FALSE RECALL AND FALSE RECOGNITION: AN EXAMINATION OF THE EFFECTS OF SELECTIVE AND COMBINED LESIONS TO THE MEDIAL TEMPORAL LOBE/DIENCEPHALON AND FRONTAL LOBE STRUCTURES

The present experiment examined the false recall and false recognition of nonstudied words that are preceded by a list of strong associates in patients with amnesia due to damage restricted to medial temporal lobe or diencephalic regions (MTL/D amnesics), in nonamnesic patients with damage restricted to the frontal lobes (FL nonamnesics), and in amnesic patients with damage to the frontal lobes in addition to medial temporal lobe damage (FL amnesics). We used the Deese/Roediger and McDermott paradigm (Deese, 1959; Roediger & McDermott, 1995) in which people frequently claim that nonstudied words appeared on a presented list. At immediate free recall, the results taken together showed that MTL/D amnesic patients and FL nonamnesic patients produced higher levels of false memory than did controls. At recognition both types of amnesic patients produced less false recognition than either frontal-lobe patients or controls. The results are consistent with the hypothesis that abnormally high levels of false memories are related to the following three conditions: (1) partial memory for the word lists, (2) the ability to extract the semantic gist of the list, and (3) a deficit in strategic monitoring processes.     

Face inversion superiority in a case of prosopagnosia following congenital brain abnormalities: What can it tell us about the specificity and origin of face-processing mechanisms?

In the current study we describe J.M., a 15-year-old boy with a history of congenital brain abnormalities and concomitant visual-processing impairments. J.M.'s most prominent deficit is his impaired face recognition, but formal testing also revealed deficits in other domains of visual processing. One aspect that emerged from J.M.'s visual-processing assessment was a tendency to focus on local features and to rely on them for the encoding and identification of visual stimuli including geometric figures, objects, words, and inverted faces. In spite of this general tendency, he was impaired on tasks requiring the encoding of local features in upright faces. Moreover, his ability to distinguish between features in upright faces was significantly worse than that for inverted faces, the opposite pattern to that typically found in normal participants. What is it that keeps J.M. from applying his otherwise intact feature-based processing to upright faces? As proposed in previous reports of face inversion superiority in individuals with acquired face recognition impairments, we suggest that J.M.'s “inverted-face inversion effect” speaks for a specialized cognitive system that is mandatorily engaged by upright (but not inverted) faces, even when it is impaired and therefore maladaptive. In addition, since J.M. suffered from congenital brain abnormalities affecting the normal development of his face-processing skills, his performance suggests that specialized and mandatorily activated face-processing mechanisms are not entirely experience dependent, and that they can remain modular during development even if they don't function properly and are therefore maladaptive.     

A case study of reproduction conduction aphasia I: Word production

Abstract

We present data regarding word production and short-term auditory verbal memory in a patient, RL, who falls into the class of “reproduction conduction aphasia”. RL shows similar disturbances of single word production in naming, repetition, and reading aloud. He shows qualitatively similar and quantitatively worse performance in repetition of nonwords. His STM is good on tasks (pointing and recognition) which do not require verbal output. We conclude that his disturbance lies at a stage of word production, rather than in the process of perception or in the transfer of perceived representations to motor planning processes. We discuss existing models of the deficit in conduction aphasia and models of word recognition and production in the light of RL's performance, and we argue that none can account for the pattern of his results. We suggest that a model which incorporates two stages of phonological representations, in accordance with contemporary linguistic theory, is supported by the pattern of RL's performances.     

