Neuropsychological and neuroradiological distinctions between Alzheimer's and Huntington's diseases.

Examined neuropsychological and magnetic resonance imaging (MRI) differences among 23 Ss (mean age 70 yrs) with Alzheimer's disease (AD), 9 Ss (mean age 49.2 yrs) with Huntington's disease (HD), and 13 normal controls (mean age 71.7 yrs). Neuropsychological results show that HD Ss' episodic and semantic memory deficits were attributable to retrieval deficiencies, whereas AD Ss' impairments reflected a lack of storage and a breakdown in the structure of semantic knowledge. MRI results show that these cognitive changes were mirrored by significant group differences in striatal and cortical degeneration. AD Ss evidenced more widespread cortical damage, and HD Ss showed more striatal destruction. Both groups evidenced significant deterioration in medial temporal lobe and diencephalic structures. (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)     

Age differences in integrated semantic memory.

Used J. D. Bransford and J. J. Franks's (1971) paradigm of linguistic abstraction to examine age differences in the nature of stored semantic information. 20 young (mean age 18.7 yrs) and 18 old adults (mean age 67.3 yrs) served as Ss. Specifically, age differences on 2 dimensions of memory were examined: (a) integration of related content from separate sentences and (b) retention of precise semantic content. Young and old Ss were not found to differ in the precision of retained semantic information. Furthermore, while both age groups evidenced integration of information as indexed by a strong linear trend of recognition rate across sentence complexity, this trend did not interact with age, supporting the idea that both age groups showed comparable integration of linguistic information into holistic ideas. Implications for current conceptualizations of age differences in memory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sparing of semantic memory in Alzheimer's disease.

A number of investigators have suggested that unlike the normal elderly population, patients with Alzheimer's disease have a severe semantic-memory deficit. However, the semantic-memory tasks used in previous studies have been confounded by the heavy demands they placed on effortful processing. In the present study, 20 demented (mean age 71 yrs) and 20 normal (mean age 69.8 yrs) elderly Ss were given a battery of episodic-memory tasks and 3 tasks that examined how intact and accessible their semantic memory was under conditions that did not require effortful processing. Although the demented Ss were greatly inferior to the normal Ss on the episodic-memory tests, they performed equally well on the semantic-memory test: The naming latency of both groups was equally facilitated by a semantic prime, the recall accuracy of both normal and demented elderly for a string of letters was similarly affected by the degree to which the string approximated English orthography, and recall accuracy for a string of words was affected equally in the 2 groups by the degree to which the word string obeyed syntactic and semantic rules. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of semantic integration training on the recall of pictograph sentences by children in kindergarten and first grade.

Examined the effects on 30 kindergarten (mean age 5.6 yrs) and 30 1st-grade (mean age 6.6 yrs) children of semantic integration training in the context of a pictograph sentence memory task, which eliminates the usual orthographic barrier to word recognition. 10 kindergarten and 10 1st-grade Ss were assigned to each of 3 training groups: a sentence enaction group, a sentence control group, and a practice control group. The sentence enaction group, was trained to utilize a 2 component strategy (i.e., read the pictograph sequence as a sentence and act out its meaning with available toys), and the sentence control group was taught only the 1st component. The practice control group recalled the same sets of sentences without any strategy training. The sentence enaction group performed significantly better on initial and maintenance posttests than did the sentence control group, whose scores were in turn higher than those of the practice control. Significant grade effects indicated that 1st-grade Ss initially scored higher than kindergartners, and both grades responded similarly to the sentence and enaction instructions. Concurrent measures of strategy use established that training effects were due to application of the instructed strategies. The successful generalization of the sentence component of the strategy by both sentence groups to a serial version of the pictograph sentence task and the emergence of a spontaneous sentence strategy in the practice control group highlight the effectiveness of this specific component. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory and metamemory: A study of the feeling-of-knowing phenomenon in amnesic patients.

