Autobiographical memory in dysphoric and non‐dysphoric college students using a computerised version of the AMT

On autobiographical memory tests (AMTs) using positive and negative cue words, research has consistently found that depressed individuals (relative to nondepressed controls) are more likely to recall overgeneral memories (OGMs) and are less likely to recall specific memories. A total of 56 undergraduates who scored high or low on a measure of depression were shown positive and negative word cues and event cues in a computerised AMT. Dysphoric college students made significantly fewer specific and more categoric (overgeneral) responses than controls, but did not differ from controls in terms of extended responses. Results suggest that the difference in memory specificity between low and high dysphoric students generalises across word and event cues and that a computerised version of the AMT can be used as an alternative to interviews as a form of administration.     

Comprehension in "hyperlexic" readers

Mentally retarded children who can read aloud written words better than one would expect from their Mental Age are often called hyperlexic. The reading comprehension thought to be impaired in such children was investigated in four experiments. Mentally retarded advanced decoders, including autistic and nonautistic children, were compared with younger nonretarded children matched for Mental Age and Reading Age. Experiment 1 established that mildly mentally retarded readers could match sentences to pictures as well as could be expected from their verbal ability. This was the same whether they read the sentences or heard them. Experiment 2 demonstrated that only the more able retarded subjects, but not the less able ones, used sentence context in a normal way in order to pronounce homographs. Experiments 3 and 4 showed that these same more able children could extract meaning at both sentence and story level, and their performance was indistinguishable from that of normal controls. Hence, it is doubtful whether these advanced decoders should be called hyperlexic. In contrast, the readers of relatively low verbal ability performed much worse than their normal controls. Although they could be induced under certain conditions to read sentence-by-sentence rather than word-by-word, they did not do so spontaneously. Furthermore, they did not make use of already existing general knowledge in order to answer questions about the stories they had read. The ability to comprehend in terms of large units of meaning seems to be specifically impaired in these low verbal ability fluent readers. We suggest that it is this impairment that marks true hyperlexia. Since there were no differences between autistic and nonautistic readers on any of our tasks, we conclude that hyperlexia is not an autism-specific phenomenon.     

Daily moods and symptoms: effects of awareness of study focus, gender, menstrual-cycle phase, and day of the week

Evaluated changes in daily ratings of moods and symptoms in 30 normally cycling women and 23 men. Women were randomly assigned to two groups for manipulating awareness of the study focus (aware vs. unaware). Principal-components analysis revealed six factors (Dysphoric Moods, Well-being, Physical Symptoms, Personal Space, Food Cravings, Depression) that accounted for 70% of the variance in daily ratings. Repeated-measures analyses revealed cyclic variation on each factor and no significant differences between aware and unaware women during premenstrual or menstrual phases on any measure. Unaware women reported less well-being than men during the premenstrual phase but did not differ on any other measure. Aware women did not differ from men in premenstrual or menstrual ratings on any measure. The way these findings relate to retrospective symptom reports, menstrual attitudes, and changes in moods and symptoms across the week was examined.     

"Clockness" in the detection of dementia: a semantic-conceptual effect

We studied aspects of clock cognition that might underlie the sensitivity of the CDT in screening for dementia of the Alzheimer type (DAT). Two groups, 15 patients with mild-moderate DAT and 15 controls, were assessed with the CDT and specially designed tests of clock-related cognition. Patients were impaired on the CDT, but they did not differ from controls in copying a clock face or selecting the correct representation of a given time. Patients were worse than controls at distinguishing between clock and nonclock objects, detecting anomalies in clocks, and in setting time irrespective of response format. These findings suggest that semantic-conceptual aspects of clock-related cognition are important in discriminating between patients with DAT and controls.     

Neural correlates of attention to emotional facial expressions in dysphoria

The present study investigated whether dysphoric individuals have a difficulty in disengaging attention from negative stimuli and/or reduced attention to positive information. Sad, neutral and happy facial stimuli were presented in an attention-shifting task to 18 dysphoric and 18 control participants. Reaction times to neutral shapes (squares and diamonds) and the event-related potentials to emotional faces were recorded. Dysphoric individuals did not show impaired attentional disengagement from sad faces or facilitated disengagement from happy faces. Right occipital lateralisation of P100 was absent in dysphoric individuals, possibly indicating reduced attention-related sensory facilitation for faces. Frontal P200 was largest for sad faces among dysphoric individuals, whereas controls showed larger amplitude to both sad and happy as compared with neutral expressions, suggesting that dysphoric individuals deployed early attention to sad, but not happy, expressions. Importantly, the results were obtained controlling for the participants' trait anxiety. We conclude that at least under some circumstances the presence of depressive symptoms can modulate early, automatic stages of emotional processing.     

