Declarativeand nondeclarativememory in opposition:When priorevents influence amnesicpatients morethan normal subjects

Amnesic patients and normal subjects read the names of nonfamous persons. Then, after being told that all the names were nonfamous, subjects judged the fame of names on a mixed list of new famous names, old nonfamous names, and new nonfamous names. Finally, they took a recognition memory test involving old and new nonfamous names. In this way, declarative (explicit) memory and nondeclarative (implicit) memory were placed in opposition. That is, recollection that a name had been recently presented (and was therefore nonfamous) opposed the focilitatory effect by which prior presentation ordinarily increases the tendency to judge that name as famous. Normal subjects exhibited good recognition memory and no fame-judgment effect—that is, no difference in fame judgments for new and old nonfamous names. By contrast, for the amnesic patients recognition memory was poor, but astrong fame-judgment effect occurred—that is, amnesic patients judged old nonfamousnames as famous. The results provide additional evidence that the fame-judgment effect is supported fully by nondeclarative (implicit) memory and is independent of the limbic/diencephalicbrain structures damaged in amnesia.     

A direct comparison of recognition failure rates for recallable names in episodic and semanticmemory tests

In an extension of Muter’s (1978) research, subjects studied pairs of lowercase cues and uppercase targets consisting of famous names (e.g., betsy ROSS), nonfamous names (e.g., edwin CONWAY), weakly related words (e.g., grasp BABY), and unrelated words (e.g., art GO). Following recognition tests in which surname and word targets were tested in the absence of their cues, cued recall tests for the surname and word targets were given. In semantic recognition and recall tests, the response to a surname was to be made solely on the basis of its fame, regardless of whether or not it had appeared in the study list. In episodic memory tests, the response to a surname was to be made solely on the basis of whether or not it had appeared in the study list, regardless of its fame. In all tests, the response to a nonname was to be made solely on the basis of whether or not it had appeared in the study list. The Tulving-Wiseman (1975) function accurately predicted recognition failure rates for famous surnames, whether or not they were from the study list and whether the test was episodic or semantic, and for targets from the weakly relatedword pairs. However, recognition failure rates were lower than the Tulving-Wiseman function predicted for nonfamous surnames in the episodic memory test and for targets from unrelated word pairs. Discussion focused on these results’ implications for the nature of the Tulving-Wiseman function and the psychological reality of the episodic-semantic memory distinction.     

The effect of increasing the memorability of category instances on estimates of category size

According to Tversky and Kahneman’s (1973) availability heuristic, people sometimes make use of the ease with which instances are retrieved when they have to estimate proportions or frequencies. One implication of this availability heuristic is that any factor that affects memorability of instances from a category should also affect the estimated category size. In one of their experiments, Tversky and Kahneman found that, after being presented with a list of names, people judged the more famous names to be more frequent. Similarly, recall was found to be greater for the more famous names. Three experiments that used Tversky and Kahneman’s paradigm are reported. Repeating nonfamous names resulted in their increased recallability and a corresponding increase in estimates of their frequency (Experiments 1 and 3). Making nonfamous names more salient (Experiment 3) also had parallel effects on recallability and frequency estimates, indicating that different memory manipulations affected availability in a similar fashion. Furthermore, reliance on the heuristic was not changed as a function of prior knowledge (Experiment 2) or practice (Experiment 3)     

The availability heuristic with famous names: a replication

In two experiments, 195 Canadian undergraduates initially judged a list of 25 names (12 famous men and 13 nonfamous women or 12 famous women and 13 nonfamous men) for familiarity. Contrary to previous research, subsequent estimates of the perceived number of men's and women's names were not higher when the names were famous than nonfamous. When the estimated differences were compared to the true difference (-1), famous names were judged more numerous than nonfamous names, but the size of the effect (d = 0.34) was smaller than in previous research. Reasons for these findings are discussed.     

I recognize your face but I can’t remember your name: Further evidence on the tip-of-the-tongue phenomenon

Fifty faces of “famous” persons were used as stimuli to precipitate the tip-of-the-tongue (TOT) experience. Results showed that Ss in TOT states searched for target’s name by locating first his profession, where he was most often seen, and how recently. Ss also had accurate knowledge of the initial letters of target names, initial letters of similar sounding names, and numbers of syllables in target names. It was concluded that TOT states for to-be-remembered names are retrieved from semantic and episodie memory systems on the basis of verbal and imaginal encodings.     

