Association of retrospective time estimation and severity of cognitive impairment

Introduction. Time perception has an important role in everyday life, but is not commonly measured in clinical routine assessment of suspected cognitive impairment, given the complexity of available assessment methods. Furthermore, evidence on the pattern of retrospective time perception in neurodegenerative diseases is contradictory. Method. We asked 321 patients referred to neuropsychological assessment to retrospectively estimate the duration of the neuropsychological assessment session. We calculated the session actual duration, ratio, and accuracy of response. Patients were grouped into three categories: subjective cognitive impairment, mild cognitive impairment, and mild to moderate dementia. Results. We found an overall tendency for underestimation of time, but no significant differences between groups regarding time estimation. There were significant, but weak, associations between time estimation and severity of cognitive impairment in several domains, with slightly different patterns across groups. Conclusions. Regardless of etiology, the majority of patients underestimated time, which was weakly associated with the severity of cognitive impairment. Global retrospective estimation may be clinically informative, particularly in a minority of extreme cases.     

Temporal Context Actively Shapes EEG Signatures of Time Perception

Our subjective perception of time is optimized to temporal regularities in the environment. This is illustrated by the central tendency effect: When estimating a range of intervals, short intervals are overestimated, whereas long intervals are underestimated to reduce the overall estimation error. Most models of interval timing ascribe this effect to the weighting of the current interval with previous memory traces after the interval has been perceived. Alternatively, the perception of the duration could already be flexibly tuned to its temporal context. We investigated this hypothesis using an interval reproduction task in which human participants (both sexes) reproduced a shorter and longer interval range. As expected, reproductions were biased toward the subjective mean of each presented range. EEG analyses showed that temporal context indeed affected neural dynamics during the perception phase. Specifically, longer previous durations decreased contingent negative variation and P2 amplitude and increased beta power. In addition, multivariate pattern analysis showed that it is possible to decode context from the transient EEG signal quickly after both onset and offset of the perception phase. Together, these results suggest that temporal context creates dynamic expectations which actively affect the perception of duration.SIGNIFICANCE STATEMENT The subjective sense of duration does not arise in isolation, but is informed by previous experiences. This is demonstrated by abundant evidence showing that the production of duration estimates is biased toward previously experienced time intervals. However, it is yet unknown whether this temporal context actively affects perception or only asserts its influence in later, postperceptual stages as proposed by most current formal models of this task. Using an interval reproduction task, we show that EEG signatures flexibly adapt to the temporal context during perceptual encoding. Furthermore, interval history can be decoded from the transient EEG signal even when the current duration was identical. Thus, our results demonstrate that context actively influences perception.     

Clock drawing test in institutionalized patients with schizophrenia compared with Alzheimer's disease patients

The impaired performance of Alzheimer's disease (AD) patients on the clock drawing test (CDT) relative to age-matched normal controls is a well-documented finding in the literature. On the other hand, there is sparse information regarding the use of this test in schizophrenia. We examined three groups of subjects matched for gender and education: institutionalized patients with schizophrenia (n = 32), patients with AD (n = 32), and normal controls (n = 36). The CDT ("free-drawn", "pre-drawn", and three "examiner" conditions) and Mini-Mental State Examination (MMSE) were administered to all participants. In patients with schizophrenia, symptom severity was assessed with the Brief Psychiatric Rating Scale (BPRS). Patients with schizophrenia were significantly younger than AD patients and normal controls (56.78 versus 71.41 and 66.25, respectively), and normal controls had significantly higher MMSE scores than patients with schizophrenia and AD (27.58 versus 20.75 and 18.44, respectively). In all of the clock conditions, the two patient groups performed significantly poorer than the normal controls, with the exception of the "pre-drawn" clock in which AD patients also performed worse than patients with schizophrenia. Age and duration of illness did not correlate significantly with CDT scores. When MMSE scores were used as a covariate, all significant differences on the CDT among the three groups disappeared, with the exception of the "pre-drawn" clock (AD patients had lower scores than both control and schizophrenia groups). In patients with schizophrenia, scores on the BPRS were not related with any CDT variable. Institutionalized patients with schizophrenia and AD patients showed similar deficits on a neuropsychological test sensitive to changes in visual-analytic function, attention, receptive language, and executive functions such as planning, organization, and simultaneous processing.     

