Content and Strategy in Syllogistic Reasoning.

Syllogistic reasoning has been investigated as a general deductive process (Johnson-Laird & Byrne, 1991; Revlis, 1975; Rips, 1994). However, several studies have demonstrated the role of cognitive strategies in this type of reasoning. These strategies focus on the method used by the participants (Ford, 1995; Gilhooly, Logie, Wetherick, & Wynn, 1993) and strategies related to different interpretations of the quantified premises (Roberts, Newstead, & Griggs, 2001). In this paper, we propose that content (as well as individual cognitive differences) is an important factor in inducing a certain strategy or method for syllogistic resolution. Specifically, we suggest that syllogisms with a causal conditional premise that can be extended by an agency premise induce the use of a conditional method. To demonstrate this, we carried out two experiments. Experiment 1 provided evidence that this type of syllogism leads participants to draw the predicted conditional conclusions, in contrast with control content syllogisms. In Experiment 2, we demonstrated that the drawing of conditional conclusions is based on a causal conditional to an agent representation of the syllogism premises. These results support the role of content as inducing a particular strategy for syllogistic resolution. The implications of these results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MDMA and Performance Under a Progressive-Ratio Schedule of Water Delivery.

This study investigated the possible motivational effects of (±)3,4-methylenedioxymethamphetamine (MDMA, ecstasy) in water-deprived rats responding under a progressive-ratio 2 schedule of water delivery. Lower doses (1.0 and 1.8 mg/kg ip) had inconsistent effects on breakpoints and response rates, whereas higher doses (3.2 and 5.6 mg/kg ip) significantly decreased both response measures relative to vehicle control levels. Increasing the level of water restriction significantly increased both response measures, and decreasing restriction significantly decreased both response measures. This study found no evidence that MDMA increased the reinforcing efficacy of water, although prior findings have suggested that the drug might have such an effect. MDMA-induced changes in motor activity may account for the present results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of concurrent verbal and visual tasks on category learning.

Current theories of category learning posit separate verbal and nonverbal learning systems. Past research suggests that the verbal system relies on verbal working memory and executive functioning and learns rule-defined categories; the nonverbal system does not rely on verbal working memory and learns non-rule-defined categories (E. M. Waldron & F. G. Ashby, 2001; D. Zeithamova & W. T. Maddox, 2006). However, relatively little research has explored the importance of visual working memory or visual processing for either system. The authors investigated the role of working memory (Experiment 1a and 1b), visual processing (Experiment 2), and executive functioning for each system, using a concurrent task methodology. It was found that visual tasks with high executive functioning demands and verbal tasks with high or low executive demands disrupted rule-defined learning, whereas any visual task, regardless of executive functioning demand, disrupted non-rule-defined learning. Taken together, these results confirm the importance of verbal working memory and executive functioning for the verbal system and provide new evidence for the importance of visual processing for the nonverbal system. These results help to clarify understanding of the nonverbal system and have implications for multiple systems theories of category learning (F. G. Ashby, L. A. Alfonso-Reese, A. U. Turken, & E. M. Waldron, 1998). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Study of Verbal Working Memory in Patients With Parkinson's Disease.

The authors examined the nature of the working memory deficit in persons with Parkinson's disease (PD). Three hypotheses were tested: a limited storage capacity, an impaired executive component, and a reduction of psychomotor speed. Verbal working memory was assessed in 14 PD patients without dementia and 14 matched control participants. Participants were administered a classical verbal span test, working memory tasks that required either updating or manipulation capacities, and motor and psychomotor speed tasks. Patients' performance was comparable to that of control participants on the verbal span test. However, results on the working memory tasks indicated a deficit in manipulation with normal updating capacities. Motor and psychomotor slowing were found in the patient group, but slowing could not fully account for the impairment observed in the manipulation task. Results indicated that there is a genuine but selective working memory impairment in patients with PD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ecstasy (MDMA) does not have long-term effects on aggressive interpretative bias: A study comparing current and ex-ecstasy users with polydrug and drug-naive controls.

±3, 4-methylenedioxymethamphetamine (MDMA or ecstasy) remains a widely used recreational drug, which, in animals, can produce long-lasting changes to the brain's serotonergic system. As serotonin has been implicated in human aggression, it is possible that ecstasy users are at risk of increased aggression even after prolonged abstention from the drug. The objective of this study was to indirectly assess aggression in current and abstinent ecstasy users using an information-processing paradigm that measures cognitive bias toward material with aggressive content. The task employed has previously shown increased aggressive bias 3-4 days after ecstasy use. An interpretative bias task was administered to 105 male participants: 26 ex-ecstasy users, 25 current ecstasy users, 29 polydrug using controls, and 25 drug-naive controls. Accuracy and response times to process and recognize ambiguous sentences were tested. There were no group differences in aggressive interpretative bias. All 4 groups processed neutral sentences faster than aggressive sentences and were subsequently faster and more confident in recognizing neutral compared with aggressive sentences. Further, self-ratings of aggression also showed no group differences, even though self-rated impulsivity was significantly higher in current ecstasy users than in drug-naive controls. The findings that all groups were biased toward neutral and away from aggressive interpretations of ambiguous sentences add to the existing body of knowledge in suggesting that increased aggression found in ecstasy users a few days after taking the drug is a transient phenomenon and not a long-term, persisting effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of everyday actions in mild Alzheimer's disease.

