Recognition of faces and complex objects in younger and older adults

We examined whether (1) age-associated impairments in face recognition are specific to faces or also apply to within-category recognition of other objects and (2) age-related face recognition deficits are related to impairments in encoding second-order relations and holistic information. In Experiments 1 and 2, we found reliable age differences for recognition of faces, but not of objects. Moreover, older adults (OAs) and younger adults (YAs) displayed similar face inversion effects. In Experiment 3, unlike YAs, OAs did not show the expected decline in performance for recognition of composites (Young, Hellawell, and Hay, 1987). In Experiment 4, both OAs and YAs showed a whole/part advantage (Tanaka and Farah, 1993). Our results suggest that OAs have spared function for processing of second-order relations and holistic information. Possible explanations for the finding that OAs have greater difficulty recognizing faces than recognizing other objects are proposed.     

The origins of levels-of-processing effects in a conceptual test: evidence for automatic influences of memory from the process-dissociation procedure

In three experiments, we explored automatic influences of memory in a conceptual memory task, as affected by a levels-of-processing (LoP) manipulation. We also explored the origins of the LoP effect by examining whether the effect emerged only when participants in the shallow condition truncated the perceptual processing (the lexical-processing hypothesis) or even when the entire word was encoded in this condition (the conceptual-processing hypothesis). Using the process-dissociation procedure and an implicit association-generation task, we found that the deep encoding condition yielded higher estimates of automatic influences than the shallow condition. In support of the conceptual processing hypothesis, the LoP effect was found even when the shallow task did not lead to truncated processing of the lexical units. We suggest that encoding for meaning is a prerequisite for automatic processing on conceptual tests of memory.     

The effect of presentation rate on implicit sequence learning in aging

Implicit sequence learning is thought to be preserved in aging when the to-be learned associations are first-order; however, when associations are second-order, older adults (OAs) tend to experience deficits as compared to young adults (YAs). Two experiments were conducted using a first (Experiment 1) and second-order (Experiment 2) serial-reaction time task. Stimuli were presented at a constant rate of either 800 milliseconds (fast) or 1200 milliseconds (slow). Results indicate that both age groups learned first-order dependencies equally in both conditions. OAs and YAs also learned second-order dependencies, but the learning of lag-2 information was significantly impacted by the rate of presentation for both groups. OAs showed significant lag-2 learning in slow condition while YAs showed significant lag-2 learning in the fast condition. The sensitivity of implicit sequence learning to the rate of presentation supports the idea that OAs and YAs different processing speeds impact the ability to build complex associations across time and intervening events.     

Agreement processing and attraction errors in aging: evidence from subject-verb agreement in German

Effects of aging on lexical processing are well attested, but the picture is less clear for grammatical processing. Where age differences emerge, these are usually ascribed to working-memory (WM) decline. Previous studies on the influence of WM on agreement computation have yielded inconclusive results, and work on aging and subject-verb agreement processing is lacking. In two experiments (Experiment 1: timed grammaticality judgment, Experiment 2: self-paced reading + WM test), we investigated older (OA) and younger (YA) adults’ susceptibility to agreement attraction errors. We found longer reading latencies and judgment reaction times (RTs) for OAs. Further, OAs, particularly those with low WM scores, were more accepting of sentences with attraction errors than YAs. OAs showed longer reading latencies for ungrammatical sentences, again modulated by WM, than YAs. Our results indicate that OAs have greater difficulty blocking intervening nouns from interfering with the computation of agreement dependencies. WM can modulate this effect.     

Bistable perception in normal aging: perceptual reversibility and its relation to cognition

The effects of age on the ability to resolve perceptual ambiguity are unknown, though it depends on frontoparietal attentional networks known to change with age. We presented the bistable Necker cube to 24 middle-aged and OAs (older adults; 56–78 years) and 20 YAs (younger adults; 18–24 years) under passive-viewing and volitional control conditions: Hold one cube percept and Switch between cube percepts. During passive viewing, OAs had longer dominance durations (time spent on each percept) than YAs. In the Hold condition, OAs were less able than YAs to increase dominance durations. In the Switch condition, OAs and YAs did not differ in performance. Dominance durations in either condition correlated with performance on tests of executive function mediated by the frontal lobes. Eye movements (fixation deviations) did not differ between groups. These results suggest that OAs’ reduced ability to hold a percept may arise from reduced selective attention. The lack of correlation of performance between Hold and executive-function measures suggests at least a partial segregation of underlying mechanisms.     

Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects.     

Age-related differences in memory after attending to distinctiveness or similarity during learning

Episodic memory is vulnerable to age-related change, with older adults demonstrating both impairments in retrieving contextual details and susceptibility to interference among similar events. Such impairments may be due in part to an age-related decline in the ability to encode distinct memory representations. Recent research has examined how manipulating stimulus properties to emphasize distinctiveness can reduce age-related deficits in memory. However, few studies have addressed whether learning strategies that differentially encourage distinctiveness processing attenuate age-related differences in episodic memory. In the present study, participants engaged in two incidental encoding tasks emphasizing either distinctiveness or similarity processing. Results demonstrated higher rates of recollection for stimuli studied under the distinctiveness task than the similarity task in younger but not older adults. These findings suggest a declining capacity for distinctiveness processing to benefit memory in older adults, and raise the possibility that strategies that enhance gist-based encoding may attenuate age-related memory deficits.     

Contextual factors in vigilance testing of children with ADHD

The effect of contextual factors on continuous performance testing was examined by administering a vigilance task to 51 children with ADHD under conditions of examiner presence and absence at different times (i.e., beginning and middle) of an assessment battery. The results showed that the ability to differentiate target stimuli from distractors (d-prime) was related to examiner presence vs. absence, and that response bias (beta), a measure of the subject's carefulness in responding to stimuli, was associated with the time of task administration. The decline in d-prime under conditions of examiner absence was shown to be related more to level of aggression as opposed to level of inattention. Children with ADHD having relatively high levels of aggression demonstrated a significant decline in d-prime scores under conditions of examiner absence, but those with relatively low levels of aggression did not. The results demonstrated the importance of contextual factors on vigilance task performance and suggested a differential impact of contextual variables on children who are inattentive vs. aggressive.     

Anxiety‐induced performance catastrophes: Investigating effort required as an asymmetry factor

Two studies are reported that test the hypothesis that previous support for the cusp catastrophe model of anxiety and performance, and the hysteresis effect in particular, could have been due to a complex interaction between cognitive anxiety and effort required rather than between cognitive anxiety and physiological arousal. We used task difficulty to manipulate effort required in a letter transformation task. Experiment 1 (N=32) used high levels of trait anxiety together with a competitive environment to induce state anxiety. Experiment 2 (N=20) used a competitive environment with social pressure and ego threat instructions to induce high levels of worry. Both studies revealed significant three‐way interactions as hypothesized with follow‐up tests showing some support for the hysteresis hypothesis in Study 1, and strong support for the hysteresis hypothesis in Study 2. The findings support a processing efficiency theory explanation of anxiety‐induced performance catastrophes and indicate that two cusp catastrophe models of performance may exist; one that incorporates the interactive effects of cognitive anxiety and physiological arousal upon performance and the other that incorporates the interactive effects of cognitive anxiety and effort required upon performance.     

Retention of word pairs as a function of level of processing,instruction to remember,and delay

ABSTRACT

Modern research on the efficacy of levels of processing (LoP) tasks on memory has focused on less than 1-day retention delays, while assuming that the observed benefits of deep tasks will continue across remote delays. However, direct tests of the continued benefits of deep processes for accuracy and organisation in remote memory are rare. The current set of experiments, using auditorily-presented lists of scrambled word pairs, tested whether deep LoP tasks produced better free recall and organisation over one week (Experiment 1) and four weeks (Experiments 2 and 3). All experiments revealed significant LoP effects on free recall and organisation at immediate and delayed test, with no effect of intention to remember. However, Experiments 2 and 3 revealed poor recall and organisation at the delayed tests among all of the LoP groups, suggesting that deep processing may not produce highly accessible memories over very long delays.     

Conceptual and non-conceptual repetition priming in category exemplar generation: Evidence from bilinguals

One measure of conceptual implicit memory is repetition priming in the generation of exemplars from a semantic category, but does such priming transfer across languages? That is, do the overlapping conceptual representations for translation equivalents provide a sufficient basis for such priming? In Experiment 1 (N=96) participants carried out a deep encoding task, and priming between languages was statistically reliable, but attenuated, relative to within-language priming. Experiment 2 (N=96) replicated the findings of Experiment 1 and assessed the contributions of conceptual and non-conceptual processes using a levels-of-processing manipulation. Words that underwent shallow encoding exhibited within-language, but not between-language, priming. Priming in shallow conditions cannot therefore be explained by incidental activation of the concept. Instead, part of the within-language priming effect, even under deep-encoding conditions, is due to increased availability of language-specific lemmas or phonological word forms.     