Attention and non-REM sleep in neuroleptic-naive persons with schizophrenia and control participants

The relationship between sleep architecture and attentional performance was evaluated in neuroleptic-naive patients with schizophrenia and healthy controls. Participants were recorded in a sleep laboratory for two consecutive nights after which selective and sustained attention performance was tested. In both groups of participants, Spearman's rho statistics revealed a negative correlation between reaction time on the selective attention task and sleep spindle density. Only control participants showed a negative correlation between reaction time and duration of stage 2 sleep and a positive correlation between reaction time and duration of stage 1 ("light") sleep. Only persons with schizophrenia showed a negative correlation between reaction time and duration of stage 4 ("deep") sleep. In the sustained attention task, we found no correlation between reaction time and sleep for control participants while persons with schizophrenia showed a negative correlation between reaction time and duration of stage 4 sleep. It is proposed that EEG sleep spindle activity is associated with automatic attentional processing, while stage 2 sleep continuity in healthy individuals and percentage of stage 4 in patients with schizophrenia are associated with voluntary processes. These results support the existence of a relationship between non-rapid-eye-movement sleep and cognitive performance in healthy individuals as well as in persons with schizophrenia.     

Predictors of treatment utilisation at cognitive remediation groups for schizophrenia: the roles of neuropsychological, psychological and clinical variables

The present study highlights the importance of carefully assessing neuropsychological functioning at the outset of cognitive remediation (CR) treatment. The effects of neuropsychological, psychological, and clinical variables on treatment utilisation (TU) in CR groups for individuals with schizophrenia were examined. Data included neuropsychological and psychosocial assessments conducted with 39 adult clients enrolled in CR as part of their ongoing outpatient therapy. TU was calculated using the percentage of sessions attended over a three-month period. Better global neuropsychological functioning (r = .46, p = .007), attention/working memory (r = .39, p = .03), and processing speed (r = .44, p = .01) were each associated with greater TU. Trend-level associations with TU were observed with executive functioning (r = .33, p = .06) and verbal learning (r = .23; p = .07). Higher rates of self-reported cognitive complaints were associated with lower TU (r = -.45, p = .01). Hierarchical regression analyses revealed that both objective and subjective indicators of neuropsychological functioning independently contributed to the prediction of TU. This information can serve to help providers develop empirically informed strategies to support their clients' CR treatment utilisation. The implications from these findings can be used as a way to provide ongoing guidance for service provision and can aid in improving CR treatment utilisation, and thus treatment effectiveness, in clinical settings.     

Self-evaluation and objective assessment of cognition in major depression and attention deficit disorder: Implications for clinical practice

IntroductionOne of the major challenges associated with the assessment of cognitive functioning in psychiatric populations is the choice of an evaluation tool. Access to cognitive assessment is often limited by issues of expense and by the lengthiness of the testing procedure. As a result, an interest emerged in the development of self-administered questionnaires to assess an individual's perception of their own cognitive functioning. These questionnaires could be more easily used for screening as part of a routine psychiatric consultation. However, few studies have compared the results of the novel subjective measures with established objective tests of cognitive skills, and most have focused on psychopathologies marked by major and apparent cognitive impairments.ObjectiveThe main goal of this study was to investigate the relationship between objective and subjective cognition in patients with major depression (MDD) and attention-deficit/hyperactivity disorder (ADHD) both associated with subtle cognitive impairments on neuropsychological testing.MethodsFirst, we compared the performance of patients with MDD and ADHD to that of healthy controls (HC) on objective and subjective measures of cognition. Then, we evaluated the association between objective and subjective measures of cognitive functioning in the three groups of participants.ResultsPatients with MDD and ADHD performed worse than HC on neuropsychological tests and reported more cognitive difficulties in their daily life. Only a moderate correlation was observed between objective and subjective measures of cognition in individuals with MDD and ADHD. Subjective cognitive measures were more closely correlated with functioning than objective measures.ConclusionThese findings suggest that neuropsychological testing and self-reported scales of cognition are not interchangeable but rather give information about different constructs. The evaluation of cognitive functioning should ideally include both objective and subjective measures of cognition.     

