Subjective age-of-acquisition norms for 600 Turkish words from four age groups

The main purpose of this study was to report age-based subjective age-of-acquisition (AoA) norms for 600 Turkish words. A total of 115 children, 100 young adults, 115 middle-aged adults, and 127 older adults provided AoA estimates for 600 words on a 7-point scale. The intraclass correlations suggested high reliability, and the AoA estimates were highly correlated across the four age groups. Children gave earlier AoA estimates than the three adult groups; this was true for high-frequency as well as low-frequency words. In addition to the means and standard deviations of the AoA estimates, we report word frequency, concreteness, and imageability ratings, as well as word length measures (numbers of syllables and letters), for the 600 words as supplemental materials. The present ratings represent a potentially useful database for researchers working on lexical processing as well as other aspects of cognitive processing, such as autobiographical memory.     

Production and identification repetition priming in amnestic mild cognitive impairment

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.     

Production and Identification Repetition Priming in AmnesticMild Cognitive Impairment

ABSTRACT

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.     

Age-of-acquisition differences in young and older adults affect latencies in lexical decision and semantic categorization

An ongoing discussion about the role of age of acquisition (AoA) in word processing concerns the confound with word frequency. This study removed possible frequency confounds by comparing AoA and word familiarity differences in young (18-23 years) and older (52-56 years) adults. A first study investigated the differences in AoA and word familiarity ratings. The norms of AoA and familiarity were significantly different for young and older adults whereas these were previously considered equivalent [Morrison, C. M., Hirsh, K. W., Chappell, T., & Ellis, A. W. (2002). Age and age of acquisition: An evaluation of the cumulative frequency hypothesis. European Journal of Cognitive Psychology, 14, 435-459]. In the second study, AoA and familiarity effects were significantly different for the older and young adults in a lexical decision task. The third study replicated these findings in a semantic artifact/naturally occurring categorization experiment, thus providing further evidence for AoA-effects when word processing requires semantic mediation. Results from both studies were in line with the hypothesis that AoA effects on word processing cannot be accounted for by word frequency or other possible confounds.     

Influence of mild cognitive impairment on visual word recognition

The present study examined the effects of normal aging and mild cognitive impairment (MCI) on visual word recognition. Madden et al. (1999) reported evidence of general slowing of cognitive processes in Alzheimer's disease (AD) patients relative to younger adults and healthy older adults using a lexical decision task. It was of interest to determine whether similar effects would be observed in MCI patients relative to healthy younger and older adults. We extended the lexical decision task paradigm developed by Allen et al. (2004b) on younger adults to an examination of the effect(s) of MCI on visual word recognition. Results from the present study showed that healthy older adults and MCI patients performed similarly. That is, both groups took longer than younger adults to process words presented in mixed-case than in consistent-case letters. Mild cognitive impairment patients, however, responded significantly more slowly than healthy older adults across all lexical decision task conditions and showed a trend toward larger case-mixing effects than healthy older adults, which suggests that MCI may result in poorer analytic processing ability. Based on the current findings, evidence of a generalized slowing of cognitive processes using a standard lexical decision task can be expanded to include not only AD patients, but also the preclinical stages of the disease as well.     

Picture priming in normal aging and Alzheimer's disease

The present study investigated age invariance for naming pictures and whether implicit memory is spared in Alzheimer's disease (AD). During the study phase, young adults, AD patients, and older controls were shown outlines of familiar pictures. After a distracter task, implicit memory was assessed incidentally. The results showed similar visual priming for the three groups, although young adults responded faster than the two older groups. Moreover, the number of errors was smaller for studied than for non-studied pictures. This pattern of results was repeated across the three groups, although AD patients produced more errors than young adults and older controls, and there were no differences between these latter groups. These results confirmed previous visual and haptic findings showing unimpaired perceptual priming in normal aging and AD patients when implicit memory is assessed using identification tasks. These results are interpreted from a cognitive neuroscience perspective.     