Sleep disruption explains age-related prospective memory deficits: implications for cognitive aging and intervention

The high prevalence of sleep disruption among older adults may have implications for cognitive aging, particularly for higher-order aspects of cognition. One domain where sleep disruption may contribute to age-related deficits is prospective memory—the ability to remember to perform deferred actions at the appropriate time in the future. Community-dwelling older adults (55–93 years, N = 133) undertook assessment of sleep using actigraphy and participated in a laboratory-based prospective memory task. After controlling for education, sleep disruption (longer awakenings) was associated with poorer prospective memory. Additionally, longer awakenings mediated the relationship between older age and poorer prospective memory. Other metrics of sleep disruption, including sleep efficiency and wake after sleep onset, were not related to prospective memory, suggesting that examining the features of individual wake episodes rather than total wake time may help clarify relationships between sleep and cognition. The mediating role of awakening length was partially a function of greater depression and poorer executive function (shifting) but not retrospective memory. This study is among the first to examine the association between objectively measured sleep and prospective memory in older adults. Furthermore, this study is novel in suggesting sleep disruption might contribute to age-related prospective memory deficits; perhaps, with implications for cognitive aging more broadly. Our results suggest that there may be opportunities to prevent prospective memory decline by treating sleep problems.     

Visuospatial function in the beagle dog: an early marker of cognitive decline in a model of human aging and dementia

Visuospatial learning and memory impairments are an early marker for age-related cognitive decline and Alzheimer's disease. Similar to humans, aged dogs show visuospatial learning and memory deficits (). One hundred and nine beagle dogs ranging between 0.25 and 11.99 years were tested on a visuospatial delayed non-matching to position (DNMP) task to better characterize the progression of visuospatial deficits in the dog. Age predicted 48.2% of the variability in learning the DNMP, with dogs ranging from 1 to 11.99 years generally making more errors with increasing age. By contrast, puppies (<1 year) likely were showing developmental deficits, possibly due to an immature prefrontal cortex. Mild visuospatial deficits were detected by 6 years, which precedes the typical onset of amyloid-beta (Abeta) accumulation in the dog brain by two years, and can serve as an early marker for cognitive decline in the dog. These findings suggest that (1) age-related changes in visuospatial function in the dog models that seen in humans, further validating the dog as a model for human aging and dementia; and (2) other mechanisms, such as oxidative stress, soluble Abeta oligomers or cholinergic deficits, are likely contributing to the early impairment.     

The effects of attention on age-related relational memory deficits: evidence from a novel attentional manipulation

Healthy aging is often accompanied by episodic memory decline. Prior studies have consistently demonstrated that older adults show disproportionate deficits in relational memory (RM) relative to item memory (IM). Despite rich evidence of an age-related RM deficit, the source of this deficit remains unspecified. One of the most widely investigated factors of age-related RM impairment is a reduction in attentional resources. However, no prior studies have demonstrated that reduced attentional resources are the critical source of age-related RM deficits. Here, we used qualitatively different attention tasks and tested whether reduced attention for relational processing underlies the RM deficit observed in aging. In Experiment 1, we imposed either item-detection or relation-detection attention tasks on young adults during episodic memory encoding and found that only the concurrent attention task that involves relational processing disproportionately impaired RM performance in young adults. Moreover, by ruling out the possible confound of task difficulty on the disproportionate RM impairment, we further demonstrated that reduced relational attention is a key factor for the age-related RM deficit. In Experiment 2, we replicated the results from Experiment 1 by using different materials of stimuli and found that the effect of relational attention on RM is material general. The results of Experiment 2 also showed that reducing attentional resources for relational processing in young adults strikingly equated their RM performance to that of older adults. Thus, this study documents the first evidence that reduced attentional resources for relational processing are a critical factor for the relational memory impairment observed in aging.     

