While we did not find a main effect of social networks on either AD risk or neuropathology, we did find that social networks modified the relation of AD pathology to cognition [169]. In other words, AD pathology had much less effect on cognition among persons with larger networks. In further analyses, the effect was most strongly associated with tangle formation. We conjectured that social networks may be a proxy for social cognition and hypothesized that some types of cognition might modify the relation of AD pathology to other forms of cognition. In keeping with this idea, we found that processing resources reduced the effect of AD pathology on episodic memory, semantic memory, and visuospatial ability [170]. Further, purpose in life reduced the effect of AD pathology on the rate of change in cognition over multiple years prior to death [171].