To do or not to do? Prospective memory versus response inhibition in autism spectrum disorder and attention-deficit/hyperactivity disorder

In the present research, event-based prospective memory and response inhibition (RI) abilities were investigated in children with ASD (Study 1), with ADHD (Study 2), and their matched neurotypical controls. Children engaged in a categorisation (ongoing) task and, concurrently, in either an event-based prospective memory (PM) or a Go/No-Go secondary task. Results showed that, as compared to their matched controls, ASD children's performance was more impaired in the PM task than in the Go/No-Go task, while the performance pattern of ADHD children was reversed. In the ongoing task, ASD children were as accurate as, but significantly slower than, controls, independently of conditions. ADHD children did not differ from controls in the presence of a concurrent PM task, while they were less accurate than controls in the presence of the go/no-go task. Overall, the two patterns of findings suggest important differences in the way ASD and ADHD children remember and realise intentions requiring opposite behaviours (acting vs stopping).     

Memory for autobiographical facts and events: a comparison of women reporting childhood sexual abuse and non‐abused controls

Although there is evidence that many adult survivors of childhood sexual abuse (CSA) have a period when they forget their abuse, existing research is equivocal about whether such individuals show other autobiographical memory impairments. The present study addressed some of the sampling and measurement problems apparent in previous studies and compared 74 women reporting a history of CSA with 60 non‐abused controls on their ability to recall facts and events from childhood. The results showed that the CSA group did not differ from the controls in the quality of their memories for autobiographical incidents. However, they were significantly less able than controls to recall specific facts about their personal history, such as significant addresses and names of significant individuals, after controlling for educational level, depression and childhood address changes. CSA group participants reporting a period of abuse forgetting appeared more impaired than those with continuous abuse memories in their recall of personal semantic facts, but were similar in their recall of autobiographical incidents. The findings suggest that experiencing a period of abuse forgetting is a more influential factor in predicting the ability to recall personal semantic facts than abuse status alone. Copyright © 2002 John Wiley & Sons, Ltd.     

Memory Span,Naming Speed,and Memory Strategies in Poor and Normal Readers

Eleven-year-old severely impaired poor readers failed to show a word length effect with pictorial presentation, but showed an effect of equal magnitude to that of reading age and chronological age controls with auditory presentation. The lack of a pictorial word length effect was unlikely to be due to slow speed of naming skills, as in one study these were at least as fast as those of the reading age controls. It is possible that the poor readers failed to verbally encode the pictures. However, they reported using verbal rehearsal, and lip movements were often observed during presentation, suggesting that they did verbally encode the items. Therefore they may have failed to show a word length effect because they did not retrieve information from the phonological store at recall. Although the poor readers had impaired naming speed skills for their age on both discrete item identification and articulation rate tasks, they could not be equated with their chronological age controls on memory span or reading when these naming speed differences were controlled. However, the groups were matched on the naming speed measures when differences in reading ability were controlled.     

Comparison between Oral and Written Spelling in Alzheimer's Disease

Written and oral spelling were compared in 33 patients with Alzheimer's disease (AD) and 25 control subjects. AD patients had poorer spelling results which were influenced by orthographic difficulty and word frequency, but not by grammatical word class. Lexical spelling was also more deteriorated than phonological spelling. Moreover, oral spelling was more impaired than written spelling in AD patients, whereas no difference was present between oral and written spelling of controls. Analysis of spelling errors showed that, for controls, errors were predominantly phonologically accurate in both spelling tasks. Significantly, AD patients produced more phonologically accurate than inaccurate errors in written spelling, whereas these errors did not differ in oral spelling. In contrast to controls who produced more constant than variable responses in oral and written spelling, AD patients made more variable responses (words correctly spelled in one task but incorrectly in the other) and they showed many instances of variable errors (different misspellings from one spelling task to the other). Two stepwise regression procedures showed that written misspellings were specifically correlated with language impairment, whereas oral spelling errors were correlated with attentional and language disorders. These results suggest that AD increases the attentional demands of oral spelling process as compared to written spelling. This dissociation argues, either for a unique Graphemic Buffer in which oral spelling requires more attentional resources than written spelling or for the hypothesis of separate buffers for oral and written spelling.     

Comparison of patients with Parkinson's disease or cerebellar lesions in the production of periodic movements involving event-based or emergent timing

We have hypothesized a distinction between the processes required to control the timing of different classes of periodic movements. In one class, salient events mark successive cycles. For these movements, we hypothesize that the temporal goal is a requisite component of the task representation, what we refer to as event-based timing. In the other class, the successive cycles are produced continuously. For these movements, alternative control strategies can optimize performance, allowing timing to be emergent. In a previous study, patients with cerebellar lesions were found to be selectively impaired on event-based timing tasks; they were unimpaired on a continuously produced task. In the present study, patients with Parkinson's disease were tested on repetitive movement tasks in which timing was either event-based or emergent. Temporal variability on either type of task did not differ between on- and off-medication sessions for the Parkinson's patients nor did patient performance differ from that of controls. These results suggest that the basal ganglia play a minimal role in movement timing and that impairments on event-based timing tasks are specific to cerebellar damage.     

