Visual memory loss and autobiographical amnesia: a case study.

Amnesia typically results from trauma to the medial temporal regions that coordinate activation among the disparate areas of cortex that represent the information that make up autobiographical memories. We proposed that amnesia should also result from damage to these regions, particularly regions that subserve long-term visual memory [Rubin, D. C., & Greenberg, D. L. (1998). Visual memory-deficit amnesia: A distinct amnesic presentation and etiology. Proceedings of the National Academy of Sciences of the USA, 95, 5413-5416]. We previously found 11 such cases in the literature, and all 11 had amnesia. We now present a detailed investigation of one of these patients. M.S. suffers from long-term visual memory loss along with some semantic deficits; he also manifests a severe retrograde amnesia and moderate anterograde amnesia. The presentation of his amnesia differs from that of the typical medial-temporal or lateral-temporal amnesic; we suggest that his visual deficits may be contributing to his autobiographical amnesia.

Cultural life scripts structure recall from autobiographical memory.

Three classes of evidence demonstrate the existence of life scripts, or culturally shared representations of the timing of major transitional life events. First, a reanalysis of earlier studies on age norms shows an increase in the number of transitional events between the ages of 15 and 30 years, and these events are associated with narrower age ranges and more positive emotion than events outside this period. Second, 1,485 Danes estimated how old hypothetical centenarians were when they had been happiest, saddest, most afraid, most in love, and had their most important and most traumatic experiences. Only the number of positive events showed an increase between the ages of 15 and 30 years. Third, undergraduates generated seven important events that were likely to occur in the life of a newborn. Pleasantness and whether events were expected to occur between the ages of 15 and 30 years predicted how frequently events were recorded. Life scripts provide an alternative explanation of the reminiscence bump. Emphasis is on culture, not individuals.

Experimental manipulations of the phenomenology of memory.

We investigated the effects of visual input at encoding and retrieval on the phenomenology of memory. In Experiment 1, participants took part in events with and without wearing blindfolds, and later were shown a video of the events. Blindfolding, as well as later viewing of the video, both tended to decrease recollection. In Experiment 2, participants were played videos, with and without the visual component, of events involving other people. Events listened to without visual input were recalled with less recollection; later adding of the visual component increased recollection. In Experiment 3, participants were provided with progressively more information about events that they had experienced, either in the form of photographs that they had taken of the events or narrative descriptions of those photographs. In comparison with manipulations at encoding, the addition of more visual or narrative cues at recall had similar but smaller effects on recollection.

The neuropsychology of autobiographical memory.

This special issue of Cortex focuses on the relative contribution of different neural networks to memory and the interaction of 'core' memory processes with other cognitive processes. In this article, we examine both. Specifically, we identify cognitive processes other than encoding and retrieval that are thought to be involved in memory; we then examine the consequences of damage to brain regions that support these processes. This approach forces a consideration of the roles of brain regions outside of the frontal, medial-temporal, and diencephalic regions that form a central part of neurobiological theories of memory. Certain kinds of damage to visual cortex or lateral temporal cortex produced impairments of visual imagery or semantic memory; these patterns of impairment are associated with a unique pattern of amnesia that was distinctly different from the pattern associated with medial-temporal trauma. On the other hand, damage to language regions, auditory cortex, or parietal cortex produced impairments of language, auditory imagery, or spatial imagery; however, these impairments were not associated with amnesia. Therefore, a full model of autobiographical memory must consider cognitive processes that are not generally considered 'core processes,' as well as the brain regions upon which these processes depend.

Inner speech and bilingual autobiographical memory: a Polish-Danish cross-cultural study.

