Synthese (2007) 159:253–270DOI 10.1007/s11229-007-9207-4

Introspection & remembering

Josef Perner · Daniela Kloo · Elisabeth Stöttinger

Published online: 4 August 2007© Springer Science+Business Media B.V. 2007

Abstract We argue that episodic remembering, understood as the ability to re-experiencepast events, requires a particular kind of introspective ability and understanding. It requiresthe understanding that first person experiences can represent actual events. In this respect itdiffers from the understanding required by the traditional false belief test for children, wherea third person attribution (to others or self) of a behavior governing representation is suffi-cient. The understanding of first person experiences as representations is also required forproblem solving with images. In support of this argument we review developmental evidencethat children’s episodic remembering is independent of and emerges after mastery of the falsebelief task but emerges together with the use of imagery for solving visual rotation tasks.

Keywords Memory development · Episodic memory · Remembering · Theory of Mind ·Imagery · Introspection

1 Episodic remembering

Research on memory in psychology commonly splits our longterm memory into the hier-archical classification shown in Fig. 1. In this classification levels of consciousness playan important role. Of specific interest to us is the subdivision within the explicit/consciousmemories. This subdivision within explicit memory was introduced by Tulving (1972) whichhe later linked explicitly to further levels of consciousness. So-called “semantic memory”requires noetic consciousness while “episodic memory” requires autonoetic consciousness(implicit memories are anoetic). In this paper Tulving also suggested how to assess the dif-ference empirically, i.e., by asking people whether they “remember” or simply “know” thatan item had occurred in the learned list.

Distinguishing between remembering an event and knowing that the event has happenedis not only useful as an empirical means but is also the more adequate terminology for what

J. Perner (B) · D. Kloo · E. StöttingerDepartment of Psychology, University of Salzburg,Hellbrunnerstrasse 34, Salzburg 5020, Austriae-mail: josef.perner@sbg.ac.at

123

254 Synthese (2007) 159:253–270

Memory

implicitexplicitlack of conscious awareness with conscious awareness

anoetic

episodic semantic……………...autonoetic

consciousnessnoetic

consciousness"remember" "know"

Fig. 1 Classification of long-term memory according to levels of consciousness (after Baddeley 2001).

is intended than episodic versus semantic memory. Episodic memory suggests that its crit-ical feature is awareness of specific past episodes, and semantic memory suggests that it isknowledge of general facts. This is misleading because semantic memory is also responsiblefor knowledge about specific episodes, and knowing about specific episodes is not enoughfor episodic memory. The better way of making the distinction is with remembering andknowing. To give the remember-know distinction its due respect we will speak of EpisodicRemembering (or Remembering, for short) instead of episodic memory. Still, the adequateuse of “remember” needs some sharpening (Stöttinger et al. 2006).

The word “remember” is reserved for autonoetic/episodic memory of events only in cer-tain syntactic combinations. “Remember” can be used like “know” in combination with atensed complement phrase (that-complement). This linguistic form can be used for general,timeless facts, e.g., I know/remember that Canberra is the capital of Australia, as well as forfacts about specific events, e.g., I remember/know that the Berlin wall has come down on9/11/1989. In these constructions “remember” is typically used only for facts that requiresome retrieval effort. In the case of facts readily present in the mind one would not speakof remembering but simply of knowing them. However, “remember” can also be used incombination with a gerund in the case of one’s own actions, e.g., I remember pulling downthe Berlin Wall, or a noun phrase, e.g., I remember the fall (or the pulling down) of the Wallon 9/11/1989. These constructions, we hope the reader will agree, can only be used if onewas personally present at the event and, presumably, can still re-experience this event to somedegree. Whereas, the use of “remember” in other grammatical constructions, in particular“remember that…” can also indicate awareness of encoding effort (e.g., success in retrievingknowledge that one had tried hard to “remember” for an exam) or effort in retrieving learnedknowledge (e.g.: What was the capital of Ruanda?—Can’t remember!).

Remembering events can be distinguished from knowing about specific events in the pastby the following two conditions:

1. Origins of encoding lie in own (direct) experience (this is only required for real but notfalse memories).

2. Nature of the Recollective Experience (the way the memory is experienced):

(a) Ability to invoke (nonconceptual) contents of direct experience (re-live orre-experience episode).

(b) Recognition of the re-experience as something formerly experienced.

123

Synthese (2007) 159:253–270 255

(c) Causal self-reference: Awareness that the origins of the recollective experience are inpersonal experience.

Condition 1 ensures that knowledge that an event happened through testimony or infer-ence (indirect information) cannot be the basis for remembering the event. Such knowledgecan be detailed, but as long as it does not originate in ones own experience it can’t be genuineremembering. For instance, a young historian specialising in the Battle of Stalingrad mayknow so much more about that battle than the average soldier, who was lying in the trenchesof Stalingrad. Nevertheless, only the participant soldiers can claim to remember the battle,not the historian. It could, though, happen that the young historian is endowed with very vividimagination and over the years he comes to believe that he doesn’t imagine concrete scenesin the trenches but that he actually lived through these experiences. In this case we speak ofa “false memory” (see Markowitsch and Welzer 2005, for an overview of different memoryillusions). What is of primary importance is how the person experiences the memory, the socalled “recollective experience.” This is covered by the second condition.

Condition 2a brings in the specific phenomenal quality of episodic remembering particu-larly emphasised recently by Wheeler et al. (1997). It consists in the evocation of parts of theoriginal experience in imagination allowing to re-live or re-experience the original situation(and thus engage in mental “time travel"). The basic idea goes at least back to Locke ( Owens1996, p. 319): who said that memory is the power of the mind “to revive Perceptions, whichit has once had, …” (Locke 1975, p. 150).

Condition 2b makes clear that it is not enough to just have a re-experience but that therelationship between this re-experience and the original experience needs to be understood,as Tulving (1985, p. 3) emphasised in Ebbinghaus’ words: Remembering is “calling backinto consciousness a seemingly lost state that is then ‘immediately recognized as somethingformerly experienced’ (Ebbinghaus 1885, p. 1).” This condition can also be traced back toLocke continuing the above quote: “…with this additional perception annexed to them, thatit [the mind] has had them before.” (Owens 1996, p. 319).

