Cognitive skill learning and schizophrenia: Implications for cognitive remediation.

The ability to acquire a motor and cognitive skill was investigated in 26 patients with schizophrenia and 26 normal participants using repeated testing on the Tower of Toronto puzzle. Seven patients with defective performance were retested using additional trials and immediate feedback designed to facilitate problem solving. A component analysis of performance was used based on J. R. Anderson's (1987) model of cognitive skill learning. Patients exhibited a performance deficit on both motor and cognitive skills. However, their acquisition rate was similar to that of normal participants on most parameters, indicating that skill learning suffered little or no impairment. Performance deficit was accounted for by poor problem-solving ability, explicit memory, and general intellectual capacities. It was remediable in some, but not all, patients. Remediation failure was also related to severe defects of cognitive functions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patients with Alzheimer's disease who cannot perform some motor skills show normal learning of other motor skills.

Previous researchers have claimed that patients with Alzheimer's disease (AD) learn new motor skills normally, although many AD patients cannot perform the tasks and must be eliminated from the analysis. Excluding them assumes that they have a deficit of motor performance (competence to perform the task), but not of motor learning (ability to improve performance). The present study administered 4 motor tasks to 20 AD patients and 20 controls. The results showed that the ability to complete 1 task (performance) did not predict the rate of improvement (learning) on another task, which indicates that AD patients do indeed have a performance deficit and not a general deficit of motor skill learning. Dementia ratings predicted the ability to perform tasks but not the ability to learn them. It is concluded that it is defensible to claim that AD patients learn a motor skill normally, even if some of the patients are unable to perform the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Striatal activation during acquisition of a cognitive skill.

The striatum is thought to play an essential role in the acquisition of a wide range of motor, perceptual, and cognitive skills, but neuroimaging has not yet demonstrated striatal activation during nonmotor skill learning. Functional magnetic resonance imaging was performed while participants learned probabilistic classification, a cognitive task known to rely on procedural memory early in learning and declarative memory later in learning. Multiple brain regions were active during probabilistic classification compared with a perceptual-motor control task, including bilateral frontal cortices, occipital cortex, and the right caudate nucleus in the striatum. The left hippocampus was less active bilaterally during probabilistic classification than during the control task, and the time course of this hippocampal deactivation paralleled the expected involvement of medial temporal structures based on behavioral studies of amnesic patients. Findings provide initial evidence for the role of frontostriatal systems in normal cognitive skill learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Selective corticostriatal dysfunction in schizophrenia: Examination of motor and cognitive skill learning": Correction to Foerde et al. (2008).

Reports an error in "Selective corticostriatal dysfunction in schizophrenia: Examination of motor and cognitive skill learning" by Karin Foerde, Russell A. Poldrack, Barbara J. Knowlton, Fred W. Sabb, Susan Y. Bookheimer, Robert M. Bilder, Don Guthrie, Eric Granholm, Keith H. Nuechterlein, Stephen R. Marder and Robert F. Asarnow (Neuropsychology, 2008[Jan], Vol 22[1], 100-109). The DOI for the supplemental materials was printed incorrectly. The correct DOI is as follows: http://dx.doi.org/10.1037/0894-4105.22.1.100.supp. (The following abstract of the original article appeared in record 2008-00382-011.) It has been suggested that patients with schizophrenia have corticostriatal circuit dysfunction (Carlsson & Carlsson, 1990). Skill learning is thought to rely on corticostriatal circuitry and different types of skill learning may be related to separable corticostriatal loops (Grafton, Hazeltine, & Ivry, 1995; Poldrack, Prabhakaran, Seger, & Gabrieli, 1999). The authors examined motor (Serial Reaction Time task, SRT) and cognitive (Probabilistic Classification task, PCT) skill learning in patients with schizophrenia and normal controls. Development of automaticity was examined, using a dual task paradigm, across three training sessions. Patients with schizophrenia were impaired at learning on the PCT compared to controls. Performance gains of controls occurred within the first session, whereas patients only improved gradually and never reached the performance level of controls. In contrast, patients were not impaired at learning on the SRT relative to controls, suggesting that patients with schizophrenia may have dysfunction in a specific corticostriatal subcircuit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired implicit learning in schizophrenia.

