Combining the Projective Consciousness Model and Virtual Humans for immersive psychological research: a proof-of-concept simulating a ToM assessment

Relating explicit psychological mechanisms and observable behaviours is a central aim of psychological and behavioural science. One of the challenges is to understand and model the role of consciousness, and in particular its subjective perspective as an internal level of representation (including for social cognition) in the governance of behaviour. Toward this aim, we implemented the principles of the Projective Consciousness Model (PCM) into artificial agents embodied as virtual humans, extending a previous implementation of the model. Our goal was to offer a proof-of-concept, based purely on simulations, as a basis for a future methodological framework. Its overarching aim is to be able to assess hidden psychological parameters in human participants, based on a model relevant to consciousness research, in the context of experiments in virtual reality. As an illustration of the approach, we focused on simulating the role of Theory of Mind (ToM) in the choice of strategic behaviours of approach and avoidance to optimise the satisfaction of agents’ preferences. We designed a main experiment in a virtual environment that could be used with real humans, allowing us to classify behaviours as a function of order of ToM, up to the second order. We show that agents using the PCM demonstrated expected behaviours with consistent parameters of ToM in this experiment. We also show that the agents could be used to estimate correctly each other’s order of ToM. Furthermore, in a supplementary experiment, we demonstrated how the agents could simultaneously estimate order of ToM and preferences attributed to others to optimize behavioural outcomes. Future studies will empirically assess and fine tune the framework with real humans in virtual reality experiments.

Modeling the subjective perspective of consciousness and its role in the control of behaviours

Consciousness has been hypothesized to operate as a global workspace, which accesses and integrates multimodal information in a uni_ed manner, supports expectation violation monitoring and reduction, and the motivation, programming and control of action. One important yet open issue concerns how the subjective perspective at the core of consciousness, and subjective properties of manifestation of the environment in such perspective as an embodied experience, play a role in such process. We operationalised the concept of subjective perspective using the principles of the Projective Consciousness Model (PCM), based on the projective geometrical concept of Field of Consciousness. We show how these principles can account for documented relationships between appraisal and distance as an inverse distance law, yield a generative model of a_ective and epistemic drives based on purely subjective parameters, such as the apparent size of objects, and can be generalised to implement Theory of Mind, in a manner that is consistent with simulation theory. We used simulations of arti_cial agents, based on psychological rationale, to demonstrate how different model parameters could generate a variety of emergent adaptive and maladaptive behaviours that are relevant to developmental and clinical psychology: the ability to be resilient in the face of obstacles through imaginary projections, the emergence of social approach and joint attention behaviours, the ability to take advantage of false beliefs attributed to others, the emergence of avoidance behaviours as observed in social anxiety disorders, the presence of restricted interests as observed in autism spectrum disorders. The simulation of agents was applied to a speci_c robotic context, and agents' behaviours were demonstrated by controlling the corresponding robots. Our results contribute to advance the scienti_c understanding of the causal relationships between core aspects of the phenomenology of consciousness and its functions in human cybernetics.

Prevalence of target organ damage in subjects with high-normal blood pressure without known cardiovascular and kidney disease

Background

Heterogeneous results have been obtained regarding the presence of Target Organe Damage (TOD) in subjects with high-normal Blood Pressure (BP) value (sistoly 130–139, diastolic 85–89 mmHg).

Purpose

Aim of our study was to assess the prevalence of TOD in healthy subjects with high-normal BP comparing them with subjects with BP values that are considered normal (<130/85 mmHg) or indicative of hypertension (≥140/90 mmHg).

Methods

755 otherwise healthy subjects participated at the present analysis. TOD was evaluated as Pulse Wave Velocity (PWV), Left Ventricular Mass Index (LVMI) and carotid Intima-Media Thickness (IMT) and plaque.

