A report on Temporal lobe and Episodic memory

This ridge can also be seen as an inward fold of the archicortex into the medial temporal lobe.

Over the years, three main ideas of hippocampal function have dominated the literature: response inhibition, episodic memory, and spatial cognition.

Explicit memory can be divided into two categories: episodic memory, which stores specific personal experiences, and semantic memory, which stores factual information.

The regions of the diencephalon have shown brain activation when a remote memory is being recovered and the occipital lobe, ventral temporal lobe, and fusiform gyrus all play a role in memory formation.

Long-term memory is commonly labelled as explicit memory (declarative), as well as episodic memory, semantic memory, autobiographical memory, and implicit memory (procedural memory).

Research by Meulemans and Van der Linden (2003) found that amnesiac patients with damage to the medial temporal lobe performed more poorly on explicit learning tests than did healthy controls.

To a large degree, anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood, although it is known that the regions of the brain involved are certain sites in the temporal cortex, especially in the hippocampus and nearby subcortical regions.

Furthermore, the data do not explain the dichotomy that exists in the MTL memory system between episodic memory and semantic memory (described below).

Case studies also show that amnesia is typically associated with damage to the medial temporal lobe.

Retrograde amnesia is inability to recall memories before onset of amnesia. One may be able to encode new memories after the incident. Retrograde is usually caused by head trauma or brain damage to parts of the brain besides the hippocampus. The hippocampus is responsible for encoding new memory. Episodic memory is more likely to be affected than semantic memory. The damage is usually caused by head trauma, cerebrovascular accident, stroke, tumor, hypoxia, encephalitis, or chronic alcoholism. People with retrograde amnesia are more likely to remember general knowledge rather than specifics. Recent memories are less likely to be recovered, but older memories will be easier to recall due to strengthening over time. Retrograde amnesia is usually temporary and can be treated by exposing them to memories from the loss. Another type of consolidation (process by which memories become stable in the brain) occurs over much longer periods of time/days, weeks, months and years and likely involves transfer of information from the hippocampus to more permanent storage site in the cortex. The operation of this longer-term consolidation process is seen in the retrograde amnesia of patients with hippocampal damage who can recall memories from childhood relatively normally, but are impaired when recalling experiences that occurred just a few years prior to the time they became amnesic. (Kirwan et al.,2008)In the case of LSJ, her case shows that retrograde amnesia can affect many different parts of knowledge. LSJ was not able to remember things from her child or adult life. She was not able to remember things that most people pick up in everyday life such as logos or the names of common songs.

Semantic memory is distinct from episodic memory, which is our memory of experiences and specific events that occur during our lives, from which we can recreate at any given point.

On the one hand, many researchers and clinicians believe that semantic memory is stored by the same brain systems involved in episodic memory, that is, the medial temporal lobes (MTL), including the hippocampal formation.