A fresh look at the predictors of naming accuracy and errors in Alzheimer's disease

In recent years, a considerable number of studies have tried to establish which characteristics of objects and their names predict the responses of patients with Alzheimer's disease (AD) in the picture-naming task. The frequency of use of words and their age of acquisition (AoA) have been implicated as two of the most influential variables, with naming being best preserved for objects with high-frequency, early-acquired names. The present study takes a fresh look at the predictors of naming success in Spanish and English AD patients using a range of measures of word frequency and AoA along with visual complexity, imageability, and word length as predictors. Analyses using generalized linear mixed modelling found that naming accuracy was better predicted by AoA ratings taken from older adults than conventional ratings from young adults. Older frequency measures based on written language samples predicted accuracy better than more modern measures based on the frequencies of words in film subtitles. Replacing adult frequency with an estimate of cumulative (lifespan) frequency did not reduce the impact of AoA. Semantic error rates were predicted by both written word frequency and senior AoA while null response errors were only predicted by frequency. Visual complexity, imageability, and word length did not predict naming accuracy or errors.     

The effects of ageing and cognitive impairment on on‐line and off‐line motor learning

Skilled performance is a collective function of practice‐related experiences (online learning) and post‐practice memory consolidation during sleep (offline learning). This study examines the effects of ageing and cognitive impairment on the on‐ and offline learning of a point‐to‐point arm movement. In a 3‐day experiment, older adults (cognitively normal or impaired) and young adults (YAs) were randomly assigned to practice or no‐practice conditions. Changes in the dependent measures of movement time and timing error were analysed within and between conditions across days. The findings suggest that both age and cognitive function affect skill learning. YAs improved performance via both on‐ and offline learning whereas older adults with normal cognitive capacities appeared to learn the movement skill primarily in an online mode. Cognitive impairments were found to hinder both types of skill learning. Implications for motor skill acquisition and rehabilitation are briefly discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Chronic glucocorticoid hypersecretion in Cushing’s syndrome exacerbates cognitive aging

Cumulative exposure to glucocorticoid hormones (GC) over the lifespan has been associated with cognitive impairment and may contribute to physical and cognitive degeneration in aging. The objective of the present study was to examine whether the pattern of cognitive deficits in patients with Cushing’s syndrome (CS), a disorder characterized by chronic exposure to elevated levels of glucocorticoids (GC), is similar to that observed in older individuals. Ten subjects with CS were compared to sex-, age-, and education-matched healthy controls and older subjects (age of CS subjects + 15 yr). All participants were administered tests to assess attention, visuospatial processing, learning and memory, reasoning, concept formation and verbal fluency. MANCOVAs with depression scores as covariate and polynomial contrasts revealed that the age-matched control group performed better than the CS and older subject groups in visual target detection, trail making test, stroop task, digit symbol substitution, block design, object assembly, visual reproduction, spatial memory and similarities. The CS and older subjects performed similarly on these tasks. Further, a principal component analysis revealed two significant factors, representing general cognitive function and verbal memory explaining 39.9% and 10.0% of the variance, respectively. Additional MANCOVAs with depression as a covariate revealed that CS and older control subjects showed impaired performance on general cognitive function compared to age-matched controls. These results suggest that hypersecretion of GCs has “aging-like” effects on cognitive performance in individuals with CS.     

Community-dwelling older adults with mild cognitive impairments show subtle visual attention costs when descending stairs

BackgroundOlder adults are at greater risk of falls while descending stairs. Cognitive deficits can further influence one's ability and mild cognitive impairments (MCI) specifically affect visual attention and dual tasking behavior. The present study aimed at comparing the attentional costs at different points during the approach to and descent of a staircase between older adults with and without MCI.MethodsEleven older adults with MCI and twenty-three healthy older individuals without cognitive impairments were recruited. Neuropsychological tests were carried out. In addition, participants approached and descended a 5-step staircase while a simultaneous visual Stroop dual-task was randomly introduced during the approach, transition or steady state descent phases across trials. Three-dimensional kinematics and accuracy on the Stroop task were analyzed and dual task costs were calculated.ResultsThe MCI group showed deficits for visuo-spatial attention, memory and multi-tasking abilities, as well as balance and decreased confidence for falls efficacy, but not for daily activity scores. Despite such changes, this group of community-dwelling individuals with MCI presented a functional capacity to descend stairs even during divided visual attention. However, there were subtle, but significant, group differences for movement fluidity and performance on the simultaneous cognitive task, particularly during the approach and transition to descent phases. The MCI group also tended to descend slower while using the handrails more than healthy older adults.ConclusionThe present cohort of community-dwelling older adults with MCI were functional, but appeared to prioritize locomotor demands over the simultaneous cognitive task in a possible “posture first” strategy to descend stairs. The present findings should be considered for developing more ecologically based clinical assessments of mobility deficits following cognitive impairments, with the approach and transition phases during stair descent as key points of focus.     