Schizophrenia patients consistently show deficits on tasks of explicit learning and memory. In contrast, their performance on implicit processing tasks often appears to be relatively intact, although most studies have focused on implicit learning of motor skills. This study evaluated implicit learning in 59 medicated schizophrenia outpatients and 43 controls using 2 different cognitive skill tasks. Participants completed a probabilistic classification task to assess procedural habit learning and an artificial grammar task to assess incidental learning of complex rule-based knowledge, as well as an explicit verbal learning and memory task. In addition to performing worse than controls on the explicit learning task, patients showed worse overall performance on the probabilistic classification task, which involves gradual learning through trial-by-trial performance feedback. However, patients and controls showed similar levels of learning on the artificial grammar task, suggesting a preserved ability to acquire complex rule-based knowledge in the absence of performance feedback. Discussion focuses on possible explanations for schizophrenia patients' poor probabilistic classification task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A neuropsychological theory of motor skill learning

This article describes a neuropsychological theory of motor skill learning that is based on the idea that learning grows directly out of motor control processes. Three motor control processes may be tuned to specific tasks, thereby improving performance: selecting spatial targets for movement, sequencing these targets, and transforming them into muscle commands. These processes operate outside of awareness. A 4th, conscious process can improve performance in either of 2 ways: by selecting more effective goals of what should be changed in the environment or by selecting and sequencing spatial targets. The theory accounts for patterns of impairment of motor skill learning in patient populations and for learning-related changes in activity in functional imaging studies. It also makes a number of predictions about the purely cognitive, including accounts of mental practice, the representation of motor skill, and the interaction of conscious and unconscious processes in motor skill learning.     

Correction to Foerde et al. (2008).

Reports an error in "Selective corticostriatal dysfunction in schizophrenia: Examination of motor and cognitive skill learning" by Karin Foerde, Russell A. Poldrack, Barbara J. Knowlton, Fred W. Sabb, Susan Y. Bookheimer, Robert M. Bilder, Don Guthrie, Eric Granholm, Keith H. Nuechterlein, Stephen R. Marder and Robert F. Asarnow (Neuropsychology, 2008[Jan], Vol 22[1], 100-109). Table 1 on page 102 should have included the BPRS Depression-Anxiety subscale score 9.00 (3.99) under the column heading Schiz pts. Table displays means with standard deviations in parentheses. (The following abstract of the original article appeared in record 2008-00382-011.) [Correction Notice: An erratum for this article was reported in Vol 22(2) of Neuropsychology (see record 2008-02526-002). The DOI for the supplemental materials was printed incorrectly. The correct DOI is as follows: http://dx.doi.org/10.1037/0894-4105.22.1.100.supp.] It has been suggested that patients with schizophrenia have corticostriatal circuit dysfunction (Carlsson & Carlsson, 1990). Skill learning is thought to rely on corticostriatal circuitry and different types of skill learning may be related to separable corticostriatal loops (Grafton, Hazeltine, & Ivry, 1995; Poldrack, Prabhakaran, Seger, & Gabrieli, 1999). The authors examined motor (Serial Reaction Time task, SRT) and cognitive (Probabilistic Classification task, PCT) skill learning in patients with schizophrenia and normal controls. Development of automaticity was examined, using a dual task paradigm, across three training sessions. Patients with schizophrenia were impaired at learning on the PCT compared to controls. Performance gains of controls occurred within the first session, whereas patients only improved gradually and never reached the performance level of controls. In contrast, patients were not impaired at learning on the SRT relative to controls, suggesting that patients with schizophrenia may have dysfunction in a specific corticostriatal subcircuit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of the striatum, cerebellum and frontal lobes in the automatization of a repeated visuomotor sequence of movements