The illusion of fame: how the nonfamous become famous

This article reports 2 experiments in which nonfamous faces were paired with famous (e.g., Oprah Winfrey) or semifamous (e.g., Annika Sorenstam) faces during an initial orienting task. In Experiment 1, the orienting task directed participants to consider the relationship between the paired faces. In Experiment 2, participants considered distinctive qualities of the paired faces. Participants then judged the fame level of old and new nonfamous faces, semifamous faces, and famous faces. Pairing a nonfamous face with a famous face resulted in a higher fame rating than pairing a nonfamous face with a semifamous face. The fame attached to the famous people was misattributed to their nonfamous partners. We discuss this pattern of results in the context of current theoretical explanations of familiarity misattributions.     

A neuropsychological study of fact memory and source amnesia

We investigated the ability of amnesic patients to learn new facts (e.g., Angel Falls is located in Venezuela) and also to remember where and when the facts were learned (i.e., source memory). To assess the susceptibility of fact and source memory to retrograde amnesia, patients prescribed electroconvulsive therapy were presented facts prior to the first treatment and were tested after their second treatment. All amnesic patients exhibited marked fact memory impairment. In addition, some amnesic patients exhibited source amnesia (i.e., they recalled a few facts but then could not remember where or when those facts had been learned). Source amnesia was unrelated to the severity of the memory deficit itself, because patients who exhibited source amnesia recalled as many facts as the patients who did not. These results show that the deficit in amnesia includes an impairment in acquiring and retaining new facts. Source amnesia can also occur, but it is dissociable from impaired recall and recognition and appears to reflect difficulty in remembering the specific context in which information is acquired. The findings are discussed in terms of their significance for how memory is organized.     

Effects of aging on source monitoring: differences in susceptibility to false fame

Older adults were less likely than young adults to spontaneously recollect the source of familiarity for previously read nonfamous names. Older adults were more likely to call old nonfamous names famous when subsequently encountered in a fame judgment task. Poor source monitoring by the elderly could not be accounted for by inability to recognize earlier read nonfamous names when specifically asked to do so. Both source-monitoring errors and recognition memory performance were based on attributions made about the experience of familiarity. Elderly subjects most prone to making familiarity errors recalled fewer items on a verbal learning task and were less likely to chunk information into semantic categories as it was recalled. This finding suggests that a decline in the tendency to spontaneously organize and integrate information underlies the poor source monitoring observed.     

Masked repetition and phonological priming in picture naming

We report a series of picture naming experiments in which target pictures were primed by briefly presented masked words. Experiment 1 demonstrates that the prior presentation of the same word prime (e.g.,rose-rose) facilitates picture naming independently of the target’s name frequency. In Experiment 2, primes that were homophones of picture targets (e.g.,rows-rose) also produced facilitatory effects compared with unrelated controls, but priming was significantly larger for targets with low-frequency names relative to targets with high-frequency names. In Experiment 3, primes that were higher frequency homophones of picture targets produced facilitatory effects compared with identical primes. These results are discussed in relation to different accounts of the effects of masked priming in current models of picture naming.     

Impaired priming of new associations in amnesia

We assessed priming of new associations in amnesic patients and healthy control subjects in a paradigm developed by Graf and Schacter (1985). Subjects were presented unrelated word pairs embedded in sentences (e.g., A BELL was hanging over the baby's CRADLE) and were asked to rate how well the sentences related the two words. Subjects were then given a word completion test. They were shown three-letter word stems and were asked to complete the stem with the first word that came to mind. In the same context condition, each word stem was presented together with the word that had appeared in the same sentence during study (e.g., BELL-CRA--). In the different context condition, each stem was presented together with a new word that had never been presented (e.g., APPLE-CRA--). Control subjects completed more words in the same context condition than in the different context condition. In contrast, amnesic patients did not complete any more words in the same context condition than in the different context condition. Indeed, across two experiments none of the amnesic patients exhibited consistent priming of new associations. Thus, although amnesic patients do exhibit entirely normal priming of preexisting memory representations, they do not appear to exhibit priming of new associations in this paradigm.     

The fractionation of retrograde amnesia

This single case study describes our investigations of the retrograde memory deficit of a patient who became severely and selectively amnesic after an encephalitic illness. On clinical assessment his retrograde deficit for both personal and public events appeared to encompass his entire adult life. However, he retained knowledge of words introduced into the vocabulary during the retrograde period. The experimental investigation documented his inability to recall, recognize, and place in temporal order the names and faces of famous people for all time periods sampled. By contrast, his recall of either a famous face or a famous name was significantly facilitated by the verbal cue of the person's first name and initial of the surname (i.e., Margaret T...). His performance on a test of "familiarity" that required him to select the famous name or the famous face from two distractors (unknown) was within normal limits. It is argued that names and faces of famous people are represented in more than one system: both in a vocabulary-like fact memory system that is preserved and also in a congnitively mediated schemata that in this case is functionally inoperative.     

