Biomedical subjects

A J Parkin

Publications and source records attributed to A J Parkin.

At least 19 recordsLinked to original sources

PubMed2001

Source monitoring and false memories in children: relation to certainty and executive functioning.

We presented children aged 6, 8, and 10 years with a video and then an audio tape about a dog named Mick. Some information was repeated in the two sources and some was unique to one source. We examined: (a) children's hit rate for remembering whether events occurred and their tendency to make false alarms, (b) their memory for the context in which events occurred (source monitoring), (c) their certainty about hits, false alarms, and source, and (d) whether working memory and inhibition were related to hits, false alarms, and source monitoring. The certainty ratings revealed deficits in children's understanding of when they had erred on source questions and of when they had made false alarms. In addition, inhibitory ability accounted for unique variance in the ability to avoid false alarms and in some kinds of source monitoring but not hits. In contrast, working memory tended to correlate with all forms of memory including hits.

Child↗

PubMed2001

Data-driven recognition memory: a new technique and some data on age differences.

In this study, we investigate the effect on recognition memory of having target and distractor stimuli consisting of different combinations of low-level elements (letters), relative to when targets and distractors consist of combinations of the same elements (nonoverlap and overlap conditions, respectively). It was found that recognition memory was enhanced in the nonoverlap condition, even though subjects reported being unaware of this experimental manipulation. This confirms the importance of perceptually driven processing in the implicit memory component of recognition memory. The extent to which this effect occurs is found to be age dependent, with elderly subjects benefiting more from having targets and distractors consisting of nonoverlapping elements. This is consistent with the notion that elderly subjects show less reliance on item-specific/contextual detail to support recognition memory.

Adult↗

PubMed2001

British memory research: a journey through the 20th century.

A century of research in memory has generated a wealth of knowledge encompassing theoretical developments within a number of distinct domains of memory. The aim of this article is to explore the progress made in memory research during the 20th century, to indicate critical influences on the direction of research, and to illustrate the important contribution made by British researchers. This article is confined to human memory research, and reviews research findings from the various psychological disciplines studied over the past 100 years.

History, 20th Century↗

PubMed2000

The role of semantics in reading and spelling: evidence for the 'summation hypothesis'.

This study documents a patient, SA, with an impairment of semantic memory arising as a result of Semantic Dementia (Pick's disease). The patient is impaired at deriving semantic knowledge from both words and pictures. However, his ability to derive semantic knowledge of countries is relatively spared compared to concrete nouns and famous people. The presence of a semantic deficit was used to investigate the role of semantics in reading and spelling. Several novel cueing/priming paradigms are reported which suggest that SA is able to use partial semantic knowledge to constrain his reading and spelling. These results are broadly consistent with the 'summation hypothesis' [27] and suggest that normal reading and spelling may take place by integrating both semantic information and knowledge of direct orthography-phonology correspondences.

Atrophy↗

PubMed2000

Reversed negative priming following frontal lobe lesions.

The present study investigated whether lesions to the prefrontal cortex would lead to impaired inhibitory control in selective attention. Patients with uni- and bilateral frontal lobe damage and age-matched control participants were compared in an identity negative priming task involving letter naming. Whereas all control groups revealed robust negative priming and distractor interference, the majority of patients showed positive instead of negative priming and not all of them were more susceptible to interference. These results suggest that frontal lobe lesions disrupt distractor inhibition and cannot be explained in terms of a retrieval deficit. However, the level of interference may not only be determined by inhibition but also by excitation of the target stimulus.

Adult↗

PubMed1999

Human memory.

Explore the source record for details and available documents.

Amnesia↗

PubMed1998

Levels of processing and single word priming in amnesic and control subjects.

This paper describes an experiment which examined how levels of processing (LOP) affected word fragment completion in a group of Wernicke-Korsakoff patients, a group of patients with closed head injury, and matched controls. The data showed that both the memory-impaired groups and the controls showed a LOP effect but that the effect was larger in controls. Data from other studies are reviewed and, in conjunction with the present findings, it is concluded that LOP effects obtained when memory-impaired individuals are tested using implicit memory tasks arise mainly from the contribution of lexical processing of targets and from contamination by explicit recollection.