Tested accuracy of the feeling of knowing in 2 experiments, using 8 patients with Korsakoff's syndrome (mean age 54 yrs), 8 electroconvulsive shock therapy (ECT) patients (mean age 46.5 yrs), 4 Ss (mean age 47 yrs) with other causes of amnesia, 2 alcoholic control groups (7 Ss with a mean age of 47.6 yrs and 19 Ss with a mean age of 48.5 yrs), and 18 healthy controls (mean age 49 yrs). In Exp I, feeling-of-knowing accuracy for the answers to general information questions that could not be recalled was tested. Ss were asked to rank nonrecalled questions in terms of how likely they thought they would be to recognize the answers and were then given a recognition test for these items. Only Korsakoff's syndrome Ss were impaired in making feeling-of-knowing predictions. The other amnesic Ss were as accurate as control Ss in their feeling-of-knowing predictions. In Exp II, these findings were replicated in a sentence memory paradigm that tested newly learned information. Results show that impaired metamemory is not an obligatory feature of amnesia, because amnesia can occur without detectable metamemory deficits. The impaired metamemory exhibited by patients with Korsakoff's syndrome reflects a cognitive impairment that is not typically observed in other forms of amnesia. (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of training in sentence construction on the comprehension of learning disabled children.

30 learning-disabled Hispanic, White, and Black children (mean IQ 88.60 and mean age 11.73 yrs) were randomly assigned to 2 conditions focusing on sentence comprehension: a sentence anagram/word grouping treatment and a more traditional sentence study treatment. With age, IQ, and pretest comprehension (Gates-MacGinitie Reading Tests) controlled, Ss in the sentence anagram/word grouping condition had significantly higher cloze scores than Ss in the sentence study group. The greatest achievement benefits associated with the anagram treatment, however, accrued to Ss with higher initial reading achievement. As level of pretreatment achievement decreased, the magnitude of the treatment differences also tended to decrease. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recall of pleasant and unpleasant words in depressed subjects.

In Exp I, 20 clinically depressed inpatients (mean age 39.9 yrs), 20 nondepressed inpatients (mean age 42.65 yrs), and 20 nonpatients (mean age 44 yrs) were shown a word list containing pleasant and unpleasant words. One-half of Ss in each group were given free-recall instructions, the other half were asked to rate each word on a pleasantness scale prior to recall. Results show that only depressed Ss given free-recall instructions recalled more unpleasant words than pleasant words. In Exp II, 30 clinically depressed inpatients (mean age 39.33 yrs) were shown a word list consisting of either (1) pleasant and unpleasant words, (2) unpleasant words, or (3) pleasant words. Results show that only Ss receiving the mixed list recalled more unpleasant than pleasant words. Findings support the hypothesis that depressed Ss selectively process unpleasant words and that this processing is at the expense of attention to pleasant words. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paired-associate learning and priming effects in amnesia: A neuropsychological study.

Conducted 4 experiments investigating the role of priming effects in paired-associate learning. Ss for all 4 experiments were 5 male and 3 female alcoholics (mean age 53.8 yrs; WAIS—R IQs 85–203) with Korsakoff syndrome. Control Ss were 26 male alcoholics (mean age 47.6 yrs). Exp I illustrated the distinction between the memory impairment of amnesic (Korsakoff) Ss and their intact priming ability. In Exp II, amnesic Ss showed good paired-associate learning for related word pairs but controls performed significantly better. Exp II also showed that the forgetting of related word pairs by amnesic Ss followed the same time course as the decay of word priming. Exp III showed that amnesic Ss were as good as controls at learning related word pairs when word-association tests were used. Exp IV showed that amnesic Ss exhibited normal priming when they were asked to free associate to words that were semantically related to previously presented words. Results indicate that both priming effects and paired-associate learning of related words depended on activation, a process that is preserved in amnesia. Activation is a transient phenomenon presumed to operate on and facilitate access to preexisting representations. (67 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Encoding orientation and the remembering of schizophrenic young adults.

