Exploring Relation between Cognitive Perceptual Deficits and Functional Performance in Schizophrenia- A Mini Review

Schizophrenia is a serious mental illness that affects how a person thinks, feels and behaves. People with schizophrenia may seem like they have lost touch with reality, which causes significant distress for the individual, their family members and friends. If left untreated, symptoms of schizophrenia can be persistent and disabling. Cognitive perceptual impairment is a core feature of schizophrenia and several studies have demonstrated that it is strongly related with daily functioning and other functional outcomes. Several RCTs have demonstrated that patients with schizophrenia improve negative symptomatology after cognitive rehabilitation. The prevalence of schizophrenia affects patient’s participation in functional tasks. The aim of this review was to explore literature; published in the past 15 years in the area of cognitive perceptual deficits in schizophrenia and functional impairments caused due to it. We also explored the strategies for remediation. In this integrated mini review, published researches were reviewed including RCTs, observational studies, interventional , experimental, correlational studies, case reports and systematic reviews. To conclude, it was analyzed that dysfunctions in working memory, attention and abstract thinking and problem solving have been extensively documented in schizophrenia, which may improve slightly with remedial strategies.

Self-Perception of the Knee Is Associated with Joint Motion during the Loading Response in Individuals with Knee Osteoarthritis: A Pilot Cross-Sectional Study

Small knee flexion motion is a characteristic of gait in individuals with knee osteoarthritis. This study examined the relationship between knee flexion excursion in loading response and knee self-perception in individuals with knee osteoarthritis. Twenty-one individuals with knee osteoarthritis participated in this study. Knee flexion excursions in loading response while walking at a comfortable and a fast-walking speed were measured using an inertial measurement unit-based motion capture system. The degree of knee perceptual impairment was evaluated using the Fremantle Knee Awareness Questionnaire (FreKAQ). The relationships between the FreKAQ score and gait variables and knee function were evaluated by calculating the correlation coefficient. The unique contributions of knee self-perception and muscle strength to knee flexion excursion in loading response were analyzed using hierarchical linear regression. Knee self-perception was significantly correlated with pain during walking, muscle strength and knee flexion excursion at fast speed. In the fast speed condition only, impaired knee self-perception was inversely proportional to knee flexion excursion and accounted for 21.8% of the variance in knee flexion excursion. This result suggests that impaired self-perception of the knee may help to explain the decrease in the knee flexion excursion in the loading response in individuals with knee osteoarthritis.

Influence of Alcohol and Cognitive Capacity on Visual Number Judgements

We used an enumeration task to address the question of whether acute alcohol intoxication reduces cognitive or perceptual capacity. To control for individual differences in cognitive resources, we took a sober record of each participant’s working memory capacity (WMC). Alcohol was expected to impair enumeration performance, either for the automatic parallel counting of small stimulus sets indicating a perceptual impairment, or the controlled counting or estimating of larger sets indicating a cognitive impairment. Enumeration showed an overall decline in accuracy following a vodka beverage and the deficit was negligible for small sets, which is inconsistent with a loss of perceptual capacity. Having a higher WMC facilitated the enumeration of larger sets and the correlation between WMC and accuracy was stronger in the alcohol condition suggesting that low-WMC participants were more impaired by the beverage. Our findings therefore suggest that alcohol diminished cognitive rather than perceptual capacity.

The Performance of Visual Perceptual Tasks in Patients with Schizotypal Personality Disorder