Early neuropsychological deficits associated with mild Alzheimer's disease (AD) have been characterized as memory deficits and impaired executive function or attention. The functional impact of early impairment was investigated by evaluating performance of everyday actions in older adults with mild AD (n = 15) as compared with healthy age-matched controls (n = 16). Everyday actions were familiar activities, for example, making a cup of tea, but were varied in complexity (simple, complex) and were performed under varied attention demand (single task, dual task). Although both participant groups responded to increasing task complexity by making more errors, the AD group made more errors under dual-task conditions regardless of the complexity of the task. Furthermore, a task requiring strategic retrieval of semantic information from long-term memory and manipulation of attention online (category fluency) was able to account for a large proportion of the group-related variance in everyday task performance. Results are discussed in relation to the role of components of working memory in performance of everyday actions in mild AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attenuation of the disruptive effects of (+/-)3,4-methylene dioxymethamphetamine (MDMA) on delayed matching-to-sample performance in the rat.

Recent evidence suggests that the disruptive effects of acute exposure to (+/-)3,4-methylene dioxymethamphetamine (MDMA) on memory performance may be the result of increased confusion between previous-trial and current-trial events. The current study tested this hypothesis by examining the effects of MDMA on performance of rats in a delayed matching-to-sample procedure when the length of the intertrial interval (ITI) was altered. Consistent with the possibility that limiting the conditions under which responses made on a previous trial would interfere with current-trial choice, a 15-s ITI ameliorated the disruptive effects caused by MDMA on trial performance when the ITI was 5 s. Therefore, the disruptive effects of MDMA on memory can be attenuated by methods that separate current-trial "to-be-remembered" events from previous-trial events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Generality of Working Memory Capacity: A Latent-Variable Approach to Verbal and Visuospatial Memory Span and Reasoning.

A latent-variable study examined whether verbal and visuospatial working memory (WM) capacity measures reflect a primarily domain-general construct by testing 236 participants in 3 span tests each of verbal WM. visuospatial WM, verbal short-term memory (STM), and visuospatial STM. as well as in tests of verbal and spatial reasoning and general fluid intelligence (Gf). Confirmatory' factor analyses and structural equation models indicated that the WM tasks largely reflected a domain-general factor, whereas STM tasks, based on the same stimuli as the WM tasks, were much more domain specific. The WM construct was a strong predictor of Gf and a weaker predictor of domain-specific reasoning, and the reverse was true for the STM construct. The findings support a domain-general view of WM capacity, in which executive-attention processes drive the broad predictive utility of WM span measures, and domain-specific storage and rehearsal processes relate more strongly to domain-specific aspects of complex cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

3,4 Methylenedioxymethamphetamine (ecstasy) impairs eight-arm radial maze performance and arm entry pattern in rats.

The recreational use of 3,4 methylenedioxymethamphetamine (ecstasy) in humans has been associated with memory impairment. The present study examined whether ecstasy impairs short- and long-term working memory and the pattern of arm entries in rats tested in the 8-arm radial maze with a 2-hr delay. After completing the training session, the rats were given a single dose of ecstasy (1, 2, or 3 mg/kg ip) 20 min before the test. The highest dose slightly affected short-term working memory. Under conditions of delay, there was a progressive deficit in long-term working memory, starting from I mg/kg. Under both test conditions, 2 and 3 mg/kg flattened the pattern of arm entry. None of the doses caused hyperlocomotion or stereotypy in the radial maze. These findings suggest that acute ecstasy mainly affects the long-term components of working memory and disrupts the pattern of arm entry in a way similar to serotonergic agents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological disturbance in schizophrenia: A diffusion tensor imaging study.