Thirty years after fleeing from Poland to Denmark, 20 immigrants were enlisted in a study of bilingual autobiographical memory. Ten "early immigrators" averaged 24 years old at the time of immigration, and ten "late immigrators" averaged 34 years old at immigration. Although all 20 had spent 30 years in Denmark, early immigrators reported more current inner speech behaviours in Danish, whereas late immigrators showed more use of Polish. Both groups displayed proportionally more numerous autobiographical retrievals that were reported as coming to them internally in Polish (vs Danish) for the decades prior to immigration and more in Danish (vs Polish) after immigration. We propose a culture- and language-specific shaping of semantic and conceptual stores that underpins autobiographical and world knowledge.

Music, emotion, and autobiographical memory: they're playing your song.

Very long-term memory for popular music was investigated. Older and younger adults listened to 20-sec excerpts of popular songs drawn from across the 20th century. The subjects gave emotionality and preference ratings and tried to name the title, artist, and year of popularity for each excerpt. They also performed a cued memory test for the lyrics. The older adults' emotionality ratings were highest for songs from their youth; they remembered more about these songs, as well. However, the stimuli failed to cue many autobiographical memories of specific events. Further analyses revealed that the older adults were less likely than the younger adults to retrieve multiple attributes of a song together (i.e., title and artist) and that there was a significant positive correlation between emotion and memory, especially for the older adults. These results have implications for research on long-term memory, as well as on the relationship between emotion and memory.

The neural basis of naming impairments in Alzheimer's disease revealed through positron emission tomography.

The naming impairments in Alzheimer's disease (AD) have been attributed to a variety of cognitive processing deficits, including impairments in semantic memory, visual perception, and lexical access. To further understand the underlying biological basis of the naming failures in AD, the present investigation examined the relationship of various classes of naming errors to regional brain measures of cerebral glucose metabolism as measured with 18 F-Fluoro-2-deoxyglucose (FDG) and positron emission tomography (PET). Errors committed on a visual naming test were categorized according to a cognitive processing schema and then examined in relationship to metabolism within specific brain regions. The results revealed an association of semantic errors with glucose metabolism in the frontal and temporal regions. Language access errors, such as circumlocutions, and word blocking nonresponses were associated with decreased metabolism in areas within the left hemisphere. Visuoperceptive errors were related to right inferior parietal metabolic function. The findings suggest that specific brain areas mediate the perceptual, semantic, and lexical processing demands of visual naming and that visual naming problems in dementia are related to dysfunction in specific neural circuits.

Memory and learning for a novel written style.

Subjects read and recalled a series of five short stories in one of four plot and style combinations. The stories were written in one of two styles that consisted of opposing clause orders (i.e., independent-dependent vs. dependent-independent), tense forms (i.e., past vs. present), and descriptor forms (modifier modifier vs. modifier as a noun). The subjects incorporated both plot and style characteristics into their recalls. Other subjects, who, after five recalls, either generated a new story or listed the rules that had been followed by the stories read, included the marked forms of the characteristics they learned more often, except for tense. The subjects read and recalled four stories of the same plot and style and then read and recalled a fifth story of the same plot and style or of one of the other three plot/style combinations. Ability to switch style depended on both the characteristic and the markedness.

The spacing effect depends on an encoding deficit, retrieval, and time in working memory: evidence from once-presented words.

The spacing effect in list learning occurs because identical massed items suffer encoding deficits and because spaced items benefit from retrieval and increased time in working memory. Requiring the retrieval of identical items produced a spacing effect for recall and recognition, both for intentional and incidental learning. Not requiring retrieval produced spacing only for intentional learning because intentional learning encourages retrieval. Once-presented words provided baselines for these effects. Next, massed and spaced word pairs were judged for matches on their first three letters, forcing retrieval. The words were not identical, so there was no encoding deficit. Retrieval could and did cause spacing only for the first word of each pair; time in working memory, only for the second.

Visual memory-deficit amnesia: a distinct amnesic presentation and etiology.