Disruption of temporal processing in a subject with probable frontotemporal dementia

Previous research suggests that the frontal lobes are essential for temporal processing. We report a patient, MN, with probable frontotemporal dementia (FTD) who was tested on a battery of timing tasks with stimuli in the sub- and supra-second range. MN demonstrated a substantial over-estimation and under-production of target intervals on estimation and production tasks respectively but was as accurate as controls on a reproduction task. Furthermore, this deficit was markedly different for auditory and visual stimuli on production and estimation tasks; estimates of the duration of auditory stimuli were three to four times longer than for comparable visual stimuli. She performed normally on a task requiring her to judge whether a stimulus was longer or shorter than a standard duration with both sub- and supra-second stimuli. She performed well on control tasks involving estimation, production and reproduction of line lengths suggesting that her deficits were not attributable to a generalized cognitive impairment or an inability to make magnitude judgments. These data suggest that bifrontal pathology disrupts the "clock" or memory for time.     

Effect of literacy on neuropsychological test performance in nondemented, education-matched elders.

The current investigation compared neuropsychological test performance among nondemented literate and illiterate elders. The sample included participants in an epidemiological study of normal aging and dementia in the Northern Manhattan community. All participants were diagnosed as nondemented by a neurologist, and did not have history of Parkinson's disease, stroke, or head injury. Literacy level was determined by self-report. MANOVAs revealed a significant overall effect for literacy status (literate vs. illiterate) on neuropsychological test performance when groups were matched on years of education. The overall effect of literacy status remained significant after restricting the analyses to elders with no formal education, and after controlling for the effects of language of test administration. Specifically, illiterates obtained lower scores on measures of naming, comprehension, verbal abstraction, orientation, and figure matching and recognition. However tests of verbal list delayed recall, nonverbal abstraction, and category fluency were unaffected by literacy status, suggesting that these measures can be used to accurately detect cognitive decline among illiterate elders in this sample. Differences in organization of visuospatial information, lack of previous exposure to stimuli, and difficulties with interpretation of the logical functions of language are possible factors that contribute to our findings.     

Problems posed by the evaluation of pain and its psychological aspects

Pain is a complex, multidimensional and multifactorial neuropsychological phenomenon with sensory-discriminative, affective, cognitive and behavioral components. Issues on pain assessment are related to the objective evaluation of a subjective phenomenon. Different levels of evaluation are to be considered. Some methods such as visual analog scale, numerical scale and verbal permit a global pain estimation. The aim of other methods such as the McGill Pain Questionnaire is a quantitative and qualitative evaluation of the sensory and affective pain components. The measure of objective behavioral changes is an interesting approach, but at the present time there is no valid, simple and commonly used method. There is also a need for methods permitting better exploration of pain, and in particular a selective evaluation of organic and functional factors. The limits of psychological factor evaluation are reported.     

Subjective well-being,but not subjective mental functioning shows positive associations with neuropsychological performance in schizophrenia-spectrum disorders

Objective

To assess the association of subjective quality of life as measured by the Subjective Well-being under Neuroleptic Treatment questionnaire (SWN-K) with neuropsychological functioning; to address interactions with the SWN-K domain mental functioning as a measure of subjective cognitive dysfunction; and to examine the interaction of subjective well-being and psychopathology ratings.

Methods

Forty-five patients diagnosed with schizophrenia spectrum disorder (SSD) were assessed regarding subjective well-being (SWN-K), neuropsychological impairment, and psychopathology (Brief Psychiatric Rating Scale; BPRS).

Results

After controlling for multiple comparisons, SWN-K total score showed significant positive correlations with concentration/attention (r = .498), working memory (r = .537), verbal memory (r = .522), and global cognition (r = .459). No correlations of SWN mental functioning and neuropsychological impairment remained significant after Bonferroni correction. Correlations between SWN-K subscales and neuropsychological functioning were generally positive, indicating higher subjective well-being in patients with better neurocognition. In multivariate analyses, global cognition was a significant predictor (p = .011), accounting for 19.7% of SWN total score variance. Adding BPRS total score as predictor (p = .054) explained an additional 6.9% of SWN-K variance. Linear regression analyses with SWN-K mental functioning as dependent variable did not yield statistically significant models.