Schizophrenic memory following an experimenter-imposed encoding task was examined in a levels-of-processing framework. In Session 1, 17 schizophrenics (mean age 23.5 yrs), 17 nonschizophrenic psychiatric patients (mean age 24.3 yrs), and 17 normal college students (mean age 20.0 yrs) were required to make yes–no judgments about whether a probe word contained 2 letters, rhymed with a word, belonged to a conceptual category, or fitted into a sentence. In Session 2, they were required to produce an appropriate word for each question. The 3 groups recalled semantically processed words better than nonsemantically processed words and "yes" words better than "no" words and revealed similar recall and recognition patterns over the different levels of encodings. However, the schizophrenics' recall for "yes" words (Session 1) and for the self-generated words (Session 2) was inferior to that of normals. Theoretical implications are discussed. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in the inhibition of recall as a function of retrieval cues.

Asked 64 Ss from 3 age ranges (18–37, 50–64, and 65–88 yrs) to look at word lists in which the words were either categorized under headings or additionally subcategorized. Ss were then asked to recall the words when (a) the category name was given, or (b) the category name and half of the list words were given. Words recalled decreased with increasing age in all conditions. The youngest age group recalled more words when the category name only was used as a recall cue. There were no significant differences between the 2 recall conditions for the other age groups, suggesting that they were not as susceptible to recall inhibition as the younger adults. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comprehension of pronouns in young and older adults.

Explored, in 3 experiments, the issue of whether young (19–37 yrs old) and older (57–84 yrs old) adults differ in their use of pragmatic information in anaphor resolution. 64 Ss from each age group were required to select the antecedent for the pronoun he in sentence pairs such as "Henry spoke at a meeting while John drove to the beach. He brought along a surfboard." Results indicate that young and older Ss were equally influenced by contextual constraints in choosing pronoun referents when the sentence containing the pronoun followed immediately after the context-setting sentence. When extraneous material intervened, however, both age groups became less consistent in their pronoun choices, with older Ss being more affected. Evidence is presented that the failure to use pragmatic constraints in pronoun assignment resulted from inability to recall the relevant contextual information. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of long-term vocabulary instruction on lexical access and reading comprehension.

To examine the relationship between knowledge of word meanings and semantic processes, 27 4th-grade children were taught 104 words over a 5-mo period. Following instruction, Ss performed tasks designed to require semantic processes ranging from single word semantic decisions to simple sentence verification and memory for connected text. On all these tasks, instructed Ss performed at a significantly higher level than controls matched on pre-instruction vocabulary knowledge and comprehension. Thus, instructed Ss gave evidence both of learning word meanings taught by the program and of being able to process instructed words more efficiently in tasks more reflective of comprehension. Implications for vocabulary instruction and the role of individual word meanings in comprehension are discussed. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional mapping of human memory using PET: Comparisons of conceptual and perceptual tasks.

Tested whether different neurological regions subserved the conceptual and perceptual memory components by using positron emission tomography (PET). Regional cerebral blood flow (RCBF) of 14 Ss (mean age 25 yrs) during 2 conceptual tasks of semantic cued recall and semantic association was compared to a control condition in which Ss made semantic associations to nonstudied words. RCBF during 2 perceptual tasks of word fragment cued recall and word fragment completion was also compared to a word fragment nonstudied control condition. There were clear dissociations in RCBF that reflected differences in brain regions subserving the 2 types of memory processes. Conceptual processing produced more activation in the left frontal and temporal cortex and the lateral aspect of the bilateral inferior parietal lobule. Perceptual memory processing activated the right frontal and temporal cortex and the bilateral posterior areas. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical access and age.

Lexical access, the time required to recover the meaning of a word, was measured in 12 young (mean age 24 yrs) and 12 old (mean age 73 yrs) Ss. Access time was unaffected by age, and a word-naming task. The facilitative effect of semantic associations between words was also comparable in young and old Ss. These results were obtained both under normal viewing conditions and under degraded conditions with overall latencies considerably increased. Findings indicate that aging does not affect either the encoding of the stimulus or access to the associated lexical entry, both directly and indirectly via contextual cues. This sparing of linguistic function is considered to underlie the preservation of verbal intelligence with age. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in cued recall.

