distinct	events in	that	sense	modality,	and	because	we	tend	to	individuate	longer events	by	goals	and	intentions	rather	than	durations. Section	1.	The	philosophy,	psychology,	and	neuroscience	of	experiences	of	duration 1.1.	The	experience	of	duration	in	philosophy.	Kelly	(2005: 210)	isolates	the	experience	of	concern	here	in	terms	of	what	he calls	the	Puzzle	of	Temporal	Experience:	"How	is	it	possible	for	us to	have	experiences	as	of	continuous,	dynamic, temporally	structured,	unified	events	given	that	we	start	with	(what	at	least	seems to be) a sequence of independent and static snapshots of the world	at	a	time?"	I	call	this	the	puzzle	of	duration,	given	that	the phrase	"temporal	experience"	also	includes	experiences	of	simultaneity	and	temporal	order. 3	While it is	not	obvious	phenomenologically that	we do start	with	what seems to be a sequence of snapshots, the fundamental question is	how	we come to experience	events	as	occurring	through	time	at	all. A	vivid	illustration	of	this	type	of	experience	involves	hearing	a	soprano	at	the	opera.	The	soprano	hits	a	high	C,	and	holds	it, and holds it, and holds it, and holds it ... and at some point, as Kelly	(op.cit).	208)	puts it,	what	we	hear	"no	longer	seems	to	be 3	These	experiences	generate	distinct	puzzles	and	are	also	targets	of	empirical research. The Time-Stamp Problem is about	when in temporal order	we experience something as having occurred, and the Simultaneity Problem is about	which	events	we	experience	as	simultaneous	(Kelly	op.cit.).	He	also	distinguishes the puzzle of duration from the hard problem of consciousness, which he sets aside. In contrast, Merino-Rajme (2014) considers the hard problem	of	consciousness	extended	to	certain	temporal	experiences. 4 limited to the pitch, timbre, loudness, and other strictly audible qualities	of	the	note.	You	seem	in	addition	to	experience,	even	to hear, something about its temporal extent. ... one is tempted to say	...	that	the	note	now	sounds	as	though	it	has	been	going	on	for a	very	long	time."	A	minimally	apt	description	of	this	experience	is that we do experience it as having an unusually long duration, which	entails	that	we	have	an	experience	of	its	duration.	This	type of experience is also	present	when	we	consider	ordinary	events, such	as	brewing	coffee	or	checking	out	items	at	the	grocery	store. Unlike	a	passive	acoustic	experience	of	hearing	a	single	held	note, many of these events have temporal subparts, involve multiple objects,	include	our	active	participation,	and	integrate	multimodal sensory inputs,	each	with	proprietary	temporal-perceptual	properties.	Simple	or	complex,	the	experience	of	duration	marks	a	psychologically	important	difference	between	perceptual	experiences of	ordinary	events	and	ordinary	objects. How	do	we	explain	it? Kelly considers two	philosophical theories of	how	we experience	duration,	and	argues	that	both	are	inadequate.	These	are what	he	calls	the	Specious	Present	Theory	and	the	Retention	Theory	(Dainton	2017	calls	them	the	extensional	and	retentional	theories).	On	the	Specious	Present	Theory,	which	he	associates	with William	James,	the	present	of	which	we	are	directly	aware	may	be considered	to	be	somewhat	extended in	time, like	a	saddle-back. We	do	not	perceive	a	static	snapshot,	but	instead	a	temporally	extended duration that includes what has recently occurred and what	is	about	to	occur. 4	This	proposal	requires	either	that	we	have direct perceptual access to the recent past and future	moments close	to	the	present,	or	else	that	we	are	directly	aware	of	the	duration.	Neither	choice	makes	sense,	Kelly	argues:	we	don't	have	direct	perceptual	awareness	of	what	has	recently	occurred	or	what is	about	to	occur,	while	the	"default	position"	on	direct	awareness 4	Poppel	(2004)	has	argued	that	our	neurocognitive	machinery	is	such	that the	sensed	now	is	in	the	range	of	3	seconds.	Kelly	also	takes	note	of	Poppel's claim. 5 seems	to	be	that	we	are	directly	aware	of	what	is	present	now,	not of	duration. The	Retention	Theory,	which	Kelly	associates	with	Husserl, holds	that	perception	presents	us	with	snapshots,	but that these momentary	snapshots	of	which	we	are	directly	aware in	perception	are	augmented	by states	of retention	and	protension.	These are not memories and anticipations, but sui generis intentional acts.	Kelly	argues	that	this	theory	merely	provides	labels	for	what must	be	explained.	For	example,	retention is	defined	as	a	way	of being	directed	towards	objects	and	events	as	just-having-been.	It is	neither	instantaneous	remembering	(such	as	when	one	suddenly	remembers	having	left	one's	keys	in	the	kitchen),	nor	entertaining	a	memory	(in	the	way	one	can	relive	now	a	past	event).	What we	need	is	an	explanation	of	what	it	is	to	experience	something	as just-having-been	that	goes	beyond	saying it is	a	phenomenon involved in	the	experience	of	duration.	Kelly	does	not	elaborate	on the	nature	of	protension,	but	presumably	a	similar	problem	would arise	for	that	state	as	well. Kelly	does	not	try	to	solve	the	puzzle	of	duration,	but	hopes to have shown that there is an interesting problem to be addressed. In	what follows, I	will elaborate	an	account	of	duration based in contemporary science and articulate its solution to the puzzle.	With	the	account's	prima	facie	empirical	and	philosophical validity thus established, our experiences of duration so understood	will	be	examined	in	the	discussion	of	the	cognitive	penetrability	of	duration	perception	in	Part	2. 1.2.	The	psychology	and	neuroscience	of	event	perception. Event segmentation is analogous to, and	as	basic as, object individuation:	even	infants	are	able	to	parse	evolving	scenes	into	discrete segments (Wynn	1996).	This is a fruitful perspective from which	to	understand	duration	perception	because	durations	are	a matter of interval timing, and event segmentation yields the intervals	perceived	as	durations.	Interval	timing	is	the	midrange	of timing	involved	in	conscious	time	estimation,	cognitive	processing (such as decision-making) and behavior (such as foraging) 6 (Buhusi	and	Meck	2005:	Fig.	1).	