Encoding and retrieval processes in velo-cardio-facial syndrome (VCFS)

Velo-cardio-facial syndrome (VCFS) is a neurogenetic disorder associated with very high risk for developing schizophrenia. More than half of affected individuals experience transient psychotic symptoms during childhood and a third may develop schizophrenia. Memory regulation deficits disturbing both the encoding and retrieval stages of memory represent core deficits in the cognitive profile associated with schizophrenia. In this study, the authors investigate memory regulation processes in 33 individuals with VCFS along with 33 age- and sex-matched control participants. By using a directed forgetting paradigm and a continuous recognition paradigm, the authors examined selective encoding and suppression of irrelevant contents during retrieval in VCFS. Group comparison analyses revealed comparable performances on selective encoding and recognition accuracy between the VCFS group and control group. However, individuals with VCFS were more likely to make false recognitions and showed deficits in the suppression of irrelevant contents. Results suggest that trait-like deficits of memory regulation in VCFS can be observed during the retrieval stage, while selective encoding remains efficient. Memory regulation processes during retrieval may constitute a trait deficit in the memory profile of individuals with VCFS and may contribute to the cognitive deficits underlying an increased risk for developing schizophrenia in this population.     

VERIDICAL AND FALSE MEMORIES IN HEALTHY OLDER ADULTS AND IN DEMENTIA OF THE ALZHEIMER'S TYPE

Five groups of participants (young, healthy old, healthy old-old, very mild Dementia of the Alzheimer's Type, Mild Dementia of the Alzheimer's Type) studied and were tested on six 12-item lists of words selected from the DRM (Deese, 1959; Roediger & McDermott, 1995) materials. These lists of words strongly converged semantically on a nonpresented critical word. The results indicated that both veridical recall and recognition performance decreased both as a function of age of the participants and as a function of dementia severity. However, the recall and recognition of the highly related nonpresented items actually increased as a function of age, and only slightly decreased as a function of DAT. When false memory was considered as a proportion of veridical memory, there was a clear increase as a function of both age of the participants and as a function of disease severity. The results are discussed in terms of (a) age and DAT-related changes in attention and memory performance, and (b) the underlying mechanisms that produce false memories in the DRM paradigm.     

The effect of encoding on false memory: examination on levels of processing and list presentation format

Using the Deese/Roediger-McDermott paradigm, the effects of lists presentation format (blocked/random) and levels of processing of critical nonpresented lures were examined. A levels-of-processing effect in a blocked presentation order was not observed for lures. Rates of false recognition and remember judgments for lures in a shallow level of processing were significantly lower than those in a deep level of processing when items from various themes were inter-mixed instead of blocked. Results showed an interaction between levels of processing and list presentation format. It is thus concluded that encoding of each word and whole list should be both considered in understanding false memory.     

False memory and schizophrenia: evidence for gist memory impairment

BACKGROUND: In this study we examined patients' false memory, that is memory for a non-presented event, to search for a further source of converging evidence for the impairment of semantic memory in individuals with schizophrenia. In two experiments we compared the pattern of false memory created by the Deese-Roediger-McDermott (DRM) paradigm between individuals with schizophrenia and those of a normal control group. METHOD: Experiment 1 tested participants on both recall and recognition of lists of semantically related words. Experiment 2 adopted the meaning recognition test, in addition to the standard recognition test, to assess the participants' gist memory. RESULTS: Individuals with schizophrenia performed worse than normal controls on both recall and recognition of studied words. The schizophrenia patients had higher rates of false recall and false recognition for semantically unrelated words than did the normal controls, suggesting an abnormal pattern of semantic activation in the former group. More importantly, no differences were found between the two groups with regard to false recall and false recognition of semantically related words. When the participants were tested for meaning recognition, however, the schizophrenia patients gave fewer 'old' responses to non-studied semantically related words than did the control group, indicating an impaired gist memory in schizophrenia patients. CONCLUSIONS: When asked to consciously retrieve word lists, individuals with schizophrenia showed impairment not only in item-specific memory but also in gist memory. The pattern of results is consistent with the storage deficit view of semantic memory in schizophrenia.     

