We present evidence that certain learning parameters can make a memory, even a very recent one, become independent of the hippocampus. We confirm earlier findings that damage to the hippocampus causes severe retrograde amnesia for context memories, but we show that repeated learning sessions create a context memory that is not vulnerable to the damage. The findings demonstrate that memories nor...

We used a free-recall paradigm to establish a behavioral index of the retrograde and anterograde interference of emotion with episodic memory encoding. In two experiments involving 78 subjects, we show that negatively valenced items elicit retrograde amnesia, whereas positively valenced items elicit retrograde hypermnesia. These data indicate item valence is critical in determining retrograde a...

The role of the hippocampus in retrograde amnesia remains controversial and poorly understood. Two cases are reported of discrete bilateral hippocampal damage, one of which was a rare case of limbic encephalitis secondary to the human herpes virus 6. Detailed memory testing showed marked anterograde memory impairment, but only mild, temporally-limited retrograde amnesia that covered a period of...

background: the use of intravenous sedatives is common in gastrointestinal endoscopy. this study is to evaluate the safety and ef_cacy of propofol and/or midazolam in induction of proper sedation in esophagogastroduodenoscopy (egd) compared with a control group, which does not receive sedation for egd. â  methods: four groups (a, b, c and d) of 30 patients each for whom egd had been indicated w...

Evidence of partial retrograde amnesia for episodic memories of no personal salience was found in head injured patients (n = 10) tested during posttraumatic amnesia or shortly after its resolution (n = 10), but there was no selective preservation of the earliest memories. In contrast, head injured patients tested during posttraumatic amnesia exhibited relatively preserved retention of early aut...

We carried out the first neuropsychological study of a series of patients with functional amnesia. We evaluated 10 patients, first with a neurological examination and then with three tests of anterograde amnesia and four tests of retrograde amnesia. Excluding one patient who later admitted to malingering, all patients had a significant premorbid psychiatric history and one or more possible prec...

background: the cholinergic system plays an important role in learning and memory. administration of crocus sativus (saffron) or its constituent, crocin, facilitates the formation of memory. based on above findings, in the current study the effect of crocin in antagonizing retrograde amnesia induced by scopolamine, a cholinergic receptor antagonist, in rats was investigated by using shuttle box...

Several recent studies have shown a flat retrograde amnesia for spatial information following lesions to the hippocampus in rats and mice. However, the results of the present investigation demonstrate that in rats that presurgically learned a spatial reference memory task based on extramaze cues, a temporally graded retrograde amnesia is evident following lesions to the hippocampus (1, 16, 32 o...

A 54-year-old patient of average intelligence with a severe and enduring loss of old autobiographical memories after herpes simplex type 1 infection is described. She was tested with a comprehensive neuropsychological battery 2 years after the infection. Special emphasis was laid on examining different aspects of retrograde memory. The neurological examination involved MRI and SPECT. Brain dama...