Learning, retention, and conceptual usage in elderly patients with memory disorder.

Elderly patients clinically judged to be suffering from memory disorder show difficulty in learning paired-associates and the kind of tasks found in the Wechsler Performance Scale. The learning difficulty extends to other kinds of learning problems and retention processes are also affected. The relevance of some of Hebb's notions concerning the likely relations between learning and cognitive functioning in human adults was also examined. The results confirmed expectations and suggested that the sort of neuropsychological model elaborated by Hebb may be a useful source of working hypotheses in this area. 18 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term memory in autism spectrum disorder.

Three experiments examined verbal short-term memory in comparison and autism spectrum disorder (ASD) participants. Experiment 1 involved forward and backward digit recall. Experiment 2 used a standard immediate serial recall task where, contrary to the digit-span task, items (words) were not repeated from list to list. Hence, this task called more heavily on item memory. Experiment 3 tested short-term order memory with an order recognition test: Each word list was repeated with or without the position of 2 adjacent items swapped. The ASD group showed poorer performance in all 3 experiments. Experiments 1 and 2 showed that group differences were due to memory for the order of the items, not to memory for the items themselves. Confirming these findings, the results of Experiment 3 showed that the ASD group had more difficulty detecting a change in the temporal sequence of the items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal and nonverbal memory processing in patients with obsessive-compulsive disorder: Its relationship to clinical variables.

Memory deficits have been reported in several neuropsychological studies of obsessive-compulsive disorder (OCD). Dysfunction in nonverbal memory has been consistently reported, whereas findings on verbal memory are more heterogeneous. The authors studied 50 patients with OCD who were matched for sex, age, educational level, and hand dominance with 50 healthy controls (HC). Cognitive performance in both groups was assessed on verbal and nonverbal memory tasks, and several clinical variables were also assessed in the patient group. Patients with OCD showed a pattern of cognitive dysfunction with alterations in areas of nonverbal memory (recall and recognition), and verbal memory (learning and recall). Older age at onset of OCD was associated with poorer performance on verbal memory tasks. Low scores on some verbal memory tasks were associated with severity of OCD, and nonverbal memory was influenced by depressive symptoms. The study suggests the existence of dysfunction in the execution of verbal and nonverbal memory tasks in OCD; the influence of clinical variables depends on the specific neuropsychological function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interidentity memory transfer in dissociative identity disorder.

Controversy surrounding dissociative identity disorder (DID) has focused on conflicting findings regarding the validity and nature of interidentity amnesia, illustrating the need for objective methods of examining amnesia that can discriminate between explicit and implicit memory transfer. In the present study, the authors used a cross-modal manipulation designed to mitigate implicit memory effects. Explicit memory transfer between identities was examined in 7 DID participants and 34 matched control participants. After words were presented to one identity auditorily, the authors tested another identity for memory of those words in the visual modality using an exclusion paradigm. Despite self-reported interidentity amnesia, memory for experimental stimuli transferred between identities. DID patients showed no superior ability to compartmentalize information, as would be expected with interidentity amnesia. The cross-modal nature of the test makes it unlikely that memory transfer was implicit. These findings demonstrate that subjective reports of interidentity amnesia are not necessarily corroborated by objective tests of explicit memory transfer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overgeneral memory extends to pictorial retrieval cues and correlates with cognitive features in posttraumatic stress disorder.

Individuals with posttraumatic stress disorder (PTSD) show overgeneral memory (OGM) when retrieving autobiographical memories to word cues. We investigated whether OGM extends to picture cues and whether it is related to PTSD symptoms and cognitions. Trauma survivors with (n = 29) and without (n = 26) PTSD completed the standard Autobiographical Memory Test (AMT) and a novel picture version. Compared to the no-PTSD group, the PTSD group showed OGM in both test versions. Pictures facilitated specific memory retrieval, but this effect was no longer significant when verbal intelligence or depressive symptoms were controlled. OGM correlated with PTSD symptoms and perceived self-change; with intrusive memories, their perceived "nowness," responses to intrusions (thought suppression, rumination, dissociation), and negative interpretations of symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal discounting of rewards in patients with bipolar disorder and schizophrenia.