Conclusion

Subjective well-being and objective neuropsychological functioning show only moderate associations and can be seen as largely independent parameters. In particular, subjective mental functioning cannot serve as a proxy for objective neuropsychological testing.     

Cannabis, atropine, and temporal information processing

In experiment 1, subjects judged time by duration production under no-counting instructions. The productions were made following intravenous injection of atropine sulfate or saline, and after smoking cigarettes with and without (-)-delta 9-tetrahydrocannabinol (THC). THC increased the subjective time rate (STR); i.e., the rate at which subjective time passes relative to clock time, whereas atropine had no effect on STR. Thus, reduction in central acetylcholine activity is not a sufficient explanation of THC's effect on STR. Experiment 2 replicated the THC effect on STR when subjects were counting subjective seconds. This result indicates that THC affects the experience of time as it is passing, and not solely the memory for duration experience after a time period.     

The relationship between objective sleep variables and subjective sleep estimation in schizophrenia

AIM: Few investigations of sleep structure in schizophrenia have concentrated on the relationship between objective and subjective sleep variables. The aim of this study was to assess objective sleep variables and subjective estimation of sleep duration and sleep quality. METHODS: Polysomnography was performed in 20 chronic patients with schizophrenia during three consecutive nights. After final awakenings subjects answered questions concerning subjective estimations of sleep duration, sleep latency, number of awakenings, and sleep depth. Pearson correlations between ranged subjective reports and objective sleep variables were performed. RESULTS: The results showed a high positive correlation between objective sleep latency and its subjective estimation; a positive correlation between subjective estimation of sleep depth and percentage of slow wave sleep (SWS%); a positive correlation between eye movement (EM) density and subjective estimation of wakefulness during the night; and a negative correlation between EM density and dream reports. CONCLUSION: We concluded that objective sleep variables are related to subjective sleep estimation in schizophrenic patients. In these patients, EM activity in REM sleep is related to the subjective feeling of wakefulness. (Int J Psych Clin Pract 2000; 4:63-67)     

Correlation of neuropsychological evaluation and SPECT imaging in patients with Alzheimer's disease

BACKGROUND: Mini-Mental State Examination (MMSE) is a very useful tool for diagnosing changes in cognitive functions by the general practitioner or other medical staff who is not familiar with neuropsychological tests. On the other hand, HMPAO brain SPECT has been shown to have a high sensitivity to detect neurodegenerative processes, which lead to dementia. The correlation between both methods is unknown. We compared both methods in order to find a rational evaluation tool for the practitioner to obtain a higher efficacy and cost effective way of using both methods. PATIENTS AND METHODS: Fifty-one patients diagnosed as having Alzheimer's disease (AD) were examined. Each patient underwent MMSE analysis, as well as HMPAO brain SPECT. The severity of SPECT abnormalities was categorized into mild, moderate and severe. Statistical analysis was performed in order to evaluate the correlation between imaging findings and neuropsychological testing. RESULTS: Marginal inverse correlation was found between global MMSE SPECT imaging on right and left side (p = 0.05) and the left temporal region (p = 0.05). MMSE subgroup component of orientation was highly significantly inversely associated with SPECT imaging of right and left frontal region (p > 0.0001). The MMSE subgroup of immediate memory was significantly correlated to left and right temporal regions (p = 0.001 and p = 0.002 respectively). Age was not significantly correlated to global MMSE or any of its subtest components. CONCLUSION: MMSE score has no linear correlation to SPECT perfusion findings. In cases of abnormal orientation score subgroup SPECT imaging is not recommended. In most instances, a combination of both methods should be employed by the general practitioner for further evaluation of dementia.     

