Aging,memory load,and resource allocation during reading

To test the notion that aging brings an inability to self-initiate processing, the authors investigated the effects of memory load on online sentence understanding. Younger and older adults read a series of short passages with or without a simultaneous updating task, which would be expected to deplete resources by consuming memory capacity. Regression analyses of word-by-word reading times onto text variables within each condition were used to decompose reading times into resources allocated to the array of word-level and textbase-level processes needed for comprehension. Among neither the young nor the old were word-level processes disrupted by a simultaneous memory load. However, older readers showed relatively greater levels of resource allocation to conceptual integration than the younger adults when under load, regardless of working-memory span or task priority. These results suggest that the ability to self-initiate the allocation of processing resources during reading is preserved among older readers.     

Aging, parafoveal preview, and semantic integration in sentence processing: Testing the cognitive workload of wrap-up

The current study investigated the degree to which semantic-integration processes ("wrap-up") during sentence understanding demand attentional resources by examining the effects of clause and sentence wrap-up on the parafoveal preview benefit (PPB) in younger and older adults. The PPB is defined as facilitation in processing word N + 1, based on information extracted while the eyes are fixated on word N, and is known to be reduced by processing difficulty at word N. Participants read passages in which word N occurred in a sentence-internal, clause-final, or sentence-final position, and a gaze-contingent boundary-change paradigm was used to manipulate the information available in parafoveal vision for word N + 1. Wrap-up effects were found on word N for both younger and older adults. Early-pass measures (first-fixation duration and single-fixation duration) of the PPB on word N + 1 were reduced by clause wrap-up and sentence wrap-up on word N, with similar effects for younger and older adults. However, for intermediate (gaze duration) and later-pass measures (regression-path duration, and selective regression-path duration), sentence wrap-up (but not clause wrap-up) on word N differentially reduced the PPB of word N + 1 for older adults. These findings suggest that wrap-up is demanding and may be less efficient with advancing age, resulting in a greater cognitive processing load for older readers. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

New and updated tests of print exposure and reading abilities in college students

The relationship between print exposure and measures of reading skill was examined in college students (N = 99, 58 female; mean age = 20.3 years). Print exposure was measured with several new self-reports of reading and writing habits, as well as updated versions of the Author Recognition Test and the Magazine Recognition Test (Stanovich & West, 1989). Participants completed a sentence comprehension task with syntactically complex sentences, and reading times and comprehension accuracy were measured. An additional measure of reading skill was provided by participants' scores on the verbal portions of the ACT, a standardized achievement test. Higher levels of print exposure were associated with higher sentence processing abilities and superior verbal ACT performance. The relative merits of different print exposure assessments are discussed.     

Breaking the waves: age differences in electrical brain activity when reading text with distractors

The authors tested whether older adults have greater difficulty than younger adults in ignoring task-irrelevant information during reading as a result of age-related decline in inhibitory processes. Participants were shown target sentences containing distractor words. They were instructed to read aloud each sentence and ignore distractors. The N400 event-related potential (ERP) was used to measure the extent of semantic processing of target and distracting information. It showed that younger adults semantically processed both target and distracting material, whereas online processing of target sentences in older adults was disrupted by the distractors. In older adults, memory for target information related to their susceptibility to distraction and inhibition efficiency. Implications for age-differences in inhibitory control, working memory, and resource capacity are discussed.     

The structure of verbal abilities in young and older adults

Four language sample measures as well as measures of vocabulary, verbal fluency, and memory span were obtained from a sample of young adults and a sample of older adults. Factor analysis was used to analyze the structure of the vocabulary, fluency, and span measures for each age group. Then an "extension" analysis was performed by using structural modeling techniques to determine how the language sample measures were related to the other measures. The measure of grammatical complexity was associated with measures of working memory including reading span and digit span. Two measures, sentence length in words and a measure of lexical diversity, were associated with the vocabulary measures. The fourth measure, propositional density, was associated with the fluency measures as a measure of processing efficiency. The structure of verbal abilities in young and older adults is somewhat different, suggesting age differences in processing efficiency.     

