study state-dependent memory. This study found that invertebrates did indeed experience the phenomenon as well, particularly in regard to conditions of low or high nutritional intake. 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. For these grasshoppers, their low nutritional state sparked cognitive connections to similar states of duress and primed the insects to make decisions they had made when faced with low nutrition in previous conditions. 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. Substances Research has shown evidence for the roles that numerous substances play in state-dependent memory. For example, stimulants like Ritalin can produce state-dependent memory effects in children with hyperactive disorders. Additionally, state-dependent memory effects have been found in regard to other substances such as morphine, caffeine, and alcohol. Substantial amounts of research have been conducted on the effects of alcohol. A very clear description of state-dependent memory is found in John Elliotson's Human Physiology (1835): "Dr. Abel informed me," says Mr. Combe [presumably George Combe], "of an Irish porter to a warehouse, who forgot, when sober, what he had done when drunk: but, being drunk, again recollected the transactions of his former state of intoxication. On one occasion, being drunk, he had lost a parcel of some value, and in his sober moments could give no account of it. Next time he was intoxicated, he recollected that he had left the parcel at a certain house, and there being no address on it, it had remained there safely, and was got on his calling for it." This man must have had two souls, one for his sober state, and one for him when drunk. Research shows that individuals are less likely to remember information learned while intoxicated when they are once again sober. However, information learned or memories created while intoxicated are most effectively retrieved when the individual is in a similar state of intoxication. Alcoholism can enhance state-dependent memory as well. In a study comparing the state-dependent memory effects of alcohol on both subjects with alcoholism and subjects without alcoholism,