False recency and false fame of faces in young adulthood and old age

Studies of age differences in face recognition have shown age-related increases in false-alarm errors: elderly persons exceed young adults in judging new faces to be old. To distinguish among theoretical accounts of this finding, we compared young and elderly subjects in two recognition tasks: (1) that of judging whether faces were recent or nonrecent, and (2) that of judging whether faces were famous or nonfamous. The major independent variable was prior presentation of faces-including nonrecent and nonfamous foils-1 week before the test. False recent judgments in response to nonrecent faces and false famous judgments in response to nonfamous faces were higher among the elderly. Moreover, these age-related differences in false-alarm rates were larger for faces viewed 1 week previously than for entirely new faces. The findings suggest that, compared to young adults, older individuals rely relatively more on perceived familiarity, and relatively less on recollection of context, in making recognition decisions.     

Intact and long-lasting repetition priming in amnesia.

In 2 experiments, we evaluated the ability of amnesic patients to exhibit long-lasting perceptual priming after a single exposure to pictures. Ss named pictures as quickly as possible on a single occasion, and later named the same pictures mixed with new pictures. In Experiment 1, amnesic patients exhibited fully intact priming effects lasting at least 7 days. In Experiment 2, the priming effect for both groups was shown to depend on both highly specific visual information and on less visual, more conceptual information. In contrast, recognition memory was severely impaired in the patients, as assessed by both accuracy and response time. The results provide the first report of a long-lasting priming effect in amnesic patients, based on a single encounter, which occurs as strongly in the patients as in normal Ss. Together with other recent findings, the results suggest that long-lasting priming and recognition memory depend on separate brain systems.     

Functional amnesia: clinical description and neuropsychological profile of 10 cases

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 precipitating factors for their amnesia. Eight of the 10 patients still had persistent retrograde amnesia at our last contact with them (median = 14 mo after the onset of amnesia). On tests of anterograde amnesia, the patients performed normally as a group, though some patients scored poorly on tests of verbal memory. On tests of retrograde amnesia, all patients had difficulty re-collecting well-formed autobiographical memories of specific events from their past. In contrast, patients performed as well as controls at distinguishing the names of cities from fictitious city names. On remote memory tests for past public events and famous faces, different patients exhibited different but internally consistent patterns of impaired and spared performance. The variability in the clinical and neuropsychological findings among our patients may be understood by supposing that memory performance is poor in proportion to how directly a test appears to assess a patient's common sense concept of memory. The presentation of patients with functional amnesia is as variable as humankind's concept of what memory is and how it works.     

Discriminating famous from fictional names based on lifetime experience: evidence in support of a signal-detection model based on finite mixture distributions

It is widely accepted that signal-detection mechanisms contribute to item-recognition memory decisions that involve discriminations between targets and lures based on a controlled laboratory study episode. Here, the authors employed mathematical modeling of receiver operating characteristics (ROC) to determine whether and how a signal-detection mechanism contributes to discriminations between moderately famous and fictional names based on lifetime experience. Unique to fame judgments is a lack of control over participants' previous exposure to the stimuli deemed "targets" by the experimenter; specifically, if they pertain to moderately famous individuals, participants may have had no prior exposure to a substantial proportion of the famous names presented. The authors adopted established models from the recognition-memory literature to examine the quantitative fit that could be obtained through the inclusion of signal-detection and threshold mechanisms for two data sets. They first established that a signal-detection process operating on graded evidence is critical to account for the fame judgment data they collected. They then determined whether the graded memory evidence for famous names would best be described with one distribution with greater variance than that for the fictional names, or with two finite mixture distributions for famous names that correspond to items with or without prior exposure, respectively. Analyses revealed that a model that included a d' parameter, as well as a mixture parameter, provided the best compromise between number of parameters and quantitative fit. Additional comparisons between this equal-variance signal-detection mixture model and a dual-process model, which included a high-threshold process in addition to a signal-detection process, also favored the former model. In support of the conjecture that the mixture parameter captures participants' prior experience, the authors found that it was increased when the analysis was restricted to names in occupational categories for which participants indicated high exposure.     