The role of age and inhibitory efficiency in working memory processing and storage components

In this study, we examined the extent to which inhibitory efficiency accounted for age-related decline in the processing and storage components of working memory. Older and younger adults performed a sequential task, which served as an index of deletion-type inhibition (the ability to suppress no-longer-relevant information). The reading span task was used to measure working memory components by examining processing accuracy, processing time, and end-word recall of sentences presented. Reduced inhibitory efficiency, which was poorer in older adults, predicted age-related decline in recall, over and above the effects of processing speed. Similar results were observed for processing accuracy, although the age effect in this component was marginal. These results highlight the important role of deletion-type inhibition in explaining age-related decline in working memory performance, particularly in the storage component, and extend previous research by examining this relationship at a componential level.     

The role of age and inhibitory efficiency in working memory processing and storage components

In this study, we examined the extent to which inhibitory efficiency accounted for age-related decline in the processing and storage components of working memory. Older and younger adults performed a sequential task, which served as an index of deletion-type inhibition (the ability to suppress no-longer-relevant information). The reading span task was used to measure working memory components by examining processing accuracy, processing time, and end-word recall of sentences presented. Reduced inhibitory efficiency, which was poorer in older adults, predicted age-related decline in recall, over and above the effects of processing speed. Similar results were observed for processing accuracy, although the age effect in this component was marginal. These results highlight the important role of deletion-type inhibition in explaining age-related decline in working memory performance, particularly in the storage component, and extend previous research by examining this relationship at a componential level.     

Recall of morphologically complex forms is affected by memory task but not dyslexia

The authors studied the effect of morphological complexity on working memory in list recall tasks with base words (boy), inflected words (boy + 's) and derived words (boy + hood) in a morphologically rich language: Finnish. Simple serial recall was compared to complex working memory tasks, combining word recall with sentence verification in 8-year-old normally reading participants, dyslexic children, and adults. The normally reading children performed better than dyslexic children on both memory tasks and a test of morphology. Base words were better recalled than morphologically complex words. Memory was better for derived than inflected words in simple but not complex span tasks. There was no interaction between word type and reading group and thus no suggestion of dyslexia being associated with specific problems to represent complex morphology in working memory. Morphological processing in working memory appeared to depend on the task.     

The Measurement of Verbal Working Memory Capacity and Its Relation to Reading Comprehension

Ninety-four subjects were tested on the Daneman and Carpenter (1980) reading span task, four versions of a related sentence span task in which reaction times and accuracy on sentence processing were measured along with sentence-final word recall, two number generation tasks designed to test working memory, digit span, and two shape-generation tasks designed to measure visual-spatial working memory. Forty-four subjects were retested on a subset of these measures at a 3-month interval. All subjects were tested on standard vocabulary and reading tests. Correlational analyses showed better internal consistency and test-retest reliability of the sentence span tasks than of the Daneman-Carpenter reading span task. Factor analysis showed no factor that could be related to a central verbal working memory; rotated factors suggested groupings of tests into factors that correspond to digitrelated tasks, spatial tasks, sentence processing in sentence span tasks, and recall in sentence span tasks. Correlational analyses and regression analyses showed that the sentence processing component of the sentence span tasks was the best predictor of performance on the reading test, with a small independent contribution of the recall component. The results suggest that sentence span tasks are unreliable unless measurements are made of both their sentence processing and recall components, and that the predictive value of these tasks for reading comprehension abilities lies in the overlap of operations rather than in limitations in verbal working memory that apply to both.     

Self-regulated reading in adulthood

Young and older adults read a series of passages of 3 different genres for an immediate assessment of text memory (measured by recall and true/false questions). Word-by-word reading times were measured and decomposed into components reflecting resource allocation to particular linguistic processes using regression. Allocation to word and textbase processes showed some consistency across the 3 text types and was predictive of memory performance. Older adults allocated more time to word and textbase processes than the young adults did but showed enhanced contextual facilitation. Structural equation modeling showed that greater resource allocation to word processes was required among readers with relatively low working memory spans and poorer verbal ability and that greater resource allocation to textbase processes was engendered by higher verbal ability. Results are discussed in terms of a model of self-regulated language processing suggesting that older readers may compensate for processing deficiencies through greater reliance on discourse context and on increases in resource allocation that are enabled through growth in crystallized ability.     

Adult age differences in the effects of goals on self-regulated sentence processing

The authors examined age differences in adults' allocation of effort when reading text for either high levels of recall accuracy or high levels of efficiency. Participants read a series of sentences, making judgments of learning before recall. Older adults showed less sensitivity than the young to the accuracy goal in both reading time allocation and memory performance. Memory accuracy and differential allocation of effort to unlearned items were age equivalent, so age differences in goal adherence were not attributable to metacognitive factors. However, comparison with data from a control reading task without monitoring showed that learning gains among older adults across trial were reduced relative to those of the young by memory monitoring, suggesting that monitoring may be resource consuming for older learners. Age differences in the responsiveness to (information-acquisition) goals could be accounted for, in part, by independent contributions from working memory and memory self-efficacy. Our data suggest that both processing capacity ("what you have") and beliefs ("knowing you can do it") can contribute to individual differences in engaging resources ("what you do") to effectively learn novel content from text.     