Many	ordinary	events,	including those	targeted	in	event	segmentation	research,	fall	in	this	range. A leading contemporary theory of how we segment continuous	activity	to	generate	perceptions	of	discrete	events	is	Event Segmentation	Theory	(Zacks	and	Tversky	2001;	Zacks	et	al.	2007; Kurby	and	Zacks	2007;	Zacks,	Tversky, and Iyer	2001;	Reynolds, Zacks, and	Braver	2007;	Tversky,	Zacks, and	Hard	2008;	Shipley and Zacks 2008; for a predecessor, see Newtson, Engquist, and Bois 1977). The targets of EST are perceptual experiences of Quinean	events,	whether	dynamic (events)	or	concrete (objects) (Zacks	and	Tversky	2001:	5).5	An	event	is	defined	as	a	segment	of time	at	a	given	location	that	is	perceived	by	an	observer	to	have	a beginning and an end. This definition, while not exhaustive, includes	events that involve	goal-directed	human	activity	and	have durations from seconds to tens of minutes (Zacks and Tversky 2001:	5). In EST, event segmentation is a side effect of our use of prediction	for	perception.	It	is	thus	is	a	specific	case	of	the	predictive processing or predictive coding framework of overall brain function (Kurby and Zacks	2007: 73, Friston and Stephan	2007; Clark	2013;	Hohwy	2014).6	It	is	considered	a	spontaneous,	ongoing	process	that	does	not	require	conscious	attention	and	occurs at various timescales simultaneously. The model posits event models	and	event	schemata.	Event	models	are	multimodal,	actively maintained representations in working memory of "what is happening	now"	(Zacks	et	al.	2007:	7).	Their	content	is	influenced by	event schemata,	which	are semantic	memory representations 5	This	perspective	coheres	with	Kelly's	position that	adequate	answers to the puzzle of duration should not fundamentally distinguish between object and event	perception,	even though their relation to interval timing	and	perceived duration differs phenomenally. I set aside here the question of how interval timing	is	related	to	object	perception. 6While	publications	elaborating	EST	do	not	cite	major	advocates	of	the	predictive	processing framework, the	conceptual relationship is	obvious	and	sometimes	explicit	(e.g.	Radvansky	and	Zacks	2017:	133). 7 of information from previously encountered events and are encoded	in	permanent	synaptic	changes. The	mechanism	of	EST	is	the	detection	of	variations	in	the incoming	sensory	stream	and	comparison	of them	to	values	predicted by event models. Transient increases in prediction error based	on	comparison	between	actual	and	predicted	sensory	input at	a	given	timescale	triggers	updating	of	the	relevant	event	model, after	which	another	period	of	stability	begins.	This	increased	processing	is	perceived	as	the	subjective	experience	that	a	new	event has begun, while periods of stability are perceived as ongoing events	(Kurby	and	Zacks	op.cit.:	72).	We	can	selectively	attend	to particular timescales in	response	to instruction,	but	also	spontaneously segment	at finer	grains	when there is less	predictability and	we seek	more information to understand	what is going on. The	account	implicitly	distinguishes	experiences	of	duration	from those	of	succession:	succession	implies	at	least	two	events,	while durations are of one. Philosophical accounts of duration sometimes	conflate	succession	and	duration	as	one	phenomenon	(Phillips	2014:	140).7 Zacks	et	al.	(2007:	4) illustrate	EST	with	the	example	of	a man	scraping	plates in the course	of	washing	dishes.	The	whole plate-scraping segment of the dish-washing event is predictable until	the	last	plate	is	scraped,	when	the	goal	of	scraping	the	plates would	no	longer	have	predictive	value	and	updating	mechanisms would kick in. At a more fine-grained timescale, each platescraping	activity	will	generate	a	small	predictive	error	when	that plate	has	been	scraped,	and	this	error	will	correspond	to	a	boundary	between	each	individual	plate-scraping.	It	follows	that	prediction errors	will be relative to timescales, such that variations in input	that	count	as	prediction	errors	at	one	timescale	(the	start	of a	particular	plate-scraping)	fall	within	expected	or	predicted	lim- 7	It also	may	conflict	with	Phillips' (2014) "naïve"	account	of the relation	between	objective	durations	and	subjective	experiences	of	duration,	in	which	the latter	"inherit"	the	"temporal	structure"	of	the	former.	It	depends	on	how	"inheritance"	is	elaborated. 8 its	at	another	(the	whole	dishwashing	activity).	The	boundaries	of each	dish-scraping	are	prediction	errors	relative	to	the	timescale of the event model for plate-scraping, but are within predicted values	at	the	timescale	of	the	dish-washing	event	model	in	which the dish-scrapings occur.	Many everyday events	will exhibit this complexity: they have temporal segments (entailing part-whole relations) and temporal abstraction relations across timescales and	levels	of	generality	(entailing	hierarchical	relations).8 While event schemata are explicitly thought to include such items as goals and statistical information about paths and motions	of	objects,	they	also	presumably	contain	statistical	information	about	how	long	types	of	events	generally	take.	In	classical conditioning,	after	learning	the	subject	is	able	to	predict	the	duration between stimulus onset and reward presentation and will begin to exhibit anticipatory behavior	when the reward is nigh. But top-down expectations of duration can also influence the quality	of	ongoing	experiences	of	duration	without	inducing	prediction	errors	and	thus	segmentation.	For	example,	we	may	know from	experience that a typical episode	of checking	out	groceries takes	a	few	minutes.	An	event	model	for	a	token	of	this	event	may reliably	predict a temporal range	within	which the	event should end.	With	this	range	and	goal	set,	there	is	no	need	to	allocate	attention to its duration if it is taking about as long as expected. When	the	duration	extends	to	the	far	end	or	beyond	the	approximate	range,	our	experience	may	qualitatively	change:	we	suddenly become aware that	we are in a very slow checkout line. The qualitative	difference	may	be	felt	as	a	change	of	affect	(e.g.	impatience) that is assigned to the duration rather than some other aspect.	But there is	no	segmentation: the	duration	that	comes	to seem	too	long	is	the	duration	of	the	same	event.9 8	Thanks	to	Andy	Clark	for	raising	the	need	for	this	clarification. 9	Animals likely have similar qualitative differences: your dog experiences a duration	between	when	you	walk	in	the	door	and	when	he	is	fed,	but	this	experience	(and	not just	his increasingly	frantic	behavior)	can	change	in	quality if you	are	slower	than	usual	in	feeding	him. 9 These changes in our experiences of ongoing durations make vivid the fact that	while EST tells us	when and	why event boundaries	are	perceived,	it	says	little	about	how	event	durations are	perceived.	It	says	only	that	they	may	be	perceived	during	periods	of	processing	stability.	