Impairment of memory for sequences in conduction aphasia.
Explore the source record for details and available documents.
Adult↗
SEARCH · Search PubMed
Results for “Serial Learning”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Intravenous diazepam in humans: effects on acquisition and performance of response chains.
A technique based upon an individual-subject design was used to investigate the effects of intravenous diazepam on the acquisition and performance of response chains in humans. In each of two conditions subjects were required to emit a different sequence of ten responses in a predetermined order on three levers. The conditions alternated within each session under a multiple schedule. In the performance condition the sequence of responses was the same each session. The second condition was a repeated-acquisition task. In this condition subjects were required to learn a different sequence of responses each session. Diazepam produced dose-dependent decreases in the overall rate of responding in each subject under both conditions. In two of the three subjects tested, errors were increased in the learning condition at doses lower than those required to disrupt accuracy in the performance condition. In one subject, accuracy in both the learning and performance conditions was equisensitive to the disruptive effects of diazepam. These data are consistent with the effects of the benzodiazepines in analogous animal procedures. Furthermore, the data suggest that the behavioral effects of intravenous diazepam may exhibit marked variations across subjects at clinically relevant doses (5-10 mg).
Adult↗
Memory for frequency in rats: role of the hippocampus and medial prefrontal cortex.
On a radial arm maze rats were tested for frequency memory of specific spatial locations, a task that presumably involves the coding of temporal information. On any trial during the study phase rats were allowed to visit three different spatial locations only once and one spatial location twice. During the test phase the rats were given a choice between a spatial location that had been visited once and spatial location that had been visited twice. The rats were reinforced for selecting the twice-visited spatial location. The number of spatial locations between a repetition (lag) was varied from one to three. After extensive training rats displayed memory for frequency only for a lag of three spatial locations, i.e., they displayed a repetition lag effect. Animals then received control, medial prefrontal cortex, or hippocampal lesions. Upon subsequent retests control rats continued to display frequency memory, but animals with medial prefrontal cortex or hippocampal lesions displayed a marked impairment. These data support the idea that both the hippocampus and medial prefrontal cortex code temporal order information.
Animals↗
Endogenous plasma testosterone levels and commission errors in women: A preliminary report.
A correlation between elevated testosterone and aggressive behavior has been demonstrated in animals and to a lesser degree in humans, primarily in the context of dominance. Some aggression, namely non-premeditated aggression, is characterized by impaired impulse control. Real-world aggressive histories and self-reported impulsivity have correlated with commission errors (failures to withhold responses to nontarget stimuli) in versions of the continuous performance test (CPT). To begin exploring whether testosterone may play a role in aggression due more to a direct relationship with impaired impulse control, we related plasma total testosterone concentrations of 27 psychiatrically healthy women to commission errors in two variants of the CPT - with and without interstimulus distracters. Controlling for age and IQ, testosterone did not relate to rates of correct detections in either task, but correlated positively with commission errors in the distracter CPT variant. In light of the fact previous studies find commission errors on the CPT are associated with impulsivity, the results of this study support a positive relationship between testosterone and impulsivity.
Aggression↗
Effects of cholinesterase inhibitors on a two-component chained schedule performance in rats.
