Stress and Motivated Behavior Institute

Human Learning and Memory

Post-traumatic stress disorder (PTSD)  Amnesia  Alzheimer’s disease  Parkinson’s disease Behavioral genetics of individual differences  Personality traits that affect learning and memory in healthy individuals 




Amnesia is a general term for memory loss.   Anterograde amnesia is a particular form of memory loss due to brain injury or disease in which individuals selectively lose the ability to form new memory for facts and events, while their memory for older information is left largely intact, as are other cognitive functions such as intelligence, attention, and perception.  Amnesic patients remember their own identity and their past history, but are generally unable to remember anything that’s happened to them since the brain injury.  The syndrome is devastating and irreversible.
Humans can develop anterograde amnesia through damage to the hippocampus, a brain structure important for new memory formation.  Such damage can occur due to various types of injury including traumatic brain injury (TBI), oxygen deprivation (e.g. carbon monoxide poisoning, near-suffocation, cardiac/respiratory arrest), certain forms of epilepsy, and certain types of brain infection (e.g. herpes simplex encephalitis).  Humans can also develop anterograde amnesia through damage to other brain structures that interact with the hippocampus, such as the basal forebrain.  Basal forebrain damage can occur in patients who suffer a common type of brain aneurysm (stroke).

Left: MRI image of a healthy adult human brain, showing the hippocampus (grey matter circled in red).  Right: hippocampal damage is visible in the MRI of a patient who became amnesic following a period of oxygen deprivation. Adapted from Figure 2 of Hopkins, Myers et al. (2004) Neuropsychologia, 42:524-535.

An interesting feature of anterograde amnesia is that some types of learning and memory are spared, such as the ability to learn new motor skills (such as mirror-reversed handwriting), cognitive skills (such as reading mirror-reversed text), and emotional responses (such as responding with unease to a stimulus that has been paired with mild electric shock) – even though patients have no conscious memory of learning this information.  On the other hand, even when amnesic patients do acquire new information, they are often still impaired when challenged to generalize or use this information when it is presented in new ways or new contexts.

Understanding the precise pattern of impaired and spared abilities in individuals with hippocampal damage is critical for developing therapy – because, by definition, any rehabilitation must be based on the patient’s surviving memory abilities rather than those that have been lost due to the brain damage.  Further, dissociating the patterns of memory ability in individuals whose amnesia is due to hippocampal damage vs. basal forebrain damage is critical in developing therapies optimized to each type of patient.

Representative Publications:

Myers, C. E., et al. (2008). Learning and generalization deficits in patients with memory impairments due to anterior communicating artery aneurysm rupture or hypoxic brain injury. Neuropsychology, 22(5):681-686. Hyperlink to abstract: PMID: 18763887

Myers, C., et al. (2006).  Conditional discrimination and reversal in amnesia subsequent to hypoxic brain injury or anterior communicating artery aneurysm rupture. Neuropsychologia, 44(1):130-139. Hyperlink to abstract: PMID: 15885718

Myers, C., et al. (2003).  Dissociating medial temporal and basal ganglia memory systems with a latent learning task. Neuropsychologia, 41:1919-1928. Hyperlink to abstract: PMID: 14572525      

Prior Funding: National Institute of Mental Health.