Nevertheless,	since	event	segmentation yields intervals, EST is ipso facto a theory of what activates or triggers interval timing and thus of	what makes experiences of durations	possible.	We	can	therefore	expect	to	gain	further	insight into experiences of duration by augmenting EST with what we know about our internal interval timing	mechanism, sometimes known	as	the	stopwatch.	While	the	circadian	clock	has	been	localized	in	the	suprachiasmatic	nucleus	and	millisecond	timing	in	the cerebellum, the stopwatch involves thalamo-cortico-striatal circuitry, including the basal ganglia, supplementary motor area, prefrontal	cortex,	and	posterior	parietal	cortex	(Allman	2014:	746 and	Table 1; Buhusi and	Meck 2005; Grondin	2010).10	After two preliminary	remarks, in the	rest	of this	subsection	I	briefly	summarize	main	themes from the literature	on interval timing, combine EST and the leading theory	of interval timing, and indicate how the combined account makes contact with epistemic concerns. The first, minor, remark is that much psychological and neurobiological research	on interval timing	has	been	directed	at unimodal	events	with	timescales	of	a	few	hundred	milliseconds	to a	few	seconds	(Matthews	and	Meck	2016,	Grondin	2010).	Scalingup	assumptions	are implied	when	results	are	extended	to longer intervals	and	more	complex	events	within	the	midrange.11 10	These	timing	mechanisms	interact:	for	example,	older	adults	make	more	accurate	duration	estimates	in	the	morning,	young	adults	in	the	evening	(Allman et	al.	op.cit:	758). 11	For example, Hommel et al. 2001 propose a theory of common coding for event	perception	and	action	planning.	While	their	focus	is	simple,	brief	events like key-pressing tasks, Zacks (2001: 910) and Hommel et al. (op.cit.: 914) agree	that	a	modified	version	of	their	basic	framework	should	apply	to	longer events	(e.g.,	making	coffee). 10 The second,	major, remark is related to the distinction in research protocols between those eliciting prospective timing judgments and those eliciting retrospective timing judgments (Wearden 2005). In prospective timing experiments, human or animal subjects	are told (or trained) in	advance that an interval estimate (provided verbally or behaviorally)	will be sought (e.g. "Hold	down	the	button	for	1	second").	In	retrospective	timing	experiments,	human	subjects	are	asked	unexpected	questions	about intervals	(e.g.	"how	much	time	has	passed	since	you	started	reading this	paragraph?").	The targets	of these	estimates	are considered distinct: prospective judgments are reports of episodes of interval timing, and retrospective judgments	are	outputs	of general	cognitive	mechanisms	not	specifically	related	to	time.	For illustration, in Kelly's case of the soprano presumably we could have	made	a	prospective	judgment	of	the	note's	duration	had	we been asked to do so. In contrast, cases where (e.g.) after 25 minutes of a boring movie you say, "It feels like the movie has been	going	on for	an	hour" (Merino-Rajme	2014),	we	are	giving retrospective	judgements	(and	arguably	in	this	case	we	are	really reporting an affective response). The internal clock theory discussed	below is about the	mechanisms	of interval timing	whose experienced outputs are reported in prospective estimates. The importance	of	this	point	will	become	clear	in	Section	2. The stopwatch temporally integrates	multimodal sensory signals	that	arrive	at	different	speeds	and	are	processed	at	different	speeds	by	sensory	organs,	compensating	for	these	differences so that	we can track discrete events and objects. The dominant information-processing	hypothesis	of	interval timing is the	pacemaker-accumulator	or	PA	model	(Treisman	1963;	Wearden	2005; Allman	et	al.	2014;	Buhusi	and	Meck	2005;	Eagleman	et	al.	2005; Grondin	2010;	Block	and	Grondin	2014).	The	model implements the Scalar Expectancy Theory or SET (Gibbon 1977; Gibbon, Church, and	Meck 1984; Buhusi and	Meck 2005) in that it was formulated in	part to	explain	the	scalar	property	of interval	estimates. The scalar property is the fact that these estimates are more variable relative to the	mean as the length of the interval 11 grows,	by	a	fixed	proportion	that	follows	Weber's	law.	The	errors are larger for larger intervals,	although	not	relatively larger	than errors	for	shorter	intervals	(Wearden	2005).	Gibbon	et	al.	(1997: 170)	liken	this	feature	of	subjective	timing	to	a	rubber	ruler	that can be stretched to measure any arbitrary target interval, but where interval estimation error increases proportionally as the ruler	is	stretched. Note that the scalar property also applies to neural responses (Buhusi and	Meck	op.cit.: 756,	Fig.	2). So	while interval estimates by human and animal subjects are reliably correlated with	and	interpreted	as	reports	of	experienced	intervals,	the	psychological concept of subjective interval timing includes more than	just	experienced	intervals.	This	coheres	with	EST's	view	that event segmentation proceeds nonconsciously as well as consciously.	Also,	Block	and	Grondin	(2014:	1)	question	whether	the scalar	property	should	be	taken	for	granted	as	an	explanandum	of an adequate theory of interval timing, given that it is directly a feature	of time	estimation	rather	than	of time	perception	(which in their usage refers to what interval timing mechanisms do, whether	subjects	perceive	the	intervals	or	not).	However,	by	seeking to	explain	both	the	PA	model affirms	a tight relationship	between experienced and estimated intervals in prospective timing.12 The	PA	model	posits	a	pulse	counter	(a	clock	stage),	a	reference	memory (a	memory stage)	and	a comparator (a	decision stage),	each	with	its	own	forms	of	variance	that	can	contribute	to inaccurate perceptions of duration. At the onset of an event, a pacemaker	emits	pulses	(neural	spikes)	that	are	gated	into	an	accumulator	by	attention.	The	pulse	tally is transferred	to	working memory	for	comparison	to	an	interval	value	for	that	type	of	event 12	A	minority	view	of	interval	timing	(e.g.,	Staddon	and	Higa	2006)	is	that	it	is not	performed	by	a	specialized	mechanism	but	by	basic	memory	and	learning processes.	Buhusi	and	Meck	(2005:	763)	hold	that	interval	timing	is	a	specialized mechanism, but that it shares neural circuits with non-temporal processing.	(For	comparison:	the	circadian	clock	is	considered	a	specialized	mechanism,	and	it	has	dedicated	neural	wetware.) 12 stored in	reference	memory.	(In	prospective	timing	experiments, this	is	often	an	interval	just	presented	to	the	subject.)	