Editorial - ‘Language, Conceptual Development, and the Essence of Human Cognition’ Questions: Trends in Cognitive Sciences , Is language the key to reasoning? July 2004 - 667 words Evidence from deafness, aphasia and autism Language & spatial relations? Relationship between language and the origin and Language & numerical computations? Michael Siegal development of concepts University of Sheffield, UK Language & causality? University of Trieste, Italy Became ‘Language and Conceptual Development’ ‘essence’ lost But what do we mean by language? Language & the concept of belief? How do children come to represent Is it in the form of the grammar of language The ‘Sally-Anne’ theory of mind task that allows a structure that permits us to think beliefs as false? through propositions If dependent on language, when might or we see these effects and in what form? Does this consist of conversational pragmatics - understanding the purpose and relevance of questions? ‘THEORY OF MIND’ FALSE BELIEF TASKS (Siegal & Beattie, Cognition, 1991; Yazdi, German, Defeyer, & Siegal, RESULTS: However, children may believe that the test question Cognition, 2006) refers to where Sally has to look, or should look, for Children are told a story such as: Children aged 3 years often answer the standard the object rather where will Sally look first (in a test of Sam has a kitten. Sam wants to find his kitten. Sam question incorrectly but generally succeed on thinks it is in the lounge. It really is in the kitchen. their understanding of false beliefs). the look first question. 1. Where will Sam look for his kitten? (standard Most 4-year-olds succeed on both questions. question) 2. Where will Sam look first for his kitten? (look first question)
On ‘standard’ ToM tasks, children may However, according to the view that has often been misunderstand the experimenter’s intention. One specific claim is that syntax permits humans to expressed on the link between language and ToM, entertain false beliefs and to reason out solutions to They may think that the relevance and purpose of language provides a structure that “scaffolds” ToM tasks. the question is to indicate where the story character should look, or must look, to find the object rather propositional reasoning about mental states. than where will the story character look first. Two types of tests of the effects of Two main groups of deaf children language on reasoning: grammar vs. timing of language • Native signing deaf exposure • Late signing deaf Deaf children who have different exposure to Deaf children born to Deaf children born to conversation but have similar proficiency in the deaf parents, receive hearing parents, receive grammar of their sign language sign language input no early sign language from birth input Persons with RHD with impaired conversational Access to Little access to understanding but retain grammar and persons with conversation conversation aphasia following damage to LH language areas
ToM scores of native and late signers Controlled for BSL (from Woolfe, Want, & Siegal, Child Dev., 2002) Signposts to the essence of language (Siegal, Science, 2004) Senghas et al., 2004: Examples of gestures Senghas et al. findings challenge the notion that accompanying videos language evolves through cultural transmission. shown to Nicaraguan deaf and hearing Spanish speakers
Same pattern of ToM findings in Nicaragua for the For example, de Villiers and de Villiers have deaf as for the deaf tested in England, Australia, the proposed that proficiency in syntax, as shown by US, France, Sweden and other countries. sentence complementation , has a decisive role But how about the role of grammar? in supporting ToM reasoning in that the What specific prediction can be made? grammar of natural language provides a code Younger cohorts of deaf children with earlier access through which one proposition (false) can be to a sign language outperform the first older cohort embedded within another (e.g., understanding with later access. Other areas of cognitive sentences such as “John thought (falsely) that development (such as number) are yet to be tested. the cookies were in the cupboard”). No direct test here of the specific syntax of 3. There are some languages - both sign and spoken - complementation hypothesis. However, it is clear 2. Moreover, children solve ‘pretense’ tasks that in which complementation structure does not that proficiency in grammar does not guarantee require understanding of sentence exist: These use "clausal adjuncts" rather than success on ToM tasks for these reasons: complementation - tasks that have the same clausal complements so that (a) below can't be structure as ToM tasks except that the story used. Instead, there is (b): 