Korsakoff amnesics are poor at judging the sequence of two tones.

Alcoholic amnesics were given a test of temporal sequencing ability devised by Efron which has practically no memory component. These amnesics were very impaired on the task. However, the extent of this impairment did not relate to the magnitude of their "target memory" deficit nor did it relate to the ability to make temporal judgements from memory.

Increased reading speed for words and pronounceable non-words: evidence of preserved priming in amnesics.

Twelve amnesics with various aetiologies were compares with 12 matched control subjects on a task which examined the increase in reading speed for lists of words and pronounceable non-words that were shown several times and read twice during a training phase. After a four minute delay the reading speed for the primed lists was compared with that for an equal number of umprimed lists. No non-specific practice effects were observed.

Disproportionate intentional spatial-memory impairments in amnesia.

Twenty-four amnesics, including patients with Korsakoff's disease, post-encephalitic amnesia and amnesia caused by rupture of an anterior communicating artery aneurysm (ACoAA), were compared with 24 matched control subjects on a task in which words were presented in any one of four positions on a computer screen and subjects were instructed to remember both the words and their locations. The patients were tested after more learning opportunity, exposure to shorter lists, and after shorter delays than were their controls in order to match the word recognition performance of the two groups. Under these conditions, the amnesics' ability to locate recognized words was significantly worse than that of their controls.

Disproportionate incidental spatial-memory and recall deficits in amnesia.

Seventeen amnesics, including patients with Korsakoff's disease, post-encephalitic amnesia and amnesia caused by rupture of an anterior communicating artery aneurysm, were compared with 17 matched control subjects on a task in which 16 nameable shapes were placed on different squares of a 49-square grid. One version of the task tapped free recall and recognition of the shapes and a second version tapped three forms of spatial memory. The patients were tested after more learning opportunity and shorter delays than were the controls so as to match their recognition levels.

Indirect measures of memory in a duration-judgement task are normal in amnesic patients.

Nine amnesic patients of mixed aetiology were studied in a duration-judgement task that allowed three measures of memory to be obtained. On each trial of the task, subjects attempted to read a briefly flashed word and to estimate the duration of the flash. Both word identification and duration estimation differed as a function of prior study.

Investigation of binding site density: effects on the interaction between cibacron blue-dextran conjugates and lysozyme.

Cibacron-blue-dextran conjugates have been produced with a range of ligand loadings using a dextran preparation of average molecular weight of 2 x 10(6). The equilibrium binding capacity of these ligand conjugates for lysozyme was determined using a gel permeation procedure to separate bound from free protein. The results obtained give clear evidence for at least two types of binding showing a marked difference in affinity.

Performance on tests sensitive to frontal lobe lesions by patients with organic amnesia: Leng & Parkin revisited.

Groups of amnesics with aetiologies that included chronic alcoholism, encephalitis and ruptured anterior communicating artery aneurysm (ACoAA) were examined on the Cognitive Estimation Test (CET), FAS Word Fluency Test (FAS) and the full and Nelson (1976) versions of the Wisconsin Card Sorting Test (WCST). The alcoholic amnesics were impaired on all four tests, whereas the post-encephalitic amnesics were impaired on the FAS and CET but performed normally on both versions of the WCST. The ACoAA amnesics were impaired on both the FAS and the CET, and scored at a level in between the other amnesic subgroups on the WCST.

Why are amnesic judgements of recency and frequency made in a qualitatively different way from those of normal people?

The Huppert and Piercy (1978) test of recency and frequency judgements was given to a group of 12 non-Korsakoff amnesics of mixed aetiology and to four non-amnesic patients with selective frontal lobe lesions. The results confirmed that non-Korsakoff amnesics show a significant tendency to base their recency and frequency judgements on memory strength and that amnesics with medial temporal lobe damage show this tendency at least with recency judgements. The patients with frontal lobe lesions performed like normal subjects.

Enhancement of word completion priming in amnesics by cueing with previously novel associates.

Seventeen amnesics of mixed aetiology were given a new association word completion task to determine what factors cause variation among amnesics in the extent of such priming. As a group, the patients failed to show new association word completion although several individual amnesics had scores in the normal range. The extent of new association word completion correlated with word fluency as measured by the FAS test and with cued recall in the priming task.