Background. The most significant features for clinical diagnosis of schizotypal personality disorder (SPD) are cognitive-perceptual and disorganized symptoms. Experimental study of visual perceptual processes is important to elucidate the psychological mechanisms of cognitive-perceptual impairment in SPD. Objective. To research the performance of visual perceptual tasks in SPD. Design. Series I and II presented the subjects with visual perceptual tasks with different types of instructions (vague, verbal, or visual perceptual cues). The Wechsler Adult Intelligence Scale (WAIS-R) was also administered. The participants were 39 SPD patients, 36 obsessive-compulsive personality disorder (OCPD) patients (F.21.8, F.60.5 in ICD-10, respectively), and 102 healthy controls. Results. SPD patients had a significantly lower number of correct answers in conditions of vague instruction and verbal cues in Series I of a visual-perceptual task in comparison with healthy subjects (р ≤ 0.01). With visual perceptual cues in Series II, patients with SPD had the same number of correct answers as controls, whereas OCPD patients had the same number of correct answers as controls with verbal cues in Series I. SPD patients had significantly lower scores in most verbal and nonverbal WAIS-R subtests in comparison with controls. SPD patients differed from OCPD patients in that they had lower scores in the “Information” (p ≤ 0.05) and “Comprehension” (p ≤ 0.05) subtests. Conclusion. With visual-perceptual cues, SPD patients were able to achieve normative results in the performance of visual-perceptual tasks, whereas patients with OCPD demonstrated lower productivity. In SPD patients, the basic impairments were associated with difficulties in inhibition of peculiar responses, stability of a subjective manner of performance and inability to revise it, low orientation to the model, and slipping into subjective associations with the stimuli.

Attention Interacts With Emotion to Drive Perceptual Impairment of Images in an RSVP Task

Emotion Induced Blindness (EIB) is characterized by an impairment in the detection of a neutral target image when it appears between 100-500ms after the presentation of an emotional image. EIB has been argued to be an early level perceptual impairment resulting from spatio-temporal competition between the neutral target and the emotional distractor. While the role of attentional processes is implied in EIB, there hasn’t been a systematic comparison between EIB and Attentional Blink (AB) concerning the locus of attentional control. That is, in most of the AB studies, participants are required to identify and report T1 while in EIB studies they are asked to ignore the emotional distractor. Hence, the differences between AB and EIB may stem from this difference in attentional control. In Expt. 1 and Expt. 2 participants were asked to report two targets in an RSVP stream and we found similar impairment in both the experiments, irrespective of the emotional nature of the target. However, in Expt. 3 and 4 where participants were required to report only one target, only the emotional distractor captured attention, leading to an impairment in target detection. Our result shows that target impairment in EIB is due to the exogenous attentional allocation to the emotional image. i.e., distractor image being emotionally salient captures attention in a bottom-up manner leading to the impairment in the less salient target.

Congenital Amusia: Understanding of the musical mind and brain

Congenital amusia, commonly known as tone-deaf, is a developmental disorder that affects small population. The current paper aims to provide a comprehensive review of some of the recent researches on congenital amusia, demonstrating how the behavioural, brain-imaging, and genetic studies have extended our understanding of the musical mind and brain; additionally, identifies gaps in the literature and suggests future research directions. Previous behavioural experiments and neurological studies argued that the deficit is congenital and arise from perceptual impairment in hearing fine-grained pitch, while genetic evidence lacked to pin point specific genes that are involved. Nevertheless, new studies show that the deficit may be improved through training, suggesting amusia may not be congenital after all.

Continuous flash suppression and monocular pattern masking impact subjective awareness similarly

Peters & Lau (2015) found that when criterion bias is controlled for, there is no evidence for unconscious visual perception in normal observers, in the sense that they cannot directly discriminate a target above chance without knowing it. One criticism of that study is that the visual suppression method used, forward and backward masking (FBM), may be too blunt in the way it interferes with visual processing to allow for unconscious forced-choice discrimination. To investigate this question we compared FBM directly to continuous flash suppression (CFS) in a two-interval forced choice task. Although CFS is popular, and may be thought of as a more powerful visual suppression technique, we found no difference in the degree of perceptual impairment between the two suppression types. To the extent that CFS impairs perception, both objective discrimination and subjective awareness are impaired to similar degrees under FBM. This pattern was consistently observed across 3 experiments in which various experimental parameters were varied. These findings provide evidence for an ongoing debate about unconscious perception: normal observers cannot perform forced-choice discrimination tasks unconsciously.

