Lexical decision in aging: Stimulus variables and response time components

Word retrieval is susceptible to break down with age and brain damage (especially aphasia)

Different types of variables affect word retrieval:

1. Lexical (e.g. frequency, phonological neighborhood density) (Figure 4) 2. Sub-lexical (e.g. phonotactics, length) (Figure 4)
3. Subject (e.g. age, education, sensory functioning)
4. Task factors (e.g. mode of retrieval, composition of the stimulus set)

Neighborhood density refers to the number of similar sounding words activated at the same time as the target:

• Past research has indicated a competitive effect of neighborhood density for tasks that promote processing at the lexical level and a facilitative effect for tasks that promote processing at the sub-lexical level (Goldinger et al., 1990; Vitevitch & Luce, 1998; Vitevitch et al., 1999)

Theories of cognitive aging may explain behavioral changes observed: • Sensory Deficit

• Decrease of Inhibition

• Slowing of processing speed

Speed and accuracy with which words or decisions about words can be made can inform us

about the form and function of the mental lexicon (Figure 1) 

Psychological processes behind the mental lexicon and two-choice decisions can be further elucidated with the diffusion model