Condition 2c adds that the recollective experience has to carry the information that there-experience causally originated in the original experience. This coding of memories (andperceptions) of their own causal origin has been called causal self-referentiality by Searle(1983). A little thought experiment by Dokic (1997) neatly illustrates how causal self-reference may be needed for genuine memories. Let us assume you know of some eventabout your earliest youth but you are not sure whether you know it because you experiencedit or because you were told it. You later tell your parents, and they assure you that this in-deed happened and that no one could have told you. You must have known from experience.So now it is clear that you know of this childhood event through experience, and you havemeta-knowledge about the causal origins of your knowledge; that is, you know that you knowof this childhood event through experience. Yet this meta-knowledge with causal referenceis not truly a genuine episodic memory. What it lacks is the following: although there ismeta-knowledge that the knowledge of the event was caused directly by experiencing theevent, the meta-knowledge itself was not caused by experiencing the event but by being told(through testimony).

Condition 2, in particular b and c, seem to require some “theory of mind” competency ofself attribution, i.e., for mentally representing states of one’s own mind.

Condition 2a does not in itself require such a meta-ability, for to have a re-experiencedoes neither need attribution of having this experience to oneself, nor does it need any under-standing of how that re-experience relates to an earlier experience. In other words, one couldhave a re-experience of an earlier experience without an understanding of the fact that it is a

123

256 Synthese (2007) 159:253–270

re-experience. The re-experience is only a “re-experience” from a third person perspective.From the experiencer’s point of view it is just an imagined event.

Conditions 2b + c require that the re-experiencer be aware of having a re-experience andan earlier experience. This clearly requires the following two elements:

• A notion of perceiving, like “seeing,” an event,• A notion of imagining an event.

The two conditions differ in terms of what one has to understand about the relationshipbetween the two experiences.

Condition 2b requires the following:

• A notion of re-experience, i.e., an understanding that the imagined event is identical tothe originally perceived event (not just the same kind), and this, presumably, can only bedone if:

• the content of the re-experience is understood as a representation of the original event.

For Condition 2c the additional element is the following:

• The causal notion of one experience being responsible for another, i.e., that the originalperception of the event is causally responsible for the re-experience of the event.

Since the elements of Conditions 2b + c require mental concepts, one can expect children’sability to episodically remember (having episodic memories) to have a mutual relationshipwith their theory-of-mind development.

2 Development of theory of mind and episodic remembering

There is evidence that the development of episodic remembering relates to theory of minddevelopments at the age of 3–6 years (Naito 2003; Perner and Ruffman 1995) which hasbeen attributed to the emerging understanding that knowledge has an origin. We will arguethat the more relevant factor is children’s ability to introspect their mental experiences andunderstand them as representations of real events.

2.1 Understanding the causal link between mental states

As early as 14 months children keep track of what other people can and cannot see and adjusttheir information-giving behaviour accordingly, i.e., they hand to people preferentially objectswhich the recipient has not yet seen (Tomasello and Haberl 2003; Moll and Tomasello 2007),and by 2 years they preferentially indicate the location of objects the other hasn’t witnessedbeing stored away (O’Neill 1996). It is tempting to see this as a sign of understanding thatperception (seeing) leads to knowledge, and lack of perception to ignorance. However, thisknowledge may be implicit in children’s information-giving behavior and not available forany other use, e.g., for knowing whose advice to follow, the one who witnessed the hidingor the one who didn’t. Improving on an earlier study by Povinelli and deBlois 1992, Sodianet al. (2006) found the onset of this ability at 3 years sharp. Explicit knowledge attributionson the basis of informational access can be found in 3-year-old if differences in accessibilityto information are made very salient (Pillow 1989; Pratt and Bryant 1990), but their perfor-mance in these tasks remains highly volatile until about 4 years of age (Marvin et al. 1976;Mossler et al. 1976;Povinelli and deBlois 1992; Wimmer et al. 1988a). At this age children

123

Synthese (2007) 159:253–270 257

also become able to give explicit causal reasons for knowing. For instance, Wimmer et al.(1988a) found that 3-year-old could not give reasons for their knowledge, e.g., for knowingthe contents of a box, because they had seen what was put inside or because they had beentold about it: origins of knowledge test. This difficulty persisted even when the task was mademore obvious (Gopnik and Graf 1988).

This explicit understanding of how informational access leads to knowledge is workedout further between 4 and 6 years. O’Neill et al. (1992) report that at this age children cometo understand which sense organ to use in order to find out the weight (use hand to lift object)or the color of an object (use eyes to look at it): modality-specificity test. Similarly, Tayloret al. (1994) found that between 4 and 6 years, children become able to distinguish betweenwords (e.g., animal or color names) that they have learned recently (e.g., maroon) and thosethey have known for some time (e.g., red): When-learned test. Also within that age bracket(e.g., Sodian and Wimmer 1987) children become able to distinguish knowledge (success infinding an object after seeing where it was put) from a lucky guess (success in finding theobject without having seen where it was put): know-guess distinction.

Several studies have used these kinds of tasks to investigate whether children’s growingunderstanding of the causes of knowledge relates to their ability to episodically remember(have episodic memories). Until recently the only available measure of episodic memory waschildren’s performance under free recall in relation to their cued recall. This measure is basedon Tulving’s (e.g., 1985) claim that success in free recall depends much more heavily on theavailability of episodic traces than success in cued recall. Perner and Ruffman (1995) wereable to show that between 3 and 5 years, children’s improvement on free recall correlatessignificantly with their understanding of how knowledge depends on experience. Even whencued recall and verbal intelligence were partialled out, correlations stayed above .30. Tasksused included children’s ability to explain why they know the contents of a box (How-do-you-know test: Wimmer et al. 1988a,b), to distinguish a lucky guess from proper knowledge(Sodian and Wimmer 1987), and to understand which sense modality to use to find out aboutcolour or weight of an object (O’Neill et al. 1992). These results were partially replicated1

by Naito (2003) on a Japanese sample. She also found a relationship between free recall andchildren’s ability to understand when they had learned a fact (Taylor et al. 1994).2

In a recent study (Perner et al. in press) we used a new measure of episodic remembering,contrasting free recall of experienced events, which can in principle be episodically remem-bered, with recall of indirectly conveyed events, which can in principle not be remembered,only known. Children either put cards with drawings of simple objects into a box (own expe-rience of each card) or they were blindfolded and so could not see which cards they putinside. They were then later shown on a monitor what had been on these cards (indirectlyconveyed events). Our reasoning was that one can have episodic memories of cards, whenone experiences putting them into a box, but not, when one could not see them. Indirect infor-mation about the cards afterwards only leads to knowledge of what was on those cards. Theinserting of particular cards cannot be remembered. The effectiveness of this manipulation

1 The significant correlation between free recall and O’Neill’s sense modality (Aspectuality) test fell belowsignificance after age and verbal intelligence scores were partialled out. This is not incompatible with theearlier results. Interestingly, Naito only controlled for cued recall performance for significant correlations(p. 326). This may have been an important difference because the contrast between free and cued recall isdeemed to isolate the specific reliance on episodic traces in recall.2 Naito classified this test as a memory for source test rather than a theory of mind test assessing children’sbasic understanding that one knows facts because one has learnt them at some time. But we think that her testquestions like, “Did you know the answer was _X_ when you were 3 years old?”; make it unlikely that thistest assessed actual memory for source.