Patients with bipolar disorder (BD) and schizophrenia (SZ) often show decision-making deficits in everyday circumstances. A failure to appropriately weigh immediate versus future consequences of choices may contribute to these deficits. We used the delay discounting task in individuals with BD or SZ to investigate their temporal decision making. Twenty-two individuals with BD, 21 individuals with SZ, and 30 healthy individuals completed the delay discounting task along with neuropsychological measures of working memory and cognitive function. Both BD and SZ groups discounted delayed rewards more steeply than did the healthy group even after controlling for current substance use, age, gender, and employment. Hierarchical multiple regression analyses showed that discounting rate was associated with both diagnostic group and working memory or intelligence scores. In each group, working memory or intelligence scores negatively correlated with discounting rate. The results suggest that (a) both BD and SZ groups value smaller, immediate rewards more than larger, delayed rewards compared with the healthy group and (b) working memory or intelligence is related to temporal decision making in individuals with BD or SZ as well as in healthy individuals. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Stimulant medication improves recognition memory in children diagnosed with attention-deficit/hyperactivity disorder.

The effect of stimulant medication on recognition memory was examined in 18 children with attention-deficit/hyperactivity disorder (ADHD). Recognition memory was assessed using a delayed matching-to-sample task at 6 delays ranging from 1 to 32 s. Each child was tested on 2 separate occasions, once 60 to 90 min after taking stimulant medication and the other at least 18 hr after taking medication. Children performed significantly better on medication than off. Stimulant administration significantly increased accuracy and the number of nickel reinforcers earned. Decreases in observing response latency and correct choice response latency occurred after taking stimulant medication. The results indicate that stimulant medication improved recognition memory for children with ADHD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A clinical-experimental approach to the study of subliminal stimulation: The effects of a drive-related stimulus upon Rorschach responses.

This was an investigation of the effects of a drive-related subliminal stimulus on subsequent Rorschach images. 60 male Ss were seen for an experimental and control session in a balanced design. Ss were divided into 5 groups on the basis of their recogniton thresholds for the drive-related stimulus and a neutral stimulus. For each group, different predictions were made as to how the subliminally presented drive stimulus would affect subsequent Rorschach performance. The results indicated: for the total group, there was a clearcut subliminal effect; the nature of this effect varied considerably among Ss with regard to the relative influence of drive-expressive and defensive reactions; the different ways Ss responded to the subliminal activation were systematically related to their threshold behavior. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neural responses to masked fear faces: Sex differences and trauma exposure in posttraumatic stress disorder.

Although women have a greater propensity than men to develop posttraumatic stress disorder (PTSD) following trauma, sex differences in neural activations to threat have received little investigation. This study tested the prediction that trauma would heighten activity in automatic fear-processing networks to a greater extent in women than in men. Functional magnetic resonance imaging (fMRI) data were recorded in 23 participants with PTSD (13 women, 10 men), 21 trauma-exposed controls (9 women, 12 men), and 42 non-trauma-exposed controls (22 women, 20 men) while they viewed masked facial expressions of fear. Exposure to trauma was associated with enhanced brainstem activity to fear in women, regardless of the presence of PTSD, but in men, it was associated only with the development of PTSD. Men with PTSD displayed greater hippocampal activity to fear than did women. Both men and women with PTSD showed enhanced amygdala activity to fear relative to controls. The authors conclude that greater brainstem activation to threat stimuli may contribute to the greater prevalence of PTSD in women, and greater hippocampal activation in men may subserve an enhanced capacity for contextualizing fear-related stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotic susceptibility in patients with conversion disorder.

Conversion disorder has been associated with hypnotic susceptibility for over a century and is currently still believed to be a form of autohypnosis. There is, however, little empirical evidence for the relation between hypnotic susceptibility and conversion symptoms. The authors compared 50 patients with conversion disorder with 50 matched control patients with an affective disorder on measures of hypnotic susceptibility, cognitive dissociation, and somatoform dissociation. Conversion patients were significantly more responsive to hypnotic suggestions than control patients. In addition, conversion patients showed a significant correlation between hypnotic susceptibility and the number of conversion complaints. These results provide the first evidence of a relationship between hypnotic susceptibility and the presence and number of conversion symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced autobiographical memory specificity predicts depression and posttraumatic stress disorder after recent trauma.

