  Human memory -- the learning of new information involves changes at the
synaptic level between neurons dedicated for storage of in-formation.
Generally, memory is classified as Long-Term Memory and Short-Term Memory. The
various types of the memory and their disorder are widely studied using
neuroimaging techniques like Electroencephalography (EEG) and functional
Magnetic Resonance Imaging (fMRI). Brain is effectively occupied with the
capabilities of learning, retention and recall. The brain regions (pre-frontal
cortex, associated hippocampus cortices and their interactions with other
lobes) involved in memory recall tasks focuses on understanding the memory
retention and recall processes. However, due to highly complicated and dynamic
mechanisms of brain, the specific regions where information may reside are not
completely explored. In this research paper, recent memory literature using EEG
and fMRI studies is reviewed to understand the memory retention and recall
processes as well as the various brain regions associated with these processes.
A number of stimuli which are reported in previous studies are evaluated and
discussed. Furthermore, the challenges which are being faced by researchers in
EEG and fMRI methodologies are also presented. Recommendations for the future
research related to memory retention and recall are also discussed at the end.