Autobiographical memory specificity predicts social problem-solving ability in old and young adults

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants' specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.     

Autobiographical memory specificity predicts social problem-solving ability in old and young adults

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants' specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.     

The varying effects of age of acquisition

There are a number of theories that suggest that age of acquisition (AoA) effects are not uniform across different tasks. Catling and Johnston (2006a) found greater AoA effects within an object-naming task than in a semantic classification task. They explained these findings by suggesting that AoA effects might accumulate according to how many levels of representation a task necessitates access to. Brysbaert and Ghyselinck (2006) explain the difference in AoA effects by proposing two distinct types of AoA (frequency dependent and frequency independent), the first accounted for by a connectionist-type mechanism and the latter situated at the interface between semantics and word production. Moreover, Moore, Smith-Spark, and Valentine (2004) and Holmes and Ellis (2006) have suggested that there are two loci of AoA effects: at the phonological level and somewhere within the perceptual level of representation. Again, this could account for the varying degrees of AoA effects. This study sets about testing these ideas by assessing the effect size of AoA across a series of different tasks that necessitate access to various levels of representation. Experiments 1–4 demonstrate significant effects of AoA in a novel picture–picture verification task, an object classification task, a picture verification task, and an object-naming task. Experiment 5 showed no effects of initial phoneme on the naming of the critical objects used within Experiments 1–4. The implication of the varying AoA effect sizes found within Experiments 1–4 in relation to explanations of AoA are discussed.     

The varying effects of age of acquisition

There are a number of theories that suggest that age of acquisition (AoA) effects are not uniform across different tasks. Catling and Johnston (2006a) found greater AoA effects within an object-naming task than in a semantic classification task. They explained these findings by suggesting that AoA effects might accumulate according to how many levels of representation a task necessitates access to. Brysbaert and Ghyselinck (2006) explain the difference in AoA effects by proposing two distinct types of AoA (frequency dependent and frequency independent), the first accounted for by a connectionist-type mechanism and the latter situated at the interface between semantics and word production. Moreover, Moore, Smith-Spark, and Valentine (2004) and Holmes and Ellis (2006) have suggested that there are two loci of AoA effects: at the phonological level and somewhere within the perceptual level of representation. Again, this could account for the varying degrees of AoA effects. This study sets about testing these ideas by assessing the effect size of AoA across a series of different tasks that necessitate access to various levels of representation. Experiments 1-4 demonstrate significant effects of AoA in a novel picture-picture verification task, an object classification task, a picture verification task, and an object-naming task. Experiment 5 showed no effects of initial phoneme on the naming of the critical objects used within Experiments 1-4. The implication of the varying AoA effect sizes found within Experiments 1-4 in relation to explanations of AoA are discussed.     

Comparison of Cognitive Empathy,Emotional Empathy,and Social Functioning in Different Age Groups

Empathic responses and optimum social functioning are associated with psychological and physical health benefits. The aim of this study was to compare emotional empathy, cognitive empathy, and social functioning among different age groups, including adolescence, young adulthood, middle adulthood, and late adulthood. One hundred and ninety‐six people (92 males, 104 females) with the age range of 14 to 85 assigned to four age groups (adolescents, young adults, middle adults, and older adults) participated in this study. Participants were asked to complete the Empathy Quotient, the Revised Eyes Test, and Social Functioning Scale. The results showed that there were significant differences between older adults and other groups. Emotional empathy increased in older people, but there were deficits in some aspects of cognitive empathy. Also, the findings showed an age‐related decline in social functioning. Due to deficits in cognitive empathy affected by ageing, older adults showed some impairment in their ability to interpret emotional cues. This age‐related decline in cognitive empathy might be a reason for weak social functioning in older adults. Therefore, considering these elements would be helpful to provide healthcare strategies for elderly people.     

Effects of adult age and working memory on reasoning and spatial abilities

Three predictions were derived from the hypothesis that adult age differences in certain measures of cognitive functioning are attributable to age-related reductions in a processing resource such as working-memory capacity. Each prediction received at least some degree of empirical support in a study involving 120 males ranging between 20 and 79 years of age. First, older adults exhibited greater impairments of performance than did young adults when task complexity increased and more demands were placed on the limited processing resources; second, the magnitudes of these complexity effects were highly correlated across verbal (reasoning) and spatial (paper folding) tasks. Finally, statistical control of an index of a working-memory processing resource attenuated the effects of age on the measures of cognitive performance. It was concluded that further progress in understanding the mechanisms of the relation between age and cognitive functioning will require improved conceptualizations of the nature of working memory or other hypothesized mediating constructs.     