Results

When subjects were classified according to BP levels we found that high-normal BP group showed intermediate values of PWV and LMVI with higher value of IMT. This corresponds to intermediate prevalence of arterial stiffness (PWV>10 m/s: 3.4% vs 2.3% for normal and 9.6% for high BP groups, p=0.0014), Left Ventricular Hypertrophy – LVH (32.4% vs 25.7% for normal and 46.6% for high BP groups, p=0.0001) while there were no differences for IMT>0.9 or carotid plaque. At multivariable analysis the odds of having a PWV>10 m/s (OR=1.75, 95% C.I. 0.59–5.16), an IMT>0.9 mm (OR=1.81, 95% C.I. 0.60–5.00) or a LVH (OR=1.1, 95% C.I. 0.72–1.67) in the high-normal group resulted not different to the normal group.

Conclusions

In our otherwise healthy population, high-normal BP values were not related to aortic, carotid or cardiac TOD.

Funding Acknowledgement

Type of funding sources: None.

Hemodialysis: effects of preload reduction on novel echocardiographic parameters of left ventricular function

Funding Acknowledgements

Type of funding sources: None.

Background

Echocardiography has been widely used to study cardiac function in patients with end-stage renal disease on hemodialysis (HD), but cardiac function assessment by measuring cardiac dimensions and their rate of change is load dependent, therefore it is influenced by volume depletion. Effects of acute volume reduction on left (LV) and right ventricular (RV) function are still not well understood. Some studies investigated myocardial mechanics after dialysis using speckle tracking echocardiography (STE) but their relative load-dependency makes STE indices unable to account for changes in pre- and afterload. Myocardial work (MW) incorporates both deformation and load into its analysis and is an emerging tool to study LV myocardial function. There are no data about the effects of hemodialysis on LV MW.

Purpose

This study aimed to evaluate acute changes of novel echocardiographic indices of both LV and RV function after a HD session.

Methods

Patients with end-stage renal disease undergoing HD were prospectively enrolled. A transthoracic echo, including STE calculation of LV global longitudinal strain (GLS) and free wall RV strain, was performed before and after hemodialysis. Parameters of MW such as global work index (GWI), global constructive work (GCW), global work efficiency (GWE) and global wasted work (GWW) were quantified using a commercially available software package.

Results

27 patients were enrolled, mean baseline parameters were: LV end-diastolic volume 136 ± 38 mL, LV ejection fraction (LVEF) 56.9 ± 7.5%, LV GLS -17.1 ± 4.1%, RV free wall strain -26.9 ± 5.6%, GWI 2117 ± 602 mmHg%, GCW 2299 ± 633 mmHg%, GWW 137 ± 88 mmHg, GWE 93 ± 3.6%, systolic arterial pressure 145 ± 26 mmHg and diastolic pressure 80 ± 16mmHg. After hemodialysis we observed a significative reduction in LV GLS (p = 0.04), RV strain (p = 0.002), GWI (p = 0.002, Figure I) and GCW (p = 0.004). No significative changes in LVEF and blood pressure were observed. Comparing patients using a LVEF cut-off of 55% (19 patients with LVEF≥55%, 8 patients <55%) we observed a significative reduction of LV GLS (p = 0.004), GWI (p < 0.001), GCW (p < 0.001) only in patients with LVEF ≥55% while RV strain and LV volume showed a reduction in both groups. We observed no significative differences in extracted volumes between the groups (2.6 vs 2.1 liters,p = 0.3). Patients with normal LVEF showed a significative negative variation (D) of LVEF (-1 vs 3%), GWI (-551 vs 38 mmHg%) and GCW (-522 vs 11 mmHg%). Correlations were found between DGWI and extracted volume (r= 0.46, p = 0.01), basal GWI and both DLVEF (r= 0.39, p = 0.04) and DLV GLS (r= 0,42, p = 0.02), basal LV GLS and DLVEF (r= 0.5, p < 0.01).

Conclusions

Our preliminary data show that, immediately after the HD session, there is a reduction in biventricular STE-derived systolic parameters. Patients with normal LV systolic function are more sensitive to acute volume changes and entity of volume depletion seems to be correlated with MW reduction.

Abstract Figure.