Central response selection is present during memory scanning, but hand-specific response preparation is absent

Two experiments were performed to replicate the results of Ilan and Miller that response selection but no response-hand specific preparation is present during memory scanning. Letter-case determined which hand would respond, while memory set membership status determined whether the response was to be executed (go) or withheld (nogo). In Exp. 1, the LRP was observed as an index of response-hand specific preparation. In Exp. 2, the consistency effect derived from the response priming paradigm was observed as an index of more central response selection. The results replicate those of Ilan and Miller and suggest that central response selection is present during short-term memory scanning, but hand-specific response preparation is absent. Apparently, preliminary information is transmitted to the response selection stage during memory scanning, a finding that is inconsistent with serial stage models, but memory scanning interferes with hand-specific response preparation. Received: 30 March 1998 / Accepted: 30 November 1998     

Car following from the driver’s perspective

In this commentary, it is argued that the car following models discussed in Brackstone, M., and McDonald, M. (Transportation Research – Part F (2000), pp. 181–196) ignore one or more of the following issues that characterize to observed driver behavior. These include: (i) car following is only one of many tasks that drivers perform simultaneously and receives therefore only intermittent attention and control (task scheduling/attention management), (ii) drivers are satisfied with a range of conditions that extend beyond the boundaries imposed by perceptual and control limitation (satisficing instead of optimal performance evaluation), and (iii) in each driving task drivers use a set of highly informative perceptual variables to guide decision making and control (perceptual rather than Newtonian input). To elucidate these issues, a general driver modeling framework is presented in which the car-following task is highlighted (Boer, E. R., & Hoedemaeker, M. (1998). In Proceedings of the XVIIth European Annual Conference on Human Decision making and Manual Control December 14–16. France: Valenciennes; Boer, E. R., Hildreth, E. C., & Goodrich, M. A. (1998). In Proceedings of the XVIIth European Annual Conference on Human Decision making and Manual Control December 14–16. France: Valenciennes).     

Organization of and access to semantic memory in aphasia

Previous experiments with picture sorting and matching tasks have shown aphasics to give more deviant responses than controls when decisions require the identification of single features of concepts, whereas their responses are close to normal whenever decisions have to be based on the relative overlap of broad associative fields. The present experiment was designed to compare picture matching based on single features (property verification) with picture matching based on category membership (category verification). Fifty-five aphasics (14 amnesics, 18 Brocas, 13 Wernickes, 10 global aphasics) and 29 right-brain-damaged control patients served as subjects. Aphasics were poorer than right hemisphere controls on property as well as on category sortings, especially when the sorting criterion was not a dominant property of the object or when the object in question was not a typical member of the criterion category. Contrary to other studies, the "semantic distance" variable did not differentially affect Brocas as compared to Wernickes aphasics. Verbal labels denoting the sorting criterion and added to the picture presentation did not affect the performance of the right hemisphere controls but significantly improved that of the aphasics.     

Event-related potential indices of ambiguous sentence processing

An event-related potential (ERP) probe was used to examine various models of ambiguous sentence processing. ERPs to light flashes were recorded during and immediately after auditorily presented ambiguous and unambiguous target sentences. Each target sentence was preceded by either a relevant or a neutral context sentence. Principal component analyses of the ERPs indicated that although certain components varied as a function of ambiguity, none of the components varied as a function of preceding context. These findings provided some support for a postdecision model of ambiguity processing which suggests that both meanings of an ambiguity are always processed, even when prior disambiguating context is available.     

Effects of level of arousal and type of task on bilateral skin conductance asymmetry and conjugate lateral eye movements

Several recent studies have indicated that the degree and direction of bilateral skin conductance (BSC) asymmetry and the direction of conjugate lateral eye movements (CLEMs) both index hemispheric functioning. Evidence also suggests that BSC asymmetry decreases and CLEMs become more unidirectional as level of arousal increases. Thirty-two normal adults received an habituation series of five-second tones followed by 40 questions. All stimuli were tape recorded. The questions (Schwartz, Davidson, and Maer, 1975) were grouped in four series: 10 verbal-emotional, 10 verbalnonemotional, 10 spatial-emotional, and 10 spatial-nonemotional. The order in which the four series were presented was counterbalanced across subjects. Prior to each question, subjects fixated the face of a mannequin. Sixteen subjects (high arousal) had five seconds to contemplate their answer; the remaining 16 (low arousal) had 10 seconds. Instructions for the high arousal group specified that intelligence and problem-solving ability was being tested, and that speed and accuracy were very important. Those for the low arousal group indicated casually that subjects were to ponder a series of questions. BSC levels, SC response amplitudes, and CLEMs were measured during a five-second interval following each tone or question. BSC levels were greater under the High Arousal condition. While approximately two-thirds of the subjects showed BSC asymmetry (roughly evenly divided between those with larger left and right hand responses), neither the degree nor direction of the asymmetries changed as a function of question type. While CLEM direction was more sensitive to question type under low arousal, (i.e., verbal questions resulted in predominantly right-going CLEMs and spatial questions resulted in predominantly left-going CLEMs) they tended to be stereotyped (i.e., unidirectional) under high arousal. Finally, no relationship was observed between CLEM direction and BSC asymmetry under either high or low arousal condition.     

“It takes a village to heal a child”: Necessary spectrum of expertise and benevolence by therapists,Non-Governmental Organizations,and the United Nations in managing war-zone stress in children traumatized by political violence

This article highlights the post-traumatic stress responses in some war-zone children who were exposed to political violence—witnessing unspeakable horror, maimings, brutal beatings, torture, and murders. Children inducted into rebel military units to serve as child-soldiers further traumatized self and others by raping and killing children and adults. Additionally, some children go without food, shelter, and adult protection, while finding themselves as refugees in a foreign country. This article advances some conceptual, technical, and practical issues in intervention with these children and provides a model of intervention that seeks to integrate established international policies of the United Nations (UN) and Non-Governmental Organizations (NGOs) along with cognitive, behavioral, and psychodynamic clinical approaches in the context of cultural/racial sensitivity and indigenous folk medicine. The child's adaptational strengths are discussed, and the recognition and management of transference and countertransference are not ignored in the treatment of traumatized children. Basically, the author's point of view is that Western models of interventions are very useful, but that the personal, cultural, social, spiritual, and economic resources of the child's homeland or village probably constitute the best system for healing and integration after brief or continuous exposure to political violence.