Associative horizon is in the frontal lobe: ~80% due to white matter abundance and low latent inhibition

Sorry no posts plus bad posts. Life sucks. /whiny

Associative horizon is (primarily) a property of the frontal lobe and the conscious mind. I propose this because it is the determining factor in which things the conscious mind considers possible (vs. plausible). A person with low associative horizon will ignore anything that is “crazy”, whereas a person with high associative horizon will only ignore something really, really crazy. It is distinct from psychoticism, which is a property of the rear neocortex (occipital, cerebellum, some parietal), its overabundance of gray matter, and the subconscious mind. Please reread Cooijmans’ description of associative horizon to familiarize yourself with the context for this claim.

Low latent inhibition

Every time a neuron’s synapse activates, it’s neighbors also may activate. This leads to “chains” of activation. Operations on neurons sometimes propagate by mere association and sometimes don’t. Whether a chain halts or continues at each point depends on a “tendency” to activate. We call this tendency latent inhibition, and it turns out to be a general factor of physical brains, like intelligence.

Latent inhibition is a technical term used in classical conditioning to refer to the observation that a familiar stimulus takes longer to acquire meaning (as a signal or conditioned stimulus) than a new stimulus.[1] The term “latent inhibition” dates back to Lubow and Moore.[2] The LI effect is “latent” in that it is not exhibited in the stimulus pre-exposure phase, but rather in the subsequent test phase. “Inhibition”, here, simply connotes that the effect is expressed in terms of relatively poor learning. The LI effect is extremely robust, appearing in all mammalian species that have been tested and across many different learning paradigms, thereby suggesting some adaptive advantages, such as protecting the organism from associating irrelevant stimuli with other, more important, events.

Low latent inhibition is often cited as a possible cause of ADHD. I think it is the least significant cause, but not insignificant.

White matter abundance in the frontal lobe

The images above illustrate a comparison of two individuals with autism. The individual with more severe autism symptoms (right) has greater deviations from typical connectivity patterns compared to the individual with the less severe autism symptoms (left). The more severe the autism symptoms, the greater the synchronization and connectivity deviations.

Please note that autism is characterized by global loss of white matter whereas people with Asperger’s generally have a great deal more white matter in the frontal lobe and cerebellum than do neurotypicals. So the image ought to be taken as an indicator that autists simply have unusual concentrations because they have more potential volume, but more holes due to the disease. Hence, as Cooijmans reports, people with Asperger’s have much greater associative horizon. This is why I think Tex is always harping about “more connective tissue in the frontal lobe”.


Putting two and two together, it makes sense that activation chains will be longer or shorter based on the concentration of white matter and their general tendency to propagate activation. Think of it like news travelling through a neighborhood. If neighbors are close together and they are all talkative, even uninteresting news tends to propagate throughout the neighborhood. But in a low-density neighborhood of introverts the news would have to be very urgent and important for them to bother telling each other. We might summarize this as

Associative horizon = LLI * Synapses/neuron

As the title says, I expect this tells about 80% of the story.


About Aeoli Pera

Maybe do this later?
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5 Responses to Associative horizon is in the frontal lobe: ~80% due to white matter abundance and low latent inhibition

  1. Nottuh says:

    Good post, Aeoli. You’ve covered some new ground here, and you’ve given me a lot to consider here. :)

  2. Koanic says:


  3. Pingback: Drugs, synesthesia, rambling | Aeoli Pera

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