Recent research has uncovered additional regions of interest, as well as highlighted particular subregions of the PFC, that can be tied to performance in specific behavioral tasks. Delay discounting
Excitotoxic lesions in the nucleus accumbens core have been shown to increase preference for the smaller, immediate reward, whereas lesions to the nucleus accumbens shell have had no observable effect. Additionally, lesions of the basolateral amygdala, a region tied closely to the PFC, negatively affect impulsive choice similarly to what is observed in the nucleus accumbens core lesions. Moreover, dorsal striatum may also be involved in impulsive choice in an intricate manner. Go/No-go and Stop-signal reaction time test
The orbitofrontal cortex is now thought to play a role in disinhibiting, and injury to other brain structures, such as to the right inferior frontal gyrus, a specific subregion of the PFC, has been associated with deficits in stop-signal inhibition. 5-Choice Serial Reaction Time Task (5-CSRTT) and Differential Reinforcement of Low rates (DRL)
As with delay discounting, lesion studies have implicated the core region of the nucleus accumbens in response inhibition for both DRL and 5-CSRTT. Premature responses in the 5-CSRTT may also be modulated by other systems within the ventral striatum. In the 5-CSRTT, lesions of the anterior cingulate cortex have been shown to increase impulsive responding, and lesions to the prelimbic cortex impair attentional performance. Iowa Gambling Task
Patients with damage to the ventromedial frontal cortex exhibit poor decision-making and persist in making risky choices in the Iowa Gambling Task.
Distal intestinal obstruction syndrome (DIOS) involves obstruction of the distal part of the small intestines by thickened intestinal content  and occurs in about 20% of mainly adult individuals with cystic fibrosis. DIOS was previously known as meconium ileus equivalent, a name which highlights its similarity to the intestinal obstruction seen in newborn infants with cystic fibrosis. DIOS tends to occur in older individuals with pancreatic insufficiency. Individuals with DIOS may be predisposed to bowel obstruction, though it is a separate entity than true constipation. Signs and symptoms
Signs and symptoms of DIOS include a sudden onset of crampy abdominal pain, vomiting, and a palpable mass (often in the right lower quadrant) in the abdomen. The characteristic abdominal pain is typically located in the center or right lower quadrant of the abdomen. X-rays of the abdomen may reveal stool in the colon and air-fluid levels in the small intestines. Diagnosis
A complete history and physical examination can be suggestive, especially if a palpable mass in the right lower quadrant of the abdomen is present (though this can be present in the absence of DIOS). Ultrasound and computed tomography (CT) imaging of the abdomen can confirm the diagnosis by demonstrating dilated loops of intestine with material in the intestinal lumen with bubbles. Air-fluid levels may be seen in those affected by DIOS. Classification
DIOS is sometimes classified by the degree of obstruction as incomplete or complete DIOS. Differential diagnosis
Additional diagnoses which may present with similar symptoms to DIOS include severe constipation, appendicitis, and intussusception.