Recently, Doyon et al. [20] demonstrated that lesions to both the striatum and to the cerebellum in humans produce a similar deficit in the learning of a repeated visuomotor sequence, which occurs late in the acquisition process. We now report the results of two experiments that were designed to examine whether this impairment was due to a lack of automatization of the repeating sequence of finger movements by using a dual-task paradigm and by testing for long-term retention of this skill. In Experiment 1, the performance of groups of patients with Parkinson's disease, or with damage to the cerebellum or to the frontal lobes, was compared to that of matched control subjects on the Repeated Sequence Test (primary task) and the Brooks' Matrices Test (secondary task). These two tests were administered concomitantly in both early and late learning phases of the visuomotor sequence. Overall, the groups did not differ in their ability to execute the primary task. By contrast, in accordance with the predictions, patients in Stages 2-3 of Parkinson's disease or with a cerebellar lesion failed to reveal the expected increase in performance on the secondary task seen with learning, suggesting that the latter groups of patients did not have access to the same level of residual cognitive resources to complete the matrices compared to controls. In Experiment 2, the same groups of patients and control subjects were retested again 10-18 months later. They were given four blocks of 100 trials each of the repeating sequence task, followed by a questionnaire and a self-generation task that measured their declarative knowledge of that sequence. The results revealed a long-term retention impairment only in patients who changed from Stage I to Stage II of the disease (suggesting further striatal degeneration) during the one-year interval, or who had a cerebellar lesion. By contrast, performance of the three clinical groups did not differ from controls on declarative memory tests. These findings suggest that both the striatum and the cerebellum participate to the automatization process during the late (slow) learning stage of a sequence of finger movements and that these structures also play a role in the neuronal mechanism subserving long-term retention of such a motor sequence behavior.     

Motor sequencing deficits in schizophrenia: A comparison with Parkinson's disease.

Motor abnormalities occur in schizophrenia (SZ) and may arise from striatal dysfunction. This study examined whether the pattern of performance on simple and complex motor abilities in SZ was similar to that of patients with Parkinson's disease (PD). Quantitative tests of speeded movement and motor and cognitive sequencing were used to assess 25 SZ, 16 PD, and 84 normal controls (NCs). Sequencing performance was also examined with motor rigidity taken into account. Compared with the NC group, the SZ and PD groups were impaired on measures of motor rigidity and motor sequencing. With rigidity accounted for, the SZ group was significantly more impaired than the PD group on motor sequencing; cognitive and motor processes contributed to the motor deficit. Cognitive sequencing performance predicted motor sequencing performance in PD but not SZ. Although both SZ and PD resulted in significant motor and cognitive sequencing deficits, the pattern and correlates of these deficits differ, suggesting that the affected neural systems underlying motor deficits in SZ are different from those involved in PD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of cognitive impairment in relapsing–remitting multiple sclerosis and their relationship to neuropathology on magnetic resonance images.

Several reviews (J. M. Peyser & C. M. Poser, 1986; S. M. Rao, 1986) have suggested that multiple sclerosis (MS) results in cognitive impairment in learning and memory, abstract reasoning, information-processing efficiency, and often visual–spatial ability. MS patients may undergo idiosyncratic cognitive changes dependent on the site of white matter lesions. In the present study, researchers used cluster analysis on the neuropsychological data from a group of mildly disabled relapsing–remitting MS patients (n&≠&?77) and a well-matched control group (n&≠&?9). In those MS patients identified with unequivocal cognitive impairment, the majority clustered into groups with a specific deficit in 1 or 2 areas of cognitive functioning, with normal performance in others. On magnetic resonance imaging, an association was obtained between 2 lesion sites and 2 cognitive tests. Impairment in visual–spatial ability, as assessed by the Benton Visual Retention Test, was associated with lesions in the genu of the corpus callosum (CC) and with more lesions throughout the CC. Impaired performance on Paired Associates, a test of learning and memory, was associated with a lesion in the deep white matter of the left parietal lobe… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning and retention in preclinical and early Alzheimer's disease.

