A Unified Empirical Account of Responsibility Judgments*

Skeptical worries about moral responsibility seem to be widely appreciated and deeply felt. To address these worries—if nothing else to show that they are mistaken—theories of moral responsibility need to relate to whatever concept of responsibility underlies the worries. Unfortunately, the nature of that concept has proved hard to pin down. Not only do philosophers have conflicting intuitions; numerous recent empirical studies have suggested that both prosaic responsibility judgments and incompatibilist intuitions among the folk are influenced by a number of surprising factors, sometimes prompting apparently contradictory judgments. In this paper, we show how an independently motivated hypothesis about responsibility judgments provides a unified explanation of the more important results from these studies. According to this ‘Explanation Hypothesis’, to take an agent to be morally responsible for an event is to take a relevant motivational structure of the agent to be part of a significant explanation of the event. We argue that because of how explanatory interests and perspectives affect what we take as significant explanations, this analysis accounts for the puzzling variety of empirical results. If this is correct, the Explanation Hypothesis also provides a new way of understanding debates about moral responsibility.     

Simultaneous switching of auditory transients For two-channel presentation

A modification of the Grason-Stadler Series 829 D&E Electronic Switches that enables simultaneous cross-channel presentation of auditory signals at the two ears is described.     

Behavioral and neuronal attributes of short- and long-term habituation in the crab Chasmagnathus

Investigations using invertebrate species have led to a considerable progress in our understanding of the mechanisms underlying learning and memory. In this review we describe the main behavioral and neuronal findings obtained by studying the habituation of the escape response to a visual danger stimulus in the crab Chasmagnathus granulatus. Massed training with brief intertrial intervals lead to a rapid reduction of the escape response that recovers after a short term. Conversely, few trials of spaced training renders a slower escape reduction that endures for many days. As predicted by Wagner’s associative theory of habituation, long-term habituation in the crab proved to be determined by an association between the contextual environment of the training and the unconditioned stimulus. By performing intracellular recordings in the brain of the intact animal at the same time it was learning, we identified a group of neurons that remarkably reflects the short- and long-term behavioral changes. Thus, the visual memory abilities of crabs, their relatively simple and accessible nervous system, and the recording stability that can be achieved with their neurons provide an opportunity for uncovering neurophysiological and molecular events that occur in identifiable neurons during learning.     

Hippocampal injections of amyloid beta-peptide 1-40 impair subsequent one-trial/day reward learning

The injection of amyloid beta-peptide (Abeta) into rat CNS has been reported to induce cellular neuropathology. The present study investigated whether multiple intrahippocampal injections of Abeta 1-40 would impair one-trial/day reward learning 14 days later. Twenty-four male Sprague-Dawley rats, 3-4 months old, were injected with either Abeta 1-40 or distilled water into seven hippocampal sites bilaterally. Ten rats received 3 nmol Abeta 1-40 in 2 microl of distilled water per injection site, while 14 rats received distilled water alone. Following a 9-day recovery period, rats were gradually food deprived to 82% of their initial body weight. Fourteen days after the intrahippocampal injection, all rats received an initial training trial and three subsequent daily retention trials. Rats receiving Abeta 1-40 were significantly impaired on the second retention trial in terms of accuracy (number of unbaited alleys entered) and on the second and third retention trials in terms of speed (reciprocal of latency to reward). Histological analysis showed that Abeta 1-40 injections produced significant neuronal loss and gliosis. Abeta 1-40 immunoreactivity persisted locally at the injection site and in macrophages 2 weeks following the hippocampal injections. These effects appear to be sequence-specific; rats receiving Abeta 1-42 with a scrambled peptide sequence did not differ significantly from rats receiving distilled water alone in retention of the learning task or degree of histological damage.     

Is there an optimal factor structure of the Positive and Negative Syndrome Scale in patients with first‐episode psychosis?

The Positive and Negative Syndrome Scale (PANSS) is the most widely used scale to assess a variety of symptoms in patients with schizophrenia and other psychoses. The factor structure of the PANSS has been examined with confirmatory factor analyses in several studies, but not in a well‐defined first‐episode psychosis sample. The aim of this paper is to examine the statistical fit of five different PANSS models in a first‐episode, non‐affective psychosis sample. Confirmatory factor analyses were performed on PANSS data (n = 588). A main criterion for best fit was defined as the Expected Cross Validation Index (ECVI). No tested model revealed an optimally satisfactory model fit index. The Wallwork/Fortgang five‐factor model demonstrated the most optimal psychometric properties. The corresponding subscales of all evaluated five‐factor models were strongly intercorrelated. The Wallwork/Fortgang five‐factor model was found to be statistically and clinically ideal among patients with first‐episode psychosis. Therefore, we recommend this model in forthcoming studies among patients with first‐episode psychosis. However, to prevent the loss of clinically valuable information on an item level, we do not recommend removing any items from the original form. Our study also implies that the specific choice of model will not have a substantial effect on outcome results in studies on the course and outcome in first‐episode psychosis.     