Older adults' decoding of emotions: role of dynamic versus static cues and age-related cognitive decline

Although age-related deficits in emotion recognition have been widely explored, the nature and scope of these deficits remain poorly understood. We conducted two experiments to examine whether these deficits are less pronounced when older adults evaluate dynamic compared with static images, and second, whether age-related cognitive decline exacerbates these deficits. Our results suggest that age-related cognitive decline exacerbates older adults' deficits in detecting anger, but only from static faces. Furthermore, older adults do not show emotion recognition deficits when evaluating global emotions from dynamic images of faces.     

Effects of aging and divided attention on recognition memory processes for single and associative information

In the divided attention paradigm to test age-related associative memory deficits, whether the effects of divided attention occur at encoding or retrieval has not been clarified, and the effect on retention has not been studied. This study explored whether and how much divided attention at either encoding, retention, or retrieval diminished accuracy in recognizing a single feature (object or location) and associated features (object+location) by 23 elderly people (13 women; M age = 70.6 yr., SD = 2.8) recruited from a neighborhood community circle, and 29 female college students (M age = 20.8 yr., SD = 1.1). The results showed a significant decline in memory performance for both age groups due to divided attention in location and associative memory at retention, suggesting that the retention process demands attentional resources. Overall, regardless of their relative deficiency in associative memory, older adults showed an effect of divided attention comparable to that of younger adults in a recognition task.     

Fonctions exécutives,vieillissement cognitif et variations stratégiques

Aging is characterized by a decrease of cognitive performance in most of cognitive domains. One of the most fundamental issues is then to know what are the underlying mechanisms of these age-related changes in human cognition. Recent research suggests that in addition to speed of processing and working memory capacities, age-related impairment in executive functioning plays an important role in the cognitive decline associated to aging. Above and beyond performance, current research shows that the mediating role of executive function in age-related changes in cognitive performance occurs via changes in strategies variations (i.e., repertoire, distribution, execution, and selection of the strategies used to accomplish a cognitive task). In this article, we illustrate both strategic variations and underlying executive control mechanisms in two important cognitive domains : episodic memory and problem solving.     

Adaptive spatial working memory assessments for aging pet dogs

Assessments for spatial working memory (SWM) in pet dogs that can detect age-related cognitive deficits in a single session may aid in diagnosing canine dementia and may facilitate translational research on Alzheimer’s disease in humans. Adaptive testing procedures are widely used in single-session assessments for humans with diverse cognitive abilities. In this study, we designed and deployed two up-down staircase assessments for SWM in which 26 pet dogs were required to recall the location of a treat hidden behind one of two identical boxes following delays of variable length. In the first experiment, performance tended to decline with age but few dogs completed the test (n?=?10). However, all of the dogs that participated in the second experiment (n?=?24) completed the assessment and provided reliable evidence of learning and retaining the task. Delay length and age significantly predicted performance supporting the validity of this assessment. The relationships between age and performance were described by inverted U-shaped functions as both old and young dogs displayed deficits in weighted cumulative-scores and trial-by-trial performance. Thus, SWM in pet dogs may develop until midlife and decline thereafter. Exploratory analyses of non-mnemonic fixation strategies, sustained engagement, inhibitory control, and potential improvements for future SWM assessments which adopt this paradigm are also discussed.

     

Levels of processing effects on implicit and explicit memory tasks: using question position to investigate the lexical-processing hypothesis

One interpretation of levels of processing effects (LOP) on priming in implicit tests of memory is in terms of deficits in lexical processing during shallow study tasks. In two experiments the extent of lexical processing engaged in during standard shallow encoding tasks was manipulated by placing the encoding question either before or after the target stimulus. Clear evidence was found in explicit memory tasks that placing the question after the target stimulus increased the depth of processing of words presented in shallow encoding tasks. In contrast, there was no evidence of such an effect on the priming observed in implicit memory tasks. The results suggest that the role of lexical processing in LOP effects on priming requires further specification.     

Implicit learning of higher order sequences in middle age

Previous studies have demonstrated age-related deficits in implicit learning of higher order sequences in comparisons of college-age and elderly adults (e.g., J. H. Howard & D. V. Howard, 1997). This study examined whether these age deficits begin in middle age. Results showed a reliable age-related deficit in pattern sensitivity in "older" compared with "younger" middle-aged people, and age reliably predicted sensitivity to the sequence by using both speed and accuracy measures. The results are consistent with an age-related decline in a generic cognitive resource as reflected in T. A. Salthouse's (1996) simultaneity mechanism of cognitive aging.