Gil Zukerman

Effect of the diurnal rhythm and 24 h of sleep deprivation on dichotic temporal order judgment

The present study examined the impact of mild (24 h) sleep deprivation and of the circadian rhythm on auditory temporal resolution, measured by dichotic temporal order judgment (TOJ). The rationale for the present study was based on several areas of research. First, the ‘sleep‐based neuropsychological perspective’ hypothesis posits that sleep reduction initially impacts the functions associated with intact prefrontal cortical activity, e.g. language tasks. Secondly, recent studies indicate the importance of the role of auditory temporal resolution in speech comprehension. Thirdly, there is accumulating evidence of the involvement of prefrontal cortical structures in auditory temporal resolution. We hypothesized that mild to moderate sleep deprivation would affect dichotic TOJ negatively. The results showed that: (1) 24 h of sleep deprivation significantly reduced the overall level of accuracy in dichotic TOJ and increased dichotic TOJ threshold from 57.61 ms to 73.93 ms, a reduction in temporal resolution of 28.3%; (2) dichotic TOJ was subject to a small, but significant diurnal rhythm having a nadir in early to mid afternoon. As auditory temporal resolution of speech and non‐speech sounds seems to be dependent on intact functioning of the left inferior and left dorso‐lateral prefrontal cortex (PFC), these data strengthen the argument that even mild to moderate sleep deprivation can impact negatively on PFC‐dependent functions. Furthermore, based on these findings, we suggest that the deficit in auditory temporal resolution in individuals suffering from sleep loss may also affect language comprehension.

Affective and Behavioral Changes Following Exposure to Traumatic Events: the Moderating Effect of Religiosity on Avoidance Behavior Among Students Studying Under a High Level of Terror Event Exposure

The goals of this study were to examine the development of affective and behavioral changes following exposure to traumatic events among Israeli students studying under a high level of terror event exposure and to assess the effects of religiosity on those changes development. A questionnaire was administered to 770 students in the Ariel University Center in Judea and Samaria. Higher levels of terror exposure were associated with higher levels of avoidance behavior, subjective feelings of insecurity, and emotional distress. Higher religiosity moderated avoidance behavior, even when controlling for the level of objective exposure to terror events exposure, but had no influence on subjective sense of insecurity, or the level of emotional distress. These findings suggest that religiosity moderates behavioral changes development after traumatic event exposure mainly by reducing avoidance behavior.

Post-traumatic stress and world assumptions: the effects of religious coping.

Religiosity has been shown to moderate the negative effects of traumatic event experiences. The current study was deigned to examine the relationship between post-traumatic stress (PTS) following traumatic event exposure; world assumptions defined as basic cognitive schemas regarding the world; and self and religious coping conceptualized as drawing on religious beliefs and practices for understanding and dealing with life stressors. This study examined 777 Israeli undergraduate students who completed several questionnaires which sampled individual world assumptions and religious coping in addition to measuring PTS, as manifested by the PTSD check list. Results indicate that positive religious coping was significantly associated with more positive world assumptions, while negative religious coping was significantly associated with more negative world assumptions. Additionally, negative world assumptions were significantly associated with more avoidance symptoms, while reporting higher rates of traumatic event exposure was significantly associated with more hyper-arousal. These findings suggest that religious-related cognitive schemas directly affect world assumptions by creating protective shields that may prevent the negative effects of confronting an extreme negative experience.

Total Sleep Deprivation and Cognitive Performance: The Case for Multiple Sources of Variance

The present chapter reviews and summarizes some of the major findings of the studies of the impact of sleep deprivation on cognitive performance over the past half century. The studies discussed are limited to instances of total sleep loss and support the argument that total sleep loss may impact different cognitive functions differently. Some cognitive variables may be more sensitive to sleep loss than others and some cognitive variables may be more sensitive to the homeostatic pressures of accumulated wakefulness, while others may be more sensitive to the impact of the circadian cycle.

Early automatic hyperarousal in response to neutral novel auditory stimuli among trauma-exposed individuals with and without PTSD: An ERP study

ERP studies have associated posttraumatic stress disorder (PTSD) with enhanced P3 amplitudes in response to trauma-related stimuli, along with reduced amplitudes in the context of neutral (trauma-unrelated) stimuli. Additionally, a bias toward trauma-related stimuli is also observed among trauma-exposed participants not meeting criteria for PTSD, suggesting that trauma exposure itself, and not only the severity of posttraumatic stress (PTS), is a critical factor in information processing changes. However, previous examination of the response of trauma-exposed (PTSD and non-PTSD) participants to novel, neutral stimuli has produced conflicting findings. The current study examined ERPs in response to a novelty oddball paradigm comprised of neutral distractor sounds. Participants were 16 individuals with PTSD, 21 trauma-exposed individuals without PTSD, and 12 nontraumatized controls. Detailed trauma histories and PTS symptoms were collected. A significant effect of group on early ERPs was observed, showing an increase in the N1-P2 complex peak amplitude among the PTSD group, relative to controls. Among the entire sample, significant positive correlations were observed between PTS symptom severity, as well as trauma history, and early N1-P2 complex peak amplitudes, in response to novel stimuli. Furthermore, trauma-exposed participants with no PTS symptoms exhibited larger N1 amplitudes compared to participants with no trauma history. No trauma-related alterations in later ERP components were observed. These results suggest that trauma exposure may lead to hyperarousal at early processing levels, even in response to neutral novel stimuli. The findings concur with the neurocircuitry model that associates PTSD with hyperresponsivity of the amygdala.

Religious coping and posttraumatic stress symptoms following trauma: The moderating effects of gender.

This study examined the effects of gender on the relationships between religious coping and 2 outcome variables: posttraumatic stress (PTS) and somatic symptoms. Gender effects on the associations between an individual’s perceptions about the world and self and between PTS/somatic symptoms were also examined. Participants were 388 religious or traditional Jews who were exposed to a traumatic event according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM–5). Gender significantly moderated the relationship between negative religious coping and PTS, as well as the relationship between negative religious coping and somatic symptoms; whereas no differences between the sexes were found for low negative religious coping, high negative religious coping was associated with higher levels of PTS and somatic symptoms among women than men. Among women, negative perception of self was associated with a higher level of somatic symptoms. These findings suggest that among women, negative religious coping is associated with elevated PTS and somatic symptoms.