We describe a form of amnesia, which we have called visual memory-deficit amnesia, that is caused by damage to areas of the visual system that store visual information. Because it is caused by a deficit in access to stored visual material and not by an impaired ability to encode or retrieve new material, it has the otherwise infrequent properties of a more severe retrograde than anterograde amnesia with no temporal gradient in the retrograde amnesia. Of the 11 cases of long-term visual memory loss found in the literature, all had amnesia extending beyond a loss of visual memory, often including a near total loss of pretraumatic episodic memory. Of the 6 cases in which both the severity of retrograde and anterograde amnesia and the temporal gradient of the retrograde amnesia were noted, 4 had a more severe retrograde amnesia with no temporal gradient and 2 had a less severe retrograde amnesia with a temporal gradient.

Properties of word cues for autobiographical memory.

A sample of 124 words were used to cue autobiographical memories in 120 adults varying in age from 20 to 73 years. Individual words reliably cued autobiographical memories of different ages with different speeds. For all age groups, words rated high in imagery produced older memories and faster reaction times.

Memorabeatlia: a naturalistic study of long-term memory.

Seventy-six undergraduates were given the titles and first lines of Beatles' songs and asked to recall the songs. Seven hundred and four different undergraduates were cued with one line from each of 25 Beatles' songs and asked to recall the title. The probability of recalling a line was best predicted by the number of times a line was repeated in the song and how early the line first appeared in the song. The probability of cuing to the title was best predicted by whether the line shared words with the title. Although the subjects recalled only 21% of the lines, there were very few errors in recall, and the errors rarely violated the rhythmic, poetic, or thematic constraints of the songs. Acting together, these constraints can account for the near verbatim recall observed. Fourteen subjects, who transcribed one song, made fewer and different errors than the subjects who had recalled the song, indicating that the errors in recall were not primarily the result of errors in encoding.

Olfactory cuing of autobiographical memory.

In Experiment 1, subjects were presented with either the odors or the names of 15 common objects. In Experiment 2, subjects were presented with either the odors, photographs, or names of 16 common objects. All subjects were asked to describe an autobiographical memory evoked by each cue, to date each memory, and to rate each memory on vividness, pleasantness, and the number of times that the memory had been thought of and talked about prior to the experiment. Compared with memories evoked by photographs or names, memories evoked by odors were reported to be thought of and talked about less often prior to the experiment and were more likely to be reported as never having been thought of or talked about prior to the experiment. No other effects were consistently found, though there was a suggestion that odors might evoke more pleasant and emotional memories than other types of cues. The relation of these results to the folklore concerning olfactory cuing is discussed.

Cross-hemispheric collaboration and segregation associated with task difficulty as revealed by structural and functional connectivity.

Although it is known that brain regions in one hemisphere may interact very closely with their corresponding contralateral regions (collaboration) or operate relatively independent of them (segregation), the specific brain regions (where) and conditions (how) associated with collaboration or segregation are largely unknown. We investigated these issues using a split field-matching task in which participants matched the meaning of words or the visual features of faces presented to the same (unilateral) or to different (bilateral) visual fields. Matching difficulty was manipulated by varying the semantic similarity of words or the visual similarity of faces. We assessed the white matter using the fractional anisotropy (FA) measure provided by diffusion tensor imaging (DTI) and cross-hemispheric communication in terms of fMRI-based connectivity between homotopic pairs of cortical regions. For both perceptual and semantic matching, bilateral trials became faster than unilateral trials as difficulty increased (bilateral processing advantage, BPA). The study yielded three novel findings. First, whereas FA in anterior corpus callosum (genu) correlated with word-matching BPA, FA in posterior corpus callosum (splenium-occipital) correlated with face-matching BPA. Second, as matching difficulty intensified, cross-hemispheric functional connectivity (CFC) increased in domain-general frontopolar cortex (for both word and face matching) but decreased in domain-specific ventral temporal lobe regions (temporal pole for word matching and fusiform gyrus for face matching). Last, a mediation analysis linking DTI and fMRI data showed that CFC mediated the effect of callosal FA on BPA. These findings clarify the mechanisms by which the hemispheres interact to perform complex cognitive tasks.