The role of preference in speed choice

Individual differences with regard to speed preference may be a source of speed heterogeneity and conflicts in traffic, such as tailgating and dangerous overtaking. The main aim of the current study was to explore drivers’ speed preferences when driving for different reasons (saving money on fuel, driving safely, driving for fun or driving as usual) and the relationship of these preferences to observed speeds and self-reported speed. 193 drivers were interviewed at five different locations, and were asked about their speeds on roads they had just travelled. Drivers’ speeds on these roads were also sampled with a speed gun. The results showed large differences between speeds chosen for different driving purposes; the lowest speeds were chosen when the goal was economy and the highest when driving for fun. In addition, there were individual differences in speed preferences such that some drivers indicated that their usual speed was above what they believed was a safe speed while others indicated that they usually drove even slower than what they thought was safe. These differences may account for much of the speed heterogeneity observed in on-road behaviour. The results also showed that drivers’ speed choices are highly influenced by their usual speeds, even more so than their beliefs regarding what constitutes a safe speed, which may help explain non-compliance with speed limits. No relationship was found between speed choice and risk perception.     

Transformations of mathematical and stimulus functions

Following a pretest, 8 participants who were unfamiliar with algebraic and trigonometric functions received a brief presentation on the rectangular coordinate system. Next, they participated in a computer-interactive matching-to-sample procedure that trained formula-to-formula and formula-to-graph relations. Then, they were exposed to 40 novel formula-to-graph tests and 10 novel graph-to-formula tests. Seven of the 8 participants showed substantial improvement in identifying formula-to-graph relations; however, in the test of novel graph-to-formula relations, participants tended to select equations in their factored form. Next, we manipulated contextual cues in the form of rules regarding mathematical preferences. First, we informed participants that standard forms of equations were preferred over factored forms. In a subsequent test of 10 additional novel graph-to-formula relations, participants shifted their selections to favor equations in their standard form. This preference reversed during 10 more tests when financial reward was made contingent on correct identification of formulas in factored form. Formula preferences and transformation of novel mathematical and stimulus functions are discussed.     

The distinction between positive and negative reinforcement: use with care

It is customary in behavior analysis to distinguish between positive and negative reinforcement in terms of whether the reinforcing event involves onset or offset of a stimulus. In a previous article (Baron & Galizio, 2005), we concluded that a distinction of these terms is not only ambiguous but has little if any functional significance. Here, we respond to commentaries by a group of distinguished behavior analysts about the issues we raised. Although several of the commentators argued for preservation of the distinction, we remain unconvinced that its benefits outweigh its weaknesses. Because this distinction is so deeply embedded in the language of behavior analysis, we hardly expect that it will be abandoned. However, we hope that the terms positive and negative reinforcement will be used with circumspection and with full knowledge of the confusion they can engender.     

Conditions under which children experience inhibitory difficulty with a "button-press" go/no-go task

Go/no-go tasks seem to provide a simple marker of inhibitory development in young children. Children are told to respond to one stimulus on go trials but to make no response to another stimulus on no-go trials; responding on no-go trials is assumed to reflect a failure to inhibit the go response. However, there is evidence to suggest that a type of go/no-go task, which we call the "button-press" task, does not require inhibition. We investigated the conditions under which young children (M=3 years 6 months, N=120) experience inhibitory difficulty with this type of task. The data suggest that the speed of stimulus presentation is crucial and that other studies using this type of task have presented the stimuli too briefly. The importance of establishing the inhibitory credentials of a task before it is used as a marker of inhibitory control is emphasized.