The acetylcholinesterase (AChE) inhibitors physostigmine (PHY), tacrine (THA), and heptylphysostigmine (HEP) have been evaluated as potential therapeutics for treatment of Alzheimer's disease (AD) and as prophylactics against organophosphate (OP) poisoning. The above medical applications are based upon the neurochemical principles of elevation of transient levels of acetylcholine (ACh) in brain and reversible inhibition of AChE in blood and brain, respectively. The present study was undertaken to evaluate the effects of these drugs on performance of a two-component chained schedule of differential-reinforcement-of-high-rate (DRH) reward/differential-reinforcement-of-low-rate (DRL) nonreward contingencies, for water reinforcement in 2-h experimental sessions in rats. Both PHY (0.031-0.25 mg/kg, SC) and HEP (0.625-10.0 mg/kg, SC) decreased overall reinforcement rate and nonreinforced response in a dose-related and parallel manner, whereas THA (0.625-5.0 mg/kg) decreased the overall reinforcement rate in a dose-related manner, but did not significantly affect nonreinforced response. The least significant doses of PHY (0.625 mg/kg), THA (1.25 mg/kg), and HEP (1. 25 mg/kg) on the behavioral performance were associated with oral movements and/or muscle fasciculation. Moderate to high doses of these drugs (i.e., PHY >/= 0.624, THA >/= 1.25, and HEP >/= 1.25 mg/kg) produced behavioral suppression, which resulted mostly from the cessation of responding in the presence of cholinergic adverse events. The ED(50) values of the behavioral disruption (as documented by overall reinforcer loss) for PHY, THA, and HEP were 0. 081, 3.87, and 2.89 mg/kg, respectively, and the behavioral-deficit-free (BDF) doses were 0.031, 0.625, and 0.625 mg/kg, respectively. Preclinical data revealed that the BDF doses of both PHY and HEP have moderate inhibition of AChE, which leads to an efficacious elevation of ACh level in the brain, whereas the BDF dose of THA shows no significant AChE inhibition or elevation of brain ACh level; however, they all have cognition enhancing effects at their respective safety doses. The above data suggest that the BDF doses of PHY and HEP may have prophylactic efficacy against OP poisoning, whereas THA may not. The BDF doses of these three drugs are comparable to the maximum tolerated doses in clinical practice, suggesting that the present rat model may have potential value in predicting the clinical safety of AChE inhibitors developed for therapy of AD and prophylaxis against OP poisoning as well.
Animals↗
A study of parallel implicit and explicit information processing in patients with obsessive-compulsive disorder.
OBJECTIVE: This study examined implicit sequence learning in patients with obsessive-compulsive disorder (OCD) under dual-task conditions. Frontal-striatal networks support implicit learning and are implicated in the pathophysiology of OCD. Neuroimaging data suggest that during implicit learning, OCD patients use neural systems normally active during explicit learning to compensate for striatal dysfunction. METHOD: The authors examined implicit sequence learning in 25 OCD patients and 25 healthy comparison subjects using a dual-task paradigm, with subjects simultaneously engaged in an explicit memory task and an implicit learning task. They predicted that implicit learning in OCD subjects would be disrupted because concurrent explicit information-processing demands would prevent use of compensatory processes. RESULTS: OCD patients failed to show evidence of implicit learning and exhibited a significant deficit in comparison with healthy subjects. CONCLUSIONS: These results are consistent with the hypothesis that concurrent explicit and implicit information-processing demands interfere with implicit learning in OCD patients.
Attention↗
Visual memory skills in Japanese and Caucasians.
Two visual memory tasks were administered to 80 subjects, 48 Japanese and 32 Caucasian, 49 female and 31 male. Japanese subjects were divided into 2 groups, those brought up in Japan with knowledge of kanji and Americans of Japanese ancestry with no kanji experience. The Caucasian subjects were subdivided into two groups, those who had learned kanji as adults, and others without knowledge of kanji. The purpose of the experiment was to examine the possible influence of kanji on the finding that Japanese children and adults score higher than their Caucasian peers in tests of visual ability. A knowledge of kanji did not appear to influence the scoring pattern.
Adult↗
Subjective measures of awareness and implicit cognition.
In this article, we examine whether artificial grammar learning is implicit according to a subjective criterion of awareness based on confidence ratings. In four experiments, participants discriminated between grammatical and ungrammatical sequences in both the same (Experiment 1) and a novel (Experiments 2-4) vocabulary and indicated their confidence in each decision. Replicating earlier studies, confidence judgments reported on a continuous scale (50%-100%) were only weakly related to accuracy, suggesting that learning was implicit. In contrast, confidence judgments reported on a binary scale (high vs. low) revealed that confidence was related to accuracy. We show that participants are better able to place their phenomenal states on a binary scale, as compared with a continuous scale.
