Stronger tilt aftereffects in persons with schizophrenia.
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ABSTRACT:
SUBMITTER: Thakkar KN
PROVIDER: S-EPMC8100990 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Recent studies have shown that a variety of aftereffects occurs in a non-retinotopic frame of reference. These findings have been taken as strong evidence that remapping of visual information occurs in a hierarchic manner in the human cortex with an increasing magnitude from early to higher levels. Other studies, however, failed to find non-retinotopic aftereffects. These experiments all relied on paradigms involving eye movements. Recently, we have developed a new paradigm, based on the Ternus-Pikler display, which tests retinotopic vs. non-retinotopic processing without the involvement of eye movements. Using this paradigm, we found strong evidence that attention, form, and motion processing can occur in a non-retinotopic frame of reference. Here, we show that motion and tilt aftereffects are largely retinotopic.
| S-EPMC3277859 | biostudies-literature
Project description:It has remained unclear what factors relate to primary nonadherence to antipsychotic treatment and whether specific agents and routes of administration differ in how patients adhere to them. We collected electronic prescriptions and their dispensings from the Finnish electronic prescription database for 29 956 patients with schizophrenia prescribed antipsychotics via electronic prescription during 2015-2016. We defined primary nonadherence as being prescribed an antipsychotic, which was not dispensed from the pharmacy within one year from prescription. Using logistic regression, we analyzed whether several sociodemographic and clinical factors related to nonadherence. We found that 31.7% (N = 9506) of the patients demonstrated primary nonadherence to any of their prescribed antipsychotics. We found that young age (OR = 1.77, 95%CI = 1.59-1.96), concomitant benzodiazepines (OR = 1.47, 95%CI = 1.40-1.55) and mood stabilizers (OR = 1.29, 95%CI = 1.21-1.36), substance abuse (OR = 1.26 95%CI = 1.19-1.35), previous suicide attempt (OR = 1.21, 95%CI = 1.11-1.31), diabetes (OR = 1.15, 95%CI = 1.06-1.25), asthma/COPD (OR = 1.14, 95%CI = 1.04-1.25), and cardiovascular disease (OR = 1.12, 95%CI = 1.05-1.19), were related to primary nonadherence to antipsychotic treatment. Patients using clozapine showed the lowest nonadherence (4.77%, 95%CI = 4.66-4.89), and patients using long-acting injectables were more adherent to treatment (7.27%, 95%CI = 6.85-7.71) when compared to respective oral agents (10.26%, 95%CI = 10.02-10.49). These results suggest that selection between different pharmacological agents and routes of administration while taking into account patients' concomitant medications (benzodiazepines in particular) and comorbidities play a key role in primary nonadherence to antipsychotic treatment.
| S-EPMC9077427 | biostudies-literature
Project description:ObjectiveThe aim of this study was to identify factors associated with acceptability and efficacy of yoga training (YT) for improving cognitive dysfunction in individuals with schizophrenia (SZ).MethodsWe analysed data from two published clinical trials of YT for cognitive dysfunction among Indians with SZ: (1) a 21-day randomised controlled trial (RCT, N = 286), 3 and 6 months follow-up and (2) a 21-day open trial (n = 62). Multivariate analyses were conducted to examine the association of baseline characteristics (age, sex, socio-economic status, educational status, duration, and severity of illness) with improvement in cognition (i.e. attention and face memory) following YT. Factors associated with acceptability were identified by comparing baseline demographic variables between screened and enrolled participants as well as completers versus non-completers.ResultsEnrolled participants were younger than screened persons who declined participation (t = 2.952, p = 0.003). No other characteristics were associated with study enrollment or completion. Regarding efficacy, schooling duration was nominally associated with greater and sustained cognitive improvement on a measure of facial memory. No other baseline characteristics were associated with efficacy of YT in the open trial, the RCT, or the combined samples (n = 148).ConclusionsYT is acceptable even among younger individuals with SZ. It also enhances specific cognitive functions, regardless of individual differences in selected psychosocial characteristics. Thus, yoga could be incorporated as adjunctive therapy for patients with SZ. Importantly, our results suggest cognitive dysfunction is remediable in persons with SZ across the age spectrum.