Involuntary autobiographical memories in dysphoric mood: A laboratory study

The frequency and characteristics of involuntary autobiographical memories were compared in 25 stable dysphoric and 28 non-dysphoric participants, using a new laboratory-based task (Schlagman & Kvavilashvili, 2008). Participants detected infrequent target stimuli (vertical lines) in a simple vigilance task and recorded any involuntary autobiographical memories that came to mind, mostly in response to irrelevant words presented on the screen. Dysphoric participants reported involuntary memories as frequently and as quickly as non-dysphoric participants and their memories were not repetitive intrusive memories of negative or traumatic events. Additional content analysis showed that dysphoric participants did not recall more memories of objectively negative events (e.g., accidents, illnesses, deaths) than non-dysphoric participants. However, significant group differences emerged in terms of a mood congruency effect whereby dysphoric participants rated their memories as more negative than non-dysphoric participants. Moreover, the proportion of negatively rated involuntary memories was related to lower mood ratings at the end of the session in the dysphoric but not in the non-dysphoric group. Finally, groups did not differ on several memory characteristics such as vividness, specificity (high in both groups) and rates of rehearsal (low in both groups). Theoretical and practical implications of these findings for research on depression and autobiographical memory are discussed.     

Involuntary autobiographical memories in dysphoric mood: a laboratory study

The frequency and characteristics of involuntary autobiographical memories were compared in 25 stable dysphoric and 28 non-dysphoric participants, using a new laboratory-based task (Schlagman & Kvavilashvili, 2008). Participants detected infrequent target stimuli (vertical lines) in a simple vigilance task and recorded any involuntary autobiographical memories that came to mind, mostly in response to irrelevant words presented on the screen. Dysphoric participants reported involuntary memories as frequently and as quickly as non-dysphoric participants and their memories were not repetitive intrusive memories of negative or traumatic events. Additional content analysis showed that dysphoric participants did not recall more memories of objectively negative events (e.g., accidents, illnesses, deaths) than non-dysphoric participants. However, significant group differences emerged in terms of a mood congruency effect whereby dysphoric participants rated their memories as more negative than non-dysphoric participants. Moreover, the proportion of negatively rated involuntary memories was related to lower mood ratings at the end of the session in the dysphoric but not in the non-dysphoric group. Finally, groups did not differ on several memory characteristics such as vividness, specificity (high in both groups) and rates of rehearsal (low in both groups). Theoretical and practical implications of these findings for research on depression and autobiographical memory are discussed.     

Prism adaptation in schizophrenia

The prism adaptation test examines procedural learning (PL) in which performance facilitation occurs with practice on tasks without the need for conscious awareness. Dynamic interactions between frontostriatal cortices, basal ganglia, and the cerebellum have been shown to play key roles in PL. Disruptions within these neural networks have also been implicated in schizophrenia, and such disruptions may manifest as impairment in prism adaptation test performance in schizophrenia patients. This study examined prism adaptation in a sample of patients diagnosed with schizophrenia (N=91) and healthy normal controls (N=58). Quantitative indices of performance during prism adaptation conditions with and without visual feedback were studied. Schizophrenia patients were significantly more impaired in adapting to prism distortion and demonstrated poorer quality of PL. Patients did not differ from healthy controls on aftereffects when the prisms were removed, but they had significantly greater difficulties in reorientation. Deficits in prism adaptation among schizophrenia patients may be due to abnormalities in motor programming arising from the disruptions within the neural networks that subserve PL.     

Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

Effects of collicular lesions in the hamster during visual discrimination. An analysis from computer-video actograms

Recent reports have suggested that lesions of the superior colliculus may impair the orienting or scanning movements of the head that are thought to serve a key function in visual discrimination. In the present investigation computer-video “actograms” were used to quantify the head movements of freely moving hamsters performing a simultaneous visual discrimination. Hamsters with collicular lesions did not differ from the controls in their head movement spectra, but there was a significant reduction in the incidence of the pauses in locomotion during which these movements are made. Intact animals showed slower and irregular progression interspersed with pauses during which they made scanning movements, whereas collicular hamsters made straighter runs. Although the rate of learning of lesioned hamsters was not impaired, our data strongly suggest that they used different orienting and learning strategies. When tested for the effects of novel stimuli, unrelated to the task, normal hamsters reacted strongly with active exploratory scanning movements, but collicular animals did not, although qualitative changes in their behaviour suggested that the novel stimuli were not being ignored.     

