PALPA To PALPA or not to PALPA

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PALPATo PALPA or not to PALPA?

• Nick Joy, Marina Raytsina,
• Seon Yun Nate Wight

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Introduction

• What is PALPA?
• Psycholinguistic Assessments of Language
  Processing in Aphasia (PALPA)
• Assessment of language processing skills in
  individuals with Aphasia that examines
• Recognition
• Comprehension
• Production
• A psycholinguistic approach to the interpretation
  of processes in spoken and written words and
  sentences.
• Who is it used by?
• Speech and language therapists
• Cognitive and clinical neuropsychologists
• Population of Interest
• Individuals with Aphasia, an acquired language
  disorder resulting from damage to the areas in
  the brain responsible for language.

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Introduction

• Goals
• To identify functional and dysfunctional modules
  in the aphasic person.
• To provide a basis for developing a treatment
  program.

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Theoretical Framework

• Based on the assumption that the minds language
  system is organized in separate modules of
  processing, and that these can be impaired
  selectively by brain damage.
• The model is depicted as boxes and arrows
• Boxes have two types of function ?
• Repositors of information
• Processors of information
• Arrows allow communication between the boxes
• Exactly how these channels of communication might
  work is something about which little is known
  (Kay et al. 1992)

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In the beginning
(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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(Kay, Lesser, and Coltheart, 1992)
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Reading aloud
(Kay, Lesser, and Coltheart, 1992)
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Auditory Processing
(Kay, Lesser, and Coltheart, 1992)
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Writing Spelling
(Kay, Lesser, and Coltheart, 1992)
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Picture and Word Semantics
(Kay, Lesser, and Coltheart, 1992)
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Theoretical Framework

• This model allows the investigator (researcher /
  clinician) to pinpoint precisely, by a process of
  hypothesis testing, which modules of the system
  may be impaired and what remains relatively
  preserved. (Kay Terry, 2004)

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Assessment

• PALPA is not designed to be given in its entirety
  to an individual
• Assessments should be tailored to the clinicians
  hypothesis about the nature of the language
  impairment.
• The test makers suggest beginning at Picture and
  Word Semantics Subtest 47- Spoken Word Picture
  Matching if the clinician is unable to formulate
  a specific hypothesis.
• The test makers do not provide a rationale for
  this suggestion.
• At the end of each subtest, the test makers
  provide suggestions as to where to go next
  depending on the subjects performance on the
  subtest.
• PALPA does not specify which treatment program
  should be carried out rather its aim is to
  provide a firm grounding for an understanding of
  a particular processing disorder for which any
  treatment program must be based.

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Assessment

• PALPAs 60 subtests are divided into four
  sections
• Auditory processing
• Reading and spelling
• Picture and word semantics
• Sentence comprehension

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Auditory Processing

• Includes 17 subtests assessing the following
• Nonword minimal pairs
• Word minimal pairs
• Word Minimal Pairs Requiring Written Selection
• Word Minimal Pairs Requiring Picture Selection
• Auditory Lexical Decision Imageability x
  Frequency
• Auditory Lexical Decision Morphological Endings
• Repetition Syllable Length
• Repetition Nonwords
• Repetition Imageability x Frequency
• Repetition Grammatical Class
• Repetition Morphological Endings
• Repetition Sentences
• Digit Production/Matching Span
• Rhyme Judgments x Pictures
• Rhyme Judgments x Words
• Phonological Segmentation Initial Sounds
• Phonological Segmentation Final Sounds

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Auditory Processing

• Subtest 4 Minimal Pair Discrimination
  Requiring Picture Selection
• Assesses patients ability to match a single
  heard word with corresponding picture
• Design
• All words are monosyllabic with a CVC structure
• Task is designed for use in conjunction with
  other Minimal Pair Tasks
• Target and distractors are either minimally
  different, or two or more distinctive features
  different.
• Special Points
• For any test using picture materials, check
  beforehand that picture processing abilities are
  not impaired.
• Instructions to Subject
• Im going to say a word. Look at these three
  pictures. Point to the picture that matches it.
• Criticism
• Test requires segmentation of a phoneme from a
  heard word and a match to picture materials.
  Difficulties have been cited due to
  interpretation of the picture materials.

