Presentism,truthmakers and distributional properties

Presentists face a challenge from truthmaker theory: if you hold that the only existing objects are presently existing objects and, moreover, you agree that truth supervenes on being, then you will be hard pressed to identify some existent on which a given true but traceless claim about the past supervenes. Cameron (Philos Books 49:292–301, 2008, Oxford Studies in Metaphysics, In: D Zimmerman (ed), 2011) aims to meet this challenge by appeal to distributional properties. So, to give a simple example, the truth that you were once a child supervenes on you presently instantiating the property of being initially a child and then an adult, a property distributed over time. I argue that a presentist ought to deny that distributional properties can serve as truthmakers.     

Instrumental performance on negative schedules

Three experiments examined the performance of rats pressing a lever for food reinforcement on a schedule in which high rates of response resulted in lowered rates of reinforcement (i.e. a schedule with a negative component). In Experiment 1, rats responded on a variable interval (VI) schedule with a conjoint component such that every 30 responses a reinforcement programmed by the VI schedule was cancelled. These subjects generally emitted a lower response rate than rats responding on a VI schedule yoked to the former subjects with respect to the delivery of reinforcement, although response rate differences were sometimes not large. Similar response-rate effects were obtained in Experiment 2 using a within-subject yoking procedure. In Experiment 3, reinforced interresponse times were matched on negative and VI schedules yoked in terms of reinforcement rate, and the response rate emitted in these conditions were similar. These results give support to theories of instrumental conditioning that stress the strengthening and shaping properties of reinforcement.     

Book reviews

Gale. A., & Eysenck, M.W. (Eds.). (1992). Handbook of individual diffeences: Biological perspectives. Chicheste: Wiley. Pp. 395. ISBN 0-471-91155-0. £59.95 (Hbk.).

Honig, N. (1988). Pesonality: In seach of individuality. New York: Academic Press. Zuckeman, M. (1991). Psychobiology of Personality. Cambridge: Cambridge University Press.

McGrew, W.C (1992). Chimpanzee mateial culture: Implications fo human evolution. Cambridge: Cambridge University Press. Pp. xvi + 277. ISBN 0-521-41303-6. £40.00 (Hbk.). ISBN 0-521-42371-6. £16.95 (Pk.).

McGego, P.K. (Ed.) (1992). Playback and studies of animal communication. NATOASI Series Vol. 228. New York: Plenum Press. Pp. x + 231. ISBN 0-306-44205-1. Us$90.00 (Hbk.).

Gibson. K.R., & Ingold. T. (1993). Tools, language and cognition in human evolution. Cambridge: Cambridge University Press. Pp. xii + 483. ISBN 0-521-41474-1. £45.00 (Hbk.).

Amsel, A. (1992). Frustration theoy: An analysis of dispositional learning and memoy. Cambridge: Cambridge Univesity ress. Pp. xiii + 278. ISBN 0-521-24784-5. £35.00 (Hbk.).     

Influence of the schedule of outcome presentation on causality judgements

Experiments examined the effect of various relationships between a response (pressing the space bar of a computer) and an outcome (a triangle flashing on a screen) on judgements of the causal effectiveness of the response. As the mean number of responses required per outcome on a variable-ratio (VR) schedule (Experiment 1) or the mean temporal interval on a variableinterval (VI) schedule (Experiment 2) increased, ratings of causal effectiveness of that response decreased. In Experiment 3, yoking procedures matched either the number of responses required per outcome or the temporal distributions of outcomes on a VI and a VR schedule, and responses on the VI schedule were rated more causally effective. In Experiment 4, the overall feedback function on a tandem VI VR and a tandem VR VI schedule was matched, and responses performed on the tandem VR VI schedule were rated as more causally effective.     

