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Is our inner voice our conscience?

Hélène Lœvenbruck
Hélène Lœvenbruck
CNRS Research Director and Head of the Language team at the Laboratory of Psychology and Neurocognition in Grenoble
Key takeaways
  • Self-awareness exists in two forms. It can be ‘minimal’, which we share with some non-human animals, or ‘elaborate’, maintained throughout time, and unique to humans with the notion of time.
  • Minimal self-awareness, consisting of pure perceptual experiences, without language, seems to exist in small infants. Elaborate self-awareness seems to be built upon it by bringing lexical and syntactic tools into play.
  • Through the practice of language, human beings create a sense of self extended over time. By inhibiting the production of overt language aloud, by internally simulating it, human beings can secretly develop their self-awareness.
  • Autobiographical memory can also be enhanced by endophasia, including the ability to evoke memories, recall a past event, by speaking internally.
  • In the first two years of life, autobiographical memories are virtually absent. It has been suggested that language development would allow the structuring of self knowledge.

I say to myself…

There­fore I am ?

Lan­guage allows us to com­mu­ni­cate our thoughts, emo­tions, and feel­ings to oth­ers – its com­mu­nica­tive func­tion is essen­tial. We speak with oth­ers, but we also speak to our­selves, inter­nal­ly, to think. Hence, lan­guage also has a cog­ni­tive func­tion, as Egypt­ian schol­ars, and Greek philoso­phers from Her­a­cli­tus to Aris­to­tle, via Pla­to, already knew. Lat­er, Descartes, in the Dis­course on Method1 revealed a third essen­tial func­tion of lan­guage – metacog­ni­tive – where­by the think­ing sub­ject is aware of itself: “I think, there­fore I am”, as he wrote.

Lan­guage has indeed a cru­cial role in self-aware­ness, which can be defined as the recog­ni­tion of one’s own exis­tence. But the Carte­sian notion of the self as a sta­ble and uni­fied sub­stance has been ques­tioned, as the self is depen­dent on sit­u­a­tions – it is in per­pet­u­al motion. Con­tem­po­rary reflec­tions in phi­los­o­phy, lin­guis­tics and cog­ni­tive sci­ences have made it pos­si­ble to put for­ward new ele­ments of response to this ques­tion of self-aware­ness. We can con­sid­er that it is built up through lan­guage, start­ing from a so-called “min­i­mal” or prim­i­tive self-con­scious­ness, shared with cer­tain non-human ani­mals2. The elab­o­rate self-con­scious­ness, and the men­tal posi­tion­ing in time, called auto­noet­ic con­scious­ness, is based on lan­guage and seems to be spe­cif­ic to human beings.

Language as an instrument of self-awareness

Min­i­mal self-aware­ness, con­sist­ing of pure per­cep­tu­al expe­ri­ences, with­out lan­guage, seems to exist in infants. Visu­al per­cep­tion and somat­ic pro­pri­o­cep­tion makes it pos­si­ble to asso­ciate the feel­ing of move­ment of one’s body with the obser­va­tion of one’s body in motion. In infants, it con­tributes to the expe­ri­ence of a dif­fer­en­ti­at­ed self, sit­u­at­ed in space, with a bound­ed body.

Elab­o­rate self-aware­ness is scaf­fold­ed on min­i­mal self- aware­ness and brings lex­i­cal and syn­tac­tic tools into play. The acqui­si­tion of pro­nouns by chil­dren, around the age of two, enables them to dif­fer­en­ti­ate between “I” and “you” or “mine” and “yours”. It indi­cates the con­scious emer­gence of the con­trast between the self and the oth­er. Then, with the increase in vocab­u­lary, demon­stra­tives, adverbs, and the use of verb tense, which all organ­ise spa­tial and tem­po­ral rela­tions, with the self as the ori­gin (“this, here, now, yes­ter­day, tomor­row”), chil­dren can bet­ter rep­re­sent them­selves and oth­ers. In this way, they can con­struct nar­ra­tives about past mem­o­ries and future intentions.

Through­out life, thanks to lan­guage, human beings cre­ate an iden­ti­ty, or rather an ipse­ity, a sense of “self” expand­ed over time. Thus, while lan­guage obvi­ous­ly enables inter-human com­mu­ni­ca­tion, its major role in thought and in auto­noet­ic con­scious­ness has favoured its inter­nal­i­sa­tion. By inhibit­ing the pro­duc­tion of overt lan­guage, by inter­nal­ly sim­u­lat­ing lan­guage, human beings can secret­ly devel­op their self-awareness.

