Language DevelopmentLecture Notes: 12/9/14Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history:● Deficits in social-emotional reciprocity, ranging from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions● Deficits in nonverbal communicative behaviors used for social interaction, ranging from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication● Deficits in developing, maintaining, and understanding relationships, ranging from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers.Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently of by history:● Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypies, lining up toys or flipping objects, idiosyncratic phrases).● Insistence on sameness, inflexible adherence to routines, or ritualized patterns or verbal/nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat same food every day).● Highly restricted, fixated interests that are abnormal in intensity or focus (e.g., strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interest).● Hyper- or hypo-reactivity to sensory input or unusual interests in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement)Early Signs of Autism● Lack of mutual eye gaze● Lack of joint reference and joint attention● Lack of turn-taking in “baby games”● Lack of response to own name● Inappropriate facial expressions● Lack of pointing● Lack of babbling● Lack of overt emotional attachmentPrevalence of Autism● Prior to 1990s: Prevalence of ASD is 0.4-0.5/1,000 (i.e., 0.05%)○ An extremely rare disorderWhy sudden increase in Autism dx?● Better diagnostic criteria?○ E.g., as dx of autism increased, diagnosis of intellectual deficits decreased proportionately● Widened category of autism?● Increased awareness?Effects of Autism on Language● Early differences in intentional communication○ Lack of joint attention○ Less responsive to human voices● A substantial proportion of individuals with autism never develop spoken language● Nonverbal communication (e.g., gestures) is also often lacking● Often leads to tantrums, screaming, and other inappropriate behaviors (hitting, spitting, biting, etc.)Language in Verbal Children with ASD● Echolalia = repetition of another person’s utterance○ Not contributing any content but still allows them to have a turn● May actually have communicative intent● May signify a positive prognosis for language dvtLanguage in Verbal Children with ASD● Phonology: noticeable prosodic deficits● Vocabulary: esp. difficulty with emotion words and mental-state words; restricted use; idiosyncratic patterns of word-use● Grammar: shorter sentences; inappropriate word order; pronoun reversal (e.g. I for you).● Impaired pragmatics is the hallmark○ Lack of topic initiation and maintenance; lack of conversational repair skills; generally inappropriate speech; limited turn-taking○ Language is often not directed at or responsive to other peopleTheory of Mind● Ability of children to take the perspectives of others so that they can understand that other people have intentions, knowledge, and beliefs that may differ from their own● This ability is necessary for explaining and predicting other people’s behavior● Emerges around 3-4 yrs ● Includes joint attention, intentionality, ability to understand other people’s perspectives, use of mental/state words, and pretend play● Tested using appearance-reality tasks and false belief tasks● Language performance predicts TOM performance● Children on the spectrum perform less well on TOM tasks than TD children and than children with other developmental disabilitiesCauses of Autism: Early Ideas● “Refrigerator Mothers” theory (1940s): a psychoanalytic view that attributes autism to cold mothers and their inability to bond with the baby○ Has been rejected● Other suspected factors:○ MMR (measles, mumps, and rubella) vaccine and Thimerosal (no evidence for this)○ Diet○ ToxinsThe Real Causes of Autism● Genes○ X-linked: Substantially more boys that girls (4:1) are diagnosed with autism○ Increased risk of dx in siblings○ But specific mechanisms are not yet clear; may be heterogeneous and polygenic● Neurophysiology○ Abnormal pattern of head growth○ Increased volume in several cortical areas○ Elevated levels of the neurotransmitter serotonin● Latest○ Combination of faulty DNA and something in the environment after the child’s birth causes autism○ The mutations disrupt genes which are turned on and off by activity of neurons that are stimulated by early