Two patients with transient global amnesia are reported. Comprehensive neuropsychological evaluation, during the amnesic episode, as well as follow-up examinations on memory were performed. The course of the amnesia was exemplified by two comparable memory tests in different modalities. Partial retrograde amnesia and complete anterograde amnesia were demonstrated during the transient episode. O...

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...

In a double-blind, placebo-controlled experiment that used midazolam, a benzodiazepine that creates temporary amnesia, we compared acquisition and retention of paired associates of different types. Some word pairs were studied before the injection of saline or midazolam, and two lists of word pairs were studied after the injection. Critical comparisons involved retention of pairs that were prac...

Patients with anterograde amnesia are commonly believed to exhibit normal implicit learning. Research with the serial reaction time (SRT) task suggests that normal subjects can implicitly learn visuospatial sequences through a process that is sensitive to higher-order information that is more complex than pairwise associations between adjacent stimuli. The present research reexamined SRT learni...

K.C. has been investigated extensively over some 20 years since a motorcycle accident left him with widespread brain damage that includes large bilateral hippocampal lesions, which caused a remarkable case of memory impairment. On standard testing, K.C.'s anterograde amnesia is as severe as that of any other case reported in the literature, including H.M. However, his ability to make use of kno...

Effects of ibotenic entorhinal cortex (EC) lesions on both retrograde and anterograde amnesia in mice were assessed using two-choice discrimination tasks learned at different intervals before surgery in two eight-arm radial mazes. The results indicated that EC-lesioned mice were severely impaired in postoperative retention of discrimination problems learned 3 d or 2 weeks prior to surgery, but ...

Two principal arguments against a consolidation-block formulation of anterograde amnesia are the existence of pnor-list intrusion errors and the facilitating effect of cued recall Both of these findings can be explained if one assumes an additional process trace activation of already existing memories. This consolidation-block plus trace-activation view predicts that in densely amnesic patients...

Two patients developed anterograde amnesia following the apparently uncomplicated transcallosal-transventricular removal of a colloid cyst. Damage to the fornical columns was demonstrated on CT and MRI scans, whilst other memory related structures were entirely normal. Longitudinal neuropsychological evaluation, over 12-24 months, has revealed a very similar pattern of deficit in the two cases:...

The notion of multiple memory systems based on conscious accessibility has been supported largely by neuropsychological patient studies. Specifically, it was widely held that amnesic patients have impaired explicit memory performance but spared implicit memory performance. However, recent patient studies have called the implicit/explicit memory distinction into question. In this study, normal p...