Acti­va­tion of lan­guage and inhi­bi­tion brain regions dur­ing inner speech pro­duc­tion (Pro­jet ANR Inner­Speech 2014–18, Grand­champ et al., 2019)3

As we have shown at the Lab­o­ra­toire de Psy­cholo­gie et Neu­roCog­ni­tion in Greno­ble, in an fMRI neu­roimag­ing study, dur­ing the pro­duc­tion of inner speech, the brain regions of overt speech are acti­vat­ed, as well as regions of the pre­frontal cor­tex, involved in inhi­bi­tion4. The pos­si­bil­i­ty of inhibit­ing and speak­ing inter­nal­ly to one­self, what Georges Saint-Paul called in 1892 “endopha­sia”5, thus seems fun­da­men­tal. By talk­ing to our­selves to recall mem­o­ries, plan things, imag­ine oth­ers, or even to engage in self-cri­tique, we can cre­ate an extend­ed sense of self-aware­ness over time.

Endophasia: our inner language

The links between endopha­sia, or inner lan­guage, and mem­o­ry have been exten­sive­ly stud­ied by psy­cholin­guists. In par­tic­u­lar, inner lan­guage inter­acts with work­ing mem­o­ry, the short-term mem­o­ry that allows us to store and manip­u­late infor­ma­tion tem­porar­i­ly to accom­plish a task. To remem­ber a tele­phone num­ber or a code to dial, to remem­ber a shop­ping list, we can say them inter­nal­ly, in a loop. The inter­nal rep­e­ti­tion of the words to be remem­bered allows the infor­ma­tion to be tem­porar­i­ly held in mem­o­ry. This type of work­ing mem­o­ry is based on the sound of words. This can be ver­i­fied with an exper­i­ment that has been repli­cat­ed many times, in which par­tic­i­pants are asked to remem­ber a list of words6.

For exam­ple:

camp, foot, nail, floor, wall

Or :

bat, mat, hat, pat, cat

Words that are pro­nounced the same are like­ly to be con­fused, result­ing in poor­er recall of the sec­ond list than the first. This is known as the phono­log­i­cal sim­i­lar­i­ty effect, an effect that reveals that par­tic­i­pants use inner rep­e­ti­tion of words to retain them.

Auto­bi­o­graph­i­cal mem­o­ry can also be enhanced by endopha­sia. One can evoke mem­o­ries, recall a past event, by talk­ing to one­self inter­nal­ly. Auto­bi­o­graph­i­cal mem­o­ry is based on nar­ra­tive con­struc­tions that allow events to be organ­ised coher­ent­ly in time, and to be inscribed in a per­son­al his­to­ry. Research on the devel­op­ment of mem­o­ry in chil­dren indi­cates that in the first two years of life, auto­bi­o­graph­i­cal mem­o­ries are vir­tu­al­ly absent. It has been sug­gest­ed that lan­guage devel­op­ment that would lat­er allow the struc­tur­ing of self knowl­edge and the cre­ation of auto­bi­o­graph­i­cal mem­o­ries organ­ised in time.

Internal and external language: the chicken and the egg

When do chil­dren start talk­ing in their head? For the psy­chol­o­gist Vygot­s­ki7, inner speech is inher­it­ed from overt speech, via a grad­ual process of inter­nal­i­sa­tion that takes place dur­ing child­hood. Like Piaget before him, Vygot­s­ki observed that chil­dren begin by speak­ing aloud to them­selves. In this phase, which Vygot­s­ki called ‘pri­vate speech’, the child plays alone and repro­duces dia­logue sit­u­a­tions. Then, lit­tle by lit­tle, the child learns to inhib­it this behav­iour and inter­nalis­es it. Their pri­vate speech becomes their inter­nal lan­guage between the ages of five and seven.

Recent exper­i­men­tal psy­chol­o­gy stud­ies con­firm the hypoth­e­sis that the child can speak inter­nal­ly from this age. A clas­sic exper­i­ment uses the Tow­er of Hanoi game. If, while per­form­ing the task, chil­dren are pre­vent­ed from talk­ing to them­selves in their head, by hav­ing them repeat aloud “ba ba ba”, it is observed that their per­for­mance decreas­es. This sug­gests that the child uses inner speech for action plan­ning, as ear­ly as about five years8. It is more dif­fi­cult to know whether inner speech is used by chil­dren in such tasks at ear­li­er ages, as their reduced per­for­mance may sim­ply be relat­ed to dif­fi­cul­ties in con­cen­tra­tion or reasoning.

