Agrammatic sentence production: is verb second impaired in Dutch?

This study investigates effects of verb movement in nine Dutch-speaking agrammatic aphasics. According to linguistic theory, in verb second languages such as Dutch and German, the verb remains in its clause-final base position in embedded clauses, whereas it moves to second position in main clauses. In recent linguistic accounts of agrammatic sentence production, it has been suggested that the production of sentences with moved verbs is relatively difficult. However, we argue that evidence provided by previous studies on this matter is inconclusive. An experiment is reported in which the production of both types of clauses is compared. No evidence is found that sentences with moved verbs are relatively difficult to produce. In fact, there was a tendency for the base order sentences to be harder. Implications of these findings for theories of normal and agrammatic sentence production are discussed.     

Health service use costs by personality disorder following specialist and nonspecialist treatment: a comparative study

The impact of specialist psychosocial treatment on health service use costs by patients with personality disorder is not yet sufficiently documented. In this prospective study we compare patterns of health service costs by three groups of people with personality disorder treated in a hospital-based program (IPP), a step down program (SDP), and a general psychiatric program (GPP). Total service use costs at follow up, compared with intake costs, showed that significantly higher savings were achieved by SDP and IIP compared with GPP. Cost reductions in SDP were significantly greater than in IPP. Significant cost reductions were found between treatment programs in social worker and community psychiatric nursing and psychotherapy. The cost-effectiveness of the two specialist treatment programs was indicated by the significant association between total cost reduction and clinical outcome in GPP and IPP, but not in GPP. The effect of Major Depression and Borderline Personality Disorder on health service use alone and in combination was also investigated. The finding that Major Depression was found to be more significantly associated with higher health service use costs than Borderline Personality Disorder is discussed.     

Automatic activation of task-related representations in task shifting

Stimulus displays consisting of a target and a distractor can produce task conflicts when target and distractor are associated with different tasks. The present study examined whether these stimulus-induced task conflicts are affected by priming the irrelevant task or by increasing the salience of the distractor. In a series of three experiments, we employed a task-shifting paradigm in which subjects had to apply one of two judgments to either the global or the local level of a hierarchical stimulus. In each block, the target level and the judgment were either constant or mixed. Stimulus-induced judgment conflicts were measured by comparing performance for stimuli associated with two judgments and stimuli associated with only one. It turned out that only mixing the target level and not mixing the judgment increased the conflicts. These findings indicate that only the salience of the distractor modulates stimulus-induced conflicts.     

Nested incremental modeling in the development of computational theories: the CDP+ model of reading aloud

At least 3 different types of computational model have been shown to account for various facets of both normal and impaired single word reading: (a) the connectionist triangle model, (b) the dual-route cascaded model, and (c) the connectionist dual process model. Major strengths and weaknesses of these models are identified. In the spirit of nested incremental modeling, a new connectionist dual process model (the CDP+ model) is presented. This model builds on the strengths of 2 of the previous models while eliminating their weaknesses. Contrary to the dual-route cascaded model, CDP+ is able to learn and produce graded consistency effects. Contrary to the triangle and the connectionist dual process models, CDP+ accounts for serial effects and has more accurate nonword reading performance. CDP+ also beats all previous models by an order of magnitude when predicting individual item-level variance on large databases. Thus, the authors show that building on existing theories by combining the best features of previous models--a nested modeling strategy that is commonly used in other areas of science but often neglected in psychology--results in better and more powerful computational models.     

Cognitive control under stress: how stress affects strategies of task-set reconfiguration

This study investigated the effect of stress on cognitive control in task shifting. Subjects shifted between two tasks in an explicit cuing paradigm. Shift costs (i.e., performance decrements on task shifts relative to task repetitions) were measured for a long and a short cue-stimulus interval (CSI). Stress was varied by administering low-stress and high-stress IQ scales to two groups of subjects. In the low-stress group, shift costs were reduced with an increased CSI, a result that typically indicates anticipatory and shift-specific task-set reconfiguration. In the high-stress group, however, shift costs were independent of the CSI. This result is consistent with the idea that stress induces a change in the reconfiguration strategy, possibly to adapt to depleted resources.     

Both exposure to a novel context and associative learning induce an upregulation of AKAP150 protein in mouse hippocampus

A-kinase anchoring protein 150 (AKAP150) is a multi-enzyme signaling complex that coordinates the action of PKA, PKC, and PP2B at neuronal membranes and synapses. We measured levels of AKAP150 protein in the hippocampus 6h after training mice in a contextual fear conditioning paradigm. In contextual fear conditioning mice learn to associate a context with a footshock presentation. Mice were divided in four experimental groups with different training protocols: naive, no footshock exposure, immediate footshock exposure, and footshock 3min after exposure to the context. We found that AKAP150 protein levels were increased upon exposing mice to the novel context independent of the training protocol. However, when the animals were habituated to the experimental context, only mice that learned to associate the context with the footshock showed an upregulation of AKAP150. We suggest that upregulated levels of AKAP150 contribute to processing the exposure to a novel context and associative learning.     

Failure to replicate the 'work ethic" effect in pigeons

We report six unsuccessful attempts to replicate the "work ethic" phenomenon reported by Clement, Feltus, Kaiser, and Zentall (2000). In Experiments 1-5, pigeons learned two simultaneous discriminations in which the S+ and S- stimuli were obtained by pecking an initial stimulus once or multiple (20 or 40) times. Subsequent preference tests between the S+ stimuli and between the S- stimuli mostly revealed indifference, on average, between the S+ from the multiple-peck (high-effort) trials and the S+ from the one-peck (low-effort) trials, and likewise between the two respective Sstimuli. Using a slightly different procedure that permitted assessment of the relative aversiveness of low versus high effort, Experiment 6 again revealed a pattern of indifference despite showing that pigeons took considerably longer to begin pecking on high- than on low-effort trials. Our findings call into question the reliability of the original findings and the sufficiency of the hypothesized within-trial contrast mechanism to produce them.     

Common and distinct factors in decision making under ambiguity and risk: A psychometric study of individual differences

The relation between decision making under ambiguity and risky decision making was examined. In Studies 1 and 2, choices under ambiguity were measured for a large sample receiving an Ellsberg-type Ambiguity-Probability Tradeoff Task. Participants with extreme scores were recruited for Part 2 of each study which consisted of a risky decision making task (Study 1) or a series of decisions under ambiguity in “real life” scenarios (Study 2). Despite a time gap of up to 2 months, individual differences in scores on Part 1 predicted scores on Part 2. In Study 3 participants received in a single session several risky decision making tasks, several measures of decision making under ambiguity, and several personality scales related to uncertainty and decision making style. Taken together, the findings support the existence of a stable dispositional trait to reduce uncertainty in decision making but also task-specific differences related to gains and losses.