Memory for famous people in patients with unilateral temporal lobe epilepsy and excisions.

Memory for famous individuals was assessed by the use of a recognition test in which participants first made familiarity judgments, followed by forced-choice decisions to specific probes for identity. Patients with temporal lobe epilepsy (TLE) or excisions, 12 left hemisphere and 12 right hemisphere, and 18 control participants identified famous figures across 3 decades (1970s-1990s). Only patients with right TLE were impaired at familiarity judgments of faces; this deficit was evident only for the most recent decades. Both groups of patients, however, were impaired at naming famous faces and at providing semantic information about famous people. These findings suggest the integrity of temporal structures in both hemispheres is critical for retrieval of detailed semantic information about famous individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A within-modality test of semantic knowledge: The Size/Weight Attribute Test.

Individuals with semantic dementia (SD; n=12) or Alzheimer's disease (AD; n=20) and healthy volunteers (n=40) were tested on tasks probing attribute rather than associative knowledge of animals and objects in the visual and verbal domains. The tasks were within modality, in that they probed knowledge in a single presentation modality (pictures or written words) and did not require cross-modal matching. Participants were required to make the same simple judgment about triads of animal stimuli ("Which is the largest and smallest?") and object stimuli ("Which is the heaviest and lightest?"). Control participants scored at ceiling on this simple task. Overall, the SD patients were significantly more impaired on this task than were the AD patients, who in turn were significantly more impaired than the controls. There was a strong trend for SD but not AD patients to show worse performance with verbal than visual material. However, no significant effects of category were found in either patient group. The Size/Weight Attribute Test has the potential to assess modality-specific deficits of semantic knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic knowledge and episodic memory for faces in semantic dementia.

Previous studies have documented poor recognition memory for faces in patients with semantic dementia. Preserved face recognition memory was found in this study, however, so long as atrophy was confined predominantly to the left temporal lobe. Patients with structural damage to the right temporal lobe were typically impaired, with the status of the hippocampus and parahippocampal gyrus (including the perirhinal cortex) on the right being critical. Two single-case studies of patients with predominantly left temporal lobe pathology confirmed good recognition memory for famous faces, even if semantic knowledge about the celebrities depicted was severely degraded. An effect of semantic knowledge on recognition memory became apparent only when perceptually different photographs of the famous people were used at study and test. These results support the view that new episodic learning typically draws on information from both perceptual and semantic systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multimodal cuing of autobiographical memory in semantic dementia.

Objective: Individuals with semantic dementia (SD) have impaired autobiographical memory (AM), but the extent of the impairment has been controversial. According to one report (Westmacott, Leach, Freedman, & Moscovitch, 2001), patient performance was better when visual cues were used instead of verbal cues; however, the visual cues used in that study (family photographs) provided more retrieval support than do the word cues that are typically used in AM studies. In the present study, we sought to disentangle the effects of retrieval support and cue modality. Method: We cued AMs of 5 patients with SD and 5 controls with words, simple pictures, and odors. Memories were elicited from childhood, early adulthood, and recent adulthood; they were scored for level of detail and episodic specificity. Results: The patients were impaired across all time periods and stimulus modalities. Within the patient group, words and pictures were equally effective as cues (Friedman test; χ2 = 0.25, p = .61), whereas odors were less effective than both words and pictures (for words vs. odors, χ2 = 7.83, p = .005; for pictures vs. odors, χ2 = 6.18, p = .01). There was no evidence of a temporal gradient in either group (for patients with SD, χ2 = 0.24, p = .89; for controls, χ2     

Distinctive forms of partial retrograde amnesia after asymmetric temporal lobe lesions: possible role of the occipitotemporal gyri in memory

We tested the hypothesis that partial forms of retrograde amnesia were associated with highly asymmetric lesions to the inferior and anterior-medial temporal lobe. Postencephalitic subjects EK and DR were both impaired on standardized retrograde memory tests, but showed strikingly different profiles in cognitive tasks of name stem completion, name:face matching, temporal ordering, forced choice recognition, and occupational judgments of famous names and faces from the past 3 decades. EK sustained left inferior and anterior-medial temporal lobe lesion with a small right temporal polar lesion, and showed near-complete loss of retrieval, knowledge, and familiarity associated with famous names but minimal deficiencies with famous faces. DR sustained right inferior and anterior-medial temporal lobe lesion and showed a milder retrograde loss limited to utilizing famous face prompts in name stem completion, name:face matching, occupational judgments, and forced choice recognition. These impairments were also different from the memory retrieval deficit, but intact recognition shown by a case of ruptured anterior communicating artery aneurysm with presumed basal forebrain damage. We hypothesize that EK's extensive loss of famous name knowledge was related to left inferior temporal lobe damage, particularly in the lateral and medial occipitotemporal gyri. This region in the left temporal lobe may serve as a critical processing area for retrograde memory that permits activation of established semantic, temporal, and visual (i.e., facial) associations biographically dependent on the category of proper names. On the basis of connectional anatomy patterns in the nonhuman primate, this region receives extensive hippocampal output and is interconnected with the temporal polar region and cortical association areas, which have been implicated in retrieval and storage aspects of retrograde memory. In the right hemisphere, the occipitotemporal gyri may serve an important role in famous face processing as part of a bilateral neural network.     