Time perception of simultaneous and sequential events in early-onset schizophrenia

ABSTRACT

Timing disorders in schizophrenia are a well-known phenomenon. However, no studies have yet assessed the role of temporal distortions in early-onset schizophrenia (EOS), despite evidence that distorted time perception may share genetic risk factors with schizophrenia and may be a useful indicator in identifying individuals at risk for schizophrenia. In the present study, we investigated the ability of 10 patients with EOS (mean age = 21.5 years, SD = 6) matched with 20 healthy control participants (mean age = 25.3 years, SD = 4.6) in order to compare the durations of two visual events, presented either sequentially or overlapping in time, along with neuropsychological assessments of attention, working memory, and executive functions. Each participant had to judge a total of 336 stimuli. We found that temporal overlap had a greater negative effect on ability to judge the duration of a pair of stimuli in EOS patients than in healthy control participants. In addition, EOS patients showed impairments in attention and executive functions. Furthermore, in EOS patients, the scores for executive and attentional functions were significantly correlated with accuracy of temporal estimation in the overlap condition (r = 0.31, p < 0.05 and r = 0.57, p < 0.05, respectively). These preliminary results suggest that impairments in neuropsychological functions participate in the deficit in time estimation observed in patients with EOS. These conclusions highlight the importance of testing time perception in patients with EOS and could contribute to the development of cognitive remediation-based therapy for these patients.     

Explicit Time Deficit in Schizophrenia: Systematic Review and Meta-Analysis Indicate It Is Primary and Not Domain Specific

Although timing deficits are a robust finding in schizophrenia (SZ), the notion of a genuine time perception disorder in SZ is still being debated because distortions in timing might depend on neuropsychological deficits that are characteristics of the illness. Here we used meta-analytic methods to summarize the evidence of timing deficits in SZ and moderator analyses to determine whether defective timing in SZ arises from nontemporal sources or from defective time perception. PubMed Services, PsycNET, and Scopus were searched through March 2015, and all references in articles were investigated to find other relevant studies. Studies were selected if they included subjects with a primary diagnosis of SZ compared to a healthy control (HC) group and if they reported behavioral measures of duration estimation (perceptual and motor explicit timing). Data from 24 studies published from 1956 to 2015, which comprised 747 SZ individuals and 808 HC, were included. Results indicate that SZ individuals are less accurate than HC in estimating time duration across a wide range of tasks. Subgroup analyses showed that the fundamental timing deficit in SZ is independent from the length of the to-be-timed duration (automatic and cognitively controlled timing) and from methods of stimuli estimation (perceptual and motor timing). Thus, time perception per se is disturbed in SZ (not just task-specific timing processes) and this perturbation is independent from more generalized cognitive impairments. Behavioral evidence of disturbed automatic timing should be more thoroughly investigated with the aim of defining it as a cognitive phenotype for more homogeneous diagnostic subgrouping.Key words: schizophrenia, timing, cognitive deficits, meta-analysis

“Perception of the world consists of a hierarchy of dimensions and time occupies the highest level of that hierarchy.” Navon, 1978.

     

Clock drawing test: correlation with linear measurements of CT studies in demented patients

OBJECTIVES. To investigate a presumed correlation between clock drawing ratings and linear measurements of computerized tomography (CT) studies in demented patients. DESIGN. Blinded evaluations of clock drawing tests and CT studies of elderly dementia patients were conducted by a geriatric psychiatrist and a neuroradiologist. SUBJECTS. Fifty-one community-dwelling elderly subjects meeting the criteria for DSM-IV diagnosis of dementia (Alzheimer's type dementia: N=31; vascular dementia: N=15; "mixed" type dementia: N=5). MATERIALS. Mini-Mental State Examination (MMSE), Cambridge Cognitive Examination (CAMCOG), Clinical Dementia Rating (CDR). CAMCOG derived scored clock drawings were evaluated using adaptations of Shulman et al.'s and Freedman et al.'s methods. CT studies were evaluated using six different linear measurements of brain atrophy described in the literature. RESULTS. Of the CT linear measurements, only the Cerebro-Ventricular Index-2 (CVI-2; bicaudate index) significantly correlated with clock drawing ratings (CAMCOG's clock r=-0.407, p=0.003; Shulman's method r=0.357, p=0.01, Freedman's method r=-0.413, p=0.003) in the dementia group. There was no significant correlation between CVI-2 with demographic (age), cognitive (MMSE, CAMCOG) and clinical (duration of illness, CDR) ratings. Alzheimer's patients generally maintained a significant correlation between CVI-2 and clock drawings, but vascular dementia patients did not; CVI-2 also correlated significantly with the Praxis subtest of the CAMCOG in dementia and Alzheimer's patients but not in the vascular dementia group. Similarly, multiple stepwise regression analysis showed that only CVI-2 but not the other radiological measures studied, was selected as the significant variable to correlated with clock drawing test ratings in the dementia group and Alzheimer's patients. Partial correlation analysis controlling for demographic and clinical variables shows that controlled variables had no significant effect on the relationship between clock drawing ratings and CVI-2. CONCLUSION. A single and easy to perform measure of caudate atrophy correlates specifically and consistently with impairments revealed in the clock drawing test and with a Praxis subtest, suggesting possible caudate involvement with clock drawings in dementia in general and of the Alzheimer's type in particular.     

