Expert performance: Its structure and acquisition.

Counter to the common belief that expert performance reflects innate abilities and capacities, recent research in different domains of expertise has shown that expert performance is predominantly mediated by acquired complex skills and physiological adaptations. For elite performers, supervised practice starts at very young ages and is maintained at high daily levels for more than a decade. The effects of extended deliberate practice are more far-reaching than is commonly believed. Performers can acquire skills that circumvent basic limits on working memory capacity and sequential processing. Deliberate practice can also lead to anatomical changes resulting from adaptations to intense physical activity. The study of expert performance has important implications for our understanding of the structure and limits of human adaptation and optimal learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory knowledge and memory monitoring in adulthood.

Age differences in 2 specific processing dimensions of metamemory, namely memory knowledge and memory monitoring, were examined. Young and old Ss recalled lists of words paired with letter, rhyme, and meaning cues over 2 trials. On both trials, Ss made predictions of recall likelihood on presentation of each word-cue pair. No age differences in initial predictions (i.e., prior memory knowledge) were apparent, whereas age-based performance differences were observed. On Trial 2, both young and old Ss significantly revised their predictions; however, old adults monitored only global discrepancies between previous expectation and performance. Young adults raised and lowered expectations across cue types in accordance with their previous performance. Age differences in processing speed accounted for some but not all of the memory-monitoring differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in identifying words in synthetic speech

OBJECTIVES: We investigated whether context or different speech rates could improve older adult performance on identification of synthetically generated words. BACKGROUND: Synthetic speech systems can potentially improve the daily functioning of older adults. However, research must determine whether older adults can effectively implement current text-to-speech technologies, which few studies have examined. Older adults' sensory and cognitive declines may cause difficulties in identifying words in synthetic speech. METHODS: Ninety-six participants (young, middle-aged, and older adults) identified auditory monosyllabic words (half natural, half synthetic) presented in isolation or at the ends of sentences. Participants heard speech at either normal or slower rates. RESULTS: We found an interaction of age, context, and voice type and that slower speech rates worsened performance for all groups. Contrasts revealed that context reduced age differences, though only for natural speech. Hearing acuity was highly correlated with age and fully accounts for the interaction. CONCLUSIONS: Context improves performance for everyone in natural speech. However, whereas context improves performance for synthetic speech, it does not differentially reduce the age impairment for older adults. Slower speed generally impairs everyone's performance compared with the normal rate. APPLICATIONS: Systems using synthetic speech should avoid presenting words in isolation, and rich contextual support should be consistently adopted. Synthetic speech fidelity must be improved significantly before becoming truly useful for older adult populations.     

How artificial is psychology?

Reviews the book, The Sciences of the Artificial, 2nd Edition by Herbert A. Simon (1981), stating that Simon suggests the commonalities between psychology, computer science, engineering, economics and architecture as stemming from the fact that they all deal with the "artificial." They all deal in design issues for complex systems that are adaptive. In this updated version of earlier edition (see record 1969-14952-000), Simon has interleaved two themes, the sciences of the artificial and the sciences of design, that formed the core of two invited lecture series. The strength of this set of seven essays is that it provides a "full-width" perspective on psychology and other social sciences such as economics and systems design. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of ethanol-sensitive and insensitive fibroblast cell lines expressing human L1

Ethanol inhibits L1-mediated cell-cell adhesion in fibroblast cell lines stably transfected with human L1. Here we show that this action of ethanol is present in only a subset of transfected NIH/3T3 and L cell clonal cell lines. All L1-expressing cell lines had higher levels of cell adhesion than cell lines transfected with empty vector. In all ethanol-sensitive cell lines, L1-mediated adhesion was inhibited by ethanol (IC50 5-10 mM), 2 mM butanol, but not 5 mM pentanol. In contrast, ethanol-insensitive cell lines were not inhibited by up to 200 mM ethanol, 2 mM butanol, or 5 mM pentanol. Ethanol sensitivity or insensitivity was a stable property of each cell line and was not associated with differences in electrophoretic mobility, abundance, or cell surface localization of L1. Fab fragments prepared from anti-L1 polyclonal antisera inhibited cell adhesion only in the ethanol-sensitive cell lines. These data suggest that L1 may exist in an alcohol-sensitive or an alcohol-insensitive state that may be governed by host cell factors.     

