Sustained attention training reduces spatial bias in Parkinson’s disease: a pilot case series

Individuals with Parkinson’s disease (PD) commonly demonstrate lateralized spatial biases, which affect daily functioning. Those with PD with initial motor symptoms on the left body side (LPD) have reduced leftward attention, whereas PD with initial motor symptoms on the right side (RPD) may display reduced rightward attention. We investigated whether a sustained attention training program could help reduce these spatial biases. Four non-demented individuals with PD (2 LPD, 2 RPD) performed a visual search task before and after 1 month of computer training. Before training, all participants showed a significant spatial bias and after training, all participants’ spatial bias was eliminated.Published versio

Anticipated psychosocial stress informs sustained attention performance: A behavioral and physiological perspective

The ability to sustain attention is paramount to the completion of daily activities, such as driving or attending to a lecture. Previous studies have suggested that stress prior to cognitive testing leads to changes in attentional performance based on stressor context, but the impact of anticipated stress on attention remains unclear. To answer this question, the current study examined a sample of thirty-one undergraduate students (age 18-35, M=21.5, S.D.=3.1) who either anticipated a psychosocial stressor or completed guided meditation before completing a go/no-go sustained attention task (gradCPT). Subjective measures of anxiety, self-esteem, extraversion, and neuroticism were also gathered along with heart rate and electrodermal activity measures to objectively determine stress reactivity. Correlational analyses revealed negative associations between state anxiety and commission errors (r=-0.5, p=0.048), reaction time variability (r=-0.522, p=0.038), and a positive association between state anxiety and accuracy (d’) (r=0.521, p=0.038) in the stress condition exclusively. When controlling for state anxiety, mixed design ANOVAs revealed a significant main effect of condition on d’ (F(1,28)=5.54, p=0.026), where the stress group showed lower d’. Further, data showed a trend of an interaction on reaction time variability (F(1,28)=3.49, p=0.072) where increased variability across the task duration occurred as a function of condition assignment, and a trend of a main effect of condition (F(1,28)=3.93, p=0.057) suggesting more commission errors under stress. The results suggest that anticipation of a stressor does impact sustained attention, but that performance may exist on a spectrum based on subjective appraisal of the stressor. (Author abstract)Brau, J.M., Fortenbaugh, F.C., & Esterman, M. (2021). Anticipated psychosocial stress informs sustained attention performance: A behavioral and physiological perspective. Retrieved from http://academicarchive.snhu.ed

Shifting attention in viewer- and object-based reference frames after unilateral brain injury

The aims of the present study were to investigate the respective roles that object- and viewer-based reference frames play in reorienting visual attention, and to assess their influence after unilateral brain injury. To do so, we studied 16 right hemisphere injured (RHI) and 13 left hemisphere injured (LHI) patients. We used a cueing design that manipulates the location of cues and targets relative to a display comprised of two rectangles (i.e., objects). Unlike previous studies with patients, we presented all cues at midline rather than in the left or right visual fields. Thus, in the critical conditions in which targets were presented laterally, reorienting of attention was always from a midline cue. Performance was measured for lateralized target detection as a function of viewer-based (contra- and ipsilesional sides) and object-based (requiring reorienting within or between objects) reference frames. As expected, contralesional detection was slower than ipsilesional detection for the patients. More importantly, objects influenced target detection differently in the contralesional and ipsilesional fields. Contralesionally, reorienting to a target within the cued object took longer than reorienting to a target in the same location but in the uncued object. This finding is consistent with object-based neglect. Ipsilesionally, the means were in the opposite direction. Furthermore, no significant difference was found in object-based influences between the patient groups (RHI vs. LHI). These findings are discussed in the context of reference frames used in reorienting attention for target detection

Adolescent nonsuicidal self-injury: Examining the role of child abuse, comorbidity, and disinhibition

