Transthyretin influences spatial reference memory

Transthyretin (TTR) is a plasma and cerebrospinal fluid carrier for thyroxine and retinol, described also to sequester the amyloid beta peptide. TTR levels have been described as decreased in the cerebrospinal fluid of patients with Alzheimer's disease. In order to investigate the role of TTR in learning and memory, we studied young adult and old TTR-null 129/Sv mice for cognitive performance. In the absence of TTR, 5-month-old mice display spatial reference memory impairment when compared to age-matched wild-type mice. Interestingly, while aging in wild-type mice is associated with a worsening reference memory performance, TTR-null mice show no further impairment with increasing age. As a result, no significant differences were found in this spatial reference task in old mice. Our data show that the absence of TTR seems to accelerate the poorer cognitive performance normally associated with aging.     

A Plea For Mental Acts

Synthese - A prominent but poorly understood domain of human agency is mental action, i.e., thecapacity for reaching specific desirable mental statesthrough an appropriate monitoring of one's...     

Hope in Africa? Social representations of world history and the future in six African countries

Data on social representations of world history have been collected everywhere in the world except sub-Saharan Africa. Two studies using open-ended data involving university students from six African countries fill this gap. In Study 1, nominations from Cape Verde and Mozambique for the most important events in world history in the past 1000 years were dominated by war and politics, recency effects, and Western-centrism tempered by African sociocentrism on colonization and independence. The first three findings replicated previous research conducted in other parts of the world, but the last pattern contrasted sharply with European data. Study 2 employed a novel method asking participants how they would begin the narration of world history, and then to describe a major transition to the present. Participants most frequently wrote about the evolution of humanity out of Africa, followed by war and then colonization as a beginning, and then replicated previous findings with war, colonization, and technology as major transitions to the present. Finally, when asked about how they foresaw the future, many participants expressed hope for peace and cooperation, especially those facing more risk of collective violence (Burundi and Congo). A colonial/liberation narrative was more predominant in the data from former Portuguese colonies (Angola, Cape Verde, and Guinea-Bissau) than from former Belgian colonies (Burundi and Congo).