The effect of signaled reinforcement on rats' fixed-interval responding

Four experiments examined the effect on rats' response rate of presenting a brief (500 ms) stimulus simultaneously with the delivery of food on fixed-interval (FI) schedules. In Experiment 1, reinforcement signals that were spatially diffuse (both tones and lights) elevated rates of responding, but responding was attenuated by localized visual stimuli. The remaining experiments examined the signal-induced potentiation of responding. In Experiment 2, a tone reinforcement signal potentiated response rates on an FI schedule, but attenuated response rates on a variable-interval (VI) schedule. This difference was obtained even though the overall rate of responding was equated on the two schedules before the introduction of the signal. Signal-induced potentiation of responding occurred over a range of FI values employed in Experiment 3. In Experiment 4, presenting a reinforcement signal when high local rates of response had occurred immediately before reinforcement resulted in potentiated rates of responding on an FI schedule. The opposite effect on response rate occurred when the reinforcement signal followed only low local rates of response. These results indicate that a variety of factors influence the effects of a reinforcement signal. They imply, however, that the local rate of response at the time of reinforcement is a key factor in establishing the nature of the signaling effect.     

Is there brief temporal buffering of successive visual inputs?

The part-report advantage has been used to identify short-lived forms of visual storage (Sperling, 1960). We adopt the part-report paradigm to test whether visual memory can preserve, for a brief time, successive inputs and their temporal order. In our experiments, two successive arrays, each of 4 digits, were presented on each trial. The two arrays were spatially coincident, and each was followed by a random pattern-mask. In the part-report conditions, an auditory cue indicated whether the participant should report the first array or the second array. The results consistently showed a part-report advantage, which ranged in size from 16% to 37%. Delaying the cue by 500?ms abolished most of this advantage, in that performance was then similar to that in whole-report conditions. Subsequent experiments confirmed that the part-report superiority we measure is not achieved by (a) making eye movements that spatially displace the second array relative to the first; (b) extracting information from a single snapshot containing an integrated representation of the targets and masks; or (c) transferring a subset of material to a phonological store. We propose instead that observers have access to a limited, rapidly decaying representation of successive visual inputs stored in temporal sequence.     

"The Great Transformation" and suicide: local and long-lasting effects of 1930 bank suspensions

Depression-era bank suspensions and failures are conceptualized as products of the first part of what Polanyi (1994) called "The Great Transformation," which involved an imbalanced institutional arrangement in which the economy dominated other institutions. Relying on Durkheim (1897/1951) and Merton (1938, 1968), it is argued that these banking problems accentuated the type of chronic anomie that Durkheim theorized would create normative deregulation and elevated suicide rates over the long-term. Results from county-level analyses are supportive as the 1930 bank suspension rate is positively related to the 2000 suicide rate, controlling for contemporary and historical factors. The mediating roles of integration and chronic anomie are considered, with the latter measured using data from the geocoded General Social Survey.     

We're all career researchers now: breaking open career education and DOTS

This paper reviews career education in the UK's statutory, further and higher education sectors, and finds that, despite considerable changes in theory, provision remains based on the traditional DOTS model of decision learning, opportunity awareness, transition learning and self-awareness. It is argued that the persistent and hegemonic status of this model has delayed the adoption of innovative theory and the development of creative new frameworks. In order to provide policy and practice with new perspectives, a critical reassessment of the DOTS model is conducted, focusing on three areas: theoretical roots; individual-environment interpenetration; and self-opportunity matching. The role of students as career researchers, illustrated by examples drawn from current career education practice, is proposed to indicate new directions for both subject specialists and careers workers.     

Justice Beyond Borders

Liberal theories of social justicefocus predominantly on the national, ratherthan international, level, and where they doaddress international concerns they insist thatprinciples of justice at the national levelhave priority over principles at theinternational level. We question the coherenceof this arrangement, given liberal theory'scommitment to moral equality of persons as suchrather than to that of particular sets of persons. What isat issue is whether liberal theory can providea coherent basis for international justice atall. If it is to do so, we suggest that it mustbe prepared to theorise beyond the nationstate, and to take a historical perspectivewhich takes into account the ways in whichcolonial power and exploitation have given riseto the problems of international justice weface today. This revised version was published online in July 2006 with corrections to the Cover Date.