Amnesics Have a Disproportionately Severe Memopry Deficit for Interactive Context

Two experiments were used to compare the recognition memory of amnesic and normal subjects for intentionally encoded words (targets) and for incidentally encoded words that were meaningfully related to the targets and presented at the same time (interactive context). In both experiments the target recognition of the two groups was matched at a high level by presenting the amnesics with much shorter lists of words to remember. Experiment 1 compared 20 amnesics and their matched controls and showed that whereas the amnesics' recognition of the target words did not benefit significantly when they were presented together with their interactive context words (relative to their recognition when the target words were presented alone), that of the controls did. Experiment 2 compared 14 amnesics and their matched controls and showed that when patients and their controls were matched on their target word recognition in isolation, then the patients still showed worse recognition for the interactive context words. These effects were not found only in Korsakoff patients, and their size did not correlate with behavioural measures of frontal-lobe damage. It is concluded that amnesics may be more impaired at recognizing incidentally encoded interactive context than they are at recognizing target material, and this deficit may be an essential feature of the syndrome.     

Influence of positive affect on the subjective utility of gains and losses: it is just not worth the risk

A modification of the procedure originally used by Davidson, Suppes, and Siegel (1956) to measure subjective utility was used to study the influence of positive affect on individuals' perceived value (utility) functions. Results indicated, as expected, that persons in whom positive affect had been induced showed a more negative subjective utility for losses than did controls. This indicates that losses seem worse to people who are feeling happy than to those in a control condition. The subjective utility functions of the two groups did not differ as much, however, when people were considering potential gain. Thus, at least in the situation tested in this study, potential gains did not seem to be more appealing (nor less so) for affect subjects than they did for controls. These findings are discussed in relation to theoretical issues in decision making and work suggesting that positive affect can promote increased sensitivity to losses in situations of potential meaningful loss.     

Autobiographical memories and views of the future: In relation to dysphoria

The present study investigated dysphoric individuals' self‐referential processing of autobiographical memories and future personal events, in relation to specificity and response latency. Dysphoric individuals (n  =  17) and nondysphoric controls (n  =  17) were selected from a larger sample based on self‐reported depression. Participants completed an autobiographical memory task (AMT) and a future event task (FET), using pleasant and unpleasant (anxiety‐relevant, depression‐relevant) emotional word cues. In response to each emotional cue, participants were required to access and write down a specific personal memory and future event, respectively. Consistent with the hypotheses, dysphoric individuals were less specific in describing pleasant and unpleasant experiences (particularly pleasant), irrespective of time condition. As expected, dysphoric individuals' specificity for distinct depression‐relevant and anxiety‐relevant experiences did not differ significantly. As predicted, all participants were less specific in describing future personal events than in recalling personal memories. As predicted, dysphoric individuals took longer to think of pleasant memories and pleasant future experiences than controls but, as expected, groups did not differ significantly on mean reaction times for past and future unpleasant experiences. Overall, the data showed a degree of consistency in participants' past and future‐oriented processing of self‐referential material. Although considerable research has investigated autobiographical memories in relation to emotional disturbance, the present findings suggest that constructing future emotional experiences is also an important aspect of mental health.     

Attention for emotional facial expressions in dysphoria: an eye-movement registration study

Former research demonstrated that depression is associated with dysfunctional attentional processing of emotional information. Most studies examined this bias by registration of response latencies. The present study employed an ecologically valid measurement of attentive processing, using eye-movement registration. Dysphoric and non-dysphoric participants viewed slides presenting sad, angry, happy and neutral facial expressions. For each type of expression, three components of visual attention were analysed: the relative fixation frequency, fixation time and glance duration. Attentional biases were also investigated for inverted facial expressions to ensure that they were not related to eye-catching facial features. Results indicated that non-dysphoric individuals were characterised by longer fixating and dwelling on happy faces. Dysphoric individuals demonstrated a longer dwelling on sad and neutral faces. These results were not found for inverted facial expressions. The present findings are in line with the assumption that depression is associated with a prolonged attentional elaboration on negative information.     

Selective deficit of conceptual structures in aphasia: Class versus thematic relations

Conceptual structures in aphasia were investigated by means of a nonverbal test. The understanding of class and thematic relationships was demonstrated to be selectively impaired according to varieties of aphasic deficit. Broca's aphasics showed difficulty evaluating a thematic relationship and did not differ from normal controls as far as class relationships were concerned. The opposite happened for Wernicke's aphasics whose defect seems to be selectively restricted to class relationships.