Object naming and semantic knowledge in temporal lobe epilepsy.

Object-naming impairment is common among temporal lobe epilepsy (TLE) patients, but other aspects of semantic memory have received limited attention in this population. This study examined object-naming ability and depth of semantic knowledge in healthy controls (n?=?29) and patients with early onset TLE (n?=?21). After administration of the Boston Naming Test (BNT), the authors asked participants to provide detailed definitions of 6 BNT objects. The TLE group demonstrated a significant deficit relative to controls in both object-naming ability and semantic knowledge for the target objects, even after controlling for IQ. In a multiple regression analysis that included other neuropsychological test scores as independent variables, the semantic knowledge score was the only significant predictor of patients' object-naming performance. Thus, at the group level, early onset TLE patients have a semantic knowledge deficit that contributes to dysnomia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is knowledge of famous people disproportionately impaired with patients with early and questionable Alzheimer's disease?

Twenty-two patients with early dementia of Alzheimer's type (DAT) and 31 controls were administered tests of person-specific semantics (Experiment 1). DAT patients were impaired on all test components. In Experiment 2, 31 DAT patients, 28 questionable DAT (QDAT) patients, and 42 controls were administered the Graded Naming Test (GNT) and the newly designed Graded Faces Test (GFT), matched for difficulty with the GNT. DAT patients were impaired throughout but showed an advantage for naming objects over faces. The QDAT patients were impaired on the GFT only. Of the 7 QDAT patients who evolved to DAT within 1-2 years, 6 showed initial impairment on the GFT, whereas 17 of the nonconverters scored normally on the GFT. Results suggest greater and earlier vulnerability of person knowledge than general semantic knowledge in DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multisensory prior entry.

Despite 2 centuries of research, the question of whether attending to a sensory modality speeds the perception of stimuli in that modality has yet to be resolved. The authors highlight weaknesses inherent in this previous research and report the results of 4 experiments in which a novel methodology was used to investigate the effects on temporal order judgments (TOJs) of attending to a particular sensory modality or spatial location. Participants were presented with pairs of visual and tactile stimuli from the left and/or right at varying stimulus onset asynchronies and were required to make unspeeded TOJs regarding which stimulus appeared first. The results provide the strongest evidence to date for the existence of multisensory prior entry and support previous claims for attentional biases toward the visual modality and toward the right side of space. These findings have important implications for studies in many areas of human and animal cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The semantic and episodic subcomponents of famous person knowledge: Dissociation in healthy subjects.

Fifty-two subjects between ages 40 and 79 years were administered a questionnaire assessing their ability to recall semantic information about famous people from 4 different decades and to recollect its episodic source of acquisition together with autonoetic consciousness via the remember-know paradigm. In addition, they underwent a battery of standardized neuropsychological tests to assess episodic and semantic memory and executive functions. The analyses of age reveal differences for the episodic source score but no differences between age groups for the semantic scores within each decade. Regardless of the age of people, the analyses also show that semantic memory subcomponents of the famous person test are highly associated with each other as well as with the source component. The recall of semantic information on the famous person test relies on participants' semantic abilities, whereas the recall of its episodic source depends on their executive functions. The present findings confirm the existence of an episodic-semantic distinction in knowledge about famous people. They provide further evidence that personal source and semantic information are at once distinct and highly interactive within the framework of remote memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What does the object decision task measure? Reflections on the basis of evidence from semantic dementia.

The authors investigated the impact of semantic knowledge on visual object analysis by assessing the performance of patients with semantic dementia on a different-views object matching test and on 2 object decision tests differing, for example, in whether the nonreal items were nonsense objects or chimeras of 2 real objects. On average, the patients scored normally on both the object matching and the object decision test including nonsense objects but were impaired on the object decision test including chimeras; this latter was also the only visual object test that correlated significantly with degree of semantic impairment. These findings demonstrate that object decision is not a single task or ability and that it is not necessarily independent of conceptual knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The bilateral field advantage in a sequential face–name matching task with famous and nonfamous faces.