Patients with schizophrenia and healthy control subjects underwent both neuropsychological evaluation and magnetic resonance diffusion tensor imaging, during which the cingulum bundle (CB) and the uncinate fasciculus (UF) were defined with fiber tractography and their integrity was quantified. On the basis of prior findings, it was hypothesized that neuropsychological disturbance in schizophrenia may be characterized, in part, by 2 dissociable functional neuroanatomical relationships: (a) executive functioning-CB integrity and (b) episodic memory-UF integrity. In support of the hypothesis, hierarchical regression results indicated that reduced white matter of the CB and the UF differentially and specifically predicted deficits in executive functioning and memory, respectively. Neuropsychological correlates of the CB also extended to lower generalized intelligence, as well as to reduced visual memory that may be related to failures of contextual monitoring of to-be-remembered scenes. Reduced white matter of the CB and the UF may each make distinct contributions to neuropsychological disturbance in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

(±)3,4-Methylenedioxymethamphetamine, d-Amphetamine, and Cocaine Impair Delayed Matching-to-Sample Performance by an Increase in Susceptibility to Proactive Interference.

This study compared the effects of (±)3,4-methylenedioxymethamphetamine, d-amphetamine, and cocaine on performance of rats in a delayed matching-to-sample procedure using a variety of indices of performance to determine the mechanism by which working memory task impairments arise. All 3 drugs produced an overall delay-independent decrease in accuracy rather than a delay-dependent increase in the rate of forgetting. This impairment arose as a result of current-trial choice responses being progressively more affected by responses made in the immediately preceding trial as drug dose increased. Therefore, all 3 drugs produced qualitatively similar disruptions in memory task performance best characterized as an impairment arising from proactive sources of interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The association between the negative effects attributed to ecstasy use and measures of cognition and mood among users.

In self reports, abstinent ecstasy/polydrug users claim that they experience certain ongoing affective and psychological changes including elevated anxiety, arousal, and depression. In addition, various aspects of cognition (e.g., everyday memory, reasoning, executive functioning) appear to be affected. The present paper investigated the link between these two psychological sequelae. Ninety-five ecstasy/polydrug users completed tests of reasoning, intelligence, information processing speed, executive functioning, and everyday memory. Affect was measured via a mood adjective checklist. Adverse effects attributed to ecstasy were measured via responses to adjectives reflecting changes in users since they started using the drug. In addition, indicators of sleep quality and daytime sleepiness were obtained. Users attributed a number of adverse effects to ecstasy, namely heightened irritability, depression, paranoia, and deteriorating health. Adverse effects were significantly and negatively correlated with aspects of intelligence, everyday memory, and sleep quality. Length of use of ecstasy use was positively correlated with adverse effects. While many users attribute a number of adverse affects to their use of ecstasy, it remains unclear whether these self-perceptions are a corollary of the psychopharmacological effects of the drug or reflect factors which in fact predate its use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive function in preschoolers: A review using an integrative framework.

During the last 2 decades, major advances have been made in understanding the development of executive functions (EFs) in early childhood. This article reviews the EF literature during the preschool period using an integrative framework. The framework adopted considers EF to be a unitary construct with partially dissociable components (A. Miyake et al., 2000). The authors focus on 3 EF components: working memory, response inhibition, and shifting. For the present purposes, the central executive is conceived of as a central attention system that is involved in all EF component operations. Research to date suggests that elementary forms of the core EF components are present early during the preschool period. Changes in EF during the latter half of the preschool period appear to be due to the development of attention and integration of component EFs. Finally, the review outlines a number of areas that warrant further investigation if researchers are to move forward in understanding early EF development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Hypertension on Attention, Memory, and Executive Function in Older Adults.

Hypertension is associated with impairments in cognitive function in older adults, but the nature and extent of these deficits are unclear. Brief cognitive measures lack sensitivity, whereas comprehensive assessments produce numerous variables that are difficult to interpret. The authors performed a principal-components analysis using a computerized cognitive assessment battery and neuropsychological measures of executive function in 506 hypertensive and normotensive older participants. Composite factor scores were used to reanalyze data from 223 untreated participants without vascular complications. The hypertensive group had deficits in Speed of Cognition, Episodic and Working Memory, and Executive Function but not Continuity of Attention. Using composite scores simplified data interpretation and suggested differential effects of hypertension on cognitive performance not clearly evident in individual test results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examining the nature of impairment in visual paired associate learning in amnestic mild cognitive impairment.

Objective: Visual spatial learning is impaired in mild cognitive impairment (MCI) although the nature of this impairment is not clear. This study investigated the nature and magnitude of errors made by adults with amnestic MCI (aMCI) when learning pattern-location paired associations in a continuous manner. Method: Visual associate learning was measured using the Continuous Paired Associate Learning (CPAL) task in which 30 adults who met clinical criteria for aMCI and 30 matched controls were required to learn a set of associations between patterns and locations across increasing memory loads (two, four, six, and eight). Results: As hypothesized, the aMCI group made more total errors than controls for all memory loads above two. However, the rate of increase in errors with memory load in the aMCI group was approximately twice that for controls. Conclusions: In controls, errors on the CPAL task reflected almost exclusively difficulty in memory. In the aMCI group, errors on the CPAL reflected limitations in associative learning but also in short-term memory and response monitoring. These results suggest that impairments in specific aspects of executive function and working memory might contribute to poor performance on visual paired associate learning in aMCI. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Age differences in proactive interference, working memory, and abstract reasoning.