Adult↗

PubMed1998

Are the benefits of errorless learning dependent on implicit memory?

The effectiveness of errorless and errorful learning methods was compared in two experiments in which a group of memory-impaired individuals learned lists of single words. In both experiments, error prevention during learning resulted in higher levels of cued recall performance than trial-and-error learning. Experiment 1 showed that the beneficial effects of the errorless learning method extended over a delay of up to 48 hr and were also observed in free recall. The hypothesis that the benefits of errorless learning rely upon implicit memory was tested in Experiment 2. No evidence was found to support the hypothesis. Implicit memory was observed following both errorless and errorful learning, but there was no indication that enhanced performance in the errorless condition could be accounted for by implicit memory. There was no correlation between performance on a direct test (cued recall) and performance on an indirect test (fragment completion) for the same materials. Furthermore, the extent of priming was no greater for recalled items than non-recalled items in the cued recall test. It is proposed that the benefits of errorless learning in this paradigm stem from the effects of error prevention on residual explicit memory.

Adult↗

PubMed1998

The central executive does not exist.

In this article I critically review the concept of the central executive. I argue that the experimental evidence for a central executive lacks rigor to the point where it is an unfalsifiable construct. I examine the neuropsychological and neuroradiological evidence and demonstrate that there is no localization evidence for a central executive. What emerges instead is a pattern of extensive heterogeneity with different executive tasks associated with different neural substrates. In sum it is argued that the idea of a central executive should be abandoned, and, from a neuropsychological perspective, tests that purport to measure executive function should do so in a qualitative way rather than assume that a range of tests load on a unitary dimension of performance.

Animals↗

PubMed1998

Revising current two-process accounts of spacing effects in memory.

Memory for repeated items improves when presentations are spaced during study. In Experiment 1A, words were repeated either immediately or after 6 intervening items. Intentional learning occurred under either focused or divided attention. Retention was tested by either free recall or yes-no recognition. Divided attention did not affect the influence of spacing in free recall, whereas it removed the spacing effect in recognition. In Experiment 1B, recognition memory was tested after incidental semantic study of words performed under either focused or divided attention. An equivalent spacing effect occurred in both attentional conditions. In Experiments 2 and 3, recognition memory for unfamiliar faces was assessed. A reliable spacing effect was found under both intentional learning and incidental structural study. These data are, collectively, incompatible with current theories of spacing effects. A theoretical proposal to account for these new findings is outlined.

Attention↗

PubMed1998

Consequences of violating the assumption of independence in the process dissociation procedure: a word fragment completion study.

In three experiments that used levels of processing and study time manipulations as independent variables in a word fragment completion task, the validity of the assumption of independence between recollection and automatic influences of memory was assessed. This assumption underlies the use of the process dissociation procedure (Jacoby, 1991), a tool suggested for distinguishing the different contributions of recollection and automatic influences of memory. Overall, it appeared that semantic processing, as compared with physical processing at study, positively affected recollection but negatively affected automatic influences of memory in word fragment completion. This negative effect on the automatic influences was reduced when the available study time decreased. The incompatibility of these results with the assumption of independence between recollection and automatic influences of memory and their impact on the applicability of the process dissociation procedure are discussed.

Adult↗

PubMed1997

Human memory: novelty, association and the brain.

The hippocampus has been clearly implicated in memory, but its precise role is unclear. Recent imaging studies suggest that the hippocampus is particularly concerned with the detection of novelty, as opposed to the prefrontal cortex, which seems more concerned with encoding associations.

Brain Mapping↗

PubMed1997

Errorless learning of novel associations in amnesia.