Accelerated forgetting has been proposed as the first sign in preclinical and early Alzheimer's disease (AD). The authors investigated learning and retention in participants who later developed AD with free and cued selective reminding (FCSR; H. Buschke, 1984; E. Grober & H. Buschke, 1987), a test that maximizes learning by inducing deep semantic processing and by controlling study and test conditions. AD patients in the preclinical stage recalled significantly fewer words than did matched control participants, indicating an impairment of learning; nonetheless, patients' retention was identical to that of control participants. A retention deficit was documented 3 years later for AD patients but not for control participants, whose retention was still perfect. Thus, a retention deficit is not present in preclinical AD when hallmark learning deficits can be documented. Detection of preclinical and very early AD may be best accomplished by using robust learning tests that control cognitive processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective corticostriatal dysfunction in schizophrenia: Examination of motor and cognitive skill learning.

[Correction Notice: An erratum for this article was reported in Vol 22(3) of Neuropsychology (see record 2008-05020-015). Table 1 on page 102 should have included the BPRS Depression-Anxiety subscale score 9.00 (3.99) under the column heading Schiz pts. Table displays means with standard deviations in parentheses.] [Correction Notice: An erratum for this article was reported in Vol 22(2) of Neuropsychology (see record 2008-02526-002). The DOI for the supplemental materials was printed incorrectly. The correct DOI is as follows: http://dx.doi.org/10.1037/0894-4105.22.1.100.supp.] It has been suggested that patients with schizophrenia have corticostriatal circuit dysfunction (Carlsson & Carlsson, 1990). Skill learning is thought to rely on corticostriatal circuitry and different types of skill learning may be related to separable corticostriatal loops (Grafton, Hazeltine, & Ivry, 1995; Poldrack, Prabhakaran, Seger, & Gabrieli, 1999). The authors examined motor (Serial Reaction Time task, SRT) and cognitive (Probabilistic Classification task, PCT) skill learning in patients with schizophrenia and normal controls. Development of automaticity was examined, using a dual task paradigm, across three training sessions. Patients with schizophrenia were impaired at learning on the PCT compared to controls. Performance gains of controls occurred within the first session, whereas patients only improved gradually and never reached the performance level of controls. In contrast, patients were not impaired at learning on the SRT relative to controls, suggesting that patients with schizophrenia may have dysfunction in a specific corticostriatal subcircuit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual versus kinesthetic mental imagery: Efficacy for the retention and transfer of a closed motor skill in young children.

The main purposes of this study were (a) to compare the effects of mental imagery combined with physical practise and specific physical practise on the retention and transfer of a closed motor skill in young children; (b) to determine the mental imagery (visual vs. kinesthetic), which is the most efficient for retention and transfer of a closed motor skill; and (c) to verify the relationship between movement image vividness and motor performance. As for the secondary purpose, it was to compare the effects of gender on motor learning. Participants (n = 96) were selected from 3 primary schools. These participants were divided into 6 groups and submitted to different experimental conditions. The experimental task required the participants to throw, with the nondominant hand (left hand), a ball toward a target composed of 3 concentric circles. The results demonstrated that performance obtained by the mental imagery (visual or kinesthetic) combined with physical practise group was, during the retention phase, equivalent to that produced by the specific physical practise group but significantly superior during the transfer of closed motor skill. These results showed the potential benefits of mental imagery as a retention strategy intended for motor skills and performance enhancement. Such results could be explained by the similarity of 3 principal functional evidences shared by mental and physical practise: behavioural, central, and peripheral (as suggested by Holmes & Collins, 2001). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitating acquisition and transfer of a continuous motor task in healthy older adults and patients with Alzheimer's disease.

This study examined the acquisition and transfer of a fine motor skill, namely the rotary pursuit, in 99 patients with Alzheimer's disease (AD) and 100 normal controls (NCs). To identify optimal learning strategies, the authors had participants practice the rotary pursuit under constant, blocked, random, or no training conditions. Transfer was assessed using speeds that were different from those practiced during acquisition. AD patients and NCs receiving constant practice outperformed their peers in the blocked and random conditions during acquisition. Whereas all 3 types of practice facilitated transfer in the NCs, AD patients only benefited from constant practice. The inability of the AD patients to benefit from variable practice suggests that these individuals may have difficulty accessing and/or forming motor schemas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cerebellum contributes to mental skills.

