Priming, recognition and autonomic discrimination in amnesia.

Six individuals with amnesia and matched healthy controls participated. There were two objectives. First, determine whether physiological activity at encoding relates to whether a word shows autonomic priming or is recognized.

Effects of the timing and identity of retrieval cues in individual recall: an attempt to mimic cross-cueing in collaborative recall.

Inhibitory effects in collaborative recall have been attributed to cross-cueing among partners, in the same way that part-set cues are known to impair recall in individuals. However, studies of part-set cueing in individuals typically involve presenting cues visually at the start of recall, whereas cross-cueing in collaboration is likely to be spoken and distributed over time. In an attempt to bridge this gap, three experiments investigated effects of presenting spoken part-set or extra-list cues at different times during individual recall.

Mutual inhibition in collaborative recall: evidence for a retrieval-based account.

In Experiment 1 participants gave 3 successive free recalls of items learned either individually or in pairwise collaboration. The first and third recalls were performed individually, the second alone or in collaboration. Collaborative recall led to an inhibitory effect after individual learning but not after collaborative learning, in which partners had similar retrieval strategies.

New learning and remote memory in the same and different domains of experience: implications for normal memory and amnesia.

This study investigated the correlation between new and remote memory ability in normal young subjects and evaluated whether using tests that tapped different domains of experience had any effect on the relationship between new and remote memory. Remote memory was assessed using a famous face test and new memory was evaluated using both novel faces and words. The main finding was a significant correlation between New and Remote face familiarity scores.

Do novel associative word stem completion and cued recall share the same memory retrieval processes?

The aim of this study was to determine whether word stem completion for novel associations between cue and target words was mediated by automatic unconscious memory processes or effortful memory processes under conscious control. This was done by applying full and divided attention conditions at test to stem completion, cued recall, and recognition, and by administering a questionnaire that probed the memory strategies used by subjects during the completion test. Divided attention had no effect on stem completion performance, but did reduce associative cued recall.

Shattered illusions: the effect of explicit memory mediation on an indirect memory test.

Four experiments were conducted to explore the possible involvement of explicit memory in an indirect memory test in which white noise accompanying old sentences was judged to be quieter than white noise accompanying new sentences (Jacoby, Allan, Collins & Larwill, 1988). Experiment 1 established that this effect lasted up to 1 week. Experiment 2 found that a group of amnesic patients showed a noise effect that was marginally above chance and not significantly less that that of their matched controls after a delay of one day.

Simulating a memory impairment: can amnesics implicitly outperform simulators?

Objectives: The purpose of this study was to examine the effectiveness of a variety of tests in differentiating simulating test performances from genuine memory-impaired and normal (control) test performances.

Design: A simulation design was implemented, based on an analogue design in which normal participants were given experimental instructions to feign a mental impairment and are compared to (a) other normal participants with instructions to perform honestly, and (b) a comparison group, for example, acquired brain-injured persons, with similar instructions.

Method: Forty individuals comprised the simulating and control group and all participants were randomly assigned to the simulating and control groups.

Autonomic and recognition indices of memory in amnesic and healthy control subjects.

Autonomic and recognition indices were examined in six amnesic subjects of mixed aetiology and six control subjects matched with respect to age, education and intelligence. The key objectives of this study were: (a) assess amnesics level of recognition and autonomic discrimination for recently shown words compared with controls; (b) determine if amnesics' level of autonomic discrimination was preserved when compared with the control subjects, level of recognition; and (c) assess confidence in hits and false alarms. The results showed that: (1) despite showing impaired recognition, amnesics displayed significantly better autonomic discrimination; (2) the level of autonomic discrimination displayed by amnesics did not significantly differ from the control subjects' level of recognition; (3) the level of confidence expressed in false alarms and hits did not significantly differ between amnesics and controls, which is in sharp contrast to the significantly greater levels of confidence expressed by healthy subjects in hits versus false alarms.

Collaboration in recall: do pairs of people cross-cue each other to produce new memories?

When people collaborate over their recall of a shared experience, it might be expected that they could "cross-cue" each other so as to produce new memories not available to either member of the pair on their own. In a previous series of experiments (Meudell et al., 1992), we found that pairs of people always recalled more than one person, but we failed to show that social interaction facilitated performance so as to produce such "emergent" new memories.

Long lasting indirect memory performance for abstract shapes in amnesics and matched controls.