This	step	is also	described	in	terms	of	the	transfer	of	the	pulse	count	directly to reference	memory for comparison to the stored reference interval (Allman et al. op.cit: 750). Either	way,	when these values are	close	enough,	a	decision	rule	determines	an	interval	estimate and	appropriate	response.13 EST	and	the	PA	model	can	be	integrated	in	part	in	the	following	way.	If	EST	is	correct,	working	memory	contains	an	active event model whose predictive processing of incoming stimuli triggers the first stage of the PA model; presumably nonattentional	mechanisms	can	also	do	the	gating	in	this	stage.	Working	memory also comes to contain the pulse tally received from the accumulator in the second stage of interval processing. Importantly, there	must be coordination between the event	model that	generates	prediction	errors	(event	boundaries)	and the reference	interval	to	which	the	accumulated	pulse	count	that	begins at	a	given	boundary	is	compared.	A	simple	hypothesis	is	that	the reference	interval	is	part	of	the	event	model,	although	other	relations	are	possible.	However	coordination	occurs,	event	schemata presumably influence duration perception as well as boundary perception	by	helping	determine	which	reference	interval	is	relevant.	This	may	included	in	determining	which	event	model	is	active.	For	example, the	event-model for	dish-scraping includes information	about	how	long	this type	of	event	normally takes,	and the interval that is triggered at the start of the dish-scraping is compared	to	this	reference	interval.	Given	that	perceived	boundaries and subsequent perceived intervals together constitute perceived	durations,	it	follows	that	both	constituents	of	duration	per- 13	The	coincidence-detection	(or striatal	beat frequency,	SBF)	model	of interval	timing	holds	that	patterns	of	spikes	of	cortical	neurons	are	continuously compared	by striatal spiny neurons	with a reference pattern. It	may be that coincidence-detection and pulse counting are just two	ways of comparing a stimulus-dependent	quantity to	a reference interval (Buhusi	and	Meck	2005: 763).	If	so,	the	SBF	model	is	of	the	neurobiological	implementation	of	the	first step	of	the	PA	model,	not	an	alternative	theory. 13 ception	are	subject to top-down	influences. I	return	to	this	point in	Part	2. In	addition,	the	fact	that	we	make	proportionally	larger	errors	when estimating larger intervals may help explain why, as events increase in temporal length, they are	more characterized by	goals,	plans,	or	intentions	rather	than	physical	features	such	as motion	(Zacks	and	Tversky	2001),	and	why	beginnings	loom	larger	than	endings	(Teigen	et	al.	2017).	We	compensate	for	the	stopwatch's	loss	of	precision	at	longer	intervals	by	using	more	reliable alternative	methods	to	fix	when	longer	events	are	over.	A	non-elite marathon runner may have a vague idea of her time when she crosses the finish line, but she knows exactly	when she has finished.	We	can	of	course	get	better	at	time	estimation.	Elite	marathon	runners	are	duration	experts	analogous	to the	way	sommeliers	are	wine experts: they can	accurately	distinguish	durations of	2	hours from	2	hours	and	5	minutes. In	any case, there is	no reason	to	think	estimates	of	durations	of	everyday	events	must	be precise	to	be	accurate.	Accuracy	often	only	requires	falling	within a	range.14 The	neurobiology	of	interval	timing	is	being	actively	investigated.	A	biological	basis	for	the	stopwatch	was	initially	inferred from	the	fact	that	higher	bodily	temperatures	in	fever	resulted	in altered subjective judgments of passing time (Wearden 2005: 9 Fig.	1).	Within	the	PA	model,	heating	implies	more	clock	ticks	per objective interval and	more	quickly accumulating the	number	of pulses in the reference interval associated	with the event being timed.	The	result	is	experiencing	and	estimating	intervals	as	longer	than	they	really	are:	when	instructed	to	count	out	a	minute,	we may count out (what feels like) 60 seconds in less than 45 seconds. Perceptions of durations are also affected by a variety of 14	Our	baseline	accuracy	for	judging	intervals	differs	across	modalities	(e.g. audition	is	generally	more	accurate	than	vision	(Allman	et	al.:	746)).	We	also tend to perceive events as occurring closer in time then they are	when the events	are	an	action	we	did	and	its	effect	(Ebert	and	Wegner	2010;	Andersen 2013),	although	measured	effects	are	in	the	millisecond	range.	Interval	timing ability	also	varies	across	subjects. 14 sensory,	psychological,	and	physiological factors, including	attention,	arousal,	memory,	affect,	psychiatric	disorders,	and	drugs	affecting	neural	and	neurotransmitter	activity	(Matthews	and	Meck 2016;	Allman	et	al.	2013;	Droit-Volet	and	Meck	2007;	Buhusi	and Meck 2005; Grondin 2010; Cheng et al. 2006; Terhune et al. 2014). In terms of the PA model, these factors can change the pulse rate (clock speed), the	working	memory representation	of the reference interval, or the baud rate at which accumulated pulses	are	transferred into	working	memory.	For	example,	dopaminergic agonists (e.g.	methamphetamine) increase clock speed while antagonists (e.g. haloperidol) decrease it (Allman et al. op.cit.:	749;	Buhusi	and	Meck	op.cit.:	757),	and	cholinergic	antagonists	(e.g.	atropine)	affect	reference	memory	in	that	the	criterion interval	a	subject	uses	is	longer	than	the	intervals	that	were	presented in	training.	Given	the	PA	model,	at least	some	of these influences	can	explain	why	car	accidents	may	be	experienced	as	occurring	in	slow	motion.	Due	to	sharp,	rapid	increases	in	attention, affect,	and	stress,	external	time	is	experienced	as	abruptly	slowing down because the internal clock rate has rapidly accelerated without	a	corresponding	shift	in	the	reference	interval	for	normal driving	that	was	active.	Yet	while	we	may	perceive	everything in slow	motion,	our	millisecond	timing	mechanisms	can	still	control our	motor	responses	automatically.15 1.3. The Philosophical Adequacy of the Account. The grounding of duration perception in perception of the now appears to be a common background assumption of the Specious Present	and	Retention	Views.	Perception	of	now	is	the	basic	item of	temporal	perception,	whether	it	is	instantaneous	or	somewhat stretched.	However,	if	the	above	account	is	on	the	right	track,	we 15	Arstila (2012) suggests that norepinephrine is likely to play an important role	as	well,	in	particular	for	attention	shifts.	