123

258 Synthese (2007) 159:253–270

has been demonstrated by its effect on the number of adults’ “remember” judgments in recallof events (Stöttinger et al. 2006; Stöttinger and Perner 2006). Free recall of experiencedevents correlated with performance on the How-do-you-know test (Wimmer et al. 1988a,b),the when-did-you-learn test (Taylor et al. 1994), and the modality-specificity test (O’Neill etal. 1992).

These results give some credence to the idea that children’s understanding of the source oftheir own knowledge relates to their growing ability for episodic remembering because thelatter depends on an encoding that the earlier perception of the event is causally responsiblefor one’s remembering the event now. However, some tasks tend to be more difficult forthe 4 to 6-year-old children (e.g., the modality-specificity test) and show the more reliablerelationship with episodic remembering than the easier tests (e.g., how-do-you-know test):a possible indication that understanding the causal relation between original experience andrecollective experience is not the most salient (at least not the only) factor in the develop-ment of episodic remembering. After discussing understanding of mental representation asanother possible factor we will conclude that it is the ability to combine this understandingwith introspection that is the most relevant factor for when episodic remembering develops.

2.2 Understanding mental representation

Our analysis of episodic remembering also showed that it incorporates the ability to under-stand the content of the recollective experience as representing the originally experiencedevent. A theory of mind test that assesses this ability is the false belief test (Wimmer andPerner 1983). It requires an understanding that a person’s mental misrepresentation of theworld governs the person’s behavior in the world. This ability also emerges at the same timeas understanding that physical signs can misrepresent (see Perner and Leekam, in press, forreview), which are both impaired in children with autism (Bowler et al. 2005). Naito (2003)and Perner, et al. (in press) included a version of this test in their ToM-battery. Children’sability to pass the test explained little in terms of episodic remembering in comparison to theother ToM measures assessing the causal understanding of children’s own perception andknowledge. However, Naito also used a version based on deceptive appearances, e.g., a pieceof sponge that looks like a rock ( Flavell et al. 1983), where children have to understand thata person just looking at the object will be misled into thinking it is a rock. Correlations offree recall with this test paralleled those with the modality-specificity test.

Apparently the understanding that a representation can be false and misleading, as testedby the traditional false belief test, is not a critical feature for the development of episodicremembering. As we have seen, the causal understanding about the origins of knowledgeseems somewhat more central but is also far from capturing the essentials, as we have seenin the above review. These results do, of course, not mean that these elements are not part ofepisodic remembering. They do suggest, however, that these factors are not the most criticalin the timing of the emergence of episodic remembering. The reason for this could be thatthe ability for episodic remembering does not develop incremental with acquisition of eachcomponent (understanding origins of knowledge and understanding representation) but isgiven its essential boost when the last necessary component develops. And there are signsthat the third component according to our analysis, introspection, is the last to be mastered.Moreover, the ToM tests that correlate best with the development of episodic rememberingare the modality-specificity test over several studies, and in Naito’s study the false belieftest with deceptive objects. And these tests may have an introspective flavor to them. Beforereturning to the link between theory of mind and episodic remembering, we briefly look atintrospection and how it differs from self-attribution of mental states.

123

Synthese (2007) 159:253–270 259

3 Introspection

We are not quite sure whether “introspection” is exactly the term we should use for whatwe have in mind,3 although the definition given by Wikipedia seems to capture it: 〈〈Intro-spection is like the activity described by Plato when he asked, “...why should we not calmlyand patiently review our own thoughts, and thoroughly examine and see what these appear-ances in us really are?” (Theaetetus, 155).〉〉 What seems important in this description is the“thoroughly, calmly, patiently.” Without these attributes, as Sydney Shoemaker points out,the awareness of our own thoughts may not count as intro-spection in the sense of innerperception: “In its broadest sense it refers to the non-inferential access … to … current men-tal states and events. … When … used in this broad sense it is an open question whetherintrospection is appropriately thought of as a kind of perception or observation, involving aninner sense.” (in Guttenplan 1994, p. 395). To make clear what more specific use we have inmind it is best to contrast introspection with perception, hypothetical thinking, imagination,and consciousness.

When we perceive something (i.e., an original experience of an event), e.g., the pictureof the spider being put into the box, what we see from our first-person perspective is simplythe event—nothing else. Perception is transparent: we see the perceived event, first of all,and not the way in which we perceive the event. Since we are talking phenomenology herewe presumably mean conscious perception (not like a blindsight patient’s way of havinginformation about the world through his visual senses).

In conscious perception of an event we are also typically aware of how we perceive theevent, i.e., that we saw the spider picture being put inside the box.4 But this awareness ofone’s mental states that comes with consciousness we do not yet want to call introspection.Introspection is more contemplative, observing what happens when one sees something. InRosenthal’s (2001) view it is one step up from conscious perception. Conscious perceptionrequires a second-order thought representing the perceived event as well as the first-orderstate of perceiving the event. Introspection requires a third-order thought that represents inaddition one’s second-order thought about one’s first order state of seeing. That third-orderthought, one could say, represents our preoccupation (the second-order thought) with our firstorder state of seeing, or in Plato’s words, the thorough examination of what the processesof seeing really are. Perhaps a most striking case would be experimentation with your eyes,noticing that the spatial relation (left-right) of two objects can change depending on whetheryou look at them with your left or right eye. This amounts to introspection in a very strongsense, i.e., observe the workings of our perceptual apparatus and mind, that goes beyondwhat we need for episodic remembering.

Imagination comes closer to what we have in mind. It involves a weaker sense of intro-spection because we do not observe the workings of our mind but only the products of ourmental activity. However, we need to distinguish within the realm of imagination the enter-taining of hypothetical thoughts from imagery: “Certain acts of imagination have a distinctivephenomenology which others do not. … to imagine that Scotland should be an independent

3 “The nature of introspection and sometimes even its existence are a subject of controversy, and so it isdifficult to provide a neutral account of it.” Noordhof p. 414 in Honderich 1995.4 In other words, it is impossible to conceive of an occasion where one could genuinely claim to be con-sciously aware of an event and at the same time remain completely in the dark as to whether one sees the event,hears the event, or dreams of the event. This connection between being consciously aware of an event andbeing conscious of one’s mental state with which one beholds the event is a cornerstone of the higher-orderthought theory of consciousness (Rosenthal 1986).

