Age differences in central (semantic) and peripheral processing: the importance of considering both response times...

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Aging Research

Background:

• Visual word recognition is crucial for language processing.
• Age-related cognitive changes can impact various aspects of perception and cognition.
• Previous studies on age effects in word recognition yielded conflicting results when analyzing reaction time and accuracy separately.

Purpose of the Study:

• To investigate the effects of adult age on visual word recognition.
• To reconcile contradictory findings from separate analyses of reaction time and accuracy.
• To differentiate age-related changes in peripheral versus central processing during lexical decision.

Main Methods:

• Conducted a lexical decision task experiment with younger and older adult participants.
• Employed combined reaction time (RT) and accuracy measures, applying the Hick-Hyman law.
• Transformed error data into entropy to predict RT, analyzing effects of exposure duration (peripheral) and word frequency (central).

Main Results:

• Older adults demonstrated higher intercepts and slopes for exposure duration, indicating a peripheral encoding decrement.
• Older adults showed higher intercepts but not steeper slopes for word frequency, suggesting no central processing decrement.
• Combined RT and entropy analyses provided a unified view of age-related processing differences.

Conclusions:

• Adult aging is associated with a decrement in peripheral visual processing during word recognition.
• Central processing, specifically related to word frequency, appears unaffected by adult aging in this context.
• The Hick-Hyman law, when combined with entropy-based error analysis, offers a robust method for examining age-related cognitive function.