On	a	higher-level	account	(Tse	et al.	2004),	the	added	attention	may	result	in	fewer	temporal	cues	being	missed ("missed	temporal	cues"	interpretation)	or	the	counting	of	more	units	or	pulses	by	the	stopwatch	("attentional	boost"	interpretation),	or	both.	The	account in	the	text	is	not	intended	to	be	complete. 15 do	not	perceive	duration	as	a	number	of stitched-together	nows (or	overlapping	brief	successive	experiences:	Dainton	2014).	Perceiving durations is perceiving boundaries plus intervals – i.e. maxima	of	processing	changes	that	trigger	the	stopwatch	and	periods	of	processing	stability	between	these	boundaries	while the stopwatch ticks away. The experienced now is just an ordinary, smallish experienced duration – ordinary and smallish because we	are	easily	able to	perceive	ordinary	events	with	durations far briefer	than	3	seconds.	"Now"	is	a	vague	term	that	picks	out	these intervals.	There	is	nothing	left	to	explain	of	the	now	once	we	explain	duration	in	terms	of	event	segmentation	and	interval	timing. Note	that	this	is	not	an	account	of	simultaneity	or	temporal	order of	successive	events,	which	are	distinct	explananda. An imperfect	metaphor for	our	experiences	of	duration is many	reels	of	film	with	irregular	frames	(events	at	varying	timescales	with	varying	durations)	running	through	a	movie	projector at	once.	The	now	is	what is in the	projector's	light,	whether	this includes at least one consciously accessible boundary or not. In these terms, the traditional debate of extensional versus retentional	views	of	experiences	of	duration	concerns	whether	what	is in	the	projector's	light	is	extended	or	momentary	(see,	e.g.,	Dainton 2014: 103 Fig.	6.2).	The empirically-based account	does not ignore philosophical concerns to explain how conscious experience seems (continuous,	unified, etc.); it interprets phenomenological	descriptions	of	experiences	of	duration	and	the	now	in	the light	of	what	we	know	about	interval	processing. But	Kelly	might insist:	how	is	it that	we	both	perceive	the soprano	as	singing	the	note	now	and	yet	perceive	that	this	acoustic	event	has	been	going	on	for	a	long	time?	I	suggest	that	this	description picks out temporal and nontemporal elements of our phenomenologically accessible experience. The nowness of the event's	duration	is	the	accessible	segment	of	an	ongoing	duration. A second aspect of our experience is generated by enhanced attention to this duration,	which is prolonged beyond expectation on the assumption that the aria is not familiar. (If	we are opera experts,	we	will	not	experience	the	note	as	too	long	–	not	unless	it 16 violates the composer's actual	notation.)	This is	worthy	of additional	attentional	resources	in	the	light	of	our	limited	knowledge. Kelly	describes	this	sudden	change	in	our	experience	of the	note as	perceiving	that	it	has	been	going	on	for	a	long	time.	But	we	are not reporting experiencing the soprano's singing as slower or faster. Those changes would be reported as changes in experienced duration. Our stopwatch is clicking away at its normal speed.	Instead,	we	are	reporting	another	aspect	of	our	experience – an experience of astonishment directed at its duration, rather than,	say,	its	pitch.	This	is	a	phenomenological	change	in	our	experience	of	its	duration,	but	it	is	not	due	to	a	change	in	timing,	and so	a report	of it is	not	a report	of	our	experience	of timing.	The account	of	duration	helps	us	distinguish features	of	duration	experiences	that	phenomenological	description	does	not. Kelly also	mentions that the received view	of our experience	of	the	now	is	that	it	is	direct.	For	some,	perception	is	direct	in those cases	when it can be appropriately contrasted	with cases where inference	(or	some	other	cognitive	operation) is	added	to perception. For example, I perceive	my car by looking at it, but may	use	inference	to	recognize	it	as	my	car	if	it	has	been	totaled (Gallagher	2008).	By the account given above, experience of the now	is	direct	by	this	definition.	On	the	other	hand,	for	others	perception is direct if percepts contain exclusively sensory information, independently of any other conscious source of information,	such	as	belief	or	memory	(Chuard	2011).	By	the	account given	above,	experience	of	the	now	is	not	direct	by	this	definition. Chuard	also	asks	(2011:	4)	whether	temporal	properties	and	relations are among the "strictly speaking perceptually accessible" properties	–	that	is, if	they	are	perceptible	"in	the	same	way,	that is,	as	shapes,	colours,	and	spatial	relations"	are	perceptible.	They aren't,	but	so	what?	Appeals	to	directness	or	strict	perceptual	accessibility	do	not	seem	to isolate important features	of temporal experiences. Section	2.	The	epistemology	of	event	perception 17 2.1. Perception, Justification, and Cognitive Penetration. The	main	question in the	epistemology	of	perception is	whether beliefs about the external world are justified by the perceptual experiences they are occasioned by (Siegel and Silins 2015).16 Three	main	sources	of	doubt	that	they	are	so	justified	include	the underdetermination	or	ambiguity	of	perceptual	content	by	sensory stimuli (underdetermination), the biasing influence of cognitive states (cognitive penetrability), and the possibility of global illusion	(skepticism).	Underdetermination	and	cognitive	penetrability	can	overlap	when	cognitive	states	(or	sources	of	information considered cognitive) disambiguate the sensory input. Philosophers	have	discussed	these	concerns	primarily	in	relation	to	visual	perception	of	and	beliefs	about	objects	and	their	features.	Here I extend the discussion of cognitive penetrability to events and their	durations,	setting	aside	the	problems	of	skepticism	(or	illusion) and underdetermination.17	Also, in contemporary discussions,	experiences	are	taken	to	have	externally	directed	contents, and perceivers need not believe that things are as experiences represent them to	be (Siegel and	Silins	op.cit.: 782). Just	so,	our experiences of duration are about external events, and we can have	experiences	of	durations	that	we	do	not	believe	are	veridical 16	Siegel	and	Silins	distinguish	between	propositional	justification,	when	an experience	provides	reason	to	believe	something	whether	one	comes	to	believe it	or	not,	and	doxastic justification,	in	which	a	belief	is	based	on	experience	– more	specifically,	a	belief	is	doxastically	justified	iff	it	is	rationally	formed,	adjusted,	or	maintained	on	the	basis	of	experience	(Siegel	and	Silins	op.cit.:	784). In	another	use	of	"doxastic",	doxastic	states	are	those	accessible	to	consciousness	and	inferentially	integrated	(Macpherson	2017:	11). 