When expertise reduces age differences in performance.

Examined whether aviation expertise reduces age differences in a laboratory task that was similar to routine air traffic control (ATC) communication. In Exp 1, older (mean age 66.6 yrs) and younger (mean age 29.0 yrs) pilots and age-matched nonpilots read typical ATC messages (e.g., commands to change aircraft heading). After each message, they read back (repeated) the commands, which is a routine ATC procedure requiring short-term memory. Ss also performed less domain-relevant tasks. Expertise eliminated age differences in repeating heading commands but did not reduce age differences for the less relevant tasks. In Exp 2, expertise reduced but did not eliminate age differences in repeating heading commands from spoken messages. Results suggest that expertise compensates age declines in resources when the task is highly domain relevant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of monitoring during study and during testing on a sentence-learning task.

Adults' ability to monitor their learning and memory of sentences was investigated. Subjects read eight sentences containing within-sentence elaborations that clarified the significance of subject–verb–object relations in the sentences (precisely elaborated) and eight with elaborations that did not (imprecisely elaborated). Participants estimated their recall for each type of sentence (a) before studying the sentences, (b) after studying but before being tested on the sentences, or (c) after being tested. The precise sentences were recalled significantly better; however, only the subjects who estimated after the test accurately perceived this recall difference. Subsequent interviews showed that most subjects became aware during the study trial of differences in sentence difficulty and used this information to allocate more time and effort to the imprecise sentences. Subjects can apparently monitor the relative difficulty of items while processing them and, on that basis, attempt to regulate their study activity accordingly. However, they do not gain information concerning the memorial consequences of their study behavior until they are tested on the material. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in working memory.

Two experiments were conducted to determine whether adult age differences in working memory should be attributed to less efficient processing, a smaller working memory storage capacity, or both. In Experiment 1, young, middle-age, and older adults solved 3 additional problems before giving the answers to any. Older adults added as well as young and middle-age adults but showed a more pronounced serial position curve across the 3 problem positions. In Experiment 2, young and older adults constructed linear orderings (e.g., ABCD) from pairwise information presented in sentences (e.g., BC). Manipulations involving processing (e.g., type of sentence) did not interact with age differences, but those involving storage capacity (e.g., ordering length) did. All main effects and interactions support the hypothesis of a smaller storage capacity but do not rule out some processing deficit in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movements of young and older adults while reading with distraction.

The authors used eye-tracking technology to examine young and older adults' online performance in the reading in distraction paradigm. Participants read target sentences and answered comprehension questions following each sentence. In some sentences, single-word distracters were presented in either italic or red font. Distracters could be related or unrelated to the target text. Online measures, including probability of fixation, fixation duration, and number of fixations to distracting text, revealed no age differences in text processing. However, young adults did have an advantage over older adults in overall reading time and text comprehension. These results provide no support for an inhibition deficit account of age differences in the reading in distraction paradigm, but are consistent with J. Dywan and W. E. Murphy's (1996) suggestion that older adults are less able than the young to distinguish target and distracter information held in working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Secondary metabolites play primary roles in human affairs

Three hypotheses concerning the functional source of aphasic patients' difficulty comprehending semantically reversible sentences were tested using declarative sentences in active and passive voice and sentences with center-embedded relative clauses. Each of the three hypotheses is predicated on relative patterns of impairment and sparing of patient performance on these (and other) sentence types, yet the three hypotheses make somewhat different predictions about performance patterns across these types. Results from 5 Broca's aphasic patients were not consistent with the predictions of the linguistically motivated Trace Deletion Hypothesis or of a hypothesis based on an impairment involving grammatical morphemes. The hypothesis that aphasic comprehension impairments reflect a general limitation of working memory capacity was given partial support by the ordinal pattern of difficulty for a mixed group of 10 patients, but failed to account for patterns obtained from individual patients. Results are interpreted as having relevance for methodological as well as theoretical aspects of research on aphasic sentence comprehension.     

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. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Building syntactic structure in speaking

We investigated how people produce simple and complex phrases in speaking using a newly developed immediate recall task. People read and tried to memorize a target sentence, then read a prime sentence, then did a distractor task involving the prime sentence. Despite the delay and activity between memory and recall, people could still recall the target sentence although the syntactic form of the recalled sentence was influenced by the syntactic form of the prime sentence. This result replicates the syntactic priming effect found with other experimental paradigms. Using this task, we tested how people used abstract syntactic plans to produce simple and complex noun phrases. We found syntactic priming both when targets and prime sentences matched in complexity and when they did not match, suggesting that simple and complex noun phrases are built by the same syntactic routines during speech production.     