Examined the relative effectiveness of semantic and structural retrieval cues in 72 male college graduates of 3 age groups: Group 1 (aged 20–39 yrs), Group 2 (aged 40–59 yrs), and Group 3 (aged 60–80 yrs). The Ss had been administered 2 subtests of the WAIS to insure the compatibility of the Ss. Results of the recall tests show that there was significantly poorer recall by the older Ss in the noncued conditions (free recall) and in the cued condition when structural cues were used. When category labels were used as semantic cues, however, the age deficit in recall was eliminated. Results are discussed in terms of both a retrieval hypothesis and a processing-deficit hypothesis. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial recall by schizophrenic and affective patients during and after psychotic episodes.

Eight schizophrenics (mean age 27.3 yrs), 8 depressed patients (mean age 33.1 yrs), and 8 normal controls (mean age 27 yrs) completed the MMPI and were asked to recall short word strings in both the presence and absence of distraction. Results show a differential cognitive deficit among schizophrenics both before and after a general improvement in their level of adjustment. That is, despite an overall improvement in their accuracy of recall prior to discharge, their performance continued to be impaired relative to depressed and normal Ss on the words presented in the 1st serial position. A tendency toward greater distractibility among schizophrenics failed to reach statistical significance at both points of assessment. Further substantiation of such stable forms of cognitive impairment may facilitate the identification of individuals who are vulnerable to the development of schizophrenia and may shed light on the adjustment problems that many chronic patients continue to experience after discharge from the hospital. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical memory in poor and normal readers: Developmental differences in the use of category cues.

Examined whether differences between poor and normal reading children on lexical memory tasks may be attributed to semantic development, using 80 2nd and 6th graders. Ss were presented with 4 lists of taxonomic categories and were asked to recall items under (a) noncued and random conditions, with Ss instructed to recall as many items as possible and (b) cued and blocked conditions, with Ss told to recall items in a category. All Ss performed better with category cues. Group differences on category recall were more reliable at Grade 6, suggesting that facility in accessing taxonomic categories may differentiate poor and normal readers more reliably at older age levels. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming after severe closed head trauma: Automatic and attentional processes.

The 2-process theory of semantic priming (J. H. Neely, 1977; M. I. Posner and C. R. Snyder, 1975) was used to determine the maintenance of automatic processes after severe closed head injury (CHI) and to determine whether processes that demand attention suffer a deficit. Ss with severe CHI (N?=?18,?>?2 yrs postinjury) and 18 matched control Ss completed a lexical decision task in which a category prime was followed by a target. Automatic and attentional priming were determined by orthogonally varying prime–target relatedness, expectancy, and stimulus onset asynchrony. Although the CHI Ss had slower reaction times (RTs) overall, there were no significant group differences in the magnitude of either the automatic or attentional component of semantic priming. The present results indicate the integrity of semantic processes and normal semantic priming in long-term patients with severe CHI. The results are discussed in relation to an attentional resource hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Focal cognitively mediated blood-flow activation in Alzheimer's disease patients.

Measured regional cerebral blood flow (rCBF), estimated by the 133-Xe inhalation technique, in 7 Alzheimer's disease (AD) patients (mean age 65.6 yrs) and 7 normal elderly Ss (mean age 65.3 yrs) during the performance of a right–left discrimination task, a sensorimotor control task, and at normal rest. Significant focal task-related blood-flow activation, attributable primarily to the complex cognitive components of the cognitive task, was found in the normal and AD Ss. The determination of cognitively mediated activation was accomplished by using the blood-flow activation during sensorimotor task performance to account for most of the attentional and response requirements of the cognitive task. Although overall rCBFs were significantly higher for AD Ss, this did not result in a significant differential, cognitively mediated activation pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)