An AI-empowered indoor digital contact tracing system for COVID-19 outbreaks in residential care homes

An AI-empowered indoor digital contact-tracing system was developed using a centralized architecture and advanced low-energy Bluetooth technologies for indoor positioning, with careful preservation of privacy and data security. We analyzed the contact pattern data from two RCHs and investigated a COVID-19 outbreak in one study site. To evaluate the effectiveness of the system in containing outbreaks with minimal contacts under quarantine, a simulation study was conducted to compare the impact of different quarantine strategies on outbreak containment within RCHs. The significant difference in contact hours between weekdays and weekends was observed for some pairs of RCH residents and staff during the two-week data collection period. No significant difference between secondary cases and uninfected contacts was observed in a COVID-19 outbreak in terms of their demographics and contact patterns. Simulation results based on the collected contact data indicated that a threshold of accumulative contact hours one or two days prior to diagnosis of the index case could dramatically increase the efficiency of outbreak containment within RCHs by targeted isolation of the close contacts. This study demonstrated the feasibility and efficiency of employing an AI-empowered system in indoor digital contact tracing of outbreaks in RCHs in the post-pandemic era.

Using virtual reality to assess theory of mind subprocesses and error types in early and chronic schizophrenia

Individuals with schizophrenia often demonstrate theory of mind (ToM) impairment relative to healthy adults. However, the exact nature of this impairment (first- vs. second-order ToM and cognitive vs. affective ToM) and the extent to which ToM abilities deteriorate with illness chronicity is unclear. Furthermore, little is known about the relationships between clinical symptoms and ToM error types (overmentalising, reduced mentalising and no ToM) in early and chronic schizophrenia. This study examined the nature and types of ToM impairment in individuals with early (n = 26) and chronic schizophrenia (n = 32) using a novel virtual reality task. Clinical participants and demographically-matched controls were administered the Virtual Assessment of Mentalising Ability, which provides indices of first- and second-order cognitive and affective ToM, and quantifies three different types of mentalising errors (viz., overmentalising, reduced mentalising, and no ToM). Individuals with early schizophrenia performed significantly poorer than healthy controls on first-order affective and second-order cognitive and affective ToM, but significantly higher than individuals with chronic schizophrenia on all ToM subscales. Whereas a lack of mental state concept was associated with negative symptoms, overmentalising was associated with positive symptoms. These findings suggest that ToM abilities selectively deteriorate with illness chronicity and error types are related to these individuals' presenting symptomology. An implication of the findings is that social-cognitive interventions for schizophrenia need to consider the nature, time course and symptomatology of the presenting patient.

Prefrontal cortex connectivity dysfunction in performing the Fist-Edge-Palm task in patients with first-episode schizophrenia and non-psychotic first-degree relatives

Neurological soft signs have been considered one of the promising neurological endophenotypes for schizophrenia. However, most previous studies have employed clinical rating data only. The present study aimed to examine the neurobiological basis of one of the typical motor coordination signs, the Fist–Edge–Palm (FEP) task, in patients with first-episode schizophrenia and their non-psychotic first degree relatives. Thirteen patients with first-episode schizophrenia, 14 non-psychotic first-degree relatives and 14 healthy controls were recruited. All of them were instructed to perform the FEP task in a 3 T GE Machine. Psychophysiological interaction (PPI) analysis was used to evaluate the functional connectivity between the sensorimotor cortex and frontal regions when participants performed the FEP task compared to simple motor tasks. In the contrast of palm-tapping (PT) vs. rest, activation of the left frontal–parietal region was lowest in the schizophrenia group, intermediate in the relative group and highest in the healthy control group. In the contrast of FEP vs. PT, patients with schizophrenia did not show areas of significant activation, while relatives and healthy controls showed significant activation of the left middle frontal gyrus. Moreover, with the increase in task complexity, significant functional connectivity was observed between the sensorimotor cortex and the right frontal gyrus in healthy controls but not in patients with first episode schizophrenia. These findings suggest that activity of the left frontal–parietal and frontal regions may be neurofunctional correlates of neurological soft signs, which in turn may be a potential endophenotype of schizophrenia. Moreover, the right frontal gyrus may play a specific role in the execution of the FEP task in schizophrenia spectrum disorders.

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Examine the neurobiological basis of the typical Fist–Edge–Palm (FEP) signs

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Patients with first-episode schizophrenia showed functional connectivity of the FEP signs.

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Right frontal gyrus plays a specific role in the FEP in patients and non-psychotic first-degree relatives.

Foot massage and physiological stress in people with dementia: a randomized controlled trial

BACKGROUND

The anxiety associated with unfamiliar surroundings, the disorientation and mental confusion, and the social isolation that accompanies dementia can often create increased stress for people living in long-term care settings. Such a response is thought to affect the autonomic nervous system and result in emotional and physical symptoms of distress that may be manifested as agitation. There is the potential for such distress to influence the physiological response and in particular Blood Pressure and Heart Rate. A relaxation intervention such as massage may influence the physiological stress response.

METHODS

This randomized controlled trial aimed to compare the effect of foot massage (FM) versus a control activity (quiet presence, QP) on physiological stress response (i.e., blood pressure [BP] and heart rate [HR]) in people living with moderate-to-severe dementia in long-term-care settings.

