On time-frequence analysis of heart rate variability

The aim of this research is to develop a time-frequency method suitable to study HRV in greater detail. The following approach was used: • two known time-frequency representations were applied to HRV to understand its advantages and disadvantages in describing HRV in frequency and in amplitude, over time; • a new method was developed that describes the time-varying fluctuations in the characteristic frequency bands of HRV by means of the instantaneous frequency and the instantaneous amplitude with an optimal time-resolution; • an index was developed to separate the oscillatory from the irregular periods in the instantaneous frequency; • from the instantaneous amplitude and frequency, we derived summarizing parameters which we applied to describe the changes in the instantaneous amplitude and frequency over time for the oscillatory and irregular periods separatel

Emotional startle modulation in male patients with recent-onset schizophrenia

Patients with schizophrenia suffer from both cognitive as well as emotional disturbances, leading to reduced social functioning and quality of life. This study investigated the ongoing emotional states of medicated and antipsychotic-free patients and healthy controls using an emotional startle paradigm. During positive, neutral and negative emotional pictures, aversive acoustic startle stimuli were presented at 4 different probe latencies (300, 800, 1300 and 3800 ms) from picture onset. In both patients and controls, positive pictures, and more specifically erotic pictures, elicited significantly smaller eye blinks compared with startle stimuli presented during neutral and negative pictures. With regard to the subjective ratings, medicated patients rated erotic pictures significantly less pleasant and the adventure, nature, and household pictures as significantly more arousing than healthy control subjects. The present results indicate the need to further investigate emotional responding to specific picture contents, with specific focus on the sexual needs and expectations of schizophrenic patients, so as to eventually improve the quality of life in these patients

Cardiac responses during picture viewing in young male patients with schizophrenia

Previous research investigating emotion recognition ability in patients with schizophrenia has mainly focused on the recognition of facial expressions. To broaden our understanding of emotional processes in patients with schizophrenia, this study aimed to investigate whether these patients experience and process other emotionally evocative stimuli differently from healthy participants. To investigate this, we measured the cardiac and subjective responses of 33 male patients (9 with and 24 without antipsychotic medication) and 40 male control subjects to emotion-eliciting pictures. Cardiac responses were chosen as an outcome measure because previous research has indicated that these are linked with attentional and emotional processes and provide a more objective measure than self-report measures alone. The differences in cardiac responses between patients and controls were limited to medicated patients: only the medicated patients showed significantly decreased cardiac orienting responses compared with control subjects, regardless of picture contents. These results indicate that medicated patients directed less attention towards emotion-eliciting pictures than controls. Decreased attentional resources while processing emotional evocative stimuli could lead to incorrect appraisals of the environment, and may have detrimental emotional and social consequences, contributing to chronic stress levels and increased risk for cardiovascular disease