Amnesia and memory for modality information.

In this study, lists of words were used in a mixed-modality fashion (some read aloud by the subject, others read only by the experimenter). They were presented in this format to both Korsakoff amnesics and matched controls, with subjects only told to remember the words themselves. Controls and amnesics were matched on item-memory (forced-choice recognition) by using longer lists, tested at longer delays, for the controls.

Spatiotemporal memory and rate of forgetting in acute schizophrenics.

Some schizophrenics show anomalies in the frontal and temporal lobes. It is uncertain whether the cognitive deficits shown by Type I schizophrenics are caused directly by such anomalies, or by a deficit in the exertion of attentional effort. In this study, 16 acute schizophrenics, who broadly fitted the Type I characterization and their controls were given a battery of cognitive tests.

Location of lesions in Korsakoff's syndrome: neuropsychological and neuropathological data on two patients.

Psychometric and neuropathological findings on two Korsakoff amnesics are described. Both patients showed anterograde and retrograde amnesia, poor performance on the Peterson short-term memory task, on the Wisconsin card sort test and on certain visuo-spatial tasks. Patient J.

Neural correlates of encoding in an incidental learning paradigm.

Event-related brain potentials (ERPs) were recorded during an incidental learning paradigm. Recall and recognition were better for words initially presented in tasks requiring semantic decisions (i.e.

Amnesic sensitivity to proactive interference: its relationship to priming and the causes of amnesia.

A group of alcoholic amnesics was compared with a group of controls on an A-B, A-C word pairs interference paradigm. With memory instructions the amnesics needed 5 presentation trials to their controls' single trials to match the groups on A-B cued recall. Under these conditions they still showed more proactive interference on the A-C list.

Learning and memory disorders and their assessment.

Brain lesions cause memory to break down in several distinct ways in people. First, cortical lesions cause disturbances in short-term memory. Second, other cortical lesions disturb the retrieval of previously well-established semantic and episodic memories.

Recency and frequency judgements in alcoholic amnesics and normal people with poor memory.

Alcoholic amnesics have been reported to confuse when an event occurred with how frequently it occurred and conversely, how frequently something took place with when it happened. This lack of independence of recency and frequency judgements, shown by these amnesics (but not shown by normal people) has been interpreted as reflecting a selective amnesic failure in memory for contextual information; this failure, in turn, leading to poor recall and recognition memory. The effect is replicated on another group of Korsakoff patients and, by manipulations of retention intervals and of learning opportunity, it is also shown that normal people with memory that is as poor overall as that of amnesics still have specific contextual memory with which to make temporal judgements independently of frequency of presentation and (somewhat less obviously) frequency judgements independently of recency of presentation.

Is organic amnesia caused by a selective deficit in remembering contextual information?

An influential view of amnesia is that the recognition and recall failure is a consequence of a selective loss of memory for contextual, rather than target, information. The various forms of this viewpoint are outlined and one is considered in more detail. This hypothesis claims that amnesics suffer from a selective inability to remember background context i.

Patterns of confidence loss in the cued recall of normal people with attenuated recognition memory: their relevance to a similar amnesic phenomenon.

Amnesics show relatively good cued recall (but very poor recognition memory) yet display little confidence in the accuracy of their cued recall responses. In the two studies reported here a similar pattern of results was found in normal subjects who were either tested after a long retention interval or after being given inadequate time to learn target words, i.e.

A similarity between weak normal memory and amnesia with two and eight choice word recognition: a signal detection analysis.

Two and eight choice recognition memory was compared in a group of normal individuals shortly after learning a list of words and seven days later. In addition to selecting the correct response, subjects were required to indicate the confidence of their choices. The results showed that eight choice recognition performance was differentially worse than two choice recognition at delayed compared to immediate test.

How similar is the effect of cueing in amnesics and in normal subjects following forgetting?

Verbal recognition and cued recall were compared in normal subjects after intervals of 15 minutes, one week and six weeks. When given cues subjects were encouraged to produce as many appropriate words as possible in a 30 second period and rate the words for familiarity. Guessing controls were used and subjects' skill at generating words without a memory component was also assessed.