In 1784, a French aristocrat named Marquis de Puységur, realized that when people were put in a hypnotic state then awoken, they had no recollection of what they were told.
[1] In 1937, at the University of Illinois, Edward Girden and Elmer Culler conducted an experiment on conditioned responses in dogs under the influence of the drug curare.
Girden and Culler's research opened the door for further investigation of the influences of state of consciousness on an organism's ability to encode memory.
Overton found that the rats that had been administered 25 mg of sodium pentobarbital could no longer remember the proper escape response when they were later placed in the maze without the drug.
In 1971, Terry Devietti and Raymond Larson conducted a similar study in rats, seeing how memory was affected by various levels of electric shock.
[1] In 2019 a study of 100 college-aged women between the age of 18–24 were given questionnaires daily to access how alcohol had an effect on their memories of a past sexual assault (SA).
If these cells have a history of sending out certain signals under specific chemical conditions within the brain, they are then primed to work most effectively under similar circumstances.
[9] State-dependent memory happens when a new neural connection is made while the brain is in a specific chemical state – for instance, a child with ADHD learns their multiplication tables while on stimulant medication.
In 2006, researcher Lorena Pomplio and her team tackled this question as they investigated the presence of state-dependent memory in invertebrates, specifically grasshoppers.
Pomplio and associates (2006) concluded that their results demonstrated a potential "adaptive advantage" of state-dependent learning that explains its intrinsic presence in such a wide variety of species.
State-dependent memory recalls a time that the organism was in a similar condition, which then informs the decisions they make in the present.
The paper suggests that this phenomenon allows for quick decisions to be made when an organism does not have the time or neural capability to carefully process every option.
[15] This produces changes in cognition and so when the person with alcoholism drinks, the intoxication primes their brain towards certain associations made in similar states.
In a study, a wide array of subjects with varying levels of THC exposure were given a dosage of this compound and asked to perform tasks relating to memory function.
The final results did not produce sufficient evidence to make a strong argument regarding cannabis and state dependent memory.
Researchers have since been conducting experiments to unearth the truth about mood-dependent memory, though it remains difficult to completely eliminate unreliability from such studies.
Some studies have investigated the existence of mood-dependent memory, especially in individuals with bipolar disorder who generally vacillate over time between mood extremes, specifically depression and mania.
[21] In an experiment, subjects were asked to memorize a list of words (some of which were pain related while others not), then either submerged their hand in warm or ice cold water.
[22] It is hypothesized that state dependent memory which coincides with pain and trauma could yield negative cognitive results such as dissociative amnesia, or the inability to recall personal information that would not ordinarily be forgotten.
It is also theorized that this level of memory failure is attributed to overwhelming stress which then prevents an adequate integration of trauma relief mechanisms as well as the encoding of normal conscious experiences.
Other negative results regarding dissociative amnesia and state dependent memory include: anxiety, depression, social dysfunction, and psychosis.
After a series of therapeutical sessions, the patient experienced episodes of epilepsy and conveyed feelings of distress when given retrieval cues alluding to the house fire.
[23] Studies have shown that simply creating the same internal state that one had at the time of encoding is sufficient to serve as a retrieval cue.
This effect called context reinstatement was demonstrated by Fisher and Craik 1977 when they matched retrieval cues with the way information was memorized.
However, the power of state-dependent memory can also be harnessed to improve performance in school for those with learning disabilities or outcomes in therapy.
By remaining consistent in their state of consciousness during sessions, patients can improve the likelihood of their success and decrease the possibility of relapse.
Future directions for this kind of research might test substances other than caffeine for similar effects on patient performance during psychological treatment.
The results show that the state of consciousness produced through use of these drugs improves cognitive focus in those with hyperactive disorders when taken consistently.