In this prospective longitudinal study, the authors examined the relationship between reduced specificity in autobiographical memory retrieval and the development of depression, posttraumatic stress disorder (PTSD), and specific phobia after injury in an assault. Assault survivors (N = 203) completed the Autobiographical Memory Test (J. M. G. Williams & K. Broadbent, 1986) at 2 weeks after the trauma as well as structured clinical interviews at 2 weeks and 6 months. Participants with acute stress disorder or major depression at 2 weeks, but not those with phobia, retrieved fewer specific autobiographical memories than those without the respective disorder. Reduced memory specificity at 2 weeks also predicted subsequent PTSD and major depression at 6 months over and above what could be predicted from initial diagnoses and symptom severity. Moderator analyses showed that low memory specificity predicted later depression in participants with prior episodes of major depression but not in those without prior depression. Mediation analyses suggested that rumination partly mediated and perceived permanent change fully mediated the effects of low memory specificity on posttrauma psychopathology at follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alternative responses to dissonance.

50 male and 50 female Ss were placed in an experimental situation in which they found their judgments contradicted by a respected associate of the same sex. Ss were free to resolve the dissonance by conforming to the contrary judgments of the associate, rejecting the associate as one who was less competent than he had been thought to be, underrecalling the disagreements, or, devaluating the importance of the topics about which disagreements had occurred. Female Ss made less use of rejection than did male Ss and were more inclined to tolerate the conflict. Other findings suggest that individuals are inclined to employ the 4 responses as alternative means of reducing dissonance rather than as supplementary means. Finally, correlations relating the MA scale to conformity, underrecall, and tolerance were significantly different for the 2 sexes, suggesting that the effect of anxiety upon Ss' choice of dissonance reducing response depends upon the sex of the Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of monetary reward on memory in schizophrenia spectrum disorder.

The impact of monetary reward on verbal working memory (vWM) and verbal long-term memory (vLTM) was evaluated in 50 patients with schizophrenia spectrum disorders and 52 matched healthy participants. This research was motivated by the observations that negative symptoms in schizophrenia are associated with reduced drive and that patients with these symptoms exhibit greater mnemonic impairments. Reward-related gains were evaluated across two levels of vWM load on the n-back task and across three aspects of vLTM derived from the California Verbal Learning Test-II (i.e., learning, total immediate recall, and retention). Although healthy individuals benefited from reward at a high vWM load level, schizophrenia patients exhibited no reward-related improvements in vWM. In contrast, improvement in vLTM retention was induced by reward for both patients and controls. Finally, symptomatic and pharmacology treatment factors were associated with reward-related gains in persons with schizophrenia. In conclusion, contingent monetary rewards delivered during vWM and vLTM enhanced specific aspects of memory. The influence was relatively small and dependent on the specific neurocognitive operation examined, the mental health status of the participants, and for patients, their particular symptoms and pharmacological treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autobiographical memory specificity and emotional disorder.

The authors review research showing that when recalling autobiographical events, many emotionally disturbed patients summarize categories of events rather than retrieving a single episode. The mechanisms underlying such overgeneral memory are examined, with a focus on M. A. Conway and C. W. Pleydell-Pearce's (2000) hierarchical search model of personal event retrieval. An elaboration of this model is proposed to account for overgeneral memory, focusing on how memory search can be affected by (a) capture and rumination processes, when mnemonic information used in retrieval activates ruminative thinking; (b) functional avoidance, when episodic material threatens to cause affective disturbance; and (c) impairment in executive capacity and control that limits an individual's ability to remain focused on retrieval in the face of distraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-based prospective memory impairment in patients with thalamic stroke.