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Auditory Processing- Picture Example
(Kay, Lesser, and Coltheart, 1992)
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Reading and Spelling

• Includes 29 subtests assessing the following
• 18. Letter Discrimination Mirror Reversal
• Letter Discrimination Upper-Lower Case Matching
• Letter Discrimination Lower-Upper Case Matching
• Letter Discrimination Words Nonwords
• Letter Naming Sounding
• Spoken Letter- Written Letter Matching
• Visual Lexicon Decision Legality
• Visual Lexicon Decision Imageability x Frequency
• Visual Lexicon Decision Morphological Endings
• Visual Lexicon Decision Regularity
• Homophone Decision
• Oral Reading Letter Length
• Oral Reading Syllable Length
• Oral Reading Imageability x Frequency
• Oral Reading Grammatical Class

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Reading and Spelling

• 33. Oral Reading Grammatical Class x
  Imageability
• 34. Morphological Endings
• 35. Oral Reading Regularity
• 36. Oral Reading Nonwords
• 37. Oral Reading Sentences
• 38. Homophone Definition x Regularity
• 39. Spelling to Dication Letter Length
• 40. Spelling to Dication Imageability x
  Frequency
• 41. Spelling to Dication Grammatical Class
• 42. Spelling to Dication Grammatical Class x
  Imageability
• 43. Spelling to Dication Morphological Endings
• 44. Spelling to Dication Regularity
• 45. Spelling to Dication Nonwords
• 46. Spelling to Dication Disambiguated
  Homophones

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Reading and Spelling

• Subtest 45 Spelling to Dictation Non-words
• Assesses spelling and auditory processing
• Task requires non-words to be written to
  dictation monosyllabic words that vary in
  letter length from 3-6 letters
• Special points
• Pre-morbid spelling ability
• Patient understands that words to be spelled are
  not real words
• Any acceptable spelling ( based on existing
  sound-spelling correspondence) should be counted.

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Reading and Spelling- Picture Example
(Kay, Lesser, and Coltheart, 1992)
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Picture Word Semantics

• Includes 8 subtests assessing the following
• Spoken Word Picture Matching
• Written Word Picture Matching
• Auditory Synonym Judgments
• Written Synonym Judgments
• Word Semantic Association
• Spoken Word- Written Word Matching
• Picture Naming x Written Naming/ Repetition/ Oral
  Reading/ Written Spelling
• Picture Naming and Frequency

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Picture Word Semantics Subtest 47 spoken
word-picture matching

• Uses spoken word-pictures to assess semantic
  comprehension skills of words
• e.g. target carrot
• Four pictures are used as distractors
• Close semantic distractor (e.g. cabbage)
• Errors suggest a high level semantic impairment
• Distant semantic distractor (e.g. lemon)
• Errors suggest a more widespread semantic deficit
• Visually related distractors (e.g. saw)
• Errors suggest the possibility of a perceptual
  component to the deficit
• Visually unrelated distractors (e.g. chisel)
• Related semantically to each other to prevent the
  subject from making guesses based on their
  percieved semantic category

(Kay, Lesser, and Coltheart, 1992)
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Picture Word Semantics- Picture Example
(Kay, Lesser, and Coltheart, 1992)
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Sentence Comprehension

• Includes 6 subtests assessing the following
• Auditory Sentence Comprehension
• Written Sentence Comprehension
• Auditory Comprehension of Verbs Adjectives from
  the Sentence Set
• Auditory Comprehension of Locative Relations
• Written Comprehension of Locative Relations
• Pointing Span for Noun-Verb Sequences

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Sentence Comprehension

• Subtest 56 Written Sentence Comprehension
• Assesses patients comprehension of written
  sentences by matching sentences to pictures.
• Types of Sentences Examined
• Reversible and Non-reversible
• Reversible The dog is approaching the girl.
• Non-reversible The dog is washed by the girl.
• Active and Passive
• Active The cat is licking the man.
• Passive The horse is moved by the man.
• Directional and Non-directional
• Directional The man is following the dog.
• Non-directional The horse is kicking the man.
• Gapped sentences
• Gapped sentence The man is demonstrating what to
  do.
• Sentence comprehension is not accounted for in
  theoretical model.