The cerebellum is known to play a role in simple associative motor learning in animals. It has recently been suggested that the cerebellum might also contribute to cognitive abilities in humans, particularly those located primarily in frontal cortex. Therefore 5 patients with either cerebellar lesions or atrophy were compared with 10 controls on a range of intellectual and learning abilities. The patients were impaired on two tests of associative learning, but not on many other types of memory test. There was, however, a generalized tendency toward poorer performance by the patients. The results nevertheless indicate that the cerebellum contributes to a particular type of mental skill, although whether this is related to frontal lobe functions remains to be determined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion enhanced retention of cognitive skill learning.

Ample evidence suggests that emotional arousal enhances declarative/episodic memory. By contrast, there is little evidence that emotional enhancement of memory (EEM) extends to procedural skill based memory. We examined remote EEM (1.5-month delay) for cognitive skill learning using the weather prediction (WP) probabilistic classification task. Participants viewed interleaved emotionally arousing or neutral pictures during WP acquisition. Arousal retarded initial WP acquisition. While participants in the neutral condition showed substantial forgetting of WP learning across the 1.5-month delay interval, the arousal condition showed no evidence of forgetting across the same time period. Thus, arousal during encoding determined the mnemonic fate of cognitive skill learning. Emotional enhancement of WP retention was independent of verbally stated knowledge of WP learning and EEM for the picture contexts in which learning took place. These results reveal a novel demonstration of EEM for cognitive skill learning, and suggest that emotional arousal may in parallel enhance the neural systems that support procedural learning and its declarative context. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Cognitive components of deficit awareness in Alzheimer's disease.

Awareness of deficit was examined in 24 patients with Alzheimer's disease (AD) and their spouses (for a total of 48 participants) using performance prediction-postdiction and questionnaire discrepancy (QD) paradigms. Participants estimated their own memory performances as well the performances of spouses and of a fictional, memory-disordered patient observed on videotape. Patients overpredicted self-performances, but the extent of overestimation decreased for postdictions. Patients and caregivers accurately estimated caregiver performances but overestimated performances of the fictional patient. QD data revealed that patients underestimated their difficulties performing daily functioning tasks as compared with caregiver reports. Awareness of deficit is a complex ability, involving dissociable cognitive processes. AD patients may display intact immediate awareness of memory dysfunction but fail to incorporate incidents of memory failure into generalized self-belief systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporary subclavian steal to reduce intraprocedural embolic risk during detachable balloon occlusion of vertebrobasilar aneurysms: technical note with two case reports

In an administration of the Computerized Neuropsychological Test Battery (CNTB), stable schizophrenic outpatients (n = 26) showed significant impairment (P < 0.05) relative to normal control subjects (n = 28) in overall function and measures of verbal learning. Except on tests of motor speed, the performance profile of schizophrenic patients was similar to that of elderly normal control subjects (n = 33). This profile of deficits is consistent with findings of other investigators in similar patient populations. In addition to displaying sensitivity to the mild impairments found in outpatients, the CNTB showed high test-retest reliability (r = 0.76, P < 0.0001). It should be useful for evaluating cognitive impairment in clinical trials of prospective treatments.     

Individual differences in skill learning: An integration of psychometric and information processing perspectives.

Reexamines the nature of individual differences in novel and practiced performance on skill learning tasks from an information processing framework. Two major sources of data and discussion are reanalyzed and critically evaluated. One source concerns the changes in interindividual between-subjects variability with task practice; the other pertains to associations between intellectual abilities and task performance during skill acquisition. Early studies yielded mixed results regarding the convergence or divergence of individual differences with practice. Other studies indicated small or trivial correlations between individual differences in intelligence and "gain" scores. More recent studies indicated small correlations between performance measures on skill learning tasks and standard intellectual and cognitive ability measures, as well as increasing amounts of task-specific variance over learning trials. Data confirm the proposition that individuals converge on performance as tasks become less dependent on attentional resources with practice. When appropriate methodological techniques are used and crucial task characteristics are taken into account, intellectual abilities play a substantial part in determining individual differences in skill learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)