123

260 Synthese (2007) 159:253–270

country, one need not perform an act of the former sort, while one would do so in visualizingthe destruction of Houses of Parliament.” (Michael Martin p. 395 in Honderich 1995).

Hypothetical thinking is our term for those imaginations that do not involve imagery. Bothare cases of imagination and contrast with perception in that they are not bound by what is thecase. Their function permits breaking away from reality. The difference is that in hypotheticalreasoning we think of some state directly (transparently), e.g., Scotland is a free country,”and do not project any visual image of this state of affairs as in the case of visualizing thedestruction of a building.

Imaging scenes is the paradigm for our sort of introspection: “… mental images, thoseexercises of the imagination which correspond to our perceptual modalities. … According tothe picture theory of imagery, having a mental image consists of being aware of some mentalentity before the mind which represents the external scene imagined.”5 (Martin, p. 395 inHonderich 1995). In other words, one has the impression when imaging things and manip-ulating these images that one “looks” at these images with one’s “inner eye” (Hofstadterand Dennett 1981; Kosslyn 1980), that is: introspect. This makes imaging different fromhypothetical reasoning.

Remembering and Imaging share this kind of introspective aspect, because rememberingbrings up images (re-experiences) of the past that we can (have to) contemplate. The differ-ence between imaging and remembering, of course, is that we can image hypothetical sceneswhile we remember scenes that actually happened. The difference is not that imaging is avoluntary activity while remembering is passive. When solving a problem, e.g., the mentalrotation problems by Shepard and Metzler (1971) one has to put effort into constructing theimages and manipulating them. However, when we are day dreaming, pleasant images appearwithout any voluntary effort. Similarly in the case of memory: sometimes one has to try hardto remember something, at other times memories just invade our mind. The difference in thisrespect is more subtle. Images can be changed at will when day dreaming. While memoriescannot; they lose their authority if they are (in case of false memories they have been changedbut not consciously at will). In that sense memories are under the constraint to be intendedas truthful reflections of what actually happened, and are akin to imaging in the service ofproblem solving. For these images to serve their purpose they need to be kept intentionallyconstrained to the rules of reality.

In sum, imaging in the service of reasoning is most closely related to imaging in the serviceof episodic remembering. To exploit this fact for investigating the development of episodicremembering we need to investigate how the ability to reason with images develops.

3.1 Development of introspection

Flavell et al. (1995) expressly looked at children’s ability to introspect. For instance, theyprobed children’s self observation of intrusive thoughts. A group of 5 1/2 and 8 1/2-year-oldwere to sit in the special Don’t Think chair and they were instructed to not think for a while.After about 20 s they were allowed to move over to the normal chair and were asked: “Whileyou were sitting over there in that Don’t Think chair, you tried not to have any thoughts. Whathappened? Did you have no thoughts at all or did you have some thoughts anyway?” Very

5 Martin continues this entry: “Inasmuch as this provides an inner surrogate for the outer object of a mentalstate, this account parallels the sense-datum theory of perception. There is now almost universal hostility toboth views, not least because of the model of the mind they present: that of the subject surveying the mind’scontents as the sole audience within a private theatre.” We share this hostility for perception but do think thatit captures something of the phenomenology of imagery: there is some thing before one’s mind which is notthe thing imagined itself, as in the case of perception. We also would not want to claim that imagery amountsto “surveying the content of one’s mind.” Rather, imagery is a special way of creating a content in one’s mind.

123

Synthese (2007) 159:253–270 261

few 5-year-old (15%) but most 8-year-old (75%) and all adults admitted to the inevitable ofhaving had some thoughts. The emphasis in these studies is on children’s ability to becomeaware of the haphazardly floating, unintended contents of their thoughts but not their thoughtsin the service of reasoning.

More to the point for our concerns, Estes and Buchanan (1993; Estes 1998) investigatedthe development of mental rotation in 4, 5, 6-year-old, and adults following the same logicas the classic studies by Shepard and Metzler (1971) but using simpler stimuli than the com-plex block structures of the original studies. Children and adults had to judge whether twootherwise identical looking monkeys were lifting the same or a different arm. Reaction timeswere measured for different degrees of rotation of the monkeys in the picture plane (see Fig. 2for material using teddy bears in our replication). If the reaction times showed a significantpositive slope with degree of rotation the child (adult) was classified as “rotator.” Of the4-year-old only 35% used rotation, 41% of the 5- and 77% of the 6-year-old and 90% of theadults, respectively.

Fig. 2 Sample stimulus material for mental rotation task used by (Kloo and Perner (2006) modelled afterEstes (1998))

There is an interesting similarity and contrast with the false belief task. In both tasks, itcan be argued, one needs to understand that some mental content is used as a representationof the real world. In the false belief task one observes that the protagonist fails to witnessthe transfer of an object to a new location, therefore, mistakenly thinks that the object isstill in its original place. To predict where the protagonist will look for the object one hasto appreciate that he will be guided by his wrong belief about the world. Similarly, to usemental rotation one has to appreciate that the image of the object and how one manipulatesit mentally provides information about the imaged object. Then: Why is the false belief taskmastered considerably before mental rotation is used? The answer may lie with introspection.

There is no obvious sense in our adult phenomenology that we solve the false belief taskby forming a mental image of where the object is from the protagonist’s point of view andthen judge that he will look for the object in this place. We simply seem to know that whenthe protagonist doesn’t witness the transfer, for him, the object stays in its original loca-tion. Although this involves representing the object (counterfactually) in its old location andunderstanding that the protagonist’s action will be governed by that representation there isno image (experienced content) of the object’s location which we could inspect or introspect.

The reason for their being no image is not that we attribute the belief to a third person. Ifwe were asked what we would do under these circumstances we still would not form an imageof our mistaken belief. Also this kind of self-attribution of belief develops at the same time as

123

262 Synthese (2007) 159:253–270

attribution to third persons (Gopnik and Astington 1988). Bogdan (2005), however, correctlypoints out that some insights into one’s own mind, like the introspective abilities investigatedby Flavell et al. (1995) develop considerably later, and proposes that the real challenge ofself-ascription is what he calls “self-representingness,” i.e., grasping the “representationalrelations of one’s own attitudes” (p. 192). Our suggestion is to interpret self-representingnessas the ability to understand the perceived/experienced contents of our mind as representingsomething else. And this is exactly what is required for solving problems by mental rotationand for episodic remembering.

