Models of Semantic Organization and Lexical Access
Factors in word recognition
Factors that affect word recognition
1. lexical frequency
2. familiarity
3. concreteness
4. context
5. priming (repetition, semantic, form-based)
6. (orthographic) neighborhood effect (e.g. mine, pine, line, mane etc.)
Cf) Factors in spoken word recognition: 1, 2, 3 above + neighborhood/frequency interaction
and context vs. isolation
Factors in spoken word recognition
1. Frequency Effect: High frequency words are recognized more easily than lowfrequency words (e.g. ophthalmologist vs. eye doctor)
2. Phonological neighborhood effect:
a. measure: number of different phoneme in a word
b. word recognition is more difficult for words for which there are many
similar sounding words in the lexicon (e.g. mail: rail, bail, wail, hail...)
3. Frequency * phonological neighborhood interaction:
 A high frequency word with low frequency neighbors is easy to recognize
(e.g. dog vs. {log, bog, ...}.
 A low-frequency word with high-frequency neighbors is more difficult to
recognize (e.g. wail vs. {tail, mail, rail, sail, ...}
4. Context effect (easier to identify word in context vs. by itself)
5. Familiarity effects
a. meaningful sentence context (easier to identify word in meaningful context
vs. alone)
b. speaking rate information (better recognition of words spoken at the same
rate vs. varied rate)
c. characteristics of individual speakers (easier to recognize words in noise
when spoken by a familiar voice)
Models of Lexical Access
1. The Autonomous Serial Search Model
1. Forster (1976, 1979)
1. Input (either visual or auditory)  bin search  access to mental lexicon
2. Access files (or storage units, or bins) are organized according to frequency (the
most frequent entries at the top)
3. Autonomous (or modular): no interaction among the access files; in other words,
only one modality (visual or auditory) can only be used one at a time
4. Serial search: search through bins and access one word at a time
5. frequency effect; repetition effect (temporary change of order of bins); lexical
priming is because of cross referencing between entries in the master file (as postaccess mechanism)
2. Cohort Model
1. Marslen-Wilson and Welsh (1978)
2. Motivation:
a. shadowing – fluent restorations
b. cross-modal priming
3. Three stages of word recognition:
“At the end of the drinking competition, the lorrydriver was the last one to sta...”
Access stage
perceptual representation used to activate lexical
items, thus generating a candidate set of items;
the cohort
Selection stage
one item only is chosen from this set
Integration stage
in which the semantic and syntactic properties of
the chosen word are utilized
4. All possible candidate words in sound sequence (i.e. the cohort) become active early
in word presentation
5. Elimination from cohort:
a. because words don’t match (bottom-up) or
b. because they are inconsistent with context (top-down)
6. Processing continues until all but one of the words are eliminated (uniqueness point)
and the survivor recognized (recognition point)
7. Criticism:
a. Role of context in prelexical stages is assumed, but empirical data show that
it helps elimination, but not generation
b. Human’s perception system is resilient to errors – it recovers from errors;
the current cohort model is not compatible with the recovery from errors
(once a lexical item is eliminated, it stays eliminated until the end)
8. Later development of the theory:
a. all-or-none (or on or off) elimination is replaced by gradual elimination (to
account for the ability of the system to recover from errors)
b. Role of context is less emphasized; in fact, context effect used only in the
integration level (each level is autonomous)
3. The Logogen Model
1. Morton (1969, 1970)
2. Words are accessed by process of activation (not search or locating a word)
3. Logogen: a scoreboard, tabulating the number of features that a lexical entry shares
with a perceptual stimulus (orthographically, phonologically)
4. Any logogen for whom the total activation reaches a predesignated threshold, based
on sufficient similarity to the stimulus word, is accessed.
5. Input  activation of logogens  logogen competition (threshold)  recognition
6. Parallel word activation
7. Interaction among different representations of a word (e.g. visual, auditory, context
8. direct access to meaning
9. Adjustment of threshold level according to frequency, priming effect
10. Neighborhood effect can well accounted for.
11. Probable non-word detection: there must be a deadline.
Models of Meaning
1. The Hierarchical Network Model
1. Collins and Quillian (1972)
2. Semantic memory: organized like a hierarchy of concepts with general terms at the
top and subordinate, specific terms lower in the hierarchy
3. cognitive economy
4. semantic verification experiments (An A is a B)
5. Criticism:
a. frequency of association (canary: sing vs. skin)
b. typicality effect (bird: sparrow vs. ostrich) category size effect (dog:
mammal vs. animal)
2. The Spreading Activation Model
1. Collins and Loftus (1975)
2. non-hierarchy
3. Concepts are associated by links between nodes
4. Length of link reflects the relationship between concepts
5. The differential node lengths and clustering of concepts can account for the strength
of association and typicality effects that were problematic for the Collins and
Quillian model.
6. Criticism: the underlying physical aspects of concepts (letters, acoustics) are not
represented; and therefore fails to provide for the role of phonetic and feature
information used to access words or how words are activated by the communication
3. Bock and Levelt (1994)
7. conceptual level: conceptual nodes are linked to other nodes through a variety of
relationships similar to those in the Collins and Loftus model
8. lemma level: syntactic aspects of words (e.g. gender if appropriate, case markings,
number etc.)
9. lexeme level: phonological properties (where TOT (tip-of-the-tongue) phenomenon
10. Advantage: comprehensive; accounting for phonological, syntactic, morphological,
and conceptual information