The purpose of the study is to examine how several well-known correlates of nonsuicidal self-injury (NSSI) might work together to contribute to the occurrence of this behavior. Specifically, we examined models including child abuse, psychiatric comorbidity, and disinhibition, testing how these factors may work together to lead to NSSI in the past month. Participants (n=194; 144 female; age 13–18 years) were recruited from a short-term, acute adolescent residential unit. Within 48 hours of admission to the hospital participants completed structured clinical interviews assessing mental disorders and patterns of NSSI. Following the interviews, participants completed a self-report questionnaire assessing childhood abuse and a computerized continuous performance task. Consistent with study hypotheses, results revealed that the association between child abuse and NSSI is partially mediated by comorbidity. Although disinhibition is associated with comorbidity, contrary to our hypothesis, disinhibition does not mediate the relation between child abuse and NSSI. Collectively, these findings provide new information about how comorbidity may increase risk for NSSI, and critically, discuss the potential importance of creating targeted programs to reduce the prevalence of child abuse.Psycholog

Motor cortical excitability and pre-supplementary motor area neurochemistry in healthy adults with substantia nigra hyperechogenicity

Substantia nigra (SN) hyperechogenicity, viewed with transcranial ultrasound, is a risk marker for Parkinson\u27s disease. We hypothesized that SN hyperechogenicity in healthy adults aged 50 – 70 years is associated with reduced short-interval intracortical inhibition in primary motor cortex, and that the reduced intracortical inhibition is associated with neurochemical markers of activity in the pre-supplementary motor area (pre-SMA). Short-interval intracortical inhibition and intracortical facilitation in primary motor cortex was assessed with paired-pulse transcranial magnetic stimulation in 23 healthy adults with normal (n = 14; 61 ± 7 yrs) or abnormally enlarged (hyperechogenic; n = 9; 60 ± 6 yrs) area of SN echogenicity. Thirteen of these participants (7 SN − and 6 SN+) also underwent brain magnetic resonance spectroscopy to investigate pre-SMA neurochemistry. There was no relationship between area of SN echogenicity and short-interval intracortical inhibition in the ipsilateral primary motor cortex. There was a significant positive relationship, however, between area of echogenicity in the right SN and the magnitude of intracortical facilitation in the right (ipsilateral) primary motor cortex (p = .005; multivariate regression), evidenced by the amplitude of the conditioned motor evoked potential (MEP) at the 10 – 12 ms interstimulus interval. This relationship was not present on the left side. Pre-SMA glutamate did not predict primary motor cortex inhibition or facilitation. The results suggest that SN hyperechogenicity in healthy older adults may be associated with changes in excitability of motor cortical circuitry. The results advance understanding of brain changes in healthy older adults at risk of Parkinson\u27s disease

Toric intraocular lens calculations - Reply

[Extract] We thank Dr Simpson for pointing out the typographical error in our article.1 He is correct. The formula should have read E = F /[1 + (d /1.336) F]. All calculations in the article were done using this correct formula, and the formula in the article has been corrected. With regard to the suitability of this formula for the task of predicting toric IOL outcome, we have demonstrated that it predicted the outcome better than the Alcon online calculator. He is right that it is related to the formula for adjusting effective powers between contact lenses and spectacle lenses, but the incorporation of an index of refraction for aqueous and cornea (1.336) makes it suitable for calculation of equivalent powers within the eye. The US patent application document for the online Alcon toric calculator2 uses such formulas in a more detailed manner, calculating vergence at the cornea and the first and second principal planes of the IOL

Visual hemispatial neglect, re-assessed

Increased computer use in clinical settings offers an opportunity to develop new neuropsychological tests that exploit the control computers have over stimulus dimensions and timing. However, before adopting new tools, empirical validation is necessary. In the current study, our aims were twofold: to describe a computerized adaptive procedure with broad potential for neuropsychological investigations, and to demonstrate its implementation in testing for visual hemispatial neglect. Visual search results from adaptive psychophysical procedures are reported from 12 healthy individuals and 23 individuals with unilateral brain injury. Healthy individuals reveal spatially symmetric performance on adaptive search measures. In patients, psychophysical outcomes (as well as those from standard paper-and-pencil search tasks) reveal visual hemispatial neglect. Consistent with previous empirical studies of hemispatial neglect, lateralized impairments in adaptive conjunction search are greater than in adaptive feature search tasks. Furthermore, those with right hemisphere damage show greater lateralized deficits in conjunction search than do those with left hemisphere damage. We argue that adaptive tests, which automatically adjust to each individual's performance level, are efficient methods for both clinical evaluations and neuropsychological investigations and have the potential to detect subtle deficits even in chronic stages, when flagrant clinical signs have frequently resolved