In mental rotation tasks one forms an image of the rotated object, one rotates the imageuntil it is parallel to the comparison object and then inspects whether the two images are iden-tical. Similarly in episodic remembering using an example given by Owens (1996, p. 320)underlining the similarity between experiential recall (his term for episodic remembering)and perception: “Suppose you attended the Mardi Gras yesterday and I now ask you howmany floats there were in the parade. You haven’t committed that fact to memory and mustreflect on what the parade was like—bringing to mind each of the floats … you can tell methat there were at least a dozen …, something you didn’t previously know. Here you learnhow many floats there were from your experience of the parade in much the same way asyou would have done had someone asked you to count them during the parade.” We wouldlike to add that there is a difference to perception: in perception one experiences the floatswhile in recall one experiences an image of the floats and one needs to understand of howthat image relates to actual floats.

4 Introspection and remembering

The argument developed so far is: episodic remembering requires introspective abilities as,e.g., involved in the use of mental rotation tasks. These introspective abilities develop between4 and 8 years. Hence we expect a developmental relationship between ability to introspectand episodic remembering.

Kloo and Perner (2006) and Rohwer (2006) subjected children in the age range of about5–8 years to the mental rotation task pioneered by Estes and Buchanan (1993) and measuredtheir episodic remembering. Kloo and Perner used the contrast between personally experi-enced events and indirectly conveyed information. Rohwer contrasted free versus cued recallof pictures, like in the earlier studies linking theory of mind development to episodic remem-bering. However, instead of using the usual theory of mind measures for these studies Rohwercorrelated measures of introspective ability (mental rotation) with episodic recall. For thisand all previous studies it is important to show that this correlation with episodic recall goesbeyond correlations with measures that rely less (e.g., cued recall) or not at all (e.g., recallof indirectly conveyed events) on episodic traces. Table 1 summarizes for all studies howmuch variance the ToM/Introspection measures can explain of free recall when controllingfor cued recall or recall of indirectly conveyed events.

The bottom part of this table shows that the ability to introspect on mental phenomena asrepresenting an external event correlates with measures of episodic remembering. The restgives a mixed picture on how children’s understanding of false beliefs and of the origins oftheir knowledge relates to episodic remembering. We can only speculate about the reasons forthese differences by arguing that the correlations are higher the more likely the task involvesan introspective element.

123

Synthese (2007) 159:253–270 263

Table 1 Summary of amount of variance in episodic remembering explained by theory-of-mind and intro-spective abilities when controlling for recall that does not rely (or less) on episodic remembering

ToM / IntrospectionMeasure of episodic remembering

Study ToM measure Proportion varianceexplained (r2)

ToMFree-cued recall

Perner and Ruffman (1995)E1 (n = 80 ) 3; 4–5; 6 Source of knowledge .13**

Know-guess distinction .29**E2 (n = 40) 3; 1–6; 8 Source of knowledge .07n.s.

Know-guess distinction .11*Modality-specificity (aspectuality) .14*

E3 (n = 64) 3; 1–6; 11 Modality-specificity (aspectuality) .15**

Naito (2003)E1 (n = 89) 3; 11–7; 7 FB-transfer .03 n.s.

FB-deceptive other .19*FB-deceptive self .17*When-learned (source errors unknown)a .27**Modality-specificity (aspectuality) .14*

Experienced-indirectly conveyedPerner et al. (in press)

E1 (n = 54) 3; 7–5; 11 FB-transfer .05 n.s.Source of knowledge .14**Modality specificity .20**

E2 (n = 38) 3; 9–6; 9 Source of knowledge .10*When-learned .09†Modality specificity .17**

Introspection Mental Rotation (RT-slope)Free-cued recallRohwer (2006, n = 59) 4; 9–8; 6 .09*experienced-indirectly conveyed

Kloo and Perner (2006, n = 31) 5; 0–6; 4 .21**

a Naito treated the when-know test by Taylor et al. (1994) not as a theory of mind test but as a source mem-ory test and correlated the number of source monitoring errors with free recall partialling out cued recall:“Cued recall was also used as a controlling factor whenever significant correlations involving free recall wereobserved, as used in the correlation analyses conducted by Perner and Ruffman (1995).” (Naito 2003, p. 236)† P ≤ .10; ∗ P ≤ .05; ∗∗ P ≤ .01

4.1 Post-hoc observations and speculations

To assess the question why some ToM/Introspection measures correlate better withepisodic remembering than others, Table 2 groups the different types of measures and givesthe range of percent variance accounted for by each measure over the different studies. Thereis naturally great variation. Nevertheless, one can distinguish measures—indicated in thelast column—that never accounted for any significant amount of variance (“nil”), those thataccounted for “some” variance of about 10% and those that accounted for around 15% andsometimes much more (“substantial”).

One way of trying to explain these differences is to look whether taking an introspectiveimaging approach helps on the task. If it does then getting a good score on the task willcorrelate more strongly with the episodic memory score than if such an approach does not

123

264 Synthese (2007) 159:253–270

Table 2 Ranges of partial correlations for each ToM/Introspection measure

ToM/introspection measure Number of Proportion variance explained Explanatory valueGeneral kind studies

Specific task Min Max

Source of knowledgeHow know 4 .07 .14 SomeWhen learned 2 .09 .276

Know/guess 2 .11 .29Modality specificity 5 .14 .20

⎫⎬

⎭Substantial

Mental representationFB-transfer 2 .03 .05 NilFB-deceptive 1 (self+other) .17 .19

IntrospectionMental rotation 2 .09 .21

⎫⎬

⎭Substantial

help. On the standard false belief task, where a false belief is engendered by an unwitnessed,unexpected transfer, imagining the protagonist’s experiences would help, but it is a fairlyinvolved process. One would have to imagine oneself as putting the object into the first loca-tion, being away (while the object is being transferred) and then asking oneself where onewould look for the object. This strategy seems rather involved and unlikely to be used bychildren and, at least in our personal phenomenology, we do not seem to use it either. How-ever, it could be that some children may try a simpler imaging technique by imagining thecurrent visible situation from the protagonist’s point of view, but that won’t yield an answersince the protagonist can’t see where the object is.

In contrast, in the deceptive false belief tasks an imaginative strategy seems more plau-sible. In Naito’s versions a false belief was created in the children themselves. They eitherlooked at the outside of a typical container (e.g., Smarties box) thinking that it containedwhat it usually contains and then they found out that the box had something else in it, orthey looked at a piece of sponge that deceptively looked like a rock, which made them thinkthat it was a rock, and later they were allowed to touch the object and find out that it was apiece of sponge. When subsequently asked, e.g., what they had originally thought was in thebox or to predict what someone else would think was in it, it seems more likely that somechildren may imagine the situation they had just gone through. Moreover, if they do so thesimpler strategy (unlike in the standard false belief task) of just imagining what the otherwill be looking at helps. Imagining looking at a Smarties box does suggest the thought thatSmarties are in it.

