Age-related impairment in a complex object discrimination task that engages perirhinal cortex.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• The perirhinal cortex (PRC) is crucial for complex object discrimination, especially when objects share many features.
• Age-related declines in PRC function have been observed in animal models, affecting object recognition and discrimination.
• Human studies investigating age-related PRC function during complex object discrimination are lacking.

Purpose of the Study:

• To investigate the influence of aging on complex object discrimination in humans.
• To compare the performance of young and older adults using a task known to engage the PRC.
• To examine age-related functional changes in the PRC using functional magnetic resonance imaging (fMRI).

Main Methods:

• An object matching paradigm with blob-like objects was employed.
• Task difficulty was manipulated by varying the number of overlapping features between objects.
• fMRI was used to assess PRC activity in young and older adult groups.

Main Results:

• Young and older adults performed similarly on simple discrimination tasks.
• Older adults were significantly impaired in discriminating objects with high feature overlap compared to younger adults.
• fMRI data revealed reduced engagement of the bilateral anterior PRC in older adults, with left anterior PRC engagement predicting performance.

Conclusions:

• Human aging is associated with functional changes in the PRC.
• These age-related PRC alterations impair complex object discrimination, particularly for stimuli with significant feature overlap.
• The findings highlight the PRC's critical role in maintaining object discrimination abilities across the lifespan.