In the romantic comedy, Lucy is the main character who suffered a brain injury in a car accident. Her main symptom was loss of short-term memory. This is caused by damage to the hippocampus, inside the temporal lobe, as the hippocampus controls memory functions.
The character Oola is a friend of Henry Roth, whom helps come up with clever ideas to help Lucy fall in love with Henry everyday. Oola is affecting his neurotransmitters by the daily use of marijuana. Marijuana works as an agonist, it blocks the receptor site, and the neurotransmitters cannot get across the synapse.
Sean Astin’s character, Doug, is Lucy’s aggressive brother. This aggression can be attributed to his abuse of steroids. This steroid abuse may have affected Doug’s amygdala, the part of the limbic system that controls aggression and fear. Conversely, it may have affected Doug’s hypothalamus, which is also involved in aggression.
In conclusion, all the characters seem to have some type of brain dysfunction. Lucy had damaged her hippocampus in the temporal lobe of her brain. Oola is affecting his neurotransmitters by the use of marijuana. Doug is affecting his amygdala through the abuse of steroids. This demonstrates how different stimuli affect different parts of the brain.