NEUROPSYCHOLOGICAL MECHANISMS OF FALSE FACIAL RECOGNITION FOLLOWING FRONTAL LOBE DAMAGE

Previous neuropsychological studies have demonstrated an association between false recognition and frontal lobe dysfunction. In the experiments reported here we explore the contribution of memory impairment and executive dysfunction to the pathogenesis of false facial recognition in patients with focal frontal lobe damage. Memory illusions in response to novel faces were observed in both anterograde and retrograde tests of face recognition memory. However, in neither memory domain could false recognition be accounted for by face memory loss. Instead, our findings suggest that false facial recognition in frontal patients reflects the breakdown of strategic memory retrieval, monitoring, and decision functions critical for attributing the experience of familiarity to a specific source. Frontal executive memory functions are primarily recruited under conditions of uncertainty when the face cue does not automatically elicit relevant contextual information, leaving the source of familiarity unspecified. Our results indicate that frontal patients do not spontaneously engage in effortful recollection of specific contexts that can normally be used to oppose and inhibit recognition decisions based on general or context-free familiarity. However, frontal patients can use context recollection to suppress false recognition once this strategy is pointed out to them. In some frontal patients false recognition may be material-specific.     

Contextual recognition memory deficits in major depression are suppressed by cognitive support at encoding

Objectives

To investigate the effect of cognitive support (an associative orienting instruction at encoding) on contextual memory in depressed patients.

Methods

Seventeen patients (age 20-40 years, 14 women) diagnosed with major depressive disorder (MDD) and 22 healthy controls matched for age, gender and education completed a recognition memory task for item (object) and context (location), with or without an incidental binding cue at encoding. In addition, participants completed the vocabulary subtest of the Wechsler Adult Intelligence Scale (WAIS III) and the Wisconsin Card Sorting Test (WCST). Salivary samples were collected at 7 AM, 4 PM and 10 PM on the day of testing for cortisol and DHEA level measurement.

Results

Depressed patients showed a deficit in contextual memory in the absence of a binding cue but did not differ from healthy controls in item memory or when a binding cue was present. Cortisol and cortisol/DHEA ratios were lower in depressed patients compared to healthy controls and correlated with memory deficits.

Conclusions

Contextual memory deficits in MDD patients can be reduced by providing cognitive support at encoding.     

TEMPORALLY GRADED SEMANTIC MEMORY LOSS IN ALZHEIMER'S DISEASE: CROSS-SECTIONAL AND LONGITUDINAL STUDIES

Abstract

Semantic knowledge of famous names and words that entered popular North American culture at different times in the 20th century was examined in 16 patients with mild-to-moderate Alzheimer's disease (AD), 12 of whom were re-tested 1 year later. All patients showed evidence of temporally graded memory loss, with names and words from the remote past being relatively better preserved than recent names and words. There was considerable between-patient variability with respect to severity of semantic impairment. Most patients exhibited losses extending back 30-40 years; however, two mildly impaired (MMSE >28) patients showed deficits restricted to the last 10-15 years. At the 1-year follow-up, patients not only exhibited more severe deficits overall, but the temporally graded period of loss extended further back in time, suggesting that this deficit reflects a loss of previously intact knowledge and not merely faulty encoding or lack of exposure to the material. The extensive period of graded semantic loss exhibited by most patients contrasts with the temporally limited retrograde semantic loss typical of medial temporal lobe amnesia. We propose that short periods of temporally graded semantic memory loss can be explained by damage to medial temporal structures, but that extensive periods of graded loss occur only with additional damage to neocortical tissue. This pattern contrasts with that of autobiographical memory loss, which is often ungraded and extends for the person's entire lifetime, even when damage is restricted to the medial temporal lobes.     

