What type of amnesia involves memory lapses following a traumatic event such as an injury or shock?

The correct answer pertains to retrograde amnesia, which is characterized by the inability to recall memories that were formed prior to a traumatic event, such as an injury or shock. This type of amnesia typically occurs when the brain is unable to access information stored before the incident, leading to gaps in memory.

Anterograde amnesia, on the other hand, refers to the inability to form new memories after the onset of amnesia, which is typically not associated directly with the immediate lapses that occur from the trauma itself. Both infantile amnesia and hyperthymesia describe different memory phenomena: infantile amnesia relates to the inability to recall memories from early childhood, and hyperthymesia denotes an extraordinary ability to remember an abnormally vast number of life experiences in vivid detail. Thus, the distinction lies in the nature of memory loss in retrograde amnesia, where prior memories are affected due to a traumatic event, making it the appropriate choice for this question.