Age relatedĮlderly individuals have been shown to exhibit source amnesia. It appears that frontal lobe damage causes a disconnection between semantic and episodic memory – in that the individuals cannot associate the context in which they acquired the knowledge to the knowledge itself. Individuals with frontal lobe damage often mistakenly attribute the knowledge they have to some other source (e.g.: they read it somewhere, saw it on TV, etc.) but rarely attribute it to having learned it over the course of the experiment.
Those individuals with frontal lobe damage have normal recall of facts, but they make significantly more errors in source memory than control subjects, with these effects becoming apparent as shortly as 5 minutes after the learning experience. It appears that those with frontal lobe damage have difficulties with recency and other temporal judgements (e.g.: placing events in the order they occurred), and as such they are unable to properly attribute their knowledge to appropriate sources – i.e.: source amnesia. It has been seen that individuals with frontal lobe damage have deficits in temporal context memory and as such, source memory has also been seen to exhibit deficits in those with frontal lobe damage. He had a railway spike driven through his frontal lobe effecting great changes on his personality. Phineas Gage is an example of an individual who suffered frontal lobe damage. Source monitoring can be improved by using more retrieval cues, discovering and noting relations and extended reasoning. Source monitoring involves a systematic process of slow and deliberate thought of where information was originally learned. Different types of acquisition processes (e.g.: reading, thinking, listening) and different types of events (e.g.: newspaper, thoughts, conversation) will produce mental depictions that perceptually differ from one another in the brain, making it harder to retrieve where information was learned when placed in a different context of retrieval. Memory representations reflect the encoding processes during acquisition. It is likely that the disconnect between having the knowledge and remembering the context in which the knowledge was acquired is due to a dissociation between semantic and episodic memory – an individual retains the semantic knowledge (the fact), but lacks the episodic knowledge to indicate the context in which the knowledge was gained.
This branch of amnesia is associated with the malfunctioning of one's explicit memory.
Source amnesia is the inability to remember where, when or how previously learned information has been acquired, while retaining the factual knowledge.