Salience,Supervenience, and Layer Cakes in Sellars's Scientific Realism,McDowell's Moral Realism,and the Philosophy of Mind

Philosophical Studies -     

The influence of response-effect compatibility in a serial reaction time task

Participants performed a serial reaction time task, responding to either asterisks presented at varying screen locations or centrally presented letters. Stimulus presentation followed a fixed second-order conditional sequence. Each keypress in the experimental groups produced a contingent, key-specific tone effect. The critical variation concerned the mapping of tones to keys. In Experiment 1, keypresses in one control condition produced noncontingent tone effects, while in another control condition there were no tone effects. In Experiment 2, three different key-tone mappings were compared to a control condition without tone effects. The results show that tone effects improve serial learning when they are mapped to the response keys contingently and in a highly compatible manner. The results are discussed with reference to an ideomotor mechanism of motor sequence acquisition.     

Prospective cognitions in anxiety and depression: Replication and methodological extension

The present study presents a replication and methodological extension of MacLeod, Tata, Kentish, and Jacobsen (1997) with a nonclinical sample, using future-directed imagery to assess prospective cognitions. Results showed that only anxiety (but not depression) was related to enhanced imagery for future negative events. Both anxiety and depression showed significant zero-order correlations with reduced imagery for future positive events. However, when the overlap between anxiety and depression was controlled for, only depression (but not anxiety) showed a unique association with reduced imagery for positive events. Implications of these findings for cognitive models of anxiety and depression are discussed.     

Effects of noradrenergic activity on temporal information processing in humans

Temporal processing of durations in the range of seconds or more is mediated by working-memory mechanisms whereas processing of brief durations in the range of milliseconds appears to be beyond cognitive control and modulated by dopaminergic activity in the basal ganglia. In the present study, the effects of the selective noradrenaline reuptake inhibitor reboxetine on temporal information processing were evaluated. In a double-blind crossover design, either placebo or 2 or 4 mg of reboxetine were administered to 24 healthy male volunteers. Performance on temporal discrimination of longer durations, as indicated by 75%-difference thresholds in relation to a 1,000-ms standard interval, was significantly improved by 2 mg of reboxetine as compared to placebo, whereas the improvement observed with the 4-mg dose just failed to reach statistical significance. There was, however, no effect of reboxetine on temporal discrimination of extremely brief durations, as indicated by threshold values in relation to a 50-ms standard interval. Findings provided additional evidence for the notion that temporal processing of durations in the range of seconds is based on working-memory processes including aspects of directed attention. In timing of brief durations in the range of milliseconds, however, noradrenergic activity didnot seem to play a critical role.