Presleep attributions about arousal during sleep: nocturnal panic

This study examined the role of presleep attributions about physiological events during sleep in nocturnal panic attacks. Patients who regularly experienced nocturnal panic were physiologically monitored as audio signals were presented during sleep. They were randomly assigned to 1 of 3 conditions: expected, in which signals of intense physiological changes were expected; unexpected, in which signals of intense physiological changes were not expected; or control, involving distinctly different signals unrelated to physiological responses. The unexpected condition led to substantially more self-reported distress and panic attacks. The experimental conditions did not elicit different autonomic reactions, but those who panicked showed stronger physiological responses than those who did not panic. The findings are consistent with a cognitive model of nocturnal panic attacks.     

The role of attachment and cognitive inhibition in children's memory and suggestibility for a stressful event

There has been increasing interest in children's abilities to report memories of and resist misleading suggestions about distressing events. Individual differences among children and their parents may provide important insight into principles that govern children's eyewitness memory and suggestibility for such experiences. In the present study, 51 children between the ages of 3 and 7 years were interviewed about an inoculation after a delay of approximately 2 weeks. Results indicated that parents' attachment Avoidance was associated with children's distress during the inoculation. Parental attachment Anxiety and the interaction between parental Avoidance and children's stress predicted children's memory for the inoculation. Cognitive inhibition was also a significant predictor of children's memory errors and suggestibility. Theoretical implications concerning effects of stress and individual differences on children's eyewitness memory and suggestibility are discussed.     

Low heart rate variability is not caused by typical neuroleptics in schizophrenia patients

Both elevated cardiovascular mortality and low cardio-vagal (parasympathetic) heart rate variability (HRV)--a risk factor for postmyocardial infarction--are reported in schizophrenia (SZ). Since a number of medications have strong effects of cardiac conductivity, we thought it important to examine if typical neuroleptic medications might also affect HRV. We examined cardiac vagal activity during both neuroleptic treatment and a drug-free condition in seven SZ patients who were participating in a pilot double-blind, crossover study of placebo and haloperidol treatment. Twenty-four-hour Holter electrocardiograms were analyzed for high frequency HRV, quantitated as the percent of successive normal interbeat intervals greater than 50 milliseconds (PNN50), which is a good index of parasympathetic cardiac modulation. The patients showed unchanged PNN50 (8.4+/-9.5 versus 8.3+/-10.5; t=.22, df=6, P=.5) between the haloperidol treatment and drug-free conditions. Despite the elapsed time, change in medication, and altered clinical state, the PNN50s were highly correlated (Spearman r=.98, P=.000). SAPS positive symptom scores declined with treatment from 12.8+/-6.5 to 8.5+/-3.5; paired t=3.26: df=6; P=.01. PNN50s were significantly associated with positive (r=-.86, df=6, P=.012) and negative symptom scores (r=-.87, df=6, P=.01). We found low cardiovagal modulation in medication-free SZ patients that was associated with core SZ symptoms and was unchanged by haloperidol and benztropine treatment. The reduced HRV in SZ patients at baseline may render them at greater cardiovascular risk than healthy subjects when treated with medications having strong cardiovascular effects.     

Epinephrine fails to enhance performance of food-deprived rats on a delayed spontaneous alternation task

Increases in blood glucose levels after epinephrine injection appear to contribute to the hormone's effects on learning and memory. The present experiment evaluated whether epinephrine-induced enhancement of spontaneous alternation performance would be attenuated in fasted rats that had blunted increases in circulating glucose levels after injections of epinephrine. Rats deprived of food for 24 h prior to injection of epinephrine exhibited significant attenuation of the increase in blood glucose levels seen in fed rats. When the rats were tested on a delayed spontaneous alternation task, epinephrine enhanced performance in fed rats but not in rats deprived of food for 24 h. These findings are consistent with the view that hyperglycemia subsequent to epinephrine injections contributes to the memory-enhancing effects of epinephrine.     