| S-EPMC8113063 | biostudies-literature
Project description:Current views on multisensory motion integration assume separate substrates where visual motion perceptually dominates tactile motion [1, 2]. However, recent neuroimaging findings demonstrate strong activation of visual motion processing areas by tactile stimuli [3-6], implying a potentially bidirectional relationship. To test the relationship between visual and tactile motion processing, we examined the transfer of motion aftereffects. In the well-known visual motion aftereffect, adapting to visual motion in one direction causes a subsequently presented stationary stimulus to be perceived as moving in the opposite direction [7, 8]. The existence of motion aftereffects in the tactile domain was debated [9-11], though robust tactile motion aftereffects have recently been demonstrated [12, 13]. By using a motion adaptation paradigm, we found that repeated exposure to visual motion in a given direction produced a tactile motion aftereffect, the illusion of motion in the opponent direction across the finger pad. We also observed that repeated exposure to tactile motion induces a visual motion aftereffect, biasing the perceived direction of counterphase gratings. These crossmodal aftereffects, operating both from vision to touch and from touch to vision, present strong behavioral evidence that the processing of visual and tactile motion rely on shared representations that dynamically impact modality-specific perception.
| S-EPMC3398123 | biostudies-literature
Project description:Although the default state of the world is that we see and hear other people talking, there is evidence that seeing and hearing ourselves rather than someone else may lead to visual (i.e., lip-read) or auditory "self" advantages. We assessed whether there is a "self" advantage for phonetic recalibration (a lip-read driven cross-modal learning effect) and selective adaptation (a contrastive effect in the opposite direction of recalibration). We observed both aftereffects as well as an on-line effect of lip-read information on auditory perception (i.e., immediate capture), but there was no evidence for a "self" advantage in any of the tasks (as additionally supported by Bayesian statistics). These findings strengthen the emerging notion that recalibration reflects a general learning mechanism, and bolster the argument that adaptation depends on rather low-level auditory/acoustic features of the speech signal.
| S-EPMC6440388 | biostudies-literature
Project description:Schizophrenia has long been framed as a disorder of altered brain connectivity, with dysfunction in thalamocortical circuity potentially playing a key role in the development of the illness phenotype, including psychotic symptomatology and cognitive impairments. There is emerging evidence for functional and structural hypoconnectivity between thalamus and prefrontal cortex in persons with schizophrenia spectrum disorders, as well as hyperconnectivity between thalamus and sensory and motor cortices. However, it is unclear whether thalamocortical dysconnectivity is a general marker of vulnerability to schizophrenia or a specific mechanism of schizophrenia pathophysiology. This study aimed to answer this question by using diffusion-weighted imaging to examine thalamocortical structural connectivity in 22 persons with schizophrenia or schizoaffective disorder (SZ), 20 siblings of individuals with a schizophrenia spectrum disorder (SIB), and 44 healthy controls (HC) of either sex. Probabilistic tractography was used to quantify structural connectivity between thalamus and six cortical regions of interest. Thalamocortical structural connectivity was compared among the three groups using cross-thalamic and voxel-wise approaches. Thalamo-prefrontal structural connectivity was reduced in both SZ and SIB relative to HC, while SZ and SIB did not differ from each other. Thalamo-motor structural connectivity was increased in SZ relative to SIB and HC, while SIB and HC did not differ from each other. Hemispheric differences also emerged in thalamic connectivity with motor, posterior parietal, and temporal cortices across all groups. The results support the hypothesis that altered thalamo-prefrontal structural connectivity is a general marker of vulnerability to schizophrenia, whereas altered connectivity between thalamus and motor cortex is related to illness expression or illness-related secondary factors.
| S-EPMC7451425 | biostudies-literature
Project description:We examined the status of the neural network mediating the default mode of brain function, which typically exhibits greater activation during rest than during task, in patients in the early phase of schizophrenia and in young first-degree relatives of persons with schizophrenia. During functional MRI, patients, relatives, and controls alternated between rest and performance of working memory (WM) tasks. As expected, controls exhibited task-related suppression of activation in the default network, including medial prefrontal cortex (MPFC) and posterior cingulate cortex/precuneus. Patients and relatives exhibited significantly reduced task-related suppression in MPFC, and these reductions remained after controlling for performance. Increased task-related MPFC suppression correlated with better WM performance in patients and relatives and with less psychopathology in all 3 groups. For WM task performance, patients and relatives had greater activation in right dorsolateral prefrontal cortex (DLPFC) than controls. During rest and task, patients and relatives exhibited abnormally high functional connectivity within the default network. The magnitudes of default network connectivity during rest and task correlated with psychopathology in the patients. Further, during both rest and task, patients exhibited reduced anticorrelations between MPFC and DLPFC, a region that was hyperactivated by patients and relatives during WM performance. Among patients, the magnitude of MPFC task suppression negatively correlated with default connectivity, suggesting an association between the hyperactivation and hyperconnectivity in schizophrenia. Hyperactivation (reduced task-related suppression) of default regions and hyperconnectivity of the default network may contribute to disturbances of thought in schizophrenia and risk for the illness.