Gender differences on the Five to Fifteen questionnaire in a non‐referred sample with inattention and hyperactivity‐impulsivity and a clinic‐referred sample with hyperkinetic disorder

Lambek, R., Trillingsgaard, A., Kadesjö, B., Damm, D. & Thomsen, P. H. (2010). Gender differences on the Five to Fifteen questionnaire in a non‐referred sample with inattention and hyperactivity‐impulsivity and a clinic‐referred sample with hyperkinetic disorder. Scandinavian Journal of Psychology 51, 540–447. The aim of the present study was to examine gender differences in children with inattention, hyperactivity, and impulsivity on the Five to Fifteen (FTF) parent questionnaire. First, non‐referred girls (n = 43) and boys (n = 51) with problems of attention and hyperactivity‐impulsivity and then clinic‐referred girls (n = 35) and boys (n = 66) with hyperkinetic disorder (HKD) were compared on the FTF. Results suggested that non‐referred boys were more hyperactive‐impulsive than non‐referred girls, whereas clinic‐referred boys and girl with HKD were more similar than dissimilar on the FTF questionnaire. Secondly, it was examined whether the application of gender mixed norms versus gender specific norms would result in varying proportions of clinic‐referred children with HKD being identified as impaired on the subdomains of the FTF questionnaire. Based on results it was concluded that the use of a gender mixed normative sample may lead to overestimation of impairment in boys with HKD, but the type of sample applied to define impairment on the FTF should depend on the purpose for applying the questionnaire.     

Effect of low dose ionizing radiation exposure in utero on cognitive function in adolescence

Heiervang, K. S., Mednick, S., Sundet, K. & Rund, B. R. (2010). Effect of low dose ionizing radiation exposure in utero on cognitive function in adolescence. Scandinavian Journal of Psychology, 51, 210–215. Radiation from the Chernobyl nuclear power plant meltdown greatly affected several Norwegian counties. The cognitive consequences of in utero exposure to radiation from the Chernobyl accident have been intensely debated. This study examines the cognitive outcomes for those Norwegians who were exposed as fetuses to the fallout from Chernobyl. The participants, 84 adolescents who were exposed in utero to radiation from the most contaminated areas in Norway and 94 adolescents from areas not contaminated by the radiation, were tested on verbal and nonverbal IQ. Two data analyses were conducted. First, using a control‐group design, the IQ scores of exposed and unexposed adolescents were compared. Second, in a timing‐of‐exposure design, those exposed during the most sensitive period were contrasted with those exposed later in gestation. Adolescents exposed to low‐dose ionizing radiation in utero scored significantly lower in full‐scale IQ than unexposed adolescents. The difference was restricted to verbal IQ and was not evident for nonverbal IQ. The effect was not observed in exposed adolescents who had passed the most sensitive gestational period prior to the accident and thus were exposed to the radiation from Chernobyl exclusively after gestational week 16. These participants performed as well as the controls. Although the results should be interpreted cautiously due to the study’s nonrandomized design, the data add new and important support to the hypothesis that the Chernobyl accident may have had a subtle effect on the cognitive functioning of those exposed to low‐dose ionizing radiation in utero during the most sensitive gestational period.     

A methodological study of auditory lateralization

The just-noticeable-shift (JNS) threshold of a centered image was determined for four naive Ss A two interval forced choice situation was used under the method of constant stimuli. The three manners of presentation of the intensity imbalance were as follows: (1) an increase in intensity at one ear, (2) a decrease in intensity at one ear, (3) an increase in intensity at one ear produced concommitantly with a decrease in intensity at the opposite ear. The sign test demonstrated significant differences between method (2) and methods (1) and (3).     

The neural basis of updating: Distinguishing substitution processes from other concurrent processes

Sörqvist, P. & Sætrevik, B. (2010). The neural basis of updating: Distinguishing substitution processes from other concurrent processes. Scandinavian Journal of Psychology, 51, 357–362. Most previous studies of updating processes have not been able to contrast processes of substituting items in memory with other concurrent processes. In the present investigation, we used a new task called “number updating” and an fMRI protocol to contrast the activation of trials that require item substitution (adding a new item to the working memory representation and suppressing an old item) with trials that involve no substitution (discarding the new item). Trials that require item substitution activated the dorsolateral prefrontal cortex, the posterior medial frontal cortex and the parietal lobes, areas typically seen activated for working memory tasks in general. Trials that do not require substitution activated the anterior medial frontal cortex. Studies examining executive functions have associated this area with cognitive conflict, and may represent suppression of the substitution processes.