What rhythmic perception and amusia can tell us about vocal social communication in schizophrenia

ABSTRACTBackgroundPerceiving social intent throughvocal intonation is impaired in schizophrenia; thisdysprosodia partly arisingfrom impaired pitch perception.Individuals with amusia (tone-deafness) are insensitive to pitch change andalso demonstrate prosody deficits. Sensitivity to rhythm is reduced in amusia when tonal sequences contain pitch changes (polytonic), but is normal for monotonic sequences, suggesting perceptual impairment originates at a secondary processing stage where pitch- and time-relatedcues are yoked. Here, we sought to ascertain: 1) whether schizophreniapatients demonstrate rhythmic deficits, 2) whether suchdeficits are restricted to polytonic sequences, and 3) how pitch and rhythm perception relate to prosodic processing.MethodsSeventy-sixparticipants (33 schizophrenia) completed tasks assessing pitch and prosody perception, as well as monotonic and polytonic rhythmic perception.ResultsIncreasing tone-deafness correlated with pitch-dependent rhythm detection impairments. Pitch and prosody correlated across all participants. Schizophreniapatients displayed basic time and pitch deficits. Correlations and path analyses indicated prosodic processing is an associatedfunction of pitch and pitch-dependent rhythm perception,with pure temporal processing playing an indirect role.In schizophrenia, deficits in monotonic and polytonic rhythmic perception did not contribute to prosodic processing dysfunction, and montonic rhythmic dysfunction and pitch perception did not covary.ConclusionsExploring similarities between amusia and schizophrenia focused our characterization of prosodic processing as the function of sub-processes reflecting pitch and time perception,whichare prerequisite for prosodic processing. The uniqueness of dysprosodia in schizophrenia relative to other illnesses may be measured by idiosyncrasy in the pattern and magnitude of the sub-process task relationships.

Perceptual impairment in face identification with poor sleep

Previous studies have shown impaired memory for faces following restricted sleep. However, it is not known whether lack of sleep impairs performance on face identification tasks that do not rely on recognition memory, despite these tasks being more prevalent in security and forensic professions—for example, in photo-ID checks at national borders. Here we tested whether poor sleep affects accuracy on a standard test of face-matching ability that does not place demands on memory: the Glasgow Face-Matching Task (GFMT). In Experiment 1, participants who reported sleep disturbance consistent with insomnia disorder show impaired accuracy on the GFMT when compared with participants reporting normal sleep behaviour. In Experiment 2, we then used a sleep diary method to compare GFMT accuracy in a control group to participants reporting poor sleep on three consecutive nights—and again found lower accuracy scores in the short sleep group. In both experiments, reduced face-matching accuracy in those with poorer sleep was not associated with lower confidence in their decisions, carrying implications for occupational settings where identification errors made with high confidence can have serious outcomes. These results suggest that sleep-related impairments in face memory reflect difficulties in perceptual encoding of identity, and point towards metacognitive impairment in face matching following poor sleep.

TOWARDS WEB-BASED VISUAL TRAINING

To an extent, vision is a function that can be learned. Broadly speaking, this learning -named visual perceptive development, takes place spontaneously. Nevertheless, it is not the case of a significant number of children who, due to their visual or perceptual impairment, have difficulties either receiving or processing visual stimuli from their environment. In this case, Visual Stimulation programs should be applied to these people so that their visual functions can be developed.The advances developed in last two decades on information and communication technologies, ICT, are not reflected in the existing software tools for the field. As a contribution to solve this problem, we have designed and developed an Interactive Educational System supported on a web platform with the main aim to provide professionals the required mechanisms to perform the basic Visual Stimulation tasks. At the same time, it takes advantage of the several opportunities offered by the Internet. In this paper, we analyze the limitations of previous existing tools and present EVIN (Visual Stimulation on the Internet). The main objective of the EVIN project is the development of a web platform which exploits the potential of ICT along with the experience gained by low vision professionals.