In two experiments involving verbal association learning by people with memory impairments, the effectiveness of errorless learning (EL) was compared with errorful learning (EF). Experiment 1 examined the effectiveness of both methods in learning remotely linked word pairs. There was an advantage for items learned by EL at immediate test which was not sustained over a delay of 1 hr. Learning appeared to be stable over this delay in the EF condition. Analysis of responses at delayed cued recall showed more evidence of spontaneous recovery in EF than in EL. Elimination of these items from analysis resulted in a similar pattern of forgetting in both methods. Experiment 2 examined the effectiveness of EL and EF in teaching novel associations, and showed an advantage for EL at immediate and delayed test. Forgetting was apparently observed following EL, but not EF. As in Experiment 1, this discrepancy was attributed to recovered responses at delayed test in EF. Eliminating these responses showed a similar pattern of forgetting in both methods for items correctly recalled at immediate test. The study shows an advantage for EL techniques in learning novel associations. The two methods also differ in that learning via EF is associated with more spontaneous recovery.

Adult↗

PubMed1996

Human memory: the hippocampus is the key.

A recent study of brain-damaged patients with various degrees of amnesia provides compelling new evidence that the hippocampus plays a vital role in the laying down of new memories. Why existing memories are also affected by hippocampal damage is particularly puzzling.

Amnesia↗

PubMed1996

Pathological false alarm rates following damage to the left frontal cortex.

In this study we present further data on case JB who developed memory impairment following a ruptured aneurysm of the anterior communicating artery which resulted in damage centered on the frontal cortex. The data reveal the JB's memory impairment is characterized by a recall impairment in which intrusion rates are abnormally high and a recognition deficit characterized by an exceptionally high false alarm rates. A comparison is made between this case and other recent cases involving impairments with a similar etiology. Theoretical interpretations of JB's deficit are also considered.

Aneurysm, Ruptured↗

PubMed1996

Things that go bump in your life: explaining the reminiscence bump in autobiographical memory.

Two experiments explore the reminiscence bump (RB)--the disproportionately higher recall of early-life memories--by older adults. In Experiment 1, participants in the age ranges of 36-40, 46-50, and 56-60 recalled events freely or under instructions to avoid recent memories. Constraint did not affect older participants but resulted in the appearance of an RB in younger participants. In Experiment 2, recall was constrained to particular life periods. Memories from these periods were compared for ease of retrieval and along subjective dimensions (e.g. vividness). Memories from early life were more easily retrieved, but this was not due to differences in subjective qualities. A higher proportion of memories for first-time events were identified from early life, and these memories were more easily retrievable. The results are discussed in relation to an existing model of autobiographical memory, and a revised model is put forward.

Adult↗

PubMed1996

Focal retrograde amnesia: a multi-faceted disorder?

In this paper I review the recently introduced syndrome of focal retrograde amnesia-a disproportionate impairment of remote memory in the presence of normal or near normal anterograde memory. It is concluded that the modal form of the syndrome has been reliably demonstrated and that the underlying pathology involves damage to the temporal lobes and relative sparing of the hippocampal formation. A variant of the syndrome associated with parietal and occipital lobe damage is also presented. Finally, a third type of focal retrograde amnesia associated with minor brain trauma is considered to be or primarily psychogenic origin.

Amnesia, Retrograde↗

PubMed1995

Functional aspects of recollective experience in face recognition.

This article describes two experiments on awareness in recognition memory for novel faces. Two kinds of awareness, recollective experience and feelings of familiarity in the absence of recollective experience, were measured by "remember" and "know" responses. Experiment 1 showed that "remember" but not "know" responses were reduced by divided attention at study. Experiment 2 showed that massed versus spaced repetition of faces in the study list had opposite effects on "remember" and "know" responses. Massed repetition increased "know" responses and reduced "remember" responses. Spaced repetition increased "remember" responses and reduced "know" responses. The results of both experiments replicate previous findings from the verbal domain in the domain of face recognition, and hence they increase the ecological validity of this experimental approach to memory and awareness and the generality of its database. These findings are discussed from a rehearsal perspective on factors influencing the two states of awareness and in relation to the alternative "process dissociation" procedure.

Adult↗