Parafoveal preview during reading: effects of sentence position

Two experiments examined parafoveal preview for words located in the middle of sentences and at sentence boundaries. Parafoveal processing was shown to occur for words at sentence-initial, mid-sentence, and sentence-final positions. Both Experiments 1 and 2 showed reduced effects of preview on regressions out for sentence-initial words. In addition, Experiment 2 showed reduced preview effects on first-pass reading times for sentence-initial words. These effects of sentence position on preview could result from either reduced parafoveal processing for sentence-initial words or other processes specific to word reading at sentence boundaries. In addition to the effects of preview, the experiments also demonstrate variability in the effects of sentence wrap-up on different reading measures, indicating that the presence and time course of wrap-up effects may be modulated by text-specific factors. We also report simulations of Experiment 2 using version 10 of E-Z Reader (Reichle, Warren, & McConnell, 2009), designed to explore the possible mechanisms underlying parafoveal preview at sentence boundaries.     

Effects of age, speed of processing, and working memory on comprehension of sentences with relative clauses

Two hundred participants, 50 in each of four age ranges (19-29, 30-49, 50-69, 70-90) were tested for working memory, speed of processing, and the processing of sentences with relative clauses. In Experiment 1, participants read four sentence types (cleft subject, cleft object, subject-subject, subject-object) in a word-by-word, non-cumulative, self-paced reading task and made speeded plausibility judgments about them. In Experiment 2, participants read two types of sentences, one of which contained a doubly center embedded relative clause. Older participants' comprehension was less accurate and there was age-related slowing of online processing times in all but the simplest sentences, which increased in syntactically complex sentences in Experiment 1. This pattern suggests an age-related decrease in the efficiency of parsing and interpretation. Slower speed of processing and lower working memory were associated with longer online processing times only in Experiment 2, suggesting that task-related operations are related to general speed of processing and working memory. Lower working memory was not associated with longer reading times in more complex sentences, consistent with the view that general working memory is not critically involved in online syntactic processing. Longer online processing at the most demanding point in the most demanding sentence was associated with better comprehension, indicating that it reflects effective processing under some certain circumstances. However, the poorer comprehension performance of older individuals indicates that their slower online processing reflects inefficient processing even at these points.     

Working memory predicts subsequent episodic memory decline during healthy cognitive aging: evidence from a cross-lagged panel design

Aging adults experience declines in working memory and episodic memory, however, it is unclear how these declines operate over time. Decreased working memory may be associated with early changes in episodic memory, by reducing older adults’ ability to meaningfully integrate new information into pre-existing schemas and recall information without the assistance of cues. Given the increased prevalence of Alzheimer’s disease, and concerns based on subjective memory changes, it is important to understand how these processes interact over time. To assess the relationship between working memory and episodic memory during healthy cognitive aging, we performed neuropsychological assessments at multiple time points in a sample of 310 community-dwelling older adults. Using a cross-lagged panel design, we demonstrated that the lagged associations between working memory and later episodic free recall were 50% larger than the lagged associations between episodic recall and later working memory, suggesting working memory may be a useful metric of future episodic memory decline.     

Experience and sentence processing: statistical learning and relative clause comprehension

Many explanations of the difficulties associated with interpreting object relative clauses appeal to the demands that object relatives make on working memory. MacDonald and Christiansen [MacDonald, M. C., & Christiansen, M. H. (2002). Reassessing working memory: Comment on Just and Carpenter (1992) and Waters and Caplan (1996). Psychological Review, 109, 35-54] pointed to variations in reading experience as a source of differences, arguing that the unique word order of object relatives makes their processing more difficult and more sensitive to the effects of previous experience than the processing of subject relatives. This hypothesis was tested in a large-scale study manipulating reading experiences of adults over several weeks. The group receiving relative clause experience increased reading speeds for object relatives more than for subject relatives, whereas a control experience group did not. The reading time data were compared to performance of a computational model given different amounts of experience. The results support claims for experience-based individual differences and an important role for statistical learning in sentence comprehension processes.     

