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Published on: June 25, 2019
Age-related differences in the automatic processing of single letters: implications for selective attention
Kirk R Daffner1, Brittany R Alperin, Katherine K Mott
1aCenter for Brain/Mind Medicine, Division of Cognitive and Behavioral Neurology, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston bDepartment of Psychology, Tufts University, Medford, Massachusetts, USA.
Older adults struggle to ignore visual information, processing letters too early. This automatic letter processing in older adults, unlike younger adults, impairs selective attention and contributes to age-related cognitive decline.
Area of Science:
- Cognitive Neuroscience
- Human Aging Research
Background:
- Older adults show reduced ability to inhibit processing of ignored visual stimuli.
- Age-related changes in early visual processing and their impact on selective attention are not fully understood.
Purpose of the Study:
- To investigate age-related differences in early visual processing during selective attention.
- To determine if automatic processing of irrelevant stimuli contributes to attention deficits in older adults.
Main Methods:
- A color selective attention task was administered to 103 adults aged 18-85.
- Event-related potentials (ERPs), specifically the N170 component, were used to assess early visual processing of letter forms.
- P3b amplitude was measured to index late selection resources.
Main Results:
- Young and middle-aged adults did not show an asymmetric N170, indicating no early automatic letter processing.
- Older adults (young-old and old-old) exhibited an asymmetric N170, suggesting automatic letter processing.
- A larger N170 to letters versus nonletters in the left hemisphere of older adults was observed.
- More asymmetric N170 responses correlated with increased P3b amplitude to ignored target letters.
Conclusions:
- Older adults automatically process letter forms early in visual selection, even when color is the primary attentional cue.
- This early, automatic processing of irrelevant letters hinders efficient selective attention in older adults.
- The failure to inhibit early letter processing contributes to age-related difficulties in ignoring distracting information.
