Dominance attributions following damage to the ventromedial prefrontal cortex

Damage to the human ventromedial prefrontal cortex (VM) can result in dramatic and maladaptive changes in social behavior despite preservation of most other cognitive abilities. One important aspect of social cognition is the ability to detect social dominance, a process of attributing from particular social signals another person's relative standing in the social world. To test the role of the VM in making attributions of social dominance, we designed two experiments: one requiring dominance judgments from static pictures of faces, the second requiring dominance judgments from film clips. We tested three demographically matched groups of subjects: subjects with focal lesions in the VM (n=15), brain-damaged comparison subjects with lesions excluding the VM (n=11), and a reference group of normal individuals with no history of neurological disease (n=32). Contrary to our expectation, we found that subjects with VM lesions gave dominance judgments on both tasks that did not differ significantly from those given by the other groups. Despite their grossly normal performance, however, subjects with VM lesions showed more subtle impairments specifically when judging static faces: They were less discriminative in their dominance judgments, and did not appear to make normal use of gender and age of the faces in forming their judgments. The findings suggest that, in the laboratory tasks we used, damage to the VM does not necessarily impair judgments of social dominance, although it appears to result in alterations in strategy that might translate into behavioral impairments in real life

Poster 259: A Quantitative Study of Morphologic Changes in the Lumbar Spine After Medial Branch Radiofrequency Neurotomy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146961/1/pmr2s116b.pd

Severe Acute Respiratory Syndrome Coronavirus Evades Antiviral Signaling: Role of nsp1 and Rational Design of an Attenuated Strain

The severe acute respiratory syndrome (SARS) epidemic was caused by the spread of a previously unrecognized infectious agent, the SARS-associated coronavirus (SARS-CoV). Here we show that SARS-CoV could inhibit both virus- and interferon (IFN)-dependent signaling, two key steps of the antiviral response. We mapped a strong inhibitory activity to SARS-CoV nonstructural protein 1 (nsp1) and show that expression of nsp1 significantly inhibited the activation of all three virus-dependent signaling pathways. We show that expression of nsp1 significantly inhibited IFN-dependent signaling by decreasing the phosphorylation levels of STAT1 while having little effect on those of STAT2, JAK1, and TYK2. We engineered an attenuated mutant of nsp1 in SARS-CoV through reverse genetics, and the resulting mutant virus was viable and replicated as efficiently as wild-type virus in cells with a defective IFN response. However, mutant virus replication was strongly attenuated in cells with an intact IFN response. Thus, nsp1 is likely a virulence factor that contributes to pathogenicity by favoring SARS-CoV replication

Determining the Impact of Autobiographical Experience on "Meaning": New Insights from Investigating Sports-related Vocabulary and Knowledge in Two Cases with Semantic Dementia

Snowden, Griffiths, and Neary (1994, 1995) have proposed thatautobiographical experience helps to maintain the integrity of semantic memory in patients with semantic dementia. We investigated this hypothesis by testing knowledge related to golf and bowls in two case studies. If Snowden and colleagues' hypothesis is correct, our two patients should have better semantic knowledge for the sport that they regularly experience, compared with knowledge of other sports. In keeping with Snowden et al's hypothesis, we found that autobiographical experience influenced the ability of the patients to match up a surname with a first name: The names of personally and currently relevant golf bowls partners were more likely to be matched correctly than such personally relevant names from the past, or the names of famous sports celebrities. Unlike Snowden et al., however, we found that knowledge of people, in all categories, was severely impoverished and that any semantic information was produced as part of an autobiographical memory. Likewise, detailed study of each patient's understanding of their favourite sportrevealed no significanteffectof autobiographical experience on true semantic knowledge. We propose that the ability of semantic dementia patients to encode, albeit temporarily, recent autobiographical memories via a spared hippocampal complex supports the production of highly autobiographically constrained semantic-like facts and, to a lesser extent, frequently encountered names. There is, however, no direct effect of autobiographical experience on previously established semantic memory, i.e. knowledge of golf, bowls, and people, presumably stored within the temporal neocortex. These results are discussed with respect to current anatomically based computational models of long-term memory