To the degree that these intuitions apply to children it explains why mastery of the decep-tive FB-tasks explained more of the variance of episodic remembering than mastery of thestandard false belief task. And it explains why the understanding that the mind can misrep-resent fails to correlate with episodic remembering in the standard task, where a plausibleintrospective strategy won’t help, but does correlate in the deceptive versions, where anintrospective strategy does help find the correct answer.

In the how-know task children, e.g., see or are told what is being put into a box. They thenknow what is in the box, but when asked how they know the younger children have problemsanswering. Performance on the task should relate to episodic remembering simply because

6 The high proportion of variance accounted for comes from Naito’s study taking source errors on previouslyunknown facts. Errors on previously known facts only accounted for 15% of episodic remembering (free recallcontrolled for cued recall). The 9% came from Perner & Ruffman’s study who did not distinguish betweenerrors on unknown and known facts.

123

Synthese (2007) 159:253–270 265

understanding the origins of knowledge is part of episodic remembering. But it is not theonly skill children have to bring to bear, as we have argued. Episodic remembering also needsan understanding of how the recollective, introspective experience relates to the actual eventin the past. This is not required and not even helpful in the how-know task. Although it isperfectly possible to imagine how one got to know the contents of the box, the image doesn’tgive the answer unless one knows which aspect of the image gives the answer. In sum, thehow-know task correlates with episodic remembering moderately because of its assessmentof the understanding of the origins of knowledge. The correlation remains moderate becausean introspective strategy, though possible, does not help find the answer but actually requiresthe answer as a prerequisite for knowing what to imagine.

In contrast, the when-learned, know-guess, and modularity-specificity test not only assessunderstanding of the origins of knowledge but are also helped by an introspective strategy.When asked in the when-learned task, whether they have known a particular fact about anitem yesterday, when they first encountered the item, it helps children to imagine by episod-ically remembering the situation and introspect whether they had known the fact then or not,i.e., the when-learned task correlates with episodic remembering because it is itself or cansuccessfully be treated as an episodic memory task.

In the know-guess test children, after correctly retrieving an object hidden in one of severalboxes, are asked whether they had known where the object was or had just guessed. Under-standing that knowledge originates in information about the object’s location but guessesdon’t help give the right answer. In addition, imagining the retrieval situation and introspecton whether one knew or didn’t know the location at that time will also help give the correctanswer.

Finally, in the modality-specificity task children have to decide how to find out about theweight or the colour of an object either by using their hand to lift or by looking at the object.Clearly if one knows about the modality specific origins of knowledge about weight andcolour then one can give the correct answer. However, if one doesn’t have that knowledgethen imagining what would happen if one looked at the object or lifted it by hand, wouldhelp one to find out whether, e.g., lifting the object would reveal its colour.

In sum, in all three tasks it helps to understand about the origins of knowledge and topursue an introspective strategy. Therefore, we suggest, it is for this reason that these taskscorrelate substantially with episodic remembering. To come to this conclusion we maderepeatedly use of the argument that in some tasks an introspective retrieval strategy is morehelpful than in other tasks. We now have a closer look of how retrieval strategies may affectour different measures of episodic remembering.

5 Retrieval

We have carried out three studies, where we used recall of experienced events and controllingfor recall of indirectly conveyed events as the measure of episodic remembering (see Table 1).In all three studies we found a puzzling pattern on recall of indirectly conveyed events. Weexpected that recall of experienced as well as indirectly conveyed events would improve (orat least stay stable) with ToM/Introspective competence (and age), except that the formershould increase much more strongly than the latter. Instead of the expected slower increasein the recall of indirectly conveyed events we observed repeatedly a decrease, as shown inFig. 3 (right hand column) in strong contrast to cued recall that improved with age (Fig. 3left column).

123

266 Synthese (2007) 159:253–270

Perner & Ruffman (1995, Exp. 3)

0

2

4

6

8

10

12

3 years 6 years(n = 12) (n = 15)

Age

etIs

mR

ecal

led

Free

Cued

Rohwer (2006)

0

2

4

6

8

10

12

No Yes(n = 32) (n = 27)

Mental Rotation Mental Rotation

Itm

eR

se

lac

led

Free

Cued

Kloo & Perner (2006)

0

1

2

3

4

5

6

No Yes(n = 19) (n = 12)

ExperiencedIndirect

To

M m

easu

res

Intr

osp

ecti

on

mea

sure

s

Perner, Kloo, & Gornik (2007, Exp. 1)

0

1

2

3

4

low medium high(n = 17) (n = 18) (n = 19)

Theory of mind Competence

etIm

sR

eca

elld

etIm

sR

eca

elld

Experienced

Indirect

Free - Cued Experienced - Indirect

Measure of Episodic Remembering

Fig. 3 Results for recall of experienced and indirectly conveyed events.

Why might children as they get older and better on ToM and introspection do worse onretrieving indirectly conveyed events? The answer may lie in the interaction of differentretrieval strategies at the disposal of the more advanced children. Tulving (1985) emphas-ised in his synergistic ecphory model of retrieval two different kinds of information that cancompensate for each other to obtain a particular level of recall. Semantic retrieval cues bringinformation back into consciousness without episodic remembering. In cued recall semanticretrieval is helped substantially by the many cues given. It is like finding the answer to manyquestions: e.g., “What was the animal presented?, What was the piece of furniture presented?... .” Each such question about a specific event helps bring forth another answer in the sameway as a question about a general fact, e.g., “What is the capital of Australia.”

In free recall there is but one cue given, that is, only one question can be asked: “What waspresented?” Consequently, reliance on semantic cue information will not yield very muchin free recall as compared to cued recall. That is why free recall depends more heavily thancued recall on episodic remembering for good performance. Episodic remembering works byimagining what happened at the time of presentation. And this imagining of the presentationhelps bring forth more and more items that have been presented. This process can, of coursealso be used in cued recall in addition to retrieval by cue information. In that case it canonly increase or, at the worst, not affect the amount recalled, but not decrease it. However,if episodic remembering is used instead of semantic cue information, it may actually reducethe amount recalled. For instance, if you know the capital of Australia and could retrieve itby association, you might ruin your success by concentrating on imagining all the large citiesyou’ve ever visited. In other words, an episodic retrieval strategy could suppress retrieval bysemantic cues and does not lead to the answer by itself.