"Expert performance: Its structure and acquisition": Reply.

Replies to H. Gardner's (see record 1996-10360-001) comments on K. A. Ericsson and N. Charness's (see record 1994-43905-001) review of the structure and acquisition of expert performance. In contrast to Gardner, they attribute differences to the individuals' history of relevant activities that differentially benefit the acquisition of associated skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting older adults’ perceptions about a computer system designed for seniors

Although computer technology may be particularly useful for older adults (e.g., for communication and information access), they have been slower adopters than their younger counterparts. Perceptions about computers, such as perceived usefulness and perceived ease of use, can pose barriers to acceptance and universal access (Davis in MIS Q 13(3):319–340, 1989). Therefore, understanding the precursors to these perceptions for older adult non-computer users may provide insight into the reasons for their non-adoption. The authors examined the relationship between perceived usefulness and perceived ease of use of a computer interface designed for older users and demographic, technology experience, cognitive abilities, personality, and attitudinal variables in a sample of 300 non-computer-using adults between the ages 64 and 98, selected for being at high risk for social isolation. The strongest correlates of perceived usefulness and perceived ease of use were technology experience, personality dimensions of agreeableness and openness to experience, and attitudes. The emotional stability personality dimension was significantly correlated with perceived ease of use though not perceived usefulness. Hierarchical regression analysis revealed that attitudes (i.e., self-efficacy, comfort, and interest) remained predictive of perceptions of usefulness and ease of use when technology experience and personality variables were accounted for. Given that attitudes are more malleable than other variables, such as demographic and cognitive abilities, these findings highlight the potential to increase technology acceptance through positive experiences, appropriate training, and educational campaigns about the benefits of computers and other technologies.     

Input devices for web browsing: age and hand effects

The work reported in this paper examined performance on a mixed pointing and data entry task using direct and indirect positioning devices for younger, middle-aged, and older adults (n=72) who were experienced mouse users. Participants used both preferred and non-preferred hands to perform an item selection and text entry task simulating a typical web page interaction. Older adults performed more slowly than middle-aged adults who in turn performed more slowly than young adults. Performance efficiency was superior with the mouse for older adults only on the first two trial blocks. Thereafter mouse and light pen yielded equivalent performance. For other age groups, mouse and light pen were equivalent at all points of practice. Contrary to prior research revealing superior performance with a light pen for pure pointing tasks, these results suggest that older adults may initially perform worse with a light pen than a mouse for mixed tasks.     

Independent variation of beta-adrenergic receptor binding and catecholamine-stimulated adenylate cyclase activity in rat erythrocytes

The pharmacokinetics, following i.v. administration of (+)-propranolol (40 mg) have been compared to in vitro measurement of protein binding and biochemical parameters of liver function in six normal subjects and twenty patients with stable chronic liver disease. The clearance of (+)-propranolol decreased with evidence of increasing severity of impairment of liver function correlating significantly with a fall in serum albumin, a rise in bilirubin and a prolongation in prothrombin index. The clearance of (+)-propranolol correlated with and was numerically similar to the clearance of indocyanine green in normal subjects and also in patients with chronic liver disease. Protein binding was decreased in chronic liver disease, but this change was not related to changes in plasma proteins. In normal subjects and patients without ascites the volume of distribution increased with decreases in protein binding. Ascites was associated with a further increase in the volume of distribution. The considerable variation in half-life largely depends on changes in liver blood flow, the degree of protein binding and the plasma protein pool size.