Auditory deficits Day 11

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Auditory deficitsDay 11

• Brain Language
• LING 411/412/489
• NSCI 411/611/489/689
• Harry Howard
• Tulane University

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Q3
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Q3 answers

• A phonological feature is a representation of (a)
  the articulation of a speech sound, (b) the
  perception of a speech sound, or (c) both (a) and
  (b).
• A formant is part of the acoustic properties of a
  (a) consonant or (b) vowel.
• The fundamental frequency is NOT (a) the basic
  frequency of the human voice that all others are
  built on, (b) the lowest band of energy in a
  vowel, or (c) higher on average in women than
  men.
• Which is NOT a feature of vowels (a) manner, (b)
  height, or (c) advancement (front/back)?
• Which is NOT a feature of consonants (a) place,
  (b) rounding, or (c) voicing?

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Q3 answers, cont.

• Would you call the following model of speech
  comprehension (a) serial or (b) parallel?
  acoustic-phonetic analysis sub-lexical
  processing lexical-semantic access
  comprehension
• The flaw in the model in (6) claimed by Hickok
  Poeppel (2004) is that (a) sub-lexical processing
  acoustic-phonetic analysis, (b) there are
  patients who cannot perform sub-lexical
  processing tasks accurately, yet have normal
  comprehension, or (c) there are patients who
  cannot perform acoustic-phonetic analysis
  accurately and have abnormal comprehension.
• We would expect to be in the ventral stream (a)
  the interface between sound and meaning, (b) the
  interface between sound and motor control, or (c)
  the basic sound codes.
• We would expect to be in the dorsal stream (a)
  the interface between sound and meaning, (b) the
  interface between sound and motor control, or (c)
  the basic sound codes.
• A double dissociation involves (a) a group of
  subjects that performs inaccurately on task A but
  not task B, (b) one group of subjects that
  performs inaccurately on task A but not on task B
  and another group of subjects that performs
  inaccurately on task B but not on task A, or (c)
  a group of subjects that performs inaccurately on
  both tasks A and B.

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Course administration

• Course home page
• http//www.tulane.edu/ling/LING411/
• Readings are found
• MyTulane BrainLanguage_CC Brain and
  Language(Combined) Course Documents
• Public Service tasks

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Polster Rose (1998)
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Abstract

• This article examines four disorders of auditory
  processing that can result from selective brain
  damage in an effort to derive a plausible
  functional and neuroanatomical model of audition.
  
• The article begins by identifying three possible
  reasons why models of auditory processing have
  been slower to emerge than models of visual
  processing
• The four auditory disorders are then reviewed and
  current theories of auditory processing
  considered.
• Taken together, these disorders suggest a modular
  architecture analogous to models of visual
  processing that have been derived from studying
  neurological patients.

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Four disorders of auditory processing

• Cortical deafness
• Pure word deafness
• Auditory agnosia
• Phonagnosia

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Reasons for delay in development of models of
auditory processing

• Neuroanatomical differences between the visual
  and auditory systems
• the auditory system has a neuroanatomical
  redundancy built into it it transmits
  information about sound in all parts of space to
  both hemispheres, rather than to one
• result disorders of auditory processing are
  quite rare
• dichotic listening tasks are less informative
  than visual-half field presentation
• diagnostic difficulty caused by the close
  relationship between speech comprehension and
  auditory processing
• Terminological confusions relating to auditory
  processing disorders
• verbal processing can conflated with auditory
  processing
• Technical factors that have made auditory stimuli
  more difficult to study than visual stimuli

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Cortical deafness

• Wernicke and Friedlander (1883) described a
  patient who was unable to hear any sounds, but
  had no apparent damage to the hearing apparatus
  and labelled the disorder cortical deafness.
• One review of the literature, reported only 12
  cases of significant deafness due to purely
  cerebral pathology (Graham, Greenwood Lecky,
  198043)
• Identifying cases of cortical deafness has proved
  to be difficult for several reasons.
• patients rarely suffer bilateral lesions in the
  critical region of auditory cortex in the lateral
  temporal lobes
• some patients believed to suffer from cortical
  deafness may, in fact, suffer from auditory
  inattention or neglect
• cortical deafness is often transient, resolving
  to a less severe, or more specific, auditory
  processing disorder such as pure word deafness or
  auditory agnosia

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Agnosia overview

• Agnosia an impairment in which a patient fails
  to recognize a stimulus in a sensory modality,
  although perception in the modality is unimpaired
• Audition
• auditory agnosia
• pure word deafness (auditory-verbal agnosia)
• phonagnosia
• Vision
• visual agnosia normal vision, cant recognize
  objects
• alexia (word blindness) normal vision, cant
  recognize written language, i.e. cant read
• prosopagnosia

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Auditory agnosia

• It is best defined as an inability to recognize
  auditorily presented sounds independent of any
  deficit in processing spoken language.
• at times, it has been replaced by a more general
  definition refering to a deficit involving any
  type of auditory stimuli
• It dates back to Freud (1891), but the first case
  of pure auditory agnosia appears to have been
  reported only thirty years ago (Spreen et al.,
  1965).
• They presented a patient who was severely
  impaired at identifying a variety of sounds such
  as coughing, whistling and a baby crying, but
  showed no evidence of impaired speech
  comprehension

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Pure word deafnessauditory-verbal agnosia

• Kussmaul (1877) coined the term pure word
  deafness to refer to an inability to comprehend
  spoken words despite intact hearing, speech
  production and reading ability.
• one patient complained that speech sounded like
  a great noise all the time . . . like a
  gramophone, boom, boom, boom, jumbled together
  like foreign folks speaking in the distance
• another said I can hear you talking but I cant
  translate it
• Examiner What did you eat for breakfast?
• Patient Breakfast, breakfast, it sounds familiar
  but it doesnt speak to me. (Obler Gjerlow
  199945)
• The experience of word sounds appears to undergo
  a qualitative change, and some word deaf patients
  cannot judge the length of a word
• However, some patients appear able to extract
  information about the speaker from their voice
  (i.e., sex, age, region of origin, or affective
  information) despite being unable to comprehend
  the spoken message
• Despite this impairment in speech comprehension,
  these patients can be unimpaired at identifying
  non-linguistic sounds

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Phonagnosia

• An impairment in the ability to recognize
  familiar voices, just as prosopagnosia reflects
  an impairment in the ability to recognize
  familiar faces (Van Lancker and Canter 1982)
• subjects were asked to identify which of four
  names or faces matched a particular famous voice
• Subsequent research produced evidence for a
  double dissociation between memory for familiar
  voices and the ability to discriminate between
  unfamiliar voices
• One group of patients performed normally on the
  discrimination task but was impaired on the
  memory task,
• whereas another group of patients performed
  normally on the memory task, but was impaired on
  the discrimination task
• Despite being unable to identify voices, patients
  suffering from phonagnosia appear to be able to
  understand speech and identify nonverbal sounds
  (Van Lancker and Kreiman, 1987).

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Summary
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Optic aphasia

• A patient CANNOT name an object presented
  visually,
• but the patient CAN
• name the object from a verbal description
• describe the function of the object
• sort pictures of objects into categories
• so it is not visual agnosia.
• Cause impairment of pathway from visual object
  perception to semantic representation
• the objects semantic representation can be
  activated only enough for basic tasks, such as
  sorting, but not enough for naming

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Next time

• Lateralization of phonology - Myers 4