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Sentence Comprehension- Picture Example
(Kay, Lesser, and Coltheart, 1992)
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Validity and Reliability

• PALPA does not demonstrate validity or
  reliability (Wertz, 1996).
• Cole-Virtue and Nickels (2004) found that there
  are a number of variables within the Spoken
  Word-Picture Matching subtest whose possible
  effects have not been adequately considered in
  the test design diminishing the internal validity
  of this particular subtest.
• Some researchers have recently questioned whether
  psychometric concepts such as validity and
  reliability should be applied to certain ways of
  investigating cognitive impairment (Bates et al.
  as cited by Kay et al, 1996).

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Standardization

• Not fully standardized.
• Assessed 32 non-brain damaged subjects (partners
  of aphasic subjects).
• Provide mean and standard deviations for some
  subtests.
• Unable to provide normative data.
• The test manual states We recommend that you
  gather relevant control data for yourself before
  judging whether a particular pattern of
  performance can be considered to be impaired (Kay
  et al., 1992).

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Criticisms

• Subjective decisions made on assessment protocol.
• Pre-morbid levels of patients unknown.
• Unclear black and white pictures used as test
  stimuli.
• Poorly written test manual and assessment packet.
• Figures in manual do not always correspond to
  written text.
• In subtest 59 Written Comprehension of Locative
  Relations, there are no written stimuli
  corresponding to pictures. As Wertz (1996)
  states Either something is missing or I am
  missing something.

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Criticisms

• Many assumptions
• We are going to assume (though not everyone
  does) that the semantic system used to understand
  printed words (and spoken words) is the same as
  the semantic systems used to understand pictures
  and seen objects (Kay et al., 1996).
• Does not specify scoring protocol.
• Cultural and Linguistic Biases
• Test was developed in the United Kingdom.
  Generalization to other cultures unknown.
• Although the test has been adapted for other
  cultures, considerations need to be placed on
  cultural and linguistic equivalence. However,
  effort is being made to develop an American
  version of PALPA.

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Our Opinion

• In light of the lack of aphasia assessment
  batteries, PALPA provides an apparently strong
  theoretical background that appears comprehensive
  and sound.
• Given the aforementioned points, many changes
  must be considered to provide a psychometrically
  sound, culturally and linguistically unbiased and
  effective assessment.

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References

• Cole-Virtue, J. and Nickels, L. (2004). Spoken
  word to picture matching from PALPA A critique
  and some new matched sets. Aphasiology, Vol 18
  (2), 77-102.
• Coltheart, M. (2004). PALPA What next?
  Aphasiology, Vol 18 (2), 181-183.
• Kay, J., Lesser, R., Coltheart, M. (1992). PALPA
  Psycholinguistic Assessments of Language
  Processing in Aphasia Introduction. Lawrence
  Erlbaum Associates East Sussex, England.
• Kay, J., Lesser, R., Coltheart, M. (1996).
  PALPA the proof of the pudding is in the eating.
  Aphasiology, Vol 10 (2), 202-215.
• Kay, J. and Terry, R. (2004). Ten years on
  Lessons learned from published studies that cite
  the PALPA. Aphasiology, Vol 18 (2), 127-151.
• Nickels, L. and Cole-Virtue, L. (2004). Reading
  tasks from PALPA How do controls perform on
  visual lexical decision, homophony, rhyme, and
  synonym judgments? Aphasiology, Vol 18 (2),
  103-126.
• Wertz, R.T. (1996). The PALPAs proof is in the
  predicting. Aphasiology, Vol 10 (2), 180-190.

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Appendix APALPA Battery Annual Citations
(Kay and Terry, 2004)
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Appendix B
From Kay, J. and Terry, R. (2004).
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Appendix C
From Kay, J. and Terry, R. (2004).
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Appendix D
From Kay, J. and Terry, R. (2004).
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Appendix E
From Kay, J. and Terry, R. (2004).
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Appendix F
From Kay, J. and Terry, R. (2004).
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Appendix G
From Kay, J. and Terry, R. (2004).