[Correction Notice: An erratum for this article was reported in Vol 23(4) of Psychology and Aging (see record 2008-19072-007). The original article contained an incorrect DOI. The correct DOI is as follows: 10.1037/a0012577.] It has been hypothesized that older adults are especially susceptible to proactive interference (PI) and that this may contribute to age differences in working memory performance. In young adults, individual differences in PI affect both working memory and reasoning ability, but the relations between PI, working memory, and reasoning in older adults have not been examined. In the current study, young, old, and very old adults performed a modified operation span task that induced several cycles of PI buildup and release as well as two tests of abstract reasoning ability. Age differences in working memory scores increased as PI built up, consistent with the hypothesis that older adults are more susceptible to PI, but both young and older adults showed complete release from PI. Young adults' reasoning ability was best predicted by working memory performance under high PI conditions, replicating M. Bunting (2006). In contrast, older adults' reasoning ability was best predicted by their working memory performance under low PI conditions, thereby raising questions regarding the general role of susceptibility to PI in differences in higher cognitive function among older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive control and lexical access in younger and older bilinguals.

[Correction Notice: An erratum for this article was reported in Vol 35(3) of Journal of Experimental Psychology: Learning, Memory, and Cognition (see record 2009-05251-016). An incorrect figure was printed due to an error in the production process. The correct version of Figure 1b is provided in the correction.] Ninety-six participants, who were younger (20 years) or older (68 years) adults and either monolingual or bilingual, completed tasks assessing working memory, lexical retrieval, and executive control. Younger participants performed most of the tasks better than older participants, confirming the effect of aging on these processes. The effect of language group was different for each type of task: Monolinguals and bilinguals performed similarly on working memory tasks, monolinguals performed better on lexical retrieval tasks, and bilinguals performed better on executive control tasks, with some evidence for larger language group differences in older participants on the executive control tasks. These results replicate findings from individual studies obtained using only 1 type of task and different participants. The confirmation of this pattern in the same participants is discussed in terms of a suggested explanation of how the need to manage 2 language systems leads to these different outcomes for cognitive and linguistic functions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time and cognitive load in working memory.

According to the time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004), the cognitive load a given task involves is a function of the proportion of time during which it captures attention, thus impeding other attention-demanding processes. Accordingly, the present study demonstrates that the disruptive effect on concurrent maintenance of memory retrievals and response selections increases with their duration. Moreover, the effect on recall performance of concurrent activities does not go beyond their duration insofar as the processes are attention demanding. Finally, these effects are not modality specific, as spatial processing was found to disrupt verbal maintenance. These results suggest a sequential and time-based function of working memory in which processing and storage rely on a single and general purpose attentional resource needed to run executive processes devoted to constructing, maintaining, and modifying ephemeral representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Longitudinal deficits to attention, executive, and working memory in subtypes of mild cognitive impairment.

Objective: Mild cognitive impairment (MCI) has emerged as a classification for a prodromal phase of cognitive decline that may precede the emergence of Alzheimer's disease (AD). Recent research suggests that attention, executive, and working memory deficits may appear much earlier in the progression of AD than traditionally conceptualized, and may be more consistently associated with the later development of AD than memory processing deficits. The present study longitudinally tracked attention, executive and working memory functions in subtypes of MCI. Method: In a longitudinal study, 52 amnestic MCI (a-MCI), 29 nonamnestic MCI (na-MCI), and 25 age- and education-matched controls undertook neuropsychological assessment of visual and verbal memory, attentional processing, executive functioning, working memory capacity, and semantic language at 10 month intervals. Results: Analysis by repeated measures ANOVA indicate that the a-MCI and na-MCI groups displayed a decline in simple sustained attention (ηp2 = .054) with a significant decline on a task of divided attention (ηp2 = .053) being evident in the a-MCI group. Stable deficits were found on other measures of attention, working memory and executive function in the a-MCI and na-MCI groups. The a-MCI group displayed stable impairments to visual and verbal memory. Conclusions: The results indicate that a-MCI and na-MCI display a stable pattern of deficits to attention, working memory, and executive function. The decline in simple sustained attention in a-MCI and n-MCI groups and to divided attention in a-MCI may be early indicators of possible transition to dementia from MCI. However, further research is required to determine this. (PsycINFO Database Record (c) 2011 APA, all rights reserved)