How­ev­er, some recent research, notably that led by Sharon Peperkamp in Paris9sug­gests that infants may be able to inter­nal­ly evoke the sound of cer­tain words as ear­ly as 20 months, before they are able to artic­u­late them aloud. The researchers from the Paris team pre­sent­ed 20-month-old infants with images of objects or ani­mals, fol­lowed by a voice nam­ing the image. They used both short (such as “cat”) and long (such as “banana”) words. After the pic­ture and sound were pre­sent­ed, the child saw two emp­ty box­es on the screen. Then the pic­ture filled in one of the box­es: the left box for short words and the right box for long words. This step was repeat­ed sev­er­al times until the infant under­stood the implic­it rule: short words on the left, long words on the right. After this famil­iari­sa­tion stage, the researchers pre­sent­ed a pic­ture with­out the sound, for exam­ple a tele­phone. They observed that the infants antic­i­pat­ed and looked to the right side even before the tele­phone filled the right-hand box. This exper­i­ment sug­gests that twen­ty-month-old infants can inter­nal­ly evoke the sound of words and thus cat­e­gorise words as mono- or tri-syl­lab­ic, while they are still unable to artic­u­late them aloud.

The devel­op­ment of cer­tain forms of inner lan­guage could thus pre­cede, or even be a deter­min­ing fac­tor in, the devel­op­ment of oral lan­guage. The ques­tion remains open. Do such exper­i­ments reveal auto­mat­ic asso­ci­a­tions between an image and a mnemon­ic sound trace, or are they evi­dence for actu­al inner speech production?

Interview by Pablo Andres

For more on the topic of inner language (or endophasia):

1René Descartes, Dis­cours de la méth­ode pour bien con­duire sa rai­son et chercher la vérité dans les sci­ences, plus la diop­trique, les météores et la géométrie, 1637. https://​gal​li​ca​.bnf​.fr/​a​r​k​:​/​1​2​1​4​8​/​b​d​6​t​5​3​7​2​3​4​8​5​/​f​9​.item
2Gor­don G. Gallup, « Chim­panzees: self-recog­ni­tion », Sci­ence, vol. 167, no 3914,‎ 2 jan­vi­er 1970, p. 86–87 (PMID 4982211, DOI 10.1126/science.167.3914.86).
4R. Grand­champ, L. Rapin, M. Per­rone-Bertolot­ti, C. Pichat, C. Haldin, E. Cousin, J.-P. Lachaux, M. Dohen, P. Per­ri­er, M. Gar­nier, M. Baciu et H. Lœven­bruck, « The Con­Di­alInt Mod­el: Con­den­sa­tion, Dialo­gal­i­ty, and Inten­tion­al­i­ty Dimen­sions of Inner Speech With­in a Hier­ar­chi­cal Pre­dic­tive Con­trol Frame­work », Fron­tiers in Psy­chol­o­gy, vol. 10, 2019.
5Georges Saint-Paul (1892), Essais sur le lan­gage intérieur, A. Stor­ck, Lyon.
6Con­rad, R. & Hull, A. J. [1964]. Infor­ma­tion, acoustic con­fu­sion and mem­o­ry span. British Jour­nal of Psy­chol­o­gy, 55, 429–432.
7Vygot­s­ki, L. S. (1934/1997), Pen­sée et lan­gage, Trad. française Françoise Sève. La Dis­pute, Paris.
8Lid­stone, J. S.; Meins, E. & Fer­ny­hough, C. (2010). The roles of pri­vate speech and inner speech in plan­ning dur­ing mid­dle child­hood: Evi­dence from a dual task par­a­digm. Jour­nal of Exper­i­men­tal Child Psy­chol­o­gy, 107, 438–451.
9Ngon, C. & Peperkamp, S. (2016). What infants know about the unsaid: Phono­log­i­cal cat­e­go­riza­tion in the absence of audi­to­ry input. Cog­ni­tion, 152, 53–60


Hélène Lœvenbruck

Hélène Lœvenbruck

CNRS Research Director and Head of the Language team at the Laboratory of Psychology and Neurocognition in Grenoble

Hélène Lœvenbruck is a CNRS research director and head of the Language team at the Laboratory of Psychology and NeuroCognition in Grenoble. As a neurolinguist, she uses an interdisciplinary approach to study three essential functions of language: the social function of communication, the cognitive function of thought elaboration, and the metacognitive function of self-consciousness in time. His work is in the field of verbal cybernetics and aims to describe the neurobiological mechanisms underlying the regulation of language production and reception, in its different manifestations: out loud and inside.

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