Final answer:
Mishkin and Ungerleider's research on brain-damaged patients focuses on temporal lobe lesions, particularly highlighting the memory-related functions of the medial temporal lobe and hippocampus as evidenced by patient HM's case.
Step-by-step explanation:
Mishkin and Ungerleider's functional evidence regarding brain-damaged patients primarily focuses on c) Temporal lobe lesions. The temporal lobe, particularly the medial temporal lobe, includes critical structures like the hippocampus and amygdala known for their roles in memory function. This was illustrated by the case of patient HM, who underwent surgery that removed both medial temporal lobes to control his epilepsy. As a result, HM's ability to form new declarative memories was significantly impaired, although his pre-surgery memories remained largely intact. This finding highlighted the hippocampus and adjacent medial temporal lobe structures' pivotal role in consolidating short-term memories into long-term storage within the cerebral cortex.