Now let us assume that when children acquire the ability to episodically rememberthey will use that ability sometimes to the detriment of retrieval by semantic cues. What

123

Synthese (2007) 159:253–270 267

developmental pattern can we expect for cued and free recall? The children incapable of epi-sodic remembering will do much better on cued than free recall. The children able of episodicremembering will do much better on free recall than those not able to use this strategy. Buthow will these children do on cued recall? Under the assumption that episodic rememberingdoes not interfere with semantic retrieval we can predict that these children maintain the leadof cued over free recall at an overall higher level of recall. However, to the degree that anepisodic strategy detracts from semantic retrieval the lead of cued over free recall may getlost. Nevertheless, even if there is complete interference cued recall should not fall belowfree recall because even in the absence of any semantic retrieval will episodic retrieval yieldas many items in cued as in free recall. In line with these predictions the data (Fig. 3, left handcolumn: unfortunately only Perner and Ruffman (1995), for their experiment 3 and Rohwer(2006), report the necessary means) show that cued recall basically maintains its advantageover free recall, with the sign of a small loss in experiment 3 by Perner and Ruffman. Thisindicates that episodic retrieval does not, or only minimally, interfere with semantic retrieval.

The next question is what the developmental pattern is for free recall of experienced andindirectly informed events. For the children not yet able to use episodic remembering weexpect equal recall of experienced and indirectly informed events.7 We expect again that freerecall of experienced events will increase as children become able of episodic remembering.But how will these children fare on indirectly conveyed events? Under the assumption thatepisodic remembering does not interfere with semantic retrieval, recall by episodic retrieversof indirectly conveyed events will stay at the same level while recall of experienced eventswill be above the level achieved by the non-episodic rememberers. However, if episodicretrieval suppresses semantic retrieval then recall could fall to the very bottom, because epi-sodic retrieval is useless for retrieving indirectly conveyed events. That is, if in answer tothe question, “Which pictures did you put inside the box?” a child tries to retrieve indirectlyconveyed events by imagining how she put the cards into the box she will not get a singleanswer because her recollective experience will be of putting cards into the box on whichshe couldn’t see the picture because she was blindfolded. The data (see Fig. 3, right handcolumn) indicate some interference; recall of indirectly conveyed events tends to drop butnot completely to zero. In the light of the above analysis this drop makes sense because thequestion asked: Which pictures did you put into the box?” leads the children able of episodicremembering to use an episodic retrieval strategy which in the case of indirectly conveyedevents brings no success. In contrast, in cued recall each cue produces immediately an answerdue to semantic retrieval and only when no further answers are coming to the fore is onelikely to switch to a purely episodic retrieval strategy. Puzzle solved!-?

6 Conclusions

Our main objective was to show that episodic remembering (experiential recall) requiresthe particular introspective understanding that a first person recollective experience can rep-resent an earlier experienced event. The specifically important part of the argument is thecombination of introspecting on a mental image and understanding it as representing the

7 The data in all experiments using this measure of episodic remembering show an unexpected initial advan-tage of indirectly conveyed over experienced events (see Fig. 3). Reports from adult subjects in similarexperiments (Stöttinger 2006) suggest that this unexpected difference is due to the fact that for experiencedevents participants had to pay attention to the items on the card while inserting the card into a box. In contrast,full attention could be given to encoding the items on the cards for indirect events, because the inserting intothe box was done before the items were shown.

123

268 Synthese (2007) 159:253–270

event of which it is an image. This can explain why some theory-of-mind tasks form a closerdevelopmental relationship with episodic remembering than others. The prediction drawnfrom it that the use of mental rotation should also co-emerge with episodic remembering wasconfirmed. The coherence of these empirical results we like to see as support for an analysisof episodic remembering inspired by Lockean and Russellian views and their more recentversions proposed by Owens (1996), Martin (2001), and by analyses of self-attributions(Bogdan 2005). We see episodic remembering as a re-experience of an original experiencewherein an experienced image of the original event must be seen as a representation of thatevent.

Acknowledgements The work by Daniela Kloo and Elisabeth Stöttinger reported in this paper received finan-cial support from the Austrian Science Fund (FWF) Project P16215-GO4: “Episodic Memory and ConsciousExperience.” The first author expresses his gratitude to the Centre for Advanced Study in the BehavioralSciences, Stanford, CA, for the opportunity to collect his thoughts on this topic and gain new inspiration.

References

Baddeley, A. (2001). The concept of episodic memory. In A. Baddeley, M. Conway, & J. Aggleton (Eds.),Episodic memory: New directions in research (pp. 1–10). Oxford: Oxford University Press.

Bogdan, R. J. (2005). Why self-ascriptions are difficult and develop late. In B. F. Malle & S. D. Hodges(Eds.), Other minds. How humans bridge the divide between self and others (pp. 190–206). New York:The Guilford Press.

Bowler, D. M., Briskman, J., Gurvidi, N., & Fornells-Ambrojo, M. (2005). Understanding the mind or pre-dicting signal-dependent action? Performance of children with and without autism on analogues of thefalse-belief task. Journal of Cognition and Development, 6, 259–283.

Dokic, J. (1997). Two metarepresentational theories of episodic memory. Paper presented at the Annual Meet-ing of the ESPP in Padua, Italy August 1997.

Ebbinghaus, H. (1885). Über das Gedächtnis. Leipzig: Duncker und Humblot.Estes, D. (1998). Young children’s awareness of their mental activity: The case of mental rotation. Child

Development, 69, 1345–1360.Estes, D., & Buchanan, L. (1993). Mental rotation and metacognition in early childhood. Paper presented at

the biennial meeting of the Society for Research in Child Development, New Orleans, March 1993.Flavell, J. H., Flavell, E. R., & Green, F. L. (1983). Development of the appearance-reality distinction.