Awareness↗
Seriation, conservation, and theory of mind abilities in individuals with autism, individuals with mental retardation, and normally developing children.
Seriation, conservation, and theory of mind abilities were examined in individuals with autism (N = 16), mental retardation (N = 16), and in normally developing children (N = 16). Seriation tasks included seriation of tubes, blocks, and flat squares. Conservation tasks included conservation of area, number, substance, quantity, and weight. Theory of mind tasks involved predicting false belief and understanding value and fact beliefs. Participants with autism performed better than participants with mental retardation on seriation, while no differences emerged between these groups on conservation and false belief. Individuals with autism performed less well than individuals with mental retardation on the value and fact belief tasks; however, when verbal ability was held as a covariant, the difference was no longer significant. Normally developing children performed better than the other two groups on all tasks. These results suggest that autism does not involve a specific impairment in theory of mind and that theory of mind deficits are not unique to autism.
Adolescent↗
Coding of spatial and temporal information in episodic memory.
Explore the source record for details and available documents.
Auditory Perception↗
Learning and memory for hierarchical relationships in the monkey: effects of aging.
Young and aged rhesus monkeys were tested on 2 versions of a transitive inference task measuring learning and memory for hierarchical relationships. Animals initially acquired 4 object discrimination problems arranged such that the relationship between the stimuli followed the hierarchy A > B > C > D > E. The second version of the task was similar but involved a series of 7 objects. Learning and memory for the hierarchical relationships were evaluated during probe trials in which novel pairs of nonadjacent items (e.g., B and D) were presented for a response. Standard task accuracy measures failed to distinguish young and aged subjects at any point in training. In contrast, response latency effects that are indicative of relational information processing in young monkeys were entirely absent in aged subjects. The findings highlight the value of a relational memory framework for establishing a detailed neuropsychological account of cognitive aging in the monkey.
Aging↗
Influence of centrality and distinctiveness of actions on script sorting and ordering in patients with frontal lobe lesions.
In order to further investigate script knowledge in patients with frontal lobe lesions (FP), 30 participants with frontal brain damage, 14 controls with posterior brain damage (PC) and 30 normal controls (NC) were asked to sort script actions with various degrees of centrality and distinctiveness according to the script to which they belonged and their order of execution. Actions were given in 3 conditions: scripts with headers (SH), scripts without headers (SwH) and scripts with distractor header (SDH). Results confirmed the dual dissociation we observed in a previous study (Allain, Le Gall, Etcharry-Bouyx, Aubin, & Emile, 1999). Twelve FP made numerous errors in sequencing actions regardless of the conditions, but rejected the irrelevant title. Fourteen FP made few sequencing errors but used the irrelevant title. The last 4 FP performed as well as the PC and NC in every condition. Sorting errors made by the FP mainly concerned actions with low levels of centrality and distinctiveness. These data are consistent with the view that frontal lobe lesions selectively impair the syntactic component of script representation without affecting its semantic component.
Adult↗
Temporal order and processing acuity of visual, auditory, and tactile perception in developmentally dyslexic young adults.
We studied the temporal acuity of 16 developmentally dyslexic young adults in three perceptual modalities. The control group consisted of 16 age- and IQ-matched normal readers. Two methods were used. In the temporal order judgment (TOJ) method, the stimuli were spatially separate fingertip indentations in the tactile system, tone bursts of different pitches in audition, and light flashes in vision. Participants indicated which one of two stimuli appeared first. To test temporal processing acuity (TPA), the same 8-msec nonspeech stimuli were presented as two parallel sequences of three stimulus pulses. Participants indicated, without order judgments, whether the pulses of the two sequences were simultaneous or nonsimultaneous. The dyslexic readers were somewhat inferior to the normal readers in all six temporal acuity tasks on average. Thus, our results agreed with the existence of a pansensory temporal processing deficit associated with dyslexia in a language with shallow orthography (Finnish) and in well-educated adults. The dyslexic and normal readers' temporal acuities overlapped so much, however, that acuity deficits alone would not allow dyslexia diagnoses. It was irrelevant whether or not the acuity task required order judgments. The groups did not differ in the nontemporal aspects of our experiments. Correlations between temporal acuity and reading-related tasks suggested that temporal acuity is associated with phonological awareness.