Cortical operational synchrony during audio-visual speech integration

Information from different sensory modalities is processed in different cortical regions. However, our daily perception is based on the overall impression resulting from the integration of information from multiple sensory modalities. At present it is not known how the human brain integrates information from different modalities into a unified percept. Using a robust phenomenon known as the McGurk effect it was shown in the present study that audio-visual synthesis takes place within a distributed and dynamic cortical networks with emergent properties. Various cortical sites within these networks interact with each other by means of so-called operational synchrony (Kaplan, Fingelkurts, Fingelkurts, & Darkhovsky, 1997). The temporal synchronization of cortical operations processing unimodal stimuli at different cortical sites reveals the importance of the temporal features of auditory and visual stimuli for audio-visual speech integration.     

The E-Z reader model of eye-movement control in reading: comparisons to other models

The E-Z Reader model (Reichle et al. 1998; 1999) provides a theoretical framework for understanding how word identification, visual processing, attention, and oculomotor control jointly determine when and where the eyes move during reading. In this article, we first review what is known about eye movements during reading. Then we provide an updated version of the model (E-Z Reader 7) and describe how it accounts for basic findings about eye movement control in reading. We then review several alternative models of eye movement control in reading, discussing both their core assumptions and their theoretical scope. On the basis of this discussion, we conclude that E-Z Reader provides the most comprehensive account of eye movement control during reading. Finally, we provide a brief overview of what is known about the neural systems that support the various components of reading, and suggest how the cognitive constructs of our model might map onto this neural architecture.     

Effects of visual center of pressure feedback on postural control in young and elderly healthy adults and in stroke patients

The goal of this study was to compare young and elderly healthy individuals and elderly stroke patients in their capacity to use visual CP feedback (VF) in controlling both quiet standing and weight shifting and to assess their sensory re-weighing when this VF is withdrawn. A total of 40 participants were involved in this study. Participants were asked to either quietly stand on a force platform for a period of 45 s with eyes open (EO), using visual feedback (VF) or without visual feedback (No VF) or to perform a dynamic weight shifting task while using VF or No VF. During the quiet standing trials with VF, only the young (YO) were able to decrease the amplitude and increase the frequency of their sway in either plane. Removal of the VF resulted in a 'destabilizing' effect in both healthy elderly (EL) and stroke patients (ST) in the sagittal plane. With regard to the dynamic task, both the YO and EL were generally more successful at weight shifting in terms of speed and control when compared to the ST. Yet, when VF was removed, only the YO were able to largely maintain speed and precision of control. Hence, providing or removing visual CP feedback during quiet standing or removing VF during visually controlled weight shifting can discriminate healthy young participants from healthy elderly, but does not clearly discriminate healthy elderly from stroke patients in the same age group. Results revealed that sagittal plane imbalance in healthy elderly and stroke patients may be largely due to the effects of aging, whereas frontal plane imbalance is much more specific for the postural problems associated with stroke.     

Mechanisms and the current state of transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) is unique among the current brain stimulation techniques because it is relatively non-invasive. TMS markedly differs from vagus nerve stimulation, deep brain stimulation and magnetic seizure therapy, all of which require either an implanted prosthesis or general anesthesia, or both. Since its rebirth in its modern form in 1985, TMS has already shown potential usefulness in at least three important domains-as a basic neuroscience research instrument, as a potential clinical diagnostic tool, and as a therapy for several different neuropsychiatric conditions. The TMS scientific literature has now expanded beyond what a single summary article can adequately cover. This review highlights several new developments in combining TMS with functional brain imaging, using TMS as a psychiatric therapy, potentially using TMS to enhance performance, and finally recent advances in the core technology of TMS. TMS' ability to non-invasively and focally stimulate the brain of an awake human is proving to be a most important development for neuroscience in general, and neuropsychiatry in particular.     

The person reference process in spontaneous trait inferences

Five studies examined whether spontaneous trait inferences uniquely reference the person who performed a trait-implying behavior. On each study trial in 5 studies, participants saw 2 faces and a behavioral sentence referring to one of them. Later, participants saw face-trait pairs and indicated whether they had seen the trait word in the sentence presented with the face. Participants falsely recognized implied traits more when these traits were paired with actors' faces than with control faces. This effect was replicated for a large set effaces (120), after a week delay between study and recognition test, when equal attention was paid to each face, and when the orientation of the face at recognition was different from the orientation at encoding.