Fiction as a Base of Interpretation Contexts

In this paper, I want to deal with the problem of how to find an adequate context of interpretation for indexical sentences that enables one to account for the intuitive truth-conditional content which some apparently puzzling indexical sentences like “I am not here now” as well as other such sentences contextually have. In this respect, I will pursue a fictionalist line. This line allows for shifts in interpretation contexts and urges that such shifts are governed by pretense, which has to be understood in terms of socially shared make-believe games. By appealing to pretense so conceived, I will show that the fictionalist perspective is halfway between an intentionalist perspective, according to which the above indexical sentences have to be interpreted in a shifted intended context, (this perspective is primarily defined by Predelli 1998, Analysis 58, 107; Mind and Language 13, 400) and a conventionalist perspective, according to which indexical reference shifts in accordance with a conventional setting. (For this perspective, cf. Corazza et al. 2002, Philosophical Studies 107, See also Corazza 2004, Reflecting the Mind: Indexicality and Quasi-Indexicality, Oxford University Press). Finally, I will claim that the fictionalist analysis of cases of non-ordinary uses of indexicals like “here” and “now” can be retained in face of a new alternative analysis of those cases in terms of an ‘unbound anaphora’ – theory (cf. Corazza 2004, Synthese 138, 145).     

Stimulus duration as a measure of stimulus generalization

Four pigeons in the line-positive group were trained with a vertical line on a green background that signalled intermittent reinforcement while a plain green field signalled extinction. Four pigeons in the line-negative group were trained with the opposite discrimination. Response to a control key terminated any trial and initiated the next trial. The birds also used the control key during generalization tests to control the durations of trials in which various line orientations were presented. These durations were summed to provide generalization gradients of stimulus duration that were positive or negative in accordance with the trained discriminations. In Experiment 2, birds from the line-positive group were tested with a procedure in which the control key was not available on some trials. This provided an independent assessment of response rates to the test stimuli. These rates were used to predict the stimulus durations obtained when the control key was available. The findings supported a general model for the prediction of response distributions among concurrent stimuli from rates observed with single stimuli.     

The Effect of Stimulus Preexposure on Responding during a Compound Stimulus

In two experiments with rats, three stimuli, A, B, and X, were used for an AX+ BX+ Xo discrimination in which food was presented after the simultaneous presentation of A and X, or B and X, but never after X by itself. For one group in each experiment, X was repeatedly presented by itself before the start of discrimination training. This manipulation weakened responding on test trials in which the three stimuli were presented together. The results are interpreted in terms of a configural theory of conditioning that assumes that preexposure to a stimulus will reduce its capacity to promote generalization among different configurations to which it belongs.     

Stimulus selection with duration as a relevant cue

To date, research has not explicitly examined how duration competes with other stimulus dimensions for control over responding. The present study investigated some familiar selective mechanisms of stimulus control over key pecking in pigeons, with duration and line tilt as discriminative stimuli in successive discrimination procedures. Specifically, pigeon's key pecking was reinforced with food or extinguished following compound stimuli comprising one of two line orientation stimuli presented for one of two different durations. Traditional experimental designs explored stimulus additivity, overshadowing, blocking, and learned irrelevance. Although stimulus additivity was observed, control by duration was masked by line tilt in extinction testing that followed facilitated acquisition with redundant, relevant cues. In addition, although prior training with duration relevant partially blocked subsequent acquisition of control by line tilt when both stimulus dimensions were relevant, there was a tendency for control by duration to decrease with continued compound training. It was suggested that the greater time required to distinguish duration on a trial—compared to more commonly studied stimulus dimensions, which can be distinguished almost immediately—puts duration at a competitive disadvantage in situations where other relevant dimensions are also available.     

The Perceptual Centre of a Stimulus as the Cue for Synchronization to a Metronome: Evidence from Asynchronies

In tasks where subjects are required to tap in synchrony to a sequence of evenly spaced uniform auditory stimuli (a metronome), tap onsets typically tend to anticipate the metronome's stimulus onsets. We investigated this phenomenon, called “negative asynchrony”, as a function of (1) the duration of the stimuli (1 or 2, 50, 100, and 300 msec), (2) the rise time of the stimuli (0%, 40%, and 80% of stimulus duration), and (3) the interstimulus onset interval duration (500, 700, and 900 msec). The results from three experiments with 28 different subjects showed a significant reduction of the negative asynchrony with longer stimulus durations, and the reduction was not significantly affected by the tempo of the stimulus sequence. Also, a prolongation of the rise time of the stimuli caused an analogous reduction of the negative asynchrony. Findings were taken to suggest that subjects use the perceptual centre rather than physical onset of stimulus as the cue with which to synchronize     

The Reinforcing Effect of a Differentiating Stimulus

Twenty Sprague Dawley rats, aged 22 to 26 months were given subcutaneous injections of 4.5 mg/kg methylphenidate or distilled water. Twelve minutes after the single injection was given, rats began 90 trials of avoidance conditioning. Drug animals made significantly more correct responses than did the control animals. Results indicate that use of methylphenidate in aged rats improved avoidance learning.     

The Conception of a Person as a Series of Mental Events

It is argued that those who accept the psychological criterion of personal identity, such as Parfit and Shoemaker, should accept what I call the 'series' view of a person, according to which a person is a unified aggregate of mental events and states. As well as defending this view against objections, I argue that it allows the psychological theorist to avoid the two lives objection which the 'animalist' theorists have raised against it, an objection which causes great difficulties for the conception of a person that most psychological theorists favour, the constitution view. It is also argued that the series view allows that people can body swap and teleport, which the constitution view–which takes a person to be a physical object (but a distinct physical object from the human being)–has great trouble with.