The Contribution of Prospective Memory Performance to the Neuropsychological Assessment of Mild Cognitive Impairment

Objective: Prospective memory difficulties are a feature of the amnestic form of mild cognitive impairment (aMCI). Although comprehensive test batteries of prospective memory are suitable for clinical practice, they are lengthy, which has detracted from their widespread clinical use. Our aim was to investigate the utility of a brief screening measure of prospective memory, which can be incorporated into a clinical neuropsychological assessment. Methods: Seventy-seven healthy older adults (HOA) and 77 participants with aMCI were administered a neuropsychological test battery, including a prospective memory screening measure (Envelope Task), a retrospective memory measure (CVLT-II), and a multi-item subjective memory questionnaire (Prospective and Retrospective Memory Questionnaire; PRMQ) and a single-item subjective memory scale. Results: Compared with HOA participants, participants with aMCI performed poorly on the Envelope Task (η² = .38), which provided good discrimination of the aMCI and HOA groups (AUC = .83). In the aMCI group, there was a small but significant relationship between the Envelope Task and the single-item subjective rating of memory, with the Envelope Task accounting for 5–6% of the variance in subjective memory after accounting for emotional status. This relationship of prospective memory and subjective memory was not significant for the multi-item questionnaire (PRMQ); and, retrospective memory was not a significant predictor of self-rated memory, single-item, or multi-item. Conclusion: A brief screening measure of prospective memory, the Envelope Task, provides useful support to traditional memory measures in detecting aMCI.     

The Working Memory Questionnaire: A scale to assess everyday life problems related to deficits of working memory in brain injured patients

The objective of the present study was to develop a scale designed to assess the consequences of working memory deficits in everyday life. The Working Memory Questionnaire (WMQ) is a self-administered scale, addressing three dimensions of working memory: short-term storage, attention, and executive control. The normative sample included 313 healthy participants. The patient group included 69 brain injured patients, who were compared to a subsample of 69 matched healthy controls. The questionnaire was found to have a good internal consistency, both in healthy participants and in patients with brain injury (Cronbach's alpha?=?.89 and .94, respectively). In healthy participants, significant effects of age (p?相似文献   

Disturbed egocentric space representation in cervical dystonia.

In addition to visual spatial input, vestibular and proprioceptive signals are used in judging the egocentric space. We asked whether the abnormal head posture of patients with cervical dystonia (CD) is associated with distortions of their internal spatial reference frame. The perception of subjective straight-ahead (SSA) was tested under various conditions in 28 CD patients and in matched controls. They were asked to direct a laser pointer to the position that they believed to be "straight ahead" relative to their bodies' orientation (body-centered spatial perception). Body-independent visual spatial perception was assessed with different neuropsychological tests. CD patients had a greater deviation of the subjective straight ahead, indicating body-centered visual spatial perception, than controls. No effects were seen in body-independent visual spatial perception. Patients with CD are impaired in body-centered, egocentric spatial perception, but not in body-independent, allocentric spatial perception.     

Towards a neuropsychology of autonomy: re-presenting forgetting,subliminality and freedom

Recent neurobiological concepts about sensomotor processes in animals exhibit that voluntary motor behavior is not due primarily to external cues but to internal activation-processes ("initial activity"). Thus questions are raised as to the role of internal "limbic" valuation-processes in relation to contexts of the past. These are not limited to the actual memorial contents but also relate to subliminal aspects of the past. The inclusion of processes of "re-presenting forgetting" means a re-evaluation of autonomy within a neuropsychological theory of freedom. Consequently, subjective freedom may be realized by intrapsychic processes of re-presentation of the past.