17	The	ambiguity	of	event	perception	is	revealed	by	the	McGurk	effect	and	the sliding/bouncing	effect	(Sekuler	et	al.	1997;	Watanabe	and	Shimojo	2005).	Experiments	inducing	illusory	duration	judgments	suggest	that	the	stopwatch	is constantly being calibrated to the external world (Eagleman et al. 2005). Moreover,	there	must	be	coordination	between	the	timing	and	durations	of	our own	movements	and	the	movements	or	motions	of	other	entities	for	the	purpose	of	adaptive	action	(Hecht	2000:	18;	Kurby	and	Zacks	op.cit.:	78;	Hommel et	al.	2001:	877). 18 (e.g.	the	illusion	of	time	passing	in	slow	motion	during	a	car	accident). To	a first approximation, cognitive	penetration	of	perception occurs	when beliefs, expectations, desires, hopes, goals and other	cognitive	states	intervene	in	the	perceptual	process	so	as	to affect	the	nature	of	the	perceptual	experience	(Stokes	2013;	Silins 2016:	24;	Vance	2015;	Siegel	2012:	205-206).	This	difference in the	nature	of	the	experience	is	usually	spelled	out	at	least	in	part in terms	of a	difference in the	experience's content.	Macpherson (2012:	29)	holds	that	a	perception	is	not	cognitively	penetrable	if it	is	not	possible	for	any	two	perceivers	(or	the	same	perceiver	at different	times)	to	have	experiences	with	distinct	content	or	character	when	one	holds	fixed	the	object	or	event	of	perception,	the perceptual conditions (e.g. lighting), the spatial attention of the subject,	and	the	conditions	of	the	sensory	organs(s).	We	may	add temporal	attention	to	the	list	(e.g.,	attention	to	the	soprano's	singing).	Macpherson	(2017)	further	specifies	that	in	cognitive	penetration	there	must	be	a	semantic	and	causal	link	at	each	step	from the	belief	(or	other	cognitive	state)	to	the	perception.18 Cognitive	penetrability	of	perception	is	an	epistemic	problem	in	the	light	of	traditional	views	of	how	perception	works	and how it is supposed to provide epistemic justification. The	metaphysical presupposition is the existence of a theoretically important perception/cognition distinction. The epistemological presupposition	is	the	idea	that	percepts	must	be	linked	to	the	external world without mediation by cognitive resources to have justificatory	power.	They	should	be	"untainted"	by	prior	assumptions	made	by	the	subject	or	a	subpersonal	part	of	her	perceptual system	(Vance	2015:	643).	As	Silins (2016)	puts it, your	experience "reflects	what is before you and does not reflect your	own mind.	Given	that	your	experience	is	not	influenced	in	any	way	by your	theories	or	expectations,	it	is	thereby	in	an	optimal	position 18	Macpherson	(2017)	also	distinguishes	between	cognitive	penetration	of	early	vision	(e.g.	Pylyshyn	1999:	343)	and	of	perceptual	experience;	the	latter	is	of concern	here. 19 to	confirm	or	disconfirm	hypotheses	about	the	world."	These	two presuppositions	ground	the idea	"that the	content	of the	perception	underwrites that	of the	belief it justifies, in the	sense	that it logically implies it, or makes it probable, or maybe just in the sense	that	an	inference	from	the	perception	to	the	belief	would,	in the present context, be reliable" (Heck 2000: 499). Cognitively penetrated perceptions lack the content independence required for	them	to	provide	rational	justification	for	belief. Siegel	(2012,	2017)	provides	a	compelling	example	of the worrisome circularity: Jill believes (without good grounds) that Jack is angry at her, she sees	his face as being angry because of this	belief,	and	she	takes	this	perception	at	face	value	to	justify	her belief that	he is angry.	He	does, after	all, appear	angry to	her. In this	way, the	penetrating	cognitive	states	are	"stacking	the	tribunal	of	experience"	in	their	favor:	the	experience	does	not	provide an independent reason for your belief (but see Lyons 2011).	Of course,	we	also	know	that learning	can improve	your	perceptual experiences and lead to	better	beliefs than	one	might	otherwise have.	A	tree	expert	knows	what	an	elm	looks	like	and	will	perceive elms	more	quickly	and	accurately,	and	these	perceptions	will	redound	to	the	credit	of	her	prior	elm	beliefs. If these	are	cases	of cognitively penetration, then cognitive penetration is not necessarily pernicious. Regardless, it seems clear that a problem can arise	in	some	cases. 2.2. Experiences of Duration and Cognitive Penetrability. On	the	EST-based	account,	experiences	of	duration	are	made	possible	by	the	triggering	of	the	stopwatch	by	prediction	errors	generated in the course of processing nontemporal sensory inputs. EST	builds	top-down	influence	into	event	segmentation,	and	thus potentially	into	experiences	of	event	boundaries,	via	the	influence on	event	models	of	prior	knowledge	contained	in	event	schemata. I	elaborated	this	account	in	plausible	ways.	Schemata	presumably include	statistical	information	about	previously	experienced	event durations. The influence of this information can be expected to extend	to	experiences	of	event	duration,	given	the	need	to	coordinate segmentation and interval timing processes. Coordination 20 would be achieved if event models simply contained previously learned reference intervals. In short, the proposed account of event	perception	appears	to	raise	worries	of	cognitive	penetrability	about	experiences	of	duration. One	reason	not	to	worry	stems	from	the	fact	that	the	presupposed	divide	between	perception	and	cognition	is	undermined by scientific advances. Without that distinction, cognitive penetrability	may	be impossible	given	how	it is	defined	(Macpherson 2017).	Even if it is	not	ruled	out	by	definition, in	predictive	processing or broadly Bayesian accounts of overall neural function, the	outputs	are	our	best	models	of	the	world.	What	is	fed	forward from the sensory	stream is a	prediction	error	(if any)	generated by a difference between the expected sensory stimulation and what	is	detected.	As	Shea	(2015:	76-77)	puts	it,	in	predictive	processing	there is	no	"cascade	of illusory justification"	bubbling	up from	below,	just	the	nudging	of	pre-existing	models	towards	better predictions using prediction errors. The account of duration perception defended above does not quite escape the	worry for this reason, because	while EST is a predictive processing	model the	PA	model is	not.	But it	could	easily	be	revised into	one	– for example,	by	interpreting	the	reference	interval	as	a	predicted	value	of	an	active	event	model.	