The common denominator seems that recognition patterns have much lower threshold for firing. In that sense, there is less cognitive filtering, but perhaps more

The common denominator seems that recognition patterns have much lower threshold for firing. In that sense, there is less cognitive filtering, but perhaps more sensory filtering? Multiple results are competing for attention, which creates the sensation of rushing thoughts. Connections across widely different concepts are made, which makes for 'woah, everything is connected' moments. Visual patterns are recognized over-zealously, which creates hallucinations. It doesn't seem weird to me that pattern recognition machine that's been trained for 15+ years will recognize same patterns for same input few hours later. Note I have never taken lsd, so I don't really know what I'm talking about.