Preserved spatial memory in old rats survives 10 months without training

Aged rats with extensive prior training on the radial maze retain the capacity for accurate spatial working memory (WM) for at least 3 months without practice. To investigate the temporal limits of this influence of prior experience we compared the reacquisition of spatial WM by a group of experienced 21.5-month-old rats to the original acquisition by naive 3-month-old rats. The aged rats had received 225 radial maze tests between 3 and 11 months of age. Despite 10 months without practice the old rats rapidly reacquired critical performance. Their reacquisition was markedly superior to original learning by the young rats, even when delays as long as 5 h were imposed between the rats' fourth and fifth choices during the daily tests in the eight-arm maze. Additional tests showed that neither young nor old rats employed a response strategy to maintain accurate spatial WM performance. Experience clearly confers long-lived protection against the otherwise deleterious effects of aging on spatial WM, but the mechanism by which this influence arises is unknown.     

Cue depreciation: when word fragment completion is undermined by prior exposure to lesser fragments

The ability to think of a previously studied item has often been shown to be impaired when, in one way or another, the extraitem context is changed from study to test. In a series of five experiments, such impairment is induced in a somewhat different way. A fragment (e.g. r-i--rop) of a just-studied word (raindrop) is shown to be less readily completed if it is presented bit by bit (r------p, r----r-p, r-i--r-p, r-i--rop) rather than all at once (Experiments 1, 3, 4, and 5). No such effect is found if the word has not been studied beforehand (Experiments 2, 3, 4, and 5). This pattern of results occurs even when fragments of studied and nonstudied words occur in the same test and under conditions in which subjects cannot tell whether a given fragment is of a studied or nonstudied word (Experiments 4 and 5). In addition, for words that have been studied beforehand, the impairment is shown to increase systematically with the number of steps involved in the presentation of the word fragment (Experiment 3) and also to persist when the time allowed for completion of the final version of the fragment is increased from 4 s to a full minute (Experiment 5).     

Catamnestic surveys on somato-psychosocial development in childhood and adolescence of patients with unipolar depressive and bipolar manic-depressive psychoses

The somatic and psychosocial development of 80 subjects with manifest affective-phasic psychoses is studied retrospectively and compared with that of an identically sized control group consisting of neuropsychiatrically healthy subjects. Statistically significant differences were found particularly in the answers to questions dealing with social situation and social adaptability. Achievement at school and vocational qualifications were lower among the parents of the patients than among those of the healthy subjects. Characteristic features of the patients' childhood and adolescence were transient depression, often for no apparent cause, and maladaption, and vocational wishes were fulfilled less often than among the controls. The patients experienced greater difficulty in settling in to a new group due to their contact difficulties.     

Acoustically evoked brain stem potential in Wilson disease

By 48 patients with Wilson's disease the brainstem acoustic evoked potentials were stated. There were 35 pathological findings (73%), 13 were normal (27%). The waves, determined by the middle and upper brainstem (Pons and Mesencephalon) showed most of all pathological changes. Those patients with forms of Wilson's disease called Pseudoskelerose and Pseudoparkinson showed the most pathological findings. But one could watch these findings by about 30% of patients in preclinical stage. This method can possibly be used for early detection of disorders of brainstem functions and in the same way it can be used for control of treatment by patients in preclinical stage.     

Death by 1000 ‘true fans’: Do marketing laws apply to music listening?

The advice to musicians and marketers is to focus on what they love: a truism for practitioners is to find 1000 ‘true fans’ and make $100 from each of them (Kelly, 2008. 1000 True fans. The Technium). If this advice is correct, we should see musicians with loyal user bases engaging more with their favourite artists and less with other music, suggesting a narrow targeting strategy would suffice. On the other hand, the established marketing laws indicate that the listeners of very different genres should overlap more than conventional wisdom would suggest, supporting the need for a much broader approach to targeting potential audiences. Given these conflicting views, musicians need to know if they should market to their existing listeners, the listeners of music similar to theirs (i.e., the same genre), or if they should try to reach a much wider audience. We turn to established choice patterns from the marketing literature to address these questions in the music context. This study examines 84,000,000 observations of music listening from 27,000 unique global users between 2013 and 2014 and survey data from 2019 containing music listening from over 1000 representative respondents in the United States. The results show that listening follows the Duplication of Purchase law for genres, artists, albums, and songs, at an annual, 6-months, 3-months, 1-month, and 1-week period, with no indication of partitioned music listening. The implication is that musicians should try to reach all potential listeners, regardless of what they already listen to. These findings contribute to the theoretical knowledge about duplication analyses of various durations, extend the contexts of choice behaviour that exhibit this pattern, and managerially, to knowledge about the extent of potential audiences and ‘share of ear’ competition.