A role for Cdc42 in macrophage chemotaxis

Grammatical morphemes, such as articles and auxiliary verbs, provide potentially useful information to language learners. However, children with specific language impairment (SLI) frequently fail to produce grammatical morphemes, raising questions about their sensitivity to them. To address this issue, two experiments were conducted in which 3- to 5-year-old children with SLI and with normally developing language (NL) heard sentences asking them to identify a picture corresponding to a named target word. The target occurred in either a grammatical sentence or one with an incorrectly used grammatical morpheme. In Experiment 1, the picture representing the target occurred with three unrelated distractor pictures. In Experiment 2, distractor sets included pictures that were semantically related to the target. In both studies, the SLI group chose fewer correct pictures when the target followed an incorrectly used morpheme. In Experiment 2, the SLI group chose more semantically related than unrelated distractors. These results suggest that children with SLI are sensitive to grammatical morphemes and that their incorrect picture choices may reflect a failure to maintain the target in memory.     

The influence of list format and category headers on age differences in understanding medication instructions

We examined whether instructions are better understood and remembered when they contain organizational cues. Our previous research found that older and younger adults organize medication information in similar ways, suggesting that they have a schema for taking medication. In the present study, list formats (vs. paragraphs) emphasized the order of information and category headers emphasized the grouping of information specified by this schema. Experiment 1 examined whether list and header cues improve comprehension (answer time and accuracy) and recall for adults varying in age and working memory capacity (measured by a sentence span task). List instructions were better understood and recalled than paragraphs, and reduced age differences in answer time and span differences in accuracy. Headers reduced paragraph comprehension for participants with lower levels of working memory capacity, presumably because they were not salient cues in the paragraphs. Experiment 2 investigated if headers were more effective when more saliently placed in paragraphs and lists, and if list and header cues helped readers draw inferences from the instructions. List formats again reduced age differences in comprehension, especially reducing the time needed to draw inferences about the medication. While headers did not impair comprehension, these cues did impair recall. The present study suggests that list-organized instructions provide an environmental support that improves both older and younger adult comprehension and recall of medication information.     

On-line processing of written text by younger and older adults.

Word-by-word reading times were measured for young and elderly adults who read single sentences for immediate recall. The reading strategies of young and old were similar in that both groups allocated time to process word-level and constituent-level features. Young and elderly readers differed mainly in how they allocated time for organizational processing: Whereas younger adults allocated extra processing time at sentence boundaries as well as at major and minor clause boundaries, older adults allocated extra time at major and minor clause boundaries only. Results were generally consistent with the notions that processes that are more microlevel (e.g., word access) become automatic with practice and that age deficits are minimal for such processes. Age differences in organization time allocated at clause boundaries, however, suggested age-related limitations in working memory processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory and aphasia

This study investigated the relationship between working memory capacity and reading comprehension in aphasia. A measurement of working memory capacity was obtained using a modified version of Daneman and Carpenter's (1980) Reading Span Task. Sets of sentences ranging in length from one to six words were presented to 22 aphasic subjects who were required to retain the terminal words following each sentence for subsequent recognition. The maximum number of words retrieved was used as an index of working memory capacity. Two versions of the task (listening and reading) were presented depending on the subjects' ability to read. Strong positive correlations were found between working memory capacity, reading comprehension, and language function. These results support the notion that the ability of aphasic individuals to comprehend language is predictable from their working memory capacities.     

Telling tales: Aging, working memory, and the narrative cohesion of story retellings.

This study investigated adult age differences in the cohesion of narrative retellings in both the reference and conjunction discourse systems and explored the role of information-processing factors in accounting for any such differences. Twenty Ss in each of the age groups 18–25, 26–55, and 60–87 either read a story or its parallel cartoon version, then retold it twice. Stories were coded for recall, clarity of referencing, and types of propositional connectives. We also obtained Daneman's (1980) measure of sentence memory span. The oldest group scored significantly lower on the memory span measure, recalled less story information, and made more referential errors in retellings. There were no age differences in complexity of conjunction usage. Working memory span scores partly accounted for the differences observed in referential quality both within and between age groups. Results are generally consistent with an information-processing account of story telling and aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in the effects of domain knowledge on reading efficiency.

In the present study, the author investigated age differences in the effects of knowledge on the efficiency with which information is processed while reading. Individuals between 18 and 85 years of age, with varying levels of cooking knowledge, read and recalled a series of short passages within the domain of cooking. Reading efficiency was operationalized as time spent reading divided by the amount recalled for each passage. Results showed that reading efficiency increased with increasing levels of knowledge among older but not younger adults. Similarly, those with smaller working memory capacities showed increasing efficiency with increasing knowledge. These findings suggest that knowledge promotes a more efficient allocation policy that is particularly helpful in later life, perhaps due to age-related declines in working memory capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in working memory capacity and episodic retrieval: Examining the dynamics of delayed and continuous distractor free recall.