1. Normal 3-year-olds spontaneously produce (a) John told everyone that Mary washed the car. character is said to pretend, rather than to sentences that involve the syntax of (b) Mary having washed the car, John told think, that an object is in a (false) location. complementation before they succeed on standard everyone (it). ToM tasks. Is there a double dissociation? Do patients with 4. ToM and causal reasoning is present in the RH damage can result in impairment in ToM damage to LH language areas retain proficiency absence of grammar (Varley, Siegal, & Want, reasoning that is supported by conversational on ToM reasoning tasks even though they have TICS, 2001) pragmatics and co-opted systems involving visuo- become agrammatic? spatial processing. Yet grammar in RHD patients is spared (Surian & Siegal, Brain and Language, 2001). CASE STUDY OF SA (Varley & Siegal, Current Biology, 2000; Siegal & Varley, Social Neuroscience, 2006)
� SA was a 50 year old right-handed male who was a SA Scan retired police sergeant. Four years prior to our study, SA is very unusual . He became an agrammatical aphasic without any explicit sign of possessing he became suddenly aphasic. • Sub-dural empyema left grammar in the form of propositional language. sylvian fissure The neurological examination revealed the presence • Vessel wall damage left of a subdural empyema (a focal bacterial infection) in middle cerebral artery • Large temporal lobe the left sylvian fissure, with accompanying lesion, extending meningitis. posterior frontal and inferior parietal zones Theory of Mind: SA In describing pictures, SA would use word strings such as: Standard format first-order false belief task (Smarties/changed container) Woman a age the red scissor Trained on predicates ‘think’ ‘is really’ A asia as man as black a shoes However, SA can do causal reasoning and ToM tasks. SA’s performance on ToM tasks ToM in MR (Varley et al., Neurocase, 2001) Recognising the false belief that a book really contains a Another patient with aphasia, MR, also necklace Picture format first-order provides evidence for the double false-belief task Trained on predicates ‘think’ dissociation between grammar and ToM Recognising the true belief and ‘is really’ that a Russian doll contains four other dolls. 10 trials on false-belief and true-belief pictures 20/20 correct on both FB/TB and reality questions Recognising the true belief that a box of tissues actually contains tissues.
Language and the development Late signing deaf children do well on measures of EF and maintenance of ToM Performance on ToM tasks is not simply a matter of but do poorly on ToM reasoning tasks. executive functioning - Evidence from both aphasia and deafness rejects the claim that, in ToM and causal reasoning, natural Following brain damage, some persons do well on language grammar instantiates thinking and a cluster of higher order capacities that include: ToM but do poorly on measures of EF - reasoning. • selective attention Aphasia: Varley et al., Neurocase, 2001 However, both SA and MR had considerable lexical Medial frontal lobe damage: Bird et al., Brain, 2004 • behavioural planning and response inhibition, knowledge still available, and exploration of the • the manipulation of information in problem-solving. role of the lexicon versus grammar in various cognitive domains is necessary. Syntax and executive functioning may be seen as Conversational experience serves as a gateway ‘co-opted systems’ that support ToM performance to others’ beliefs. It alerts children that speakers In at least in the ToM case, immersion in in normal children and adults. are epistemic subjects who store and seek to conversation - and not simply exposure to the syntax provide information about the world and, in of language - is a spur for development. doing so, allows access to a world of referents Despite impairments in syntax and on EF measures, and propositions about intangible objects, there is success on pictorial ToM tasks that do not creating the potential for imagining the past and involve syntax and on ‘look first’ tasks. future In the case of ToM, there may be a sensitive, “Look first” test questions do help normally However, “look first questions” do not help optimal, or critical period in which some minimal developing children as well as adult patients with either the late signing deaf or children with exposure to conversation is necessary to ‘trigger’ or right hemisphere damage to succeed on ToM tasks autism (with possible damage to the OFC- ‘tune’ development. This position is parallel to amygdala system that may be viewed as “core” recent findings in language acquisition more generally. neural substrate to ToM).
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