Thought connectivity is an alteration of a person's thought stream which is characterized by a distinct increase in wandering thoughts which connect into each other through a fluid association of ideas.     During this state, thoughts may be subjectively experienced as a continuous stream of vaguely related ideas which tenuously connect into each other by incorporating a concept that was contained within the previous thought. When experienced, it is often likened to a complex game of word association.
During this state, it is often difficult for the person to consciously guide the direction of their thoughts in a manner that leads into a state of increased distractibility. This will usually also result in one's train of thought contemplating an extremely broad variety of subjects, which can range from important, trivial, insightful, and nonsensical topics.
Thought connectivity is often accompanied by other coinciding effects such as thought acceleration and creativity enhancement. It is most commonly induced under the influence of moderate dosages of psychedelic compounds, such as LSD, psilocybin, and mescaline. However, it can also occur to a lesser extent under the influence of dissociatives, stimulants, and cannabinoids.
Semantic associativity is a specific subtype of thought connectivity. It is characterized by an increased association of words or phrases with others which are related in language or meaning.
The most common features of semantic associativity are novel word substitutions and an increased duration taken to put names to things.    During this state, word substitution and misnaming occur more frequently when identifying items within a given category: these substitutions may be unpredictable or free-associative, such as saying "dog" when "cat" is meant.  These changes in cognition indicate an alteration of what researchers call "semantic priming", or the kind of words that are evoked when related or competing ideas are discussed. 
It is worth noting that depending on whether a more loosely associative vocabulary is considered creatively valuable or cognitively undesirable for a given situation or context, semantic associativity may be considered as either a cognitive enhancement or a cognitive depression.
Semantic associativity most commonly occurs under the influence of moderate dosages of hallucinogens  such as cannabis, LSD, and psilocybin.    In cannabis research, the increase of semantic priming is often considered characteristic of a broad disruption of conventional thought and language.    
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