Two experiments explored the possibility that individual differences in working memory capacity (WMC) partially reflect differences in the size of the search set from which items are retrieved. High- and low-WMC individuals were tested in delayed (Experiment 1) and continuous distractor (Experiment 2) free recall with varying list lengths. Across both experiments low-WMC individuals recalled fewer items than high-WMC individuals, recalled more previous list intrusions than high-WMC individuals, and recalled at a slower rate than high-WMC individuals. It is argued that low-WMC individuals' episodic retrieval deficits are partially due to the fact that these individuals search through a larger set of items than high-WMC individuals. Simulations based on a random search model were consistent with these general conclusions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recalling Spatial Information as a Component of Recently and Remotely Acquired Episodic or Semantic Memories: An fMRI Study.

Activations produced by the recall of episodic and semantic memories differing in spatial content and age were examined. Recall of recent episodic memories with differing spatial content activated the medial temporal lobes and the retrosplenial-posterior cingulate cortex-precuneus complex more than recall of recent semantic memories with similarly differing spatial content. Some of these differences related to the amount of spatial information recalled because spatially richer recent memories, regardless of whether they were episodic or semantic, activated the right posterior parahippocampal cortex, precuneus, and posterior parietal cortex more. This spatial effect was found to be independent of memory age for semantic memories, although some episodic-semantic memory differences, including one in the left hippocampus, were not age independent. Episodic-semantic memory recall activation differences are therefore probably a function of the amount recalled, memory age, and what is recalled, particularly with respect to spatial information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming during sentence processing by young and older adults.

Examined semantic processing of sentences by 30 younger (mean age 25.1 yrs) and 30 older (mean age 68.5 yrs) adults, using a priming technique. Ss read a sentence and then made a lexical decision about a target presented immediately after the sentence. For both age groups, word targets that were instruments implied by the action of the sentence had faster latencies than unrelated word targets. There was no evidence of inhibition of unrelated targets, suggesting that the facilitation of instrument targets involved automatic processes. Results provide no evidence for age-related changes in semantic processing of sentences, including access to implied information. Older Ss did, however, have poorer memory for the sentences on a recognition test. It is suggested that previous findings by G. Cohen (see PA, Vols 63:747 and 67:958) of age deficits in comprehension may depend on techniques that measure what is remembered rather than what is understood. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bizarre imagery, interference, and distinctiveness.

Previous studies have shown that bizarre and common images produce equivalent levels of recall in unmixed-list designs. Using unmixed lists, we tested the view that bizarre images would be less susceptible than common images to common sources of interference. In all experiments, subjects imaged a list of either bizarre or common sentences and then performed some kind of interfering task before recalling the initial list of sentences. Experiment 1 showed that bizarre images were better accessed than common images after imaging an intervening list of common sentences. Also, components of common images tended to be better recalled than those of bizarre images after imaging an intervening list of bizarre sentences. Experiments 2a and 2b showed that interfering tasks consisting of studying lists of common concrete nouns did not differentially affect memory for bizarre and common images. In Experiment 3, labeling and imaging an interfering list of common pictures produced higher recall of bizarre images. Generally, bizarre images appeared to be less susceptible than common images to interference from certain types of common encodings. Importantly, the superior recall of bizarre images was always due to greater image (sentence) access, whereas higher recall of common images was associated with greater recovery of the image (sentence) constituents. Explanation of the precise pattern of results requires consideration of the distinctive properties of bizarre images. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive Ability, Expertise, and Age Differences in Following Air-Traffic Control Instructions.

Differences in cognitive ability and domain-specific expertise may help explain age differences in pilot performance. Pilots heard air-traffic controller messages and then executed them while "flying" in a simulator. Messages varied in length and speech rate. Age was associated with lower accuracy, but the expected Age x Message Difficulty interactions were not obtained. Expertise, as indexed by pilot ratings, was associated with higher accuracy; yet expertise did not reduce age differences in accuracy. The effect of age on communication task accuracy was largely explainable as an age-associated decrease in working memory span, which in turn was explainable as decreases in both speed and interference control. Results are discussed within frameworks of deliberate practice and cognitive mediation of age differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sentence comprehension in Alzheimer's disease: Effects of grammatical complexity, speech rate, and repetition.

Caregivers of patients diagnosed with Alzheimer's disease (AD) are often advised to modify their speech to facilitate the patients' sentence comprehension. Three common recommendations are to (a) speak in simple sentences, (b) speak slowly, and (c) repeat one's utterance, using the same words. These three speech modifications were experimentally manipulated in order to investigate their individual and combined effects on sentence comprehension in AD. Fifteen patients with mild to moderate AD and 20 healthy older persons were tested on a sentence comprehension task with sentences varying in terms of (a) degree of grammatical complexity, (b) rate of presentation (normal vs. slow), and (c) form of repetition (verbatim vs. paraphrase). The results indicated a significant decline in sentence comprehension for the AD group. Sentence comprehension improved, however, after the sentence was repeated in either verbatim or paraphrased form. However, the patients' comprehension did not improve for sentences presented at the slow speech rate. This pattern of results is explained vis-à-vis the patients' working memory loss. The findings challenge the appropriateness of several clinical recommendations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)