Adult↗
Can sequence learning be implicit? New evidence with the process dissociation procedure.
Can we learn without awareness? Although this issue has been extensively explored through studies of implicit learning, there is currently no agreement about the extent to which knowledge can be acquired and projected onto performance in an unconscious way. The controversy, like that surrounding implicit memory, seems to be at least in part attributable to unquestioned acceptance of the unrealistic assumption that tasks are process-pure--that is, that a given task exclusively involves either implicit or explicit knowledge. Methods such as the process dissociation procedure (PDP, Jacoby, 1991) have been developed to overcome the conceptual limitations of the process purity assumption but have seldom been used in the context of implicit learning research. In this paper, we show how the PDP can be applied to a free generation task so as to disentangle explicit and implicit sequence learning. Our results indicate that subjects who are denied preparation to the next stimulus nevertheless exhibit knowledge of the sequence through their reaction time performance despite remaining unable (1) to project this knowledge in a recognition task and (2) to refrain from expressing their knowledge when specifically instructed to do so. These findings provide strong evidence that sequence learning can be unconscious.
Adolescent↗
Efficiency of temporal order discrimination as an indicator of bradyphrenia in Parkinson's disease: the inspection time loop task.
To investigate the bradyphrenia hypothesis of Parkinson's disease (PD), 32 patients undertook an information-processing task which measured their efficiency of temporal order discrimination. Their performance was compared with 31 non-PD controls matched on age, sex, years of full-time education and pre-morbid IQ. The task was novel and designed to be sensitive to the clinical phenomenon of bradyphrenia (slowing of mental abilities), in the context of temporal order discrimination without confounding from motor ability deficits. The test (the inspection time loop task; ITloop) required judgements as to the temporal sequence of four single letters. The stimulus duration of the letters in each sequence ranged from 100 to 700ms. The PD group had a significantly lower mean score on the ITloop task than did controls (P=0.02). PD patients perform more poorly on temporal order discrimination judgements even when the task makes no motor demands.
Aged↗
Preliminary analysis of effects of "normal" aging on different memory processes and abilities.
Visual recognition-memory span, name-face association, and verbal memory with selective reminding were tested in two groups of 24 normal healthy volunteers (above and below age 50 yr.). The preliminary study suggests differential effects of aging on specific memory components and warrants careful exploration.
Adolescent↗
Higher order sequential effects in psychophysical judgments.
We found that the depth of sequential effects depends on the judgment task. An experiment with squares indicated that stimulus-response pairs up to two trials back were included in the judgment process when subjects were required to make category judgments of size, whereas only the immediately preceding event was incorporated when subjects were making magnitude estimations. In the case of category judgment, interactions between the current stimulus and prior stimuli as well as configural effects indicated that events one and two trials back meet an equivalent function in the judgment process and that these events may jointly operate in one trial. These findings can be explained by a class of models that assume that the position of preceding stimuli relative to the current stimulus is decisive in the judgment process. The multiple-standards model is a representative of this class according to which there are two types of standards: (1) the endpoints of the range as long-term standards and (2) traces of preceding stimuli as short-term standards.
Adult↗
Extinction and retraining of simultaneous and successive flavor conditioning.
In three experiments, rats received pairings of flavor conditioned stimuli with polycose unconditioned stimuli, in either a simultaneous or a sequential relation. Both temporal relations produced excellent conditioned increases in consumption of the flavors. Separate presentation of the flavors resulted in extinction in both cases. However, restoring the pairing of the flavor with polycose resulted in reconditioning only with the sequential, not with the simultaneous, relation.
Animals↗