The role of processing resources in age-related prospective and retrospective memory within old age

This study investigated the role of processing speed and working memory in prospective and retrospective memory (i.e., free recall) performance within old age. The aim was to examine age-related differences in both memory domains within the age range of 65 to 80 years. The sample consisted of 361 older adults from Wave 1 data of the Zurich Longitudinal Study on Cognitive Aging. Using structural equation modeling, prospective memory, free recall, working memory, and processing speed were identified as latent constructs. Age effects were found to be larger for prospective memory than for free recall. Furthermore, when controlling for individual differences in working memory and processing speed, unique age effects remained for prospective, but not retrospective, memory performance. Results indicate that, within old age, prospective memory represents a distinct memory construct that is partially independent of age-related individual differences in speed of processing, working memory, and retrospective memory.     

Patterns of resource allocation are reliable among younger and older readers

Younger and older adults read short expository passages across 2 times of measurement for subsequent comprehension or recall. Regression analysis was used to decompose word-by-word reading times into resources allocated to word- and textbase-level processes. Readers were more sensitive to these demands when reading for recall than when reading for comprehension. Patterns of resource allocation showed good test-retest reliabilities and were predictive of memory performance. Within age group, resource allocation parameters were not systematically correlated with other individual-difference measures, suggesting that strategies of on-line resource allocation may be a unique source of individual differences in determining comprehension of and memory for text. Age differences in allocation patterns appeared to reflect general slowing among the older adults. Because older adults showed equivalent memory performance to that of younger readers, the reading time data may represent the on-line resource allocation needed for comparable outcomes among older and younger readers.     

Memory and comprehension for health information among older adults: Distinguishing the effects of domain-general and domain-specific knowledge

While there is evidence that knowledge influences understanding of health information, less is known about the processing mechanisms underlying this effect and its impact on memory. We used the moving window paradigm to examine how older adults varying in domain-general crystallised ability (verbal ability) and health knowledge allocate attention to understand health and domain-general texts. Participants (n = 107, age: 60–88 years) read and recalled single sentences about hypertension and about non-health topics. Mixed-effects modelling of word-by-word reading times suggested that domain-general crystallised ability increased conceptual integration regardless of text domain, while health knowledge selectively increased resource allocation to conceptual integration at clause boundaries in health texts. These patterns of attentional allocation were related to subsequent recall performance. Although older adults with lower levels of crystallised ability were less likely to engage in integrative processing, when they did, this strategy had a compensatory effect in improving recall. These findings suggest that semantic integration during reading is an important comprehension process that supports the construction of the memory representation and is engendered by knowledge. Implications of the findings for theories of text processing and memory as well as for designing patient education materials are discussed.     

Reading span task performance,linguistic experience,and the processing of unexpected syntactic events

Accounts of individual differences in online language processing ability often focus on the explanatory utility of verbal working memory, as measured by reading span tasks. Although variability in reading span task performance likely reflects individual differences in multiple underlying traits, skills, and processes, accumulating evidence suggests that reading span scores also reflect variability in the linguistic experiences of an individual. Here, through an individual differences approach, we first demonstrate that reading span scores correlate significantly with measures of the amount of experience an individual has had with written language (gauged by measures that provide “proxy estimates” of print exposure). We then explore the relationship between reading span scores and online language processing ability. Individuals with higher reading spans demonstrated greater sensitivity to violations of statistical regularities found in natural language—as evinced by higher reading times (RTs) on the disambiguating region of garden-path sentences—relative to their lower span counterparts. This result held after statistically controlling for individual differences in a non-linguistic operation span task. Taken together, these results suggest that accounts of individual differences in sentence processing can benefit from a stronger focus on experiential factors, especially when considered in relation to variability in perceptual and learning abilities that influence the amount of benefit gleaned from such experience.     

Patterns of On-line Resource Allocation to Narrative Text by Younger and Older Readers

Younger and older adults read narrative texts word by word for immediate recall. There were no age differences in recall performance, showing that older adults were effective in narrative memory. Analysis of reading times demonstrated the existence of interindividual variability in sensitivity to text demands, which was predictive of subsequent memory performance. Contrary to the view that older readers do not encode text analytically, for these naturalistic narratives both younger and older adults optimized memory through the allocation of processing resources to the construction of a proposition-based representation of content. Overall, attentiveness to narrative structure also facilitated narrative memory, but this relationship was more reliable among older readers.