What biological change in development offers an explanation for the existence of infantile amnesia? Select one: a. Neurotransmitters such as glutamate, AMPA, and NMDA are in limited supply until around three years of age b. An excess of neuronal synapses at birth delays memory encoding c. The hippocampus is only partially developed in infancy d. Cortical areas involved in memory storage are understimulated by the environment
The Correct Answer and Explanation is:
Correct answer: c. The hippocampus is only partially developed in infancy
Explanation:
Infantile amnesia refers to the phenomenon where adults are unable to recall memories from the first few years of life, typically before the age of three or four. One of the most widely accepted biological explanations for this phenomenon is the incomplete development of the hippocampus during infancy.
The hippocampus is a crucial structure in the brain involved in the formation and retrieval of long-term declarative memories, which include memories of facts and events. During infancy, although the hippocampus is present, it is not fully mature. This immaturity limits the brain’s ability to encode, consolidate, and store detailed autobiographical memories. As the hippocampus develops over the early years of life, the capacity to form more stable and retrievable long-term memories also improves.
In contrast, the other answer options are either inaccurate or lack strong scientific support. While neurotransmitters like glutamate, AMPA, and NMDA are important for synaptic activity and memory formation, their availability is not the primary reason for infantile amnesia. Similarly, although there is an initial excess of synaptic connections in the infant brain, this is a normal part of brain development and does not directly delay memory encoding. The pruning of these connections later helps refine neural circuits but is not a major cause of the memory gap. Finally, although environmental stimulation does influence brain development, especially in the cortex, it is not the key limiting factor in the encoding of early memories.
Therefore, the partial development of the hippocampus is the most accurate and biologically grounded explanation for the existence of infantile amnesia. As this structure matures, the ability to form and retain long-term autobiographical memories becomes more reliable.
