Sleep deprivation and hallucinations. A qualitative study of military personnel

Much anecdotal evidence suggests that sleep deprivation not only impairs performance, but also brings about other extraordinary effects like hallucinations. However, knowledge about how sleep deprivation may trigger hallucinations is limited. To qualitatively describe hallucinatory experiences during sleep deprivation 12 male military officers from the Norwegian Armed Forces who all had experienced at least one sleep loss-induced hallucinatory experience were recruited. Data were collected and analyzed by semi-structured interviews and thematic analysis. This resulted in the identification of three distinct main themes: (1) Modalities, (2) circumstances/triggers and (3) reactions to hallucinations. Hallucinations were experienced in several modalities (visual, auditory and multi-modality), although visual hallucinations seemed to dominate. Typical reported circumstances/triggers were sleep loss, physical exhaustion, time-of-day, low calorie intake, mental exhaustion and lack of external stimuli (low sensory and social input, boring situations, and monotonous activity). Negative emotions were dominant during the hallucinatory episodes. Often some reasoning and checking on behalf of the officers were necessary to differentiate between real percepts and hallucinations. In some cases the hallucinations caused erroneous actions. Retrospectively, most officers viewed their hallucinatory experiences in light of positive emotions and several emphasized having learned something from them. The results are discussed in relation to the existing literature and suggestions for future studies are outlined.     

Visually induced gains in pitch discrimination: Linking audio-visual processing with auditory abilities

Perception is fundamentally a multisensory experience. The principle of inverse effectiveness (PoIE) states how the multisensory gain is maximal when responses to the unisensory constituents of the stimuli are weak. It is one of the basic principles underlying multisensory processing of spatiotemporally corresponding crossmodal stimuli that are well established at behavioral as well as neural levels. It is not yet clear, however, how modality-specific stimulus features influence discrimination of subtle changes in a crossmodally corresponding feature belonging to another modality. Here, we tested the hypothesis that reliance on visual cues to pitch discrimination follow the PoIE at the interindividual level (i.e., varies with varying levels of auditory-only pitch discrimination abilities). Using an oddball pitch discrimination task, we measured the effect of varying visually perceived vertical position in participants exhibiting a wide range of pitch discrimination abilities (i.e., musicians and nonmusicians). Visual cues significantly enhanced pitch discrimination as measured by the sensitivity index d’, and more so in the crossmodally congruent than incongruent condition. The magnitude of gain caused by compatible visual cues was associated with individual pitch discrimination thresholds, as predicted by the PoIE. This was not the case for the magnitude of the congruence effect, which was unrelated to individual pitch discrimination thresholds, indicating that the pitch-height association is robust to variations in auditory skills. Our findings shed light on individual differences in multisensory processing by suggesting that relevant multisensory information that crucially aids some perceivers’ performance may be of less importance to others, depending on their unisensory abilities.     

A Systematic Review of Courses,Training, and Interventions for Adoptive Parents

Adoption requires thorough preparations prior to the arrival of the child and support post-adoption among parents, to promote a positive parent–child relationship and healthy family functioning. The purpose of our study was, therefore, to systematically review the literature on pre- and post-adoption interventions for caregivers, and determine the possibility for conducting a meta-analysis. We searched 12 electronic databases and identified 7574 references that were considered for inclusion by two independent raters. Articles meeting the following criteria were retrieved in full-text; studies that examined the effects of (a) a pre- and/or post-adoption intervention, (b) against a comparator (including quasi-experimental studies), and (c) report on outcomes for parents. Finally, we included 10 studies that met our inclusion criteria and which were assessed in terms of reported intervention effects and study quality using Cochrane’s Risk of Bias tool. All studies were associated with a high risk of bias in at least one out of seven domains and unclear reporting on several domains. Eight studies examined intervention effects related to interpersonal functioning; three of which found positive effects. In addition, three studies investigated effects on parenting and stress, respectively; however, only one study demonstrated effects on parenting and none on parental stress. Overall, the study designs, interventions, and results were characterized by substantial heterogeneity, making a meta-analysis unfeasible. In conclusion, the results from the included studies in our review does not point in any particular direction. The most consistent finding across studies was the lack of studies on pre-adoption interventions, and poor design and unclear reporting. Consequently, future studies should evaluate pre-adoption interventions, and need to use more rigorous design, transparent and comprehensible reporting, as well as more homogenous interventions and methods, to move the field forward in support of adoptive parents.     

The influence of visual information on auditory lateralization

Sætrevik, B. (2010). The influence of visual information on auditory lateralization. Scandinavian Journal of Psychology. The classic McGurk study showed that presentation of one syllable in the visual modality simultaneous with a different syllable in the auditory modality creates the perception of a third, not presented syllable. The current study presented dichotic syllable pairs (one in each ear) simultaneously with video clips of a mouth pronouncing the syllables from one of the ears, or pronouncing a syllable that was not part of the dichotic pair. When asked to report the auditory stimuli, responses were shifted towards selecting the auditory stimulus from the side that matched the visual stimulus.     

The Mental Vulnerability Questionnaire: A psychometric evaluation

Eplov, L.F., Petersen, J., Jørgensen, T., Johansen, C., Birket‐Smith, M., Lyngberg, A. C. & Mortensen, E. L. (2010). The Mental Vulnerability Questionnaire: A psychometric evaluation. Scandinavian Journal of Psychology 51, 548–554. The Mental Vulnerability Questionnaire was originally a 22 item scale, later reduced to a 12 item scale. In population studies the 12 item scale has been a significant predictor of health and illness. The scale has not been psychometrically evaluated for more than 30 years, and the aim of the present study was both to evaluate the psychometric properties of the 22 and 12 item scales and of three new scales. The main study sample was a community sample comprising more than 6,000 men and women. In this sample the coefficients of homogeneity were all over 0.30 for the three new scales, but below 0.30 for the 12 and the 22 item scales. All five Mental Vulnerability scales had positively skewed score distributions which were associated significantly with both SCL‐90‐R symptom scores and NEO‐PI‐R personality scales (primarily Neuroticism and Extraversion). Coefficient alpha was highest for the 22 and 12 item scales, and the two scales also showed the highest long‐term stability. The three new scales reflect relatively independent dimensions of Psychosomatic Symptoms, Mental Symptoms, and Interpersonal Problems, but because of reliability problems it remains an open question whether they will prove useful as predictors of health and morbidity.     

Executive working memory processes in dyslexia: Behavioral and fMRI evidence

Beneventi, H., Tønnessen, F. E., Ersland, L. & Hugdahl, K. (2010). Executive working memory processes in dyslexia: Behavioral and fMRI evidence. Scandinavian Journal of Psychology, 51, 192–202. Dyslexia is an impairment in learning to read and write, primarily associated with a phonological core deficit. However, the manifestation of symptoms in dyslexia also includes impaired working memory (WM). The aim of this study was to investigate cortical activation related to verbal WM in dyslexic and normal readers aged around 13 years, controlling for phonological awareness processing. We used a modified WM n‐back task where the participants remembered the first or last speech segment (phonemes) of the names of common objects shown as pictures. Dyslexic readers were impaired compared with the control group. Compared with the dyslexic readers, controls showed increased fMRI activation in the left superior parietal lobule and the right inferior prefrontal gyrus. Unlike controls, dyslexics did not show a significant increase in activation in WM areas with increased memory load. These findings provide support for a specific working memory deficit in dyslexic individuals.