The role of the thalamus in memory is potentially very complex. However, most studies on the memory impairments of thalamic lesions have focused on retrospective memory, rarely on prospective memory. To explore the effect of thalamic lesions on event-based prospective memory (EBPM) and time-based prospective memory (TBPM), respectively, and to verify the hypothesis that the thalamus is involved in the prospective memory, EBPM and TBPM tasks were administered to 18 thalamic stroke patients and 18 age- and education-matched healthy controls. In the EBPM task, subjects were asked to perform an action whenever particular words were presented. In the TBPM task, subjects were asked to perform an action at certain times. Compared with the performance of healthy controls on EBPM and TBPM tasks (EBPM, 4.3 ± 1.5; TBPM, 5.4 ± 1.0), there was a significant difference in the performance of thalamic stroke patients in the TBPM tasks (2.4 ± 1.6), but no difference was found in EBPM tasks (3.7 ± 1.1). These results may indicate that the thalamus is involved in PM and particularly in TBPM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Take The Best versus simultaneous feature matching: Probabilistic inferences from memory and effects of reprensentation format.

In 4 experiments, the tendency to use the simple heuristic Take The Best (TTB; G. Gigerenzer & D. Goldstein, 1996) was explored for probabilistic multiattribute inferences from memory. In a newly developed procedure, participants first learned attribute patterns that formed the basis for inferences in a second phase. A Bayesian method classified strategies as TTB, compensatory, or guessing. Experiment 1 had a high rate (64%) of participants classified as TTB users when inferences were made from memory. Experiment 2 showed that this was no mere materials effect. In Experiments 3 and 4, the authors examined effects of the representational format of the attribute information. Experiment 4 showed that the representational format may be an important moderating variable for strategy use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of schizophrenia and bipolar patients on verbal and figural working memory tasks.

Working memory (WM) was studied in 82 healthy volunteers, 43 schizophrenia patients, and 81 bipolar patients. Schizophrenia patients were impaired on verbal and figural WM tasks that possessed similar test discriminating power. Bipolar patients performed similarly to healthy volunteers. A mathematical model of WM performance revealed a primary role for reduced WM span in accounting for the impaired verbal WM of schizophrenia patients and a primary role for diminished attention in accounting for impaired figural WM. Although WM impairment in schizophrenia is due neither to the general effects of severe mental illness nor to the specific type of material studied, the microarchitecture of abnormal WM in schizophrenia may depend on the stimulus material presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A central capacity limit to the simultaneous storage of visual and auditory arrays in working memory.

If working memory is limited by central capacity (e.g., the focus of attention; N. Cowan, 2001), then storage limits for information in a single modality should apply also to the simultaneous storage of information from different modalities. The authors investigated this by combining a visual-array comparison task with a novel auditory-array comparison task in 5 experiments. Participants were to remember only the visual, only the auditory (unimodal memory conditions), or both arrays (bimodal memory conditions). Experiments 1 and 2 showed significant dual-task tradeoffs for visual but not for auditory capacity. In Experiments 3-5, the authors eliminated modality-specific memory by using postperceptual masks. Dual-task costs occurred for both modalities, and the number of auditory and visual items remembered together was no more than the higher of the unimodal capacities (visual: 3-4 items). The findings suggest a central capacity supplemented by modality- or code-specific storage and point to avenues for further research on the role of processing in central storage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Episodic memory and episodic future thinking in adults with autism.

The ability to remember past experiences (episodic memory) is thought to be related to the ability to imagine possible future experiences (episodic future thinking). Although previous research has established that individuals with autism spectrum disorder (ASD) have diminished episodic memory, episodic future thinking has not previously been investigated within this population. In the present study, high-functioning adults with ASD were compared to closely matched typical adults on a task requiring participants to report a series of events that happened to them in the past and a series of events that might happen to them in the future. For each event described, participants completed two modified Memory Characteristics Questionnaire items to assess self-reported phenomenal qualities associated with remembering and imagining, including self-perspective and degree of autonoetic awareness. Participants also completed letter, category, and ideational fluency tasks. Results indicated that participants with ASD recalled/imagined significantly fewer specific events than did comparison participants and that participants with ASD demonstrated impaired episodic memory and episodic future thinking. In line with this finding, participants with ASD were less likely than comparison participants to report taking a field (first-person) perspective and were more likely to report taking an observer (third-person) perspective during retrieval of past events (but not during simulation of future events), highlighting that they were less likely to mentally reexperience past events from their own point of view. There were no group differences in self-reported levels of autonoetic awareness or fluency task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)