In	this	case,	the	worry	would	be	alleviated for duration perception as it is for any predictive coding model. However, Shea suggests that an updated reformulation of the	perception/cognition	distinction	that	might	enable	us	to	pose some	of	the	questions	raised	in	the	cognitive	penetrability	debate. It	has	turned	out that	many input-driven	processes important in cognition turn out to straddle the traditional divide. They have features	that	usually	belong	to	systems in	the	cognitive	category. For	example,	while they	are input	driven they	have an "amodal" phenomenology in that they "take as input whichever kinds of sensory inputs are relevant in the circumstances" (Shea 2015: 85).	Among	these	hybrid	systems	are	the	system	for	representing one's	spatial	position,	language	processing,	and	Carey's	systems	of 21 core	cognition,	such	as	numerosity for	representing	quantities	of items	or	perception	of	agency. Our interval timekeeping mechanisms also belong in the hybrid	class.	The	stopwatch	is	amodal	in	that	it	is	driven	by	nontemporal	inputs	in	the	sensory	modalities	that	are	relevant	in	the circumstances.	It	also	operates	at	many	timescales,	some	fast	and mandatory,	others slower	and	under cognitive control.	Note that our	timing	mechanisms	are	not	on	a	par	in	this	respect.	Millisecond	and	circadian	timing	are	automatic	and	largely	not	consciously controlled.	Circadian timing in	particular satisfies	many if	not all	of	Fodor's	(1983)	original	criteria for	modularity	– it is	automatic, has dedicated neural	wetware, and is to some	degree encapsulated in	that its	operation is impervious	to	belief	about the actual	time	right	after	a	long	flight.	Interval	timing	operates	like	a central	system	by	Fodor's	standards.	It	is	subserved	by	neural	circuitry	spanning	many	cortical	and	subcortical	regions	of	the	brain. Influences	on	the	activity	of	the	stopwatch	that	affect	our	experiences	of	duration	can	come	from	below	(e.g.	drug-induced	or	externally stimulated variation in neurotransmitter activity, affecting	the	pulse	rate	of	the	stopwatch)	and	above	(e.g.,	memory	defects	and	emotional	states,	affecting	the	reference	interval).	These effects	occur	in	normal	and	abnormal	experienced	intervals. Shea	suggests	that	we	can	at	least	characterize	how	much of a	mechanism's operation is driven by current input and how much	by	top-down	information.	Not	all	pre-existing	information	is top-down.	For	example,	a	system	can	contain	prior	information	in the form of expectations, with the latter understood as dispositions	to transition from	one	representation	or	another in	certain ways.	These	do	not	count	as	top-down	effects,	but	are	the	effect	of learning and	may be beneficial. Top-down information is occurrent and explicitly represented, such that it can act as input to many	different	systems.	More	precisely,	a	top-down	influence	is	"a representationally	mediated	effect	of	an	explicit	representation	R on	a	psychological	process,	where	R	is	not	computed	more	directly than the representational influence of current sensory inputs 22 on the process" (Shea op.cit.: 81).19	This makes top-down influence	a	matter	of	degree.	The	surviving	epistemic	question	would be	whether the	output	of	one	system	A is suitable for	belief formation (or other subsequent processing) in another system	B if B's	representations	have	affected	A's	processing.	On	this	view,	independence	from	top-down	influence	is	not	needed	for	epistemic suitability. Top-down information can influence a psychological process	whose	outputs	reinforce	that information	without	pernicious	circularity. Shea's proposal has the virtues of	updating the debate to take into	account the	actual complexity	of	much	processing, and to allow that the epistemic implications of top-down influence vary	from	case	to	case.	The	traditional	presuppositions	are	gently modified	to	leave	some	form	of	the	traditional	worry	behind.	Unfortunately, once we acknowledge the complexity of actual processing,	a	third	presupposition	of	the	traditional	debate	is	left	unsupported,	and	is	unsupportable. Perceptual belief is traditionally understood as being formed	on the	basis	of experience: the	beliefs are	occasioned	by the	perceptions.	We	see	a	red	tomato	and	form	the	belief	that	it	is red.	Structurally,	there	are	two	processes	connected	by	a	route	for information flow.	Both	the	original	perception/cognition	distinction	and	Shea's	top-down/bottom-up	distinction	embed	this	routing	assumption	in	which	information	flows	from	process	A	to	process	B,	and	maybe	from	B	back	to	A.	(There	is	no	circularity	without	a	routing	assumption.)	This	structure	presupposes	that	A	and B	are	(or	are	the	outputs	of)	distinguishable	processes.	We	have percept-forming	processes,	and	their	outputs	can	be	inputs	to	belief-forming processes. In cognitive penetration, the routing also goes	the	other	way:	outputs	of	belief-forming	processes	influence percept-forming	processes.	Predictive coding	and	Shea's analysis show that these processes cannot be neatly separated.	Duration 19	The	"directness"	requirement	is	not	patently	clear	(as	Shea	recognizes)	but	I will	not	raise	any	issues	here	about	it. 23 processing	shows	that	even	Shea's	reformulation	does	not	go far enough	in	taking	account	of	the	complexity. As	noted	above,	interval	timing	researchers	distinguish	between prospective and retrospective judgments or estimates of durations. Prospective judgments are of experienced intervals produced by interval timing mechanisms. Their close relation suggests that duration experiences and prospective duration estimates	are	outputs	of	the	same	interval	timing	mechanism.	They are	correlated	because	they	have	a	common	cause	in	the	same	endogenous process subject to top-down influences among many others.	The	duration	estimates	are	not	formed	on	the	basis	of	perception, but along side perception. These estimates are distinguished from	retrospective judgments,	which	are	outputs	of	distinct processing mechanisms not specific to time. In short, researchers distinguish duration beliefs that are about the experiences of duration arising from interval timing	mechanisms, and duration	beliefs	that	are	not	occasioned	directly	by	interval	timing at all. Of course, we can describe this processing structure in terms	that	fit	the	routing	structure	behind	traditional	epistemology of perception and the problem of cognitive penetration: just call the stored or top-down information that influences interval timing	a	belief.	