| S-EPMC2633557 | biostudies-literature
Project description:Radiologists must classify and interpret medical images on the basis of visual inspection. We examined how the perception of radiological scans might be affected by common processes of adaptation in the visual system. Adaptation selectively adjusts sensitivity to the properties of the stimulus in current view, inducing an aftereffect in the appearance of stimuli viewed subsequently. These perceptual changes have been found to affect many visual attributes, but whether they are relevant to medical image perception is not well understood. To examine this we tested whether aftereffects could be generated by the characteristic spatial structure of radiological scans, and whether this could bias their appearance along dimensions that are routinely used to classify them. Measurements were focused on the effects of adaptation to images of normal mammograms, and were tested in observers who were not radiologists. Tissue density in mammograms is evaluated visually and ranges from "dense" to "fatty." Arrays of images varying in intermediate levels between these categories were created by blending dense and fatty images with different weights. Observers first adapted by viewing image samples of dense or fatty tissue, and then judged the appearance of the intermediate images by using a texture matching task. This revealed pronounced perceptual aftereffects - prior exposure to dense images caused an intermediate image to appear more fatty and vice versa. Moreover, the appearance of the adapting images themselves changed with prolonged viewing, so that they became less distinctive as textures. These aftereffects could not be accounted for by the contrast differences or power spectra of the images, and instead tended to follow from the phase spectrum. Our results suggest that observers can selectively adapt to the properties of radiological images, and that this selectivity could strongly impact the perceived textural characteristics of the images.
| S-EPMC3795775 | biostudies-literature
Project description:Perceptual judgements are, by nature, a product both of sensation and the cognitive processes responsible for interpreting and reporting subjective experiences. Changed perceptual judgements may thus result from changes in how the world appears (perception), or subsequent interpretation (judgement). This ambiguity has led to persistent debates about how to interpret changes in decision-making, and if higher-order cognitions can change how the world looks, or sounds, or feels. Here we introduce an approach that can help resolve these ambiguities. In three motion-direction experiments, we measured perceptual judgements and subjective confidence. We show that each measure is sensitive to sensory information and can index sensory adaptation. Each measure is also sensitive to decision biases, but response bias impacts the central tendency of decision and confidence distributions differently. Our findings show that subjective confidence, when measured in addition to perceptual decisions, can supply important diagnostic information about the cause of aftereffects.
| S-EPMC6509108 | biostudies-literature
Project description:BackgroundAssociations between dizziness-related handicap and a variety of self-reported measures have been reported. However, research regarding associations between dizziness-related handicap and aspects of functioning that includes both physical tests and self-reported measures is scarce.ObjectiveThe purpose of the study was to describe the variations in signs and symptoms in people with persistent dizziness using physical tests and self-reported outcomes across three severity levels of the Dizziness Handicap Inventory (DHI) and investigate their associations with the DHI.MethodParticipants with persistent dizziness (n = 107) were included in this cross-sectional study. The participants underwent (1) physical tests (gait tests, grip strength, body flexibility, and movement-induced dizziness) and completed questionnaires regarding (2) psychological measures (Mobility Inventory of Agoraphobia, Body Sensation Questionnaire, Agoraphobic Cognitions Questionnaire, and Hospital Depression and Anxiety Questionnaire), and (3) fatigue, dizziness severity, and quality of life (Chalders Fatigue Scale, Vertigo Symptom Scale-Short Form, and EQ visual analog scale), in addition to the DHI. Data were presented by descriptive statistics for three DHI severity levels (mild, moderate, and severe). A multiple linear backward regression analysis was conducted for each group of measures in relation to the DHI total score, with additional analyses adjusting for age and sex. Based on these results, significant associations were tested in a final regression model.ResultsWith increasing severity levels of DHI, the participants demonstrated worse performance on most of the physical tests (preferred and fast gait velocity, dizziness intensity after head movements), presented with worse scores on the self-reported measures (avoidance behavior, fear of bodily sensation, fear of fear itself, psychological distress, fatigue, dizziness severity, quality of life). After adjusting for age and sex, significant associations were found between total DHI and avoidance behavior, psychological distress, dizziness severity, and quality of life, but not with any of the physical tests, explaining almost 56% of the variance of the DHI total score.ConclusionThere was a trend toward worse scores on physical tests and self-reported measurements with increasing DHI severity level. The DHI seems to be a valuable tool in relation to several self-reported outcomes; however, several signs and symptoms may not be detected by the DHI, and thus, a combination of outcomes should be utilized when examining patients with persistent dizziness.
| S-EPMC9334819 | biostudies-literature