Thoughts on Altered States of Consciousness

As I was reading a chapter in The Blackwell Companion To Consciousness by David Presti, professor of neurobiology at the University of California, Berkeley, called Altered States of Consciousness (Drug-Induced States), a thought occurred to me.

When speaking about the effects of psychoactive substances, there seems to exist a postulated threshold dividing two states of being affected by various substances (e.g., coffee, tobacco, alcohol, or more potent ones).

One state resides within the realm of one’s everyday experiences; the other state does not because the consumer is so affected by the substances consumed that a feeling of having lost one’s agency inevitably follows.

This struck me as a peculiar distinction.

Allow me to elaborate:

The Threshold Between States of Consciousness

Suppose a threshold conceivably exists—albeit too sharply drawn for the benefit of this conversation—where one believes that the conscious experience is either unaltered (or altered within the realm of one’s everyday phenomenological experience) or significantly altered (e.g., the differences between having a cup of coffee and consuming high doses of lysergic acid diethylamide, LSD), what exactly generates this threshold?

And why is there an “on-or-off” dynamic? 

Personally, I maintain that it is, at least in part, due to one’s susceptibility to one’s own storytelling in that the caffeinated “me“ is still under “my own volition“ (whatever that is) and still a part of my ordinary phenomenological experience…

…whereas a significantly intoxicated me (hypothetically, from alcohol or something more potent) could blame the substance(s) for my out-of-character behaviors because my subjective experience would have been too altered for me having “been there” as an “accountable author of my actions.”

To me, this is all one experience that is more or less altered, judged so from the anchor point of once having been sober; the state to which one automatically returns. 

Let’s take alcohol (referring to ethyl alcohol or ethanol), for example:

Tipsy or Hammered? That Is the Question

How come there is a threshold between where one is tipsy, defined as more or less subtle changes in motivational states and reductions in attentional awareness (the author is present and in charge of its behaviors), and where the consumer experiences the amnestic effects of alcohol and subsequently blacks out from having had too much (the author is no longer in charge of its behaviors)?

Obviously, one can seek answers in the neurobiology underlying the effects of alcohol—and the dose-response relationship, etc.—to explain how the effects go from states of relaxation and decreased arousal to the aforementioned amnestic effects.

These answers do not, however, get at the question of where the threshold lives.

Why not?


It is the same substance in the same individual having one (perhaps) phenomenological experience.

So how come there is a sense of there being a threshold where, on the one hand, one is the author of one’s actions and, on the other hand, one can blame circumstances (i.e., having had a too altered state of consciousness)?

To me, it seems like a cognitive sleight of hand (or what is called motivated reasoning in psychology) where one comes up with a plausible story (post-hoc; after the fact) when the outcome is already known to justify (based on emotions) that very outcome.

Robert Sapolsky, professor of neuroscience at Stanford University, explains it beautifully, writing that “what seems like rationality is often just rationalization, playing catch-up with subterranean forces that we never suspect” (Sapolsky, 2017, p. 423).

For this reason, I maintain that the threshold is nothing more than differences—or rather fluctuations—in one’s feelings of agency and appendable narratives that convince both the audience and the author that the story has adequate verisimilitude (from the Latin word verisimilitudo, meaning “likeness to truth”), rather than there being an actual, cognitively tangible threshold to which one can refer.

What do you think? Write your thoughts in the comments below because writing is thinking.


Kunda, Z. (1990). The Case for Motivated Reasoning. Psychological Bulletin, 108(3), pp.480–498.

Presti, D. (2017). ‘Altered States of Consciousness: Drug-Induced States‘ in Schneider, S., & Velmans, M. (ed.) The Blackwell Companion to Consciousness. 2nd Edition. John Wiley & Sons Ltd: West Sussex, pp. 171-186.

Sapolsky, R. (2017). Behave — The Biology of Humans At Our Best And Worst. New York, USA: Penguin Press.