The authors examined the bilateral field advantage (BFA) using a sequential name–face (Experiment 1) or face-name (Experiment 2) matching task with both famous and nonfamous stimuli. In both experiments, the first stimulus (name in Experiment 1, face in experiment 2) was followed by a delay of 1,500 ms. The second stimulus (face in Experiment 1, name in Experiment 2) was then presented during a speeded response interval. Experiment 1 indicated a BFA for famous faces, but not for recently familiarized nonfamous faces. Experiment 2 indicated a BFA for names regardless of familiarity level. These results are compatible with prior findings of a BFA for meaningful stimuli as opposed to nonmeaningful ones, but only if previously unknown personal names are considered meaningful while previously unknown faces are not. These findings suggest that personal names are processed by bilateral neural networks whether they are previously known or not, whereas this is not the case for faces. Our findings have additional implications for working memory-based theories of why the BFA arises, and for the time course of meaningful association formation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Equivalent effects of grouping by time, voice, and location on response timing in verbal serial memory.

The grouping of list items is known to improve serial memory accuracy and constrain the nature of temporal errors. A recent study (M. T. Maybery, F. B. R. Parmentier, & D. M. Jones, 2002) showed that grouping results in a temporal organization of the participants' responses that mimics the list structure but not the timing of its presentation. Here the authors tested the prediction that the temporal grouping of responses should yield the same pattern of response time (RT) irrespective of the method of grouping at presentation. Comparing temporal, location, and voice grouping, the results show that although these methods impact on recall accuracy to varying degrees, all 3 conditions produce significant and equivalent peaks in RT at the first position of each group. The RT data were accurately simulated through a model based on ACT-R's (J. R. Anderson & M. Matessa, 1997) basic principles. Altogether, the data suggest that the temporal organization of responses in verbal serial recall results from (a) declarative knowledge about the list's structure that is independent of the perceptual means by which grouping is induced at presentation and (b) the level of activation of the items per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analyzing the factors underlying the structure and computation of the meaning of chipmunk, cherry, chisel, cheese, and cello (and many other such concrete nouns).

Seven trends regarding the categories that tend to be impaired/preserved in category-specific semantic deficits were identified. The authors hypothesized that these trends arise despite the multiple sources of variation in patient testing because numerous factors that structure semantic memory probabilistically converge to make some categories of knowledge more susceptible to damage than others. Analysis of semantic feature norms and corpus data for 541 concepts revealed that differences in the distribution of knowledge types across categories are sufficient to explain 6 of the trends and are necessary to explain loss of knowledge about nonliving things. Feature informativeness, concept confusability, visual complexity, familiarity, and name frequency contributed to this patterning and provide insight into why knowledge about living things is most often impaired. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social Recognition Memory: The Effect of Other People's Responses for Previously Seen and Unseen Items.

When people discuss their memories, what one person says can influence what another person reports. In 3 studies, participants were shown sets of stimuli and then given recognition memory tests to measure the effect of one person's response on another's. The 1st study (n=24) used word recognition with participant-confederate pairs and found that the effect of confederate responses on participant responses was larger for previously unseen items than for previously seen items (ωp=.23). This finding was replicated in the 2nd study, which used photographs of cars (n=24). In the 3rd study (n=54), which used photographs of faces with participant pairs, the effect was also larger for unseen items. Results indicate that people rely more on other people's memories for unremembered objects than for remembered objects. This is important for both theories of memory and applications (e.g., witnesses talking, students studying together). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal integration in face perception: Evidence of configural processing of temporally separated face parts.

Temporal integration is the process by which temporally separated visual components are combined into a unified representation. Although this process has been studied in object recognition, little is known about temporal integration in face perception and recognition. In the present study, the authors investigated the characteristics and time boundaries of facial temporal integration. Whole faces of nonfamous and famous people were segmented horizontally into 3 parts and presented in sequence, with varying interval lengths between parts. Inversion and misalignment effects were found at short intervals (0-200 ms). Moreover, their magnitude was comparable to those found with whole-face presentations. These effects were eliminated, or substantially reduced, when the delay interval was 700 ms. Order of parts presentation did not influence the pattern of inversion effects obtained within each temporal delay condition. These results demonstrate that temporal integration of faces occurs in a temporary and limited visual buffer. Moreover, they indicate that only integrated faces can undergo configural processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An fMRI Study of Episodic Memory: Retrieval of Object, Spatial, and Temporal Information.

Sixteen participants viewed a videotaped tour of 4 houses that highlighted a series of objects and their spatial locations. Participants were tested for memory of object, spatial, and temporal-order information while undergoing functional magnetic resonance imaging. Preferential activation was observed in the right parahippocampal gyrus during the retrieval of spatial-location information. Retrieval of contextual information (spatial location and temporal order) was associated with activation in the right dorsolateral prefrontal cortex. In bilateral posterior parietal regions, greater activation was associated with processing of visual scenes regardless of the memory judgment. These findings support current theories positing roles for frontal and medial temporal regions during episodic retrieval and suggest a specific role for the hippocampal complex in the retrieval of spatial-location information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Now you see it, now you don't: Evidence for age-dependent and age-independent cross-modal distraction.