Different effects of lesions to auditory core and belt cortex on auditory recognition in dogs

Auditory recognition memory, in contrast to memory in other modalities, is not affected by damage to the perihinal cortex, and its neural basis remains unknown. In an attempt to elucidate this problem, we investigated the role of canine auditory core and belt areas in auditory recognition. Either core or posterior belt areas were surgically removed. The core and belt regions were defined on the basis of response properties and thalamocortical connectivity established in previous studies. The animals were tested on auditory delayed matching to sample (DMS, a recognition memory task) using complex, trial-unique auditory stimuli. Both core and belt lesions impaired auditory recognition, however, the underlying deficit was different. Lesions to the core areas impaired auditory localization abilities. Lesions to the posterior belt areas did not affect this component of the recognition task, but affected auditory quality discrimination and/or recognition. The deficit following the posterior belt lesion did not increase with retention delay, suggesting that auditory belt areas do not constitute a substrate for auditory recognition memory. Their main function appears to be processing of complex sound patterns, including immediate recognition. Danuta M. Kowalska deceased in 2002. The study was supported by the James S. McDonnell Foundation grant No. 98-70, and by the Polish State Committee for Scientific Research grant No. 3 P04C 038 23. Paweł Kuśmierek was also supported by the Foundation for Polish Science.     

BDNF Val66Met polymorphism significantly affects d' in verbal recognition memory at short and long delays

A functional polymorphism at the val66met locus in the BDNF gene has significant effects on the pro-form of the protein in intracellular trafficking and activity-dependent, but not constitutive, secretion. These differences are thought to underlie several findings in humans related to this polymorphism, including markers of neuronal viability, BOLD activation in medial temporal lobe regions, and some aspects of behavior. However, many important questions remain about the impact of BDNF on various mnemonic subprocesses at the behavioral level. In this study, we examined the impact of the val/met polymorphism in a verbal recognition memory paradigm involving manipulation of depth of encoding and differential delays for recall and analyses of hits for previously presented target words and correct rejections of foils. Twenty-four human val homozygous individuals and 24 met carrier individuals comprised the sample. All were healthy controls. IQ between the groups was equivalent. In the encoding phase of the study, words were presented and encoded either by a decision as to whether they were living or nonliving ("deep") or if they contained the letter "A" (shallow). After this phase, recognition was tested immediately, half an hour, and 24h later. BDNF genotype had significant effects on hits and discriminability (d'), accounting for at least 10% of the variance, but not on correct rejections or beta. BDNF did not interact with level of encoding, nor did it interact with delay. In sum, BDNF genotypes impacted "hits" in a recognition memory paradigm, findings consistent with the general notion that BDNF plays a prominent role in memory subprocesses thought to engage the medial temporal lobe.     

True and false memories in adolescents with psychosis: Evidence for impaired recollection and familiarity

Introduction. Psychotic patients are impaired on recall and recognition of studied items (true memory) and typically make more false recall (intrusions) and false recognition than controls, reflecting greater susceptibility to false memory. The functional mechanisms underlying these deficits are poorly understood. The aim of this study was to examine recollection and familiarity in true and false memory in psychotic adolescents without long-term exposure to medication and repeated hospitalisations.

Methods. Seventeen adolescents with psychosis and 17 matched controls were tested on a DRM false memory paradigm combined with a remember (R)/know (K)/guess (G) procedure. Recall and recognition of targets (studied words), critical lures (associated words) and unrelated distractors were measured. Between-group comparisons were made using t-tests and mixed ANOVAs. Independent estimates for recollection and familiarity were also calculated.

Results. True memory was impaired in patients. Similar rates of false memory for critical lures were found in both groups. False memory for unrelated distractors was increased in patients. Contrary to controls, who attributed more R and K responses to targets than lures, patients attributed similar proportions of R and K responses to targets and lures. Furthermore, patients attributed more K responses than controls to all distractors.

Conclusions. These findings suggest a deficit in recollection- and familiarity-based memory in psychotic adolescents as well as reliance on preserved gist or meaning-based memory to support poor item-specific memory.     

