The relationship between sustained attention and cognitive performance in 17–24‐month old toddlers

The purpose of this study was to investigate individual differences in sustained attention and task performance with toddlers. Participants were 61 17–24‐month old toddlers. Indices of sustained attention (duration of attention and frequency of off‐task glances) were assessed during two 4 min problem solving tasks, and then related to problem solving and the mental scale of the Bayley scales of infant development‐II (BSID‐II). As expected, toddlers who attended to tasks for longer periods of time were more successful at problem solving, and had higher scores on the BSID‐II than toddlers who attended for shorter periods of time. In addition, older toddlers had longer attention spans, more frequent off‐task glances, and were more successful at problem solving than younger toddlers. Interestingly, toddlers with more frequent off‐task glances had longer attention spans, were more successful at problem solving, and had higher BSID‐II scores than peers with fewer off‐task glances. These findings suggest that although behavioural indices can be used to identify sustained attention, the relationship between behaviours thought to capture distractibility and attention is more complex than had been previously assumed. Results are discussed in the context of current theories of infant attention and cognitive performance. Copyright © 2000 John Wiley & Sons, Ltd.     

Stimulus control of EMG burst duration in human locomotion

To better understand constraints on EMG activity, burst duration was restricted for the rectus femoris (RF) muscle as subjects walked on a motor-driven treadmill. Once in each step cycle (touchdown to touchdown of the left foot) a computer-activated light discriminated a short burst (if green) and silence (if red). All four subjects rapidly met the criterion of 90% success in 50 cycles for a burst 100–300 msec long within a performance duration, PDUR, of 700 msec. In contrast, two of the four failed to reduce the burst to conform to a 100–200 msec requirement. Several variables were ruled out as bearing on these between-subject performance differences: (1) complete failure to produce a short burst within the PDUR, since many were successful; (2) a differential effect upon subjects of two “reinforcer” types (a high tone after success and a low tone after failure, or else audible EMG biofeedback before the high or low tone); (3) appreciable differences in cycle duration or swing/stance ratios; (4) the presence or absence of concomitant activity in other leg muscles whose EMG was recorded. The frequent failure to accurately terminate the burst was suggested to be due to a greater susceptibility, whether reflexive or conditioned, to simulation arising in the contracting RF muscle itself.     

Affective deficits and pain insensitivity in schizophrenia

Affective deficits have long been considered a prominent feature of schizophrenia and play a central role in recent theory and research on the pathophysiology of this disorder. However, it has recently been argued that current approaches to the conceptualization and assessment of affective flattening in schizophrenia are confounded by the social and neuromotor deficits that are also prevalent in this disorder. Insensitivity to pain in individuals with schizophrenia — a phenomenon that has been reported frequently but never systematically investigated — provides one approach to examining affective flattening unconfounded by social and neuromotor deficits. Two studies are described in which signal detection theory measures of thermal pain sensitivity were examined in patients with schizophrenia, mood disorder, and normal controls; in addition, in the patients with schizophrenia, the relationships between these measures and measures of affective deficits were examined. Patients with schizophrenia had significantly poorer sensory discrimination of painful thermal stimuli than control subjects, but did not differ from controls with respect to their response criterion for reports of pain; patients with mood disorder had a significantly higher (i.e., more stoical) criterion for reports of pain than controls. As predicted, among the patients with schizophrenia, higher response criterion was significantly correlated with greater affective flattening and less intense affective experience (as well as with fewer positive symptoms and poorer premorbid adjustment). The results of these studies suggest that pain insensitivity in schizophrenia may reflect affective as well as sensory abnormalities, and that pain insensitivity in schizophrenia may provide a method for studying affective flattening in this disorder that is relatively independent of the social and neuromotor deficits that confound existing measures of this symptom. Continued examination of the relationship between pain insensitivity and affective deficits in schizophrenia is also important because numerous clinical reports have suggested that pain insensitivity is detrimental to health and can have life-threatening consequences in individuals with this disorder.This research was supported, in part, by research grants from the National Institute of Neurological Disorders and Stroke to Robert H. Dworkin (NS-30714) and W. Crawford Clark (NS-09263, NS-20248).     

Community engagement,greening, and violent crime: A test of the greening hypothesis and Busy Streets

Researchers have documented that vacant lot greening can reduce community-level crime and violence. Busy Streets Theory (BST) suggests that residents who are involved in the greening process can help to improve physical environments and build social connections that deter crime and violence. Yet few researchers have explored how community engagement in the greening process may affect crime and violence outcomes. We applied BST to test the effects of community-engaged vacant lot greening compared to vacant lots that received either professional mowing or no treatment, on the density of violent crime around study lots. Using mixed effects regression models, we analyzed trends in violent crime density over the summer months from 2016 to 2018 at 2102 street segments in Youngstown, OH. These street segments fell within 150 meters of an intervention parcel that was classified as one of three conditions: community-engaged maintenance, professional mowing, or no treatment (control). We found that street segments in areas receiving community-engaged maintenance or professional mowing experienced greater declines in violent crime density than street segments in areas receiving no treatment, and more decline occurred in the community-engaged condition compared to the professional mow condition. Our findings support BST and suggest that community-engaged greening of vacant lots in postindustrial cities with a concentrated vacancy can reduce crime and violence.     

Assessing the effects of peer suicide on youth suicide

Using data from all waves of the National Longitudinal Survey of Adolescent Health, we investigated the short-term and long-term impact of an adolescent friend's suicide on an adolescent's depression and suicidality. Results suggest that a friend's suicide is associated with heightened suicide thoughts and attempts and greater depression during the first year after loss. Six years later, analyses show concurrent behaviors most relevant to explain suicidality fluctuations. Findings suggest the importance of therapeutic availability, especially during the first year, for those losing a friend to suicide.     

Team cognition in experienced command-and-control teams

Team cognition in experienced command-and-control teams is examined in an UAV (Uninhabited Aerial Vehicle) simulation. Five 3-person teams with experience working together in a command-and-control setting were compared to 10 inexperienced teams. Each team participated in five 40-min missions of a simulation in which interdependent team members control a UAV to take reconnaissance photos. Experienced teams exceeded performance of inexperienced teams, suggesting transfer of previous command-and-control experience. Compared to inexperienced teams, experienced teams had fewer errors on process-related training knowledge, superior team process ratings, and communications containing fewer coordination-related utterances. These findings support the view that team cognition emerges through the interactions of team members, that interactions distinguish high-performing teams from average teams, and that these interactions transfer across different tasks.