Response factors in intermodality localization under conflict conditions

The role of response modality in resolving visual-proprioceptive spatial conflict was evaluated. Subjects responded to either the felt or the seen locations of their forefingers viewed through an ll-deg laterally displacing wedge prism. Four response conditions were used: pointing with the contralateral hand either (1) during target presentation or (2) after target offset, (3)pointing with the ipsilateral (target) hand after target offset, and (4) making a visual localization response after target offset. Using the contralateral hand produced a compromise between vision and proprioception that fell about two-thirds of the way toward the optical location. Using the visual response increased visual influence. Using the ipsilateral response decreased visual influence. It was concluded that visual-proprioceptive interaction in spatial localization is not immune to response modality effects. A possible explanation of the response modality effect, based on differential attention, is discussed.     

Associative priming and conflict differentially affect two processes underlying cognitive control: Evidence from reaching behavior

Psychonomic Bulletin & Review - Previous research has indicated that two components of reaching behavior, initiation time and reach curvature, exhibit distinct patterns of trial sequence...     

Alcohol and cognitive control: implications for regulation of behavior during response conflict

Alcohol intoxication often leads to dysregulated behavior in contexts characterized by conflict between prepotent response tendencies and incompatible alternative responses. Recent research has identified 2 components of an anterior executive attention system that are essential for adaptive behavior when response conflict exists. Event-related potential (ERP) measures of evaluative and regulative cognitive control were collected to determine if impaired executive attention was responsible for observed behavior deficits when intoxicated. Intoxicated participants displayed task performance deficits on incongruent color-naming trials relative to sober controls. Alcohol did not affect P3 magnitude/latency, indicating that timing and integrity of stimulus evaluation remained intact. In contrast, alcohol did reduce frontal components of ERP that index evaluative and regulative cognitive control processes.     

Age differences in cardiovascular and cognitive performance under noise conditions

Ambient white noise (80 dB), compared with quiet (52-dB) testing conditions, improved the performance of elderly and younger subjects on simple addition. Reliable age-related interactions were found on health measures of systolic and diastolic blood pressure, as well as heart rate. Heightened sensory conditions reduced the physiological measures of arousal in the younger group, whereas significant cardiovascular reactivity was found among the older group. The results are suggestive of the potential for increased cardiovascular risk as a function of sensory stimulation in the elderly despite improvements on cognitive tasks. Additional research is needed to evaluate the multidimensional effects of extended sensory stimulation on the elderly.     

Age differences in sleep-wake behavior under natural conditions.

Differences in lifestyle may account for a considerable portion of the reported age-related changes in overt circadian rhythmicity. By instructing a group of healthy, noninstitutionalized, elderly subjects and a group of young adults to keep a sleep-wake log for a period of two weeks, and to wear an activity monitor for an overlapping period of 11 days, we attempted to assess age-related differences in the habitual sleep-wake behavior, in particular its day-to-day variability. Four clusters of coherent variables were constructed, reflecting (1) circadian phase, (2) variability of sleep-wake behavior, (3) sleep-wake continuity and (4) subjective sleep-wake quality. The results showed that, in comparison with the young subjects, the elderly had a relatively advanced and more regular sleep-wake pattern, reported more midnight awakening and did not differ in their subjective sleep evaluation. In spite of a greater regularity in their lifestyle (which would favor a larger amplitude of the overt circadian rhythmicity) oral temperature measurements showed some evidence of a weakened 24-h periodicity in the elderly.     

On resolving conflicting views of cognitive conflict

F. B. Murray's (Developmental Review, 1983, 3, 54–61) conclusion that a theoretically ambiguous relationship exists between cognitive conflict and Piaget's notion of equilibration was considered. It was suggested that theoretical clarity can be achieved if a distinction is drawn between conflict induction (disequilibrium) and conflict resolution (equilibration). Murray's suggestion that in Piaget's theory internal (cognitive) conflict can be mentally created was disputed. G. N. Cantor's (Developmental Review, 1983, 3, 39–53) concerns about the adequacy of the measures of internal conflict in B. J. Zimmerman & D. E. Blom's (Developmental Review, 1983, 3, 18–38) study due to their independence from external conflict manipulations was discussed. We agreed with Cantor that such findings obviate direct disconfirmation of an internal conflict construct; however, we suggested that evidence of conservation learning in the absence of either external or internal conflict renders Piaget's account less tenable.     

Study of unique merging behavior under mixed traffic conditions

Roads in developing countries carry mixed traffic with wide variations in static and dynamic characteristics of vehicles. The traffic flow is also generally devoid of lane discipline, with vehicles occupying any available road space ahead. In such a regime of traffic flow, the phenomena of merging of vehicles at intersections of two roads is complex, warranting further study. The merging maneuvers at T-intersections under congested traffic conditions were studied microscopically through video-recording. In congested situations, the merging vehicle attempts a complex merging maneuver to enter the main traffic stream. Two unique merging processes are commonly observed in mixed traffic: group and vehicle cover merging (these are generally not observed in countries such as US). The author is using these words first time in this study. These reflect the different types of driver behavior – merging in groups, and by taking cover of another vehicle. Probabilistic models for group and vehicle cover merging are developed that capture this unique merging behavior. Comprehensive microscopic data collection and extraction were carried out to study the merging process at T-intersection under congested conditions. Merging models were then estimated using maximum likelihood method with disaggregate data that was collected for a case study T-intersection in Chennai city, India. Such models can find applications in simulation of highly congested traffic flow in a realistic manner under mixed traffic conditions. They can also give insights on devising better traffic control measures at such intersections.