A sensory signature that distinguishes true from false memories

Human behavioral studies show that there is greater sensory/perceptual detail associated with true memories than false memories. We therefore hypothesized that true recognition of abstract shapes would elicit greater visual cortical activation than would false recognition. During functional magnetic resonance imaging (fMRI), participants studied exemplar shapes and later made recognition memory decisions ("old" or "new") concerning studied exemplars (old shapes), nonstudied lures (related shapes) and new shapes. Within visual processing regions, direct contrasts between true recognition ("old" response to an old shape; old-hit) and false recognition ("old" response to a related shape; related-false alarm) revealed preferential true recognition-related activity in early visual processing regions (Brodmann area (BA)17, BA18). By comparison, both true and false recognition were associated with activity in early and late (BA19, BA37) visual processing regions, the late regions potentially supporting "old" responses, independent of accuracy. Further analyses suggested that the differential early visual processing activity reflected repetition priming, a type of implicit memory. Thus, the sensory signature that distinguishes true from false recognition may not be accessible to conscious awareness.     

ERP correlates of true and false recognition after different retention delays: stimulus- and response-related processes

Performance and electrophysiological correlates of true and false recognition were examined after short (40 s) and long (80 s) delays. True recognition showed no significant decrease after a long delay, whereas false recognition increased. Early frontal and parietal ERP old/new effects, considered as correlates of familiarity and recollection, were observed across delay for true recognition. No frontal effect occurred in the long delay for false recognition. This absence may arise from weakened memory traces preventing familiarity discrimination for LUREs. Response-related analysis revealed an error-related negativity (ERN) for true and false recognition, assuming that the effect reflects at least partly an internal misrepresentation of the correct response. The larger and topographically different ERNs for false recognition suggest an additional contribution of increased task demands and conditions of high response uncertainty.     

Kihi-to, a herbal traditional medicine, improves Abeta(25–35)-induced memory impairment and losses of neurites and synapses

Background

We previously hypothesized that achievement of recovery of brain function after the injury requires the reconstruction of neuronal networks, including neurite regeneration and synapse reformation. Kihi-to is composed of twelve crude drugs, some of which have already been shown to possess neurite extension properties in our previous studies. The effect of Kihi-to on memory deficit has not been examined. Thus, the goal of the present study is to determine the in vivo and in vitro effects of Kihi-to on memory, neurite growth and synapse reconstruction.

Methods

Effects of Kihi-to, a traditional Japanese-Chinese traditional medicine, on memory deficits and losses of neurites and synapses were examined using Alzheimer's disease model mice. Improvements of Aβ(25–35)-induced neuritic atrophy by Kihi-to and the mechanism were investigated in cultured cortical neurons.

Results

Administration of Kihi-to for consecutive 3 days resulted in marked improvements of Aβ(25–35)-induced impairments in memory acquisition, memory retention, and object recognition memory in mice. Immunohistochemical comparisons suggested that Kihi-to attenuated neuritic, synaptic and myelin losses in the cerebral cortex, hippocampus and striatum. Kihi-to also attenuated the calpain increase in the cerebral cortex and hippocampus. When Kihi-to was added to cells 4 days after Aβ(25–35) treatment, axonal and dendritic outgrowths in cultured cortical neurons were restored as demonstrated by extended lengths of phosphorylated neurofilament-H (P-NF-H) and microtubule-associated protein (MAP)2-positive neurites. Aβ(25–35)-induced cell death in cortical culture was also markedly inhibited by Kihi-to. Since NF-H, MAP2 and myelin basic protein (MBP) are substrates of calpain, and calpain is known to be involved in Aβ-induced axonal atrophy, expression levels of calpain and calpastatin were measured. Treatment with Kihi-to inhibited the Aβ(25–35)-evoked increase in the calpain level and decrease in the calpastatin level. In addition, Kihi-to inhibited Aβ(25–35)-induced calcium entry.

Conclusion

In conclusion Kihi-to clearly improved the memory impairment and losses of neurites and synapses.     

Comparison of various RAVLT scores in the detection of noncredible memory performance.