Metacognitive errors contribute to the difficulty in remembering proper names

While prior research has shown that proper names are more challenging to learn and remember than other types of information (e.g., occupations), little research has explored the role of metacognitive factors in proper name learning. Thus in four experiments participants learned, made predictions, and were tested on their memory for common nouns (i.e., occupations) and proper nouns (i.e., names). Results showed that memory predictions were consistently overconfident for names, whereas the discrepancy between predictions and performance was smaller for occupations. With experience, participants were able to modify predictions and, critically, Experiment 4 showed that improvements in the accuracy of memory predictions led participants to allocate more study time to names and thus improved memory for names. Such data suggest that theories of proper name learning should make provisions for deficits in metacognitive awareness.     

H.M., word knowledge, and aging: support for a new theory of long-term retrograde amnesia

This study develops a new theory of long-term retrograde amnesia that encompasses episodic and semantic memory, including word knowledge. Under the theory, retrograde amnesia in both normal individuals and hippocampal amnesics reflects transmission deficits caused by aging, nonrecent use of connections, and infrequent use of connections over the life span. However, transmission deficits cause severe and irreversible retrograde amnesia only in amnesics who (unlike normal persons) cannot readily form new connections to replace nonfunctioning ones. The results of this study are consistent with this theory: For low-frequency but not high-frequency words, a famous "hippocampal amnesic" (H.M.) at age 71 performed worse than memory-normal control participants in a lexical decision experiment and a meaning-definition task (e.g., What does squander mean?). Also as predicted, H.M.'s lexical decision performance declined dramatically between ages 57 and 71 for low-frequency words, but was age-invariant for high-frequency words.     

Visual Imagery Processing and Knowledge of Famous Names in Alzheimer's Disease and MCI

ABSTRACT

The study of memory for famous people and visual imagery retrieval was investigated in patients in the early stages of Alzheimer's disease (AD) and in the prodromal stage of AD, so-called Mild Cognitive Impairment (MCI). Fifteen patients with AD (MMSE ≥23), 15 patients with amnestic MCI (a-MCI) and 15 normal controls (NC) performed a famous names test designed to evaluate the semantic and distinctive physical features knowledge of famous persons. Results indicated that patients with AD and a-MCI generated significantly less physical features and semantic biographical knowledge about famous persons than did normal control participants. Additionally, significant differences were observed between a-MCI and AD patients in all tasks. The present findings confirm recent studies reporting semantic memory impairment in MCI. Moreover, the current findings show that mental imagery is lowered in a-MCI and AD and is likely related to the early semantic impairment.     

Recognition memory across the adult life span: The role of prior knowledge

Two experiments were performed to investigate the effects of prior knowledge on recognition memory in young adults, younger old adults, 76-year-olds, and 85-year-olds. In Experiment 1, we examined episodic recognition of dated and contemporary famous persons presented as faces, names, and faces plus names. In Experiment 2, four types of faces were presented for later recognition: dated familiar, contemporary familiar, old unfamiliar, and young unfamiliar. The results of both experiments showed that young adults performed better with contemporary than with dated famous persons, whereas the reverse was true for all groups of older adults. In addition, the data of Experiment 2 indicated that (1) young adults showed better recognition for young than for old unfamiliar faces, (2) younger old adults performed better with old than with young unfamiliar faces, and (3) the two oldest age groups showed no effect of age of face. These results suggest that the ability to utilize rich semantic knowledge to improve episodic memory is preserved in very old age, although the aging process may be associated with deficits in the ability to utilize prior knowledge to support memory when the underlying representation lacks semantic and contextual features. The overall data pattern was discussed in relation to the notion that, with increasing adult age, there is an increase in the level of cognitive support required to enhance episodic remembering.     

Long-term memory in amnesia: cued recall, recognition memory, and confidence ratings

We explored what kind of information is acquired when amnesic patients are able to exhibit significant retention on tests of cued recall and recognition memory. Amnesic patients and control subjects attempted to learn sets of sentences. Memory for the last word in each sentence was tested after 1 hr in the case of the amnesic patients, or after 1 to 2 weeks in the case of (delayed) control subjects. Amnesic patients and (delayed) control subjects performed at similar levels on tests of cued recall and recognition memory. Amnesic patients were just as confident of their correct answers as were control subjects. However, amnesic patients were no more disadvantaged than control subjects when they were cued indirectly by presenting paraphrases of the original sentences. These findings demonstrate that the residual knowledge retained by amnesic patients can be as flexible, as accessible to indirect cues, and as available to awareness as the knowledge retained by (delayed) control subjects.