RESULTS

Fifty-three residents were randomized to intervention (10-minute FM) or control group (QP). While the FM group experienced a greater reduction in HR than the control group, these reductions were not significantly different between groups (p=0.83; see Table 1 ), or across time (p=0.46). Both groups experienced a reduction in systolic BP and diastolic BP, while the mean reduction in systolic BP was greater for those in the FM group.

CONCLUSIONS

While the findings do not provide strong support for FM, the finding that both conditions allowed the person with dementia to rest in the presence of another human being is of importance in the care of people with dementia. The close presence of another person may in fact promote relaxation and therefore improve BP and HR measures.

Effects of severe traumatic brain injury on visual memory

The study aimed to clarify the effects of severe traumatic brain injury (TBI) on visual memory. Three groups of participants (14 late-recovery and 14 early-recovery TBI individuals and 18 controls) were administered the following: The Shum Visual Learning Test (SVLT), a test that measures the ability to remember visual patterns, an electronic maze test, a test that measures the ability to remember spatial positions, and the Rey Auditory Verbal Learning Test (RAVLT), a test of verbal memory and learning. The individuals with TBI (late- and early-recovery) were found to be impaired on the SVLT and the RAVLT but not on the electronic maze. Specifically, on the SVLT, they were found to learn at a slower rate and make more false-positive errors than the controls. The advantages of the SVLT over visual memory tests used in previous studies and the significance of findings of the present study were discussed.

Normative data for a new memory test: the Shum Visual Learning Test

This study reports normative data and test-retest reliabilities for a visuo-spatial memory test, the Shum Visual Learning Test (SVLT). Participants were 146 Caucasians (70 males and 76 females, age range between 17-83 years). The test was administered to 116 participants once and 30 participants twice (1 month apart). Age (but not gender and education) was found to affect SVLT test performance. The norms, therefore, were presented according to seven age groups (viz., 17-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70+ years). Three indices (learning, retention after interference, and delayed retention) were derived for descriptive and clinical purposes. The test-retest reliabilities for all trials of the SVLT (except Trial 6) were found to be significant (rs ranged from .63 to .82). Normative data reported allow neuropsychologists to compare patient performances with those of appropriate controls and are important for fostering clinical application of this test.

Effects of closed-head injury on attentional processes: generality of Sternberg's additive factor method

The present study examined the generality of Shum, McFarland, Bain, and Humphreys' (1990) findings that closed-head injury (CHI) selectively impairs different processes of attention (operationalized in terms of stages of information processing) depending on the severity of, and the time since, injury. The procedure of Shum et al. was based on Sternberg's additive factor method (AFM), with the mode of information processing involved being a physical-directional matching of visual stimuli. The present study followed a similar procedure except that a name-matching task was used. This task was administered to 16 first-year psychology students and two groups of CHI patients (viz., severe short-term (SS) and severe long-term (SL)) with matched control groups. The results obtained replicated the study by Shum in that the SS group was found to be impaired on the identification and response-selection stages of information processing whereas the SL group was found to be impaired only on the response-selection stage. The present study confirms that the AFM is not limited to one specific mode of information process and strengthens the validity of the conclusions made by Shum et al. regarding the effects of CHI on attention.

Assessment of attention: relationship between psychological testing and information processing approaches

Examined the relationship between the psychological testing and information processing approaches in assessing attention. Eighty-seven subjects (57 females, 30 males) undertook eight psychological tests of attention and a visual-spatial reaction-time task. Using the cognitive-correlate method (Posner & McLeod, 1982), it was found that three components of attention (viz., visual-motor scanning, sustained selective processing, and visual/auditory spanning) derived from the psychological tests could be significantly predicted by specific, yet different, combinations of six indices of information processing (mean reaction time (RT), mean movement time (MT), feature extraction, identification, response selection, and motor adjustment): (a) mean RT and mean MT were found to be the most important indices for predicting performance on visual-motor scanning; (b) the motor-adjustment stage was found to be the most important index for predicting performance on sustained selective processing; (c) the response-selection stage was found to be the most important index for predicting performance on visual/auditory spanning. These relationships are important for supporting the construct-related validity of the psychological tests of attention and for extending the generality and applicability of the RT task.

Effects of closed-head injury on attentional processes: an information-processing stage analysis

The present study, based on Sternberg's (1969) additive-factor method, examined attentional processes in terms of four information-processing stages (feature extraction, identification, response selection, and motor adjustment). Four task variables were used to operationally define the stages (signal quality, signal similarity, signal-response compatibility, and foreperiod uncertainty). In two studies, a visuo-spatial reaction-time task was undertaken by a group of university subjects (Experiment 1) and by three groups of closed-head-injured patients (severe short-term, severe long-term, and mild short-term) and their corresponding matched controls (Experiment 2). The results indicated that both patients and normals exhibited a similar mode of linear information processing. In addition, it was found that the severe short-term group was impaired on the response-selection stage and response selection stage; the severe long-term group was impaired only on the response-selection; and no evidence of impairment was found for the mild short-term patients. The implications of these findings with reference to the study of attentional processes in closed-head injured patients and to neuropsychological assessment and rehabilitation are discussed.