Sixty-one noncredible patients (as documented by psychometric and behavioral criteria) scored significantly below 25 controls and 88 credible clinic patients with no motive to feign on most RAVLT scores, including added indices of implicit and "automatic" memory. A combination of true recognition (i.e., recognition minus false positives) + implicit memory score (i.e., the number of word stems completed with RAVLT items) + "automatic" memory score (i.e., the number of correct temporal order judgments) < or =22 was associated with 75.7% sensitivity with specificity at 91.5%. However, sensitivity was nearly as high when scores available from the standard RAVLT administration alone (i.e., no word stem or temporal order trials) were combined. Specifically, a cut-off of < or =12 for true recognition (recognition minus false positives) + primacy recognition (i.e., number of words recognized from the first third of the test) was associated with 73.8% sensitivity at 90% specificity. These results indicate that combined indices of recognition memory from the RAVLT are effective in identifying noncredible memory performance in "real world" samples and are modestly superior to the 67.2% sensitivity obtained with the standard recognition score.     

VISUAL ERRORS IN ACQUIRED DYSLEXIA: EVIDENCE FOR CASCADED LEXICAL PROCESSING

A single case study is reported of the dyslexic and only mildly aphasic patient AT who almost exclusively produced visually related errors in reading aloud. His performance in the auditory modality (auditory comprehension, phoneme discrimination) was nearly perfect, his repetition and oral naming abilities for single-word production were almost unimpaired. Closer examinations of his reading disturbance revealed a deficit in visual processing of orthographic materials which extended to Arabic numbers and other nonlinguistic symbols. Contrasting with this prelexical deficit, AT's performance in reading aloud and also in visual lexical decision was strongly influenced by factor imageability, which could not be attributed to a general semantic deficit. It is argued that AT's pattern of reading performance (prelexical visual impairment and imageability effects on his visual errors) cannot be accounted for by a discrete stage model of lexical-orthographic processing allowing only one lexical candidate to be selected. Rather, the case AT provides empirical evidence for cascaded processing between the lexical and semantic level. The cascade account suggests that not only one but several visually related lexical candidates activate their corresponding semantic representations with different degrees of imageability.     

Impaired recall of verbal material following rupture and repair of an anterior communicating artery aneurysm

Abstract

This paper presents a detailed investigation of the memory impairment suffered by a patient, ROB, following the rupture and repair of an anterior communicating artery aneurysm that damaged her left hemisphere. ROB is severely impaired on standard tests of verbal recall such as paired-associate learning and memory for prose passages. Nevertheless she performs normally on both versions of Warrington's (1984) recognition memory test, and on tests that require recall of visuo-spatial material. She also shows no evidence of confabulation. The discrepancy between recall and recognition performance persists even when attempts are made to ensure that the two types of test are equally “difficult” (cf. Calev, 1984). The impairment does not seem to be caused by inappropriate encoding strategies, since recall performance is not improved by imagery instructions or by levels of processing manipulations (Craik&Tulving, 1975). She also performs normally on implicit memory tests regardless of whether they involve data-driven or conceptdriven retrieval processes (cf. Roediger, 1990a; 1990b). It is argued that her recall problems reflect an inability to set up effective retrieval strategies that would enable her to access information stored in episodic memory.     

The effect of selective attention to emotional stimuli on recognition memory in anxiety

It has been argued that the selective attention characteristic of trait anxiety does not significantly influence on memory. However, attention to stimuli is considered to accelerate memory performance of the stimuli in general. The present study examined whether the selective attention due to emotional valences could reflect on recognition memory in individuals with high anxiety. In the encoding phase, a set of pairs of emotional and neutral words was presented. The duration of presentation of stimuli was manipulated in two conditions (1,300 ms vs. 2,000 ms). There was no difference in responses for stimuli between with positive and with negative valences. In the short-presentation condition, compared to the control group, the high-anxious group demonstrated greater discrimination for emotional (positive and negative) stimuli relative than for neutral ones. Their false alarm rate, on the other hand, was consistently higher than the subjects in the low-anxious group. Results in the present study suggested that selective attention that the high-anxious subjects allocated to emotional stimuli could influence performance of recognition of those stimuli.