The speed with which subjects copied complex geometrical shapes was used as an indirect memory measure in a group of 12 organic amnesics of several aetiologies and their matched controls, tested at two delays. Both subject groups were found to copy previous seen shapes faster than new foil shapes, and the magnitude of the speed up effect did not differ significantly between amnesics and matched controls when tested at two delays of 10 min and 24 hr, respectively. The size of the indirect memory effect did not decline across the delay in either group.

Two tests for assessing remote public knowledge: a tool for assessing retrograde amnesia.

Guidelines for the construction and development of tests of remote memory are provided. These guidelines follow from methodological considerations and from certain theoretical issues we believe that remote memory tests should address if they are to further our understanding of amnesia. These include: the pattern of temporal gradient; memory for different broad classes of information such as famous names and famous events; and recall and recognition of different types of detail such as contextual and non-contextual information associated with remote memory.

Dual task performance in amnesic and normal people: does resource depletion cause amnesia?

Normal peoples' memory can be seriously disrupted if their cognitive resources are depleted by means of an experimental manipulation (such as distraction at encoding or at retrieval). By analogy, it has also been suggested that amnesia might result directly from pathological loss of cognitive capacity. This hypothesis was examined in 12 mixed amnesics and 12 normal people by means of a 'dual task' study.

Preserved pattern completion priming for novel, abstract geometric shapes in amnesics of several aetiologies.

Two experiments were conducted using a paradigm developed by Gabrieli et al., Neuropsychologia 28, 417-427, 1990, which assessed both indirect and direct memory performance in a completion task for novel abstract geometric patterns. The preferred method of scoring was the lines method, based on the number of correct and incorrect lines produced for each item.

Short report: is spatial information encoded automatically in memory?

A dual-task paradigm was used to test Hasher and Zacks' (1979) hypothesis that spatial memory is automatic. Subjects saw two sets of 16 words each, the words being presented singly in random corners of a monitor screen. They were asked to remember the words and the corner in which each word was shown.

Amnesics have a disproportionately severe memory deficit for interactive context.

Two experiments were used to compare the recognition memory of amnesic and normal subjects for intentionally encoded words (targets) and for incidentally encoded words that were meaningfully related to the targets and presented at the same time (interactive context). In both experiments the target recognition of the two groups was matched at a high level by presenting the amnesics with much shorter lists of words to remember. Experiment 1 compared 20 amnesics and their matched controls and showed that whereas the amnesics' recognition of the target words did not benefit significantly when they were presented together with their interactive context words (relative to their recognition when the target words were presented alone), that of the controls did.

Irrelevant, incidental and core features in the retrograde amnesia associated with Korsakoff's psychosis: a review.

A brief review of the literature on retrograde amnesia in Korsakoff's syndrome is presented. Various explanations of the phenomenon are discussed including the notions that it results from the effects of "state-dependency", that it occurs as a result of a progressive learning problem and that it arises through a failure in contextual processing. None of these hypotheses can satisfactorily account for the length and temporal gradient of alcoholic amnesics retrograde amnesia.

Priming of face matching in amnesia.

Priming was studied in a task that required a speeded response to photographs of faces. On each trial, subjects viewed two faces and decided if the same person was shown twice or if two different people were shown. Both familiar and unfamiliar (i.

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.

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.

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.

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.

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.

Age related differences in left and right hand skill and in visuo-spatial performance: their possible relationships to the hypothesis that the right hemisphere ages more rapidly than the left.

Young and old right handed people were disproportionately worse with their left hand when speed was stressed but showed no especial difficulty when accuracy of performance was emphasised. Both groups of people were also tested on the AH4 test of cognitive abilities. As frequently reported by Rabbitt, the old were disproportionately worse on the visuo-spatial part than on the verbal part compared with the young, even though both parts required "fluid" abilities and even though both were given under time constraints.

Amnesia can facilitate memory performance: evidence from a patient with dissociated retrograde amnesia.

A case is reported of a patient who experienced numerous episodes of transient global amnesia (TGA) during which anterograde amnesia was less prominent than usual, and who developed a permanent selective retrograde amnesia. On formal testing, he performed well on traditional verbal memory tests, but showed marked retrograde amnesia for verbal material, including items on a famous voices recognition test. He was administered a paired-associate learning test where the names of famous personalities for which he was amnesic were associated with incongruous activities (e.