A Meta-Analysis of Working Memory Impairments in Autism Spectrum Disorders

Autism spectrum disorders (ASD) are characterized by executive dysfunction, and working memory (WM) comprises one core component of executive function. Many studies have investigated WM impairments in individuals with ASD, however, a conclusive agreement has not been reached. The present study provided a meta-analytic review of WM impairments in individuals with ASD and evaluated potential moderating variables of this problem. Twenty-eight studies were included in this study, and the participants comprised 819 individuals with ASD and 875 healthy controls. A significant WM impairment (Cohen’s d?=??0.61) was identified in the individuals with ASD, however, this impairment was not associated with age. Results of moderation analyses showed that (a) spatial WM was more severely impaired than verbal WM and (b) the component of cognitive processing (maintenance vs. maintenance plus manipulation) did not affect the severity of WM impairments. These findings suggest that WM is impaired in individuals with ASD and may have implications for interventions related to WM impairments in these individuals.     

Additive effects of social and non‐social attention during infancy relate to later autism spectrum disorder

Emerging findings from studies with infants at familial high risk for autism spectrum disorder (ASD), owing to an older sibling with a diagnosis, suggest that those who go on to develop ASD show early impairments in the processing of stimuli with both social and non‐social content. Although ASD is defined by social‐communication impairments and restricted and repetitive behaviours, the majority of cognitive theories of ASD posit a single underlying factor, which over development has secondary effects across domains. This is the first high‐risk study to statistically differentiate theoretical models of the development of ASD in high‐risk siblings using multiple risk factors. We examined the prediction of ASD outcome by attention to social and non‐social stimuli: gaze following and attentional disengagement assessed at 13 months in low‐risk controls and high‐risk ASD infants (who were subsequently diagnosed with ASD at 3 years). When included in the same regression model, these 13‐month measures independently predicted ASD outcome at 3 years of age. The data were best described by an additive model, suggesting that non‐social attention, disengagement, and social attention as evidenced by gaze following, have a cumulative impact on ASD risk. These data argue against cognitive theories of ASD which propose that a single underlying factor has cascading effects across early development leading to an ASD outcome, and support multiple impairment models of ASD that are more consistent with recent genetic and neurobiological evidence.     

Age of acquisition ratings score better on criterion validity than frequency trajectory or ratings “corrected” for frequency

From the very first studies on the effect of age of acquisition (AoA) on word processing, researchers have validated their AoA ratings by correlating them with other, more objective indices of the age at which children know words. Still, the ratings have been questioned, and alternative measures have been proposed. Two of these are differences in word frequency between language directed at young children and language directed at older children (frequency trajectory) and AoA ratings corrected for word frequency. Surprisingly, the criterion validity of these alternative measures has never been established, partly because one of the validation criteria (the age at which children are able to name pictures) has been questioned. In the present study, four databases are used that aimed to establish the order of English word acquisition, going from the very first words learned to words taught in secondary education. The criteria for word knowledge included word production, multiple-choice questions about the meaning of the words, and teacher judgments about when words should be taught in the school curriculum. For all databases, the frequency trajectory correlated substantially less with the criterion than AoA ratings. For all but one, the same was true for AoA ratings “corrected” for other variables. On the basis of these findings, researchers should be cautious interpreting null effects with the “improved” variables as evidence against a genuine AoA effect.     

The role of age of acquisition in picture and word naming in dyslexic adults

To date, there has been numerous reports that early acquired pictures and words are named faster than late acquired pictures and words in normal reading but it is not established whether age of acquisition (AoA) has the same impact on adult dyslexic naming, especially in a transparent orthography such as Turkish. Independent ratings were obtained for AoA, frequency, name agreement, and object familiarity in Turkish for all items in the Snodgrass and Vanderwart line drawing set. Dyslexic (N= 15) and non-dyslexic (N= 15) university undergraduates were asked to name 30 early acquired and 30 late acquired pictures and picture names standardized and selected from these norms. As predicted, there were main effects for (a) AoA with reaction times (RTs) for Early items named faster than Late items, (b) reader status with non-dyslexic students faster than dyslexic students, and (c) stimuli types with pictures named slower than words. A two-way interaction between reader status and stimuli type was also significant. Implications of the results for theoretical frameworks of AoA within the cognitive architecture and normal and impaired models of reading are discussed.