Cognitive Psychology, 15, 95–120.Flavell, J. H., Green, F. L., & Flavell, E. R. (1995). Young children’s knowledge about thinking. Monographs

of the Society for Research in Child Development, 60(1, Serial No. 243).Gopnik, A., & Graf, P. (1988). Knowing how you know: Young children’s ability to identify and remember

the sources of their beliefs. Child Development, 59, 1366–1371.Gopnik, A., & Astington, J. W. (1988). Children’s understanding of representational change and its relation to

the understanding of false belief and the appearance-reality distinction. Child Development, 59, 26–37.Hofstadter, D. R., & Dennett, D. C. (1981). The mind’s I. Fantasies and reflections on self and soul. New

York: Penguin Books.Kloo, D., & Perner, J. (2006). Unpublished data. Department of Psychology, University of Salzburg, Austria.Kosslyn, S. M. (1980). Image and mind. Cambridge, MA: Harvard university Press.Locke, J. (1975). Essay concerning human understanding. Edited with an introduction, critical apparatus and

glossary by P. H. Nidditsch. Oxford: Clarendon Press.Markowitsch, H. J., & Welzer, H. (2005). Das autobiographische Gedächtnis. Stuttgart: Klett-Cota.Martin, M. (1995). Imagination. In T. Honderich (Ed.), The Oxford companion to philosophy (p. 395). Oxford:

Oxford University Press.Martin, M. G. F. (2001). Out of the past: Episodic recall as retained acquaintance. In C. Hoerl & T. McCormack

(Eds.), Time and memory: Issues in philosophy and psychology (pp. 257–284). Oxford: Clarendon Press.Marvin, R. S., Greenberg, M. T., & Mossler, D. G. (1976). The early development of conceptual perspective

taking: Distinguishing among multiple perspectives. Child Development, 47, 511–514.Moll, H., & Tomasello, M. (2007). How 14- and 18-month-olds know what others have experienced.

Developmental Psychology, 43, 309–317.

123

Synthese (2007) 159:253–270 269

Mossler, D. G., Marvin, R. S., & Greenberg, M. T. (1976). Conceptual perspective taking in 2- to 6-year-oldchildren. Developmental Psychology, 12, 85–86.

Naito, M. (2003). The relationship between theory of mind and episodic memory: Evidence for the develop-ment of autonoetic consciousness. Journal of Experimental Child Psychology, 85, 312–336.

Noordhof, P. (1995). Introspection. In T. Honderich (Ed.), The Oxford companion to philosophy (pp. 414–415).Oxford: Oxford University Press.

O’Neill, D. K., Astington, J. W., & Flavell, J. H. (1992). Young children’s understanding of the role thatsensory experiences play in knowledge acquisition. Child Development, 63, 474–490.

O’Neill, D. K. (1996). Two-year-olds children’s sensitivity to a parent’s knowledge state when making requests.Child Development, 67, 659–677.

Owens, D. (1996). A Lockean theory of memory experience. Philosophy and Phenomenological Research,LVI, 319–332.

Perner, J., & Leekam, S. R. Taking the right direction in theory of mind: Understanding false signposts indevelopment, autism and brain imaging. Festschrift for Uta Frith. Quarterly Journal of ExperimentalPsychology (in press).

Perner, J., & Leekam, S. R. (in press). The curious incident of the photo that was accused of being false: Issuesof domain specificity in development, autism, and brain imaging—Festschrift for Uta Frith. QuarterlyJournal of Experimental Psychology.

Perner, J., & Ruffman, T. (1995). Episodic memory an autonoetic consciousness: Developmental evidence anda theory of childhood amnesia. Special issue: early memory. Journal of Experimental Child Psychology,59, 516–548.

Perner, J., Kloo, D., & Gornik, E. Episodic memory development: Theory of mind is part of re-experiencingexperienced events. Infant and Child Development (in press).

Pillow, B. H. (1989). Early understanding of perception as a source of knowledge. Journal of ExperimentalChild Psychology, 47, 116–129.

Povinelli, D. J., & deBlois, S. (1992). Young children’s (Homo sapiens) Understanding of knowledge formationin themselves and others. Journal of Comparative Psychology, 106, 228–238.

Pratt, C., & Bryant, P. (1990). Young children understand that looking leads to knowing (so long as they arelooking into a single barrel). Child Development, 61, 973–982.

Rohwer, M. (2006). Zusammenhang zwischen episodischem Gedächtnis und mentaler Rotation. DiplomaTheses, University of Salzburg.

Rosenthal, D. M. (1986). Two concepts of consciousness. Philosophical Studies, 49, 329–359.Rosenthal, D. M. (2001). Introspection and self-interpretation. Philosophical Topics, 28, 201–233.Searle, J. (1983). Intentionality, Cambridge: Cambridge University Press.Shepard, R. N., & Metzler, J. (1971). Mental rotation of three-dimensional objects. Science, 171, 701–703.Shoemaker, S. (1994). Introspection. In S. Guttenplan (Ed.), A companion to the philosophy of mind (pp. 395–

400). Oxford: Basil Blackwell.Sodian, B., Thoermer, C., & Dietrich, N. (2006). Two- to four-year-old children’s differentiation of knowing

and guessing in a non-verbal task. European Journal of Developmental Psychology, 3, 222–237.Sodian, B., & Wimmer, H. (1987). Children’s understanding of inference as a source of knowledge. Child

Development, 58, 424–433.Stöttinger, E., Kaiser, W., & Perner, J. (2006). Do remember-judgments reflect episodic memory as re-

experiencing events?, Unpublished manuscript, University of Salzburg.Stöttinger, E., & Perner, J. (2006). Dissociating size representation for action and for conscious judgment:

Grasping visual illusions without apparent obstacles. Consciousness and Cognition, 15, 269–284.Stöttinger, E. (2006). Episodisches Gedächtnis—Erinnern als wirkliches Wiedererleben. [Episodic Memory—

Remembering as real reexperiencing]. Unpublished Doctoral Dissertation, Department of Psychology,University of Salzburg, Austria.

Taylor, M., Esbensen, B., & Bennett, R. T. (1994). Children’s understanding of knowledge acquisition: Thetendency for children to report they have always known what they have just learned. Child Development,65, 1581–1604.

Tomasello, M., & Haberl, K. (2003). Understanding attention: 12- and 18-month-olds know what is new forother persons. Developmental Psychology, 39, 906–912.

Tulving, E. (1972). Episodic and semantic memory. In E. Tulving & W. Donaldson (Eds.), Organization ofmemory (pp. 381–403). New York: Plenum.

Tulving, E. (1985). Memory and consciousness. Canadian Psychology, 26, 1–12.Wheeler, M. A., Stuss, D. T., & Tulving, E. (1997). Toward a theory of episodic memory: The frontal lobes

and autonoetic consciousness. Psychological Bulletin, 121, 331–354.Wimmer, H., Hogrefe, J., Perner, J. (1988a). Children’s understanding of informational access as source of

knowledge. Child Development, 59, 386–396.

123

270 Synthese (2007) 159:253–270

Wimmer, H., Hogrefe, J., & Sodian, B. (1988b). A Second stage in children’s conception of mental life:Understanding sources of information. In J. W. Astington, P. L. Harris, & D. R. Olson (Eds.), Developingtheories of mind (pp. 173–192). New York: Cambridge University Press.

Wimmer, H., & Perner, J. (1983). Beliefs about beliefs: Representation and constraining function of wrongbeliefs in young children’s understanding of deception. Cognition, 13, 103–128.

123