But the	duration	estimate that is the	outcome	of interval	timing	mechanisms	is	not	identical	to	this	belief.	The	perceptual	belief	(the	estimate	of	the	experienced	duration)	and	the stored	belief	are	not	the	same.	So	there	is	no	circularity	no	matter how	much	top-down	information	influences	interval	timing.	Duration perception and estimation do not map onto the abstract structure	of	the	problem. This analysis	points to a larger	moral.	Most philosophers agree that the behavior and states of agents (or persons, in a bland sense) are to be explained in terms of the operations of subpersonal states. But belief and perception are personal-level states	when	we	refer to them	for	epistemic	purposes.	The	visual system	does	not	perceive,	the	person	does.	It	is	a	big	and	not	entirely	coherent	step	to	argue from	the fact that	subpersonal	processing	explains	personal-level	behavior	to	the	idea	that	epistemic 24 features	attach	to	subpersonal	processing	stages.	This	treats	perception	and	belief	as	personal	and	subpersonal	at	the	same	time. It	might	have	been	harmless	to	continue	to	ascribe	epistemic	features	directly to	subpersonal states if the	processing	details	had turned	out	to	be	as	simple	as	tradition	holds.	But	in	a	complex	information	processing	system,	what is the	value	of	distinguishing particular	stages	by	epistemic features	when it's the	overall	outcome	that	is	epistemically	good	or	bad?	Complex	systems	routinely	adjust	to	compensate	for	normal	variation	or	change,	as	well	as defect	or	insult,	without	any	observable	behavioral	difference.	All stages	might	contribute	a little	bit to	a lousy	epistemic	outcome. There are simply too many influences, from too many different sources	and	functional	levels,	that	can	spoil	the	epistemic	broth. Thus, suppose an on-duty police officer on a call, service weapon in hand, perceives a man's arm movement following a pulling-object-out-of-pocket event as the start of a taking-aim event	rather	than	the	start	of	a	raising-hands	event,	and	he	shoots the	man.	A	taking-aim	event	reliably	has	a	much	briefer	duration than	a	raising-hands	event	in	these	circumstances,	but	which	type of	event	is	starting	at	the	perceived	boundary	is	ambiguous.	So	we assume the officer perceives the start of an event of predictably very	brief	rather	than	predictably	somewhat	longer	duration:	the underdetermination of the initial	motion is resolved in one	way rather	than	another.	Suppose	it	has	been	resolved	by	past	experience	stored	in	the	officer's	event	schemata	for	dangerous	policing situations,	of	which	this	context	is	a	token.	There	may	or	may	not also	have	been	a	detected	difference	in	motion	at	the	millisecond timescale	that	governs	his	automatic	response. Something	has	gone	morally	awry if the	officer shoots	an innocent man.	What is not at all clear is whether anything has gone epistemically awry that can be pinned on his subpersonal processing.	If	we	suppose	the	victim	is	black,	one	might	argue	that the	officer	had	antecedent	racist	beliefs	that	somehow	influenced his	perception,	perhaps	by	making	it	more	likely	that	this	context would	be	classified	as	dangerous	(or	more	dangerous	than	otherwise). But racist beliefs need not impinge on the officer's event 25 processing for them	to	play	a	role in	his	behavior,	nor	on	the	explanatory interests lead us to blame the officer for	his response (or	else	excuse	him,	if	we	are	also	racists).	Beliefs	can	make	us	insensitive to evidence (Lyons 2011: 301).	Much of the epistemic threat blamed on cognitive penetration may instead arise from confirmation bias and other forms of motivated reasoning, not processing	details. Of	course,	there	are	times	when	we	can	reliably	pick	out	a particular faulty stage in information processing: she believed that	the	boulder	was	a	big	dog,	but	she	wasn't	wearing	her	glasses.	But	we	extend	these	simple	cases	far	beyond	the	point	of	validity. Our penchant for doing so appears to answer to pragmatic concerns for personal responsibility and reasons-giving, not to concerns for	getting	the	processing	details	right. It	hardly	seems to matter how subpersonal information processes work: in the case of the officer, via a heightening of fear that increases the probability	of	trigger-pulling	whatever	the	current	perceptual	input, or via top-down influence on perceptual processing of the current sensory input from the	man's arm	movement, or via an implicit expectation built into his activated event	models, or via misapplied	reference	intervals,	or	via	all	of	the	above.	What	matters epistemically is uncorrected,	uncompensated for, or evidentially	problematic	learning	or	evidence	gathering. Perhaps we should distinguish an epistemic role we call belief	from	a	subpersonal	psychological	state	of	belief	that	might fill	the	epistemic	role.	In	any	case,	once	we	accept	that	we	cannot divide information-processing into intuitive	routes	to	which	subpersonal assignments of epistemic features might be made, the epistemic	problem	is	just	that	of	whether	the	person	would	have behaved better if he had better beliefs or perceptions. The accused	officer	may	plead	that	he	felt	he	was	in	danger;	he	may	say, as	a	retrospective	judgment	of	the	man's	action,	that	he	perceived the	man taking aim. Others	may try to pin the bad outcome on racism-penetrated	perception.	Both	responses	reflect the	custom of assigning responsibility to individuals, extended	now to their subpersonal processes or outputs, for when something goes 26 wrong.	Such	assignments	do	not	answer	to	the facts	of	actual information	processing.	But	we should	not think that is their	purpose	anyway. Conclusion. This	paper	had	two	main	aims.	First,	I	provided	an	empirically-based account of our experiences of duration. My account elaborates	Event	Segmentation	Theory	with current research	on interval timing mechanisms at both the information-processing and	neural	levels.	Along	the	way	I	used	this	account	to	provide	an explanation	of	changes	in	quality	of	duration	experiences	and	illusory durations. I thus demonstrated its prima facie adequacy in terms	of	taking	both	empirical	research	and	phenomenology	into account.	Second,	I	considered	the	problem	of	cognitive	penetrability for	duration	perception.	The	EST-based	account	strongly	suggests that experiences of duration involve top-down influences. However, I also argued that the structure of interval perception and	belief	does	not	map	onto	the	structure	required	by	the	epistemological problem. 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