Age-related deficits in selective attention have often been demonstrated in the visual modality and, to a lesser extent, in the auditory modality. In contrast, a mounting body of evidence has suggested that cross-modal selective attention is intact in aging, especially in visual tasks that require ignoring the auditory modality. Our goal in this study was to investigate age-related differences in the ability to ignore cross-modal auditory and visual distraction and to assess the role of cognitive control demands thereby. In a set of two experiments, 30 young (mean age = 23.3 years) and 30 older adults (mean age = 67.7 years) performed a visual and an auditory n-back task (0 ≤ n ≤ 2), with and without cross-modal distraction. The results show an asymmetry in cross-modal distraction as a function of sensory modality and age: Whereas auditory distraction did not disrupt performance on the visual task in either age group, visual distraction disrupted performance on the auditory task in both age groups. Most important, however, visual distraction was disproportionately larger in older adults. These results suggest that age-related distraction is modality dependent, such that suppression of cross-modal auditory distraction is preserved and suppression of cross-modal visual distraction is impaired in aging. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

One declarative memory system or two? The relationship between episodic and semantic memory in children with temporal lobe epilepsy.

Objective: This study explored verbal semantic and episodic memory in children with unilateral temporal lobe epilepsy to determine whether they had impairments in both or only 1 aspect of memory, and to examine relations between performance in the 2 domains. Method: Sixty-six children and adolescents (37 with seizures of left temporal lobe onset, 29 with right-sided onset) were given 4 tasks assessing different aspects of semantic memory (picture naming, fluency, knowledge of facts, knowledge of word meanings) and 2 episodic memory tasks (story recall, word list recall). Results: High rates of impairments were observed across tasks, and no differences were found related to the laterality of the seizures. Individual patient analyses showed that there was a double dissociation between the 2 aspects of memory in that some children were impaired on episodic but not semantic memory, whereas others showed intact episodic but impaired semantic memory. Conclusions: This double dissociation suggests that these 2 memory systems may develop independently in the context of temporal lobe pathology, perhaps related to differential effects of dysfunction in the lateral and mesial temporal lobe structures. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Failing to Get the Gist: Reduced False Recognition of Semantic Associates in Semantic Dementia.

In 2 experiments involving patients with semantic dementia, the authors investigated the impact of semantic memory loss on both true and false recognition. Experiment 1 involved recognition memory for categories of everyday objects that shared a predominantly semantic relationship. The patients showed preserved item-specific recollection for the pictorial stimuli but, compared with control participants, exhibited significantly reduced utilization of gist information regarding the categories of objects. The latter result is consistent with the patients' degraded semantic knowledge. Experiment 2 involved categories of abstract objects that were related to one another perceptually rather than semantically. Patients with semantic dementia obtained item-specific recollection and gist memory scores that were indistinguishable from those of control participants. These results suggest that the reduction in gist memory in semantic dementia is largely specific to semantic representations and cannot be attributed to general difficulty with abstracting and/or utilizing gistlike commonalities between stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neural structures associated with recognition of facial expressions of basic emotions

People with Huntington's disease and people suffering from obsessive compulsive disorder show severe deficits in recognizing facial expressions of disgust, whereas people with lesions restricted to the amygdala are especially impaired in recognizing facial expressions of fear. This double dissociation implies that recognition of certain basic emotions may be associated with distinct and non-overlapping neural substrates. Some authors, however, emphasize the general importance of the ventral parts of the frontal cortex in emotion recognition, regardless of the emotion being recognized. In this study, we used functional magnetic resonance imaging to locate neural structures that are critical for recognition of facial expressions of basic emotions by investigating cerebral activation of six healthy adults performing a gender discrimination task on images of faces expressing disgust, fear and anger. Activation in response to these faces was compared with that for faces showing neutral expressions. Disgusted facial expressions activated the right putamen and the left insula cortex, whereas enhanced activity in the posterior part of the right gyrus cinguli and the medial temporal gyrus of the left hemisphere was observed during processing of angry faces. Fearful expressions activated the right fusiform gyrus and the left dorsolateral frontal cortex. For all three emotions investigated, we also found activation of the inferior part of the left frontal cortex (Brodmann area 47). These results support the hypotheses derived from neuropsychological findings, that (i) recognition of disgust, fear and anger is based on separate neural systems, and that (ii) the output of these systems converges on frontal regions for further information processing.