Psycholinguistics: Lexical Processing

Psycholinguistics: Lexical Processing

• Lexical processing is the way words are stored and recognized in the mind.
• Word recognition is remarkably fast.
  • A college-educated adult knows approximately 40,000-60,000 words.
  • It takes about 250 milliseconds to locate a word in the mental lexicon.
• Finding words is difficult because many words share similar phonemes (e.g., star, stare, start).
• The presentation will discuss:
  • How words are stored in the mental lexicon.
  • The word recognition process.
  • How word recognition reveals how the mental lexicon is organized.

1. The Mental Lexicon

• The mental lexicon is a brain dictionary, located primarily in Wernicke's area.
• It contains all the known words for an individual, including:
  • Meaning
  • Pronunciation
  • Usage with other words
  • Other attributes (e.g., plural form of a noun, past tense of a verb).

Question: How Complex Words are Stored

• Are complex words (e.g., globalization) stored as complete units or broken down into morphemes in the mental lexicon?
• Three hypotheses exist:
  • Full listing: each complex word is a unique entry.
  • Affix-stripping: complex words are broken down into morphemes (e.g., "global," "-ization").
  • Combination: a combination of full listing and affix-stripping.

1. The Full Listing Hypothesis

• Strengths: Fast access via fully stored word units.
• Weaknesses: Consumes significant storage space and overlooks the interconnectedness of words.
• Each complex word (globe, global, globalize, globalization) stores a separate entry.

2. The Affix-Stripping Hypothesis

• Strengths: Efficient storage due to morpheme-based entries. Highlights relationships between words.
• Weaknesses: Slower access due to decomposition and rebuilding into a word.
• Complex words are broken down into their component morphemes (globe, nation, al, -ize, -ation, inter).

3. Combined Hypothesis (1 + 2)

• More realistic model. Storage varies depending on the affixes.

• Some complex words may be stored as whole units, others as decomposed morphemes.

• This approach considers contextual factors while storing words.

• Affixes that do not change sound and semantic meaning on attachment are transparent (e.g., -er).

• Other affixes considerably change the root's pronunciation which lowers decomposability (e.g., -ation).

• Word decomposition is more complex than transparent affixes.

2. The Process of Word Recognition

• One common model is the cohort model.
• Upon hearing speech, the listener begins narrowing the possible words.
• Initial sounds are vital, if the word starts with /s/, words starting with /b/ for example are eliminated.
• Proceeding sounds reduce possible words to one. This is called the uniqueness point.
• The cohort is the list of remaining candidate words at any given point in the auditory process.
• Initial sound mispronunciations affect recognition more adversely than mispronunciations in the latter.

Problems of the Cohort Model

• Identifying word boundaries in continuous speech is difficult
• Example: "ice cream", "I scream" identifying separate words is problematic in running speech.

Factors Affecting Word Recognition

• Frequency: More frequent words are accessed faster due to more frequent use, for example, 'water' is more frequent than 'obituary'. Storing words based on frequency.
• Recency: Recently heard words are recognized quicker than those not recently encountered.
• Context: Recognising words is made easier by preceding words providing context. For example: "The heart surgeon carefully cut into the aorta", this helps identify "aorta" more rapidly.

Lexical Ambiguity

• Single words can have multiple meanings (e.g., "right").
• Two theories explaining how ambiguity is resolved.
  • All meanings are accessed.
  • Only the first meaning is accessed; additional contexts provide support for re-evaluation.
• Sentence completion tasks show this ambiguity, with slightly longer times if the word is ambiguous.
• Ambiguity resolution depends on word frequency and context. For example, 'chair' (as in furniture) more frequent than 'chair' (as in committee leader).

Explore the fascinating world of lexical processing in psycholinguistics. This quiz delves into the mental lexicon, word recognition speed, and the organization of words in the mind. Perfect for those interested in understanding how language is stored and retrieved.