The fallacy beneath the base rate fallacy is that we know what a base rate is. We talk as if base rates and individuating information were two different kinds of information. From a Bayesian perspective, however, the only difference between base rate and individuating information is – which comes first.

The role of the cerebellum as a comparator of desired motor output and actual performance may be most important during learning of a novel motor task, when movement errors are common and corrective movements are produced to compensate for them. It is suggested that PET and recent fMRI data are compatible with such an interpretation. Increased activity in motor cortical areas during motor learning indicates that these areas also contribute to the learning process, [THACH]

Heyman's analysis of addiction in terms of matching to local relative value can be supplemented by stimulus-control processes. Stimulus equivalence can broaden the set of situations that occasion addictive behavior, and the situation-reinforcer correlation can enhance its persistence. The joint effects of stimulus-control and reinforcement processes may complicate treatment.

Investigations of metacognition – and also the application of the storehouse and correspondence metaphors – seem as appropriate for laboratory research as for naturalistic research. In terms of measurement, the only quantitative difference between the “input-bound percent correct” and “output-bound percent correct” is the inclusion versus exclusion (respectively) of omission errors in the denominator of the percentages.

Heyman's target article seeks to resolve the apparent paradox surrounding the issue of control in relation to addictive behaviour. The present commentary argues that addiction is in fact less paradoxical and more easily understandable than Heyman supposes. A fully satisfactory model of addiction, however, requires a more multifaceted approach than that provided by the type of behavioural choice theory favoured by Heyman.

Koriat & Goldsmith propose that the correspondence metaphor captures the essence of everyday memory research. We suggest that correspondence is often not at issue because objective assessments of everyday events are frequently lacking. In these cases, other questions arise, such as how individuals evaluate the validity of memories and the significance they attach to those evaluations.

We argue that the function of the cerebellum is more than just an error-detecting mechanism. Rather, the cerebellum plays an important role in all movements. The bias in (re)calibration is an unfortunate restrictive result of a very successful and important experiment, [SMITH, THACH]

Any instance (i.e., event, behavior, trait) belongs to infinitely many reference classes, hence there are infinitely many base rates from which to choose. People clearly do not entertain all possible reference classes, however, so something must be limiting the search space. We suggest some possible mechanisms that determine which reference class is evoked for the purpose of judgment and decision.

Heyman's model explains the irrationality of addictive behavior, but it does not satisfactorily answer the question of whether this behavior is voluntary because it does not address the issue of the choice of preference functions. Furthermore, although Heyman disconfirms the disease model of addiction, this does not resolve the issue of whether addiction should be classified as a mental illness.

The research guided by the correspondence metaphor is lauded for its emphasis on functional analysis, but the term “correspondence” itself needs clarification. Of the two terms in the relationship, only one is well defined. It is suggested that behavior at acquisition needs to be analyzed and that molecular principles from the learning laboratory might be useful in doing so.

Information for motor learning is likely to be stored by groups of Purkinje cells in the cerebellum as suggested by HOUK et al., though their proposal that Purkinje cells act as bistable elements is open to question. THACH's excellent article breaks new ground on what type of information the cerebellum may store. I have queries on whether the cerebellum can generate “thought” or is likely to engage in the purely mental learning of movements, [HOUK et al.; THACH]

Koehler is right that base rate information is used, to various degrees, both in laboratory tasks and in everyday life. However, it is not time to turn our backs on laboratory tasks and focus solely on ecologically valid decision making. Tightly controlled experimental data are still needed to understand how base rate information is used, and how this varies among groups.

The correspondence metaphor is useful in developing functional models of memory. However, the storehouse metaphor is still useful in developing structural and process models of memory. Traditional research techniques explore the structure of memory; everyday techniques explore the function of memory. We illustrate this point with two examples: amnesia and metamemory. In each phenomenon, both metaphors are useful.

Heyman s analysis of the relevant complex behavioral variables associated with addiction is evaluated in relation to identifying the appropriate variables in behavior analysis. The model of behavioral allocation and choice known as melioration, discussed by Heyman as a way to understand the complexities of addiction, is examined and contrasted with another model of matching called ratio invariance, which is offered in this commentary as another behavioral account with a significant potential for resolving the contradictions of addiction.

To examine the model of the biological motor control proposed by A. Smith, this commentary briefly introduces some result of stiffness measurements during multi-joint arm movements, and, in the light of these results, discusses how likely it is that stiffness is a control parameter and that the cerebellum solely codes the stiffness, [SMITH]

Consistent with Koehler's position, we propose a generalization of the base rate fallacy and earlier conservatism literatures. In studies using both traditional tasks and new tasks based on ecologically valid base rates, our subjects typically underweight individuating information at least as much as they underweight base rates. The implications of cue consistency for averaging heuristics are discussed.

Extreme sensations – thirst, pain – can focus attention on local consequences at the expense of the overall, perhaps for good evolutionary reasons. Maybe the same phenomenon evolves from prolonged use of addictive substances. The matching law explains mistaken choice, not how a person who has confronted personal catastrophe manages to ignore it in making a locally induced choice.

Classical antiquity provides not just the storehouse metaphor, which postdates Plato, but also parts of the correspondence metaphor. In the fifth century B.C., Thucydides (1.22) considered the role of gist and accuracy in writing history, and Aristotle (Poetics 1451b, 1460b 8–11) offered an explanation. Finally, the Greek for truth (alêtheia) means “that which is not forgotten.”

Base rates are vital in predicting violent criminal recidivism. However, both lay people given simulated prediction tasks and professionals milking real life predictions appear insensitive to variations in the base rate of violent recidivism. Although there are techniques to help decision makers attend to base rates, increased decision accuracy is better sought in improved actuarial models as opposed to improved clinicians.

This commentary reviews the case of a patient who could alter the coordination of her prehensile movements when removal of visual feedback reduced her kinetic tremor, but could not coordinate her hand aperture with her hand transport within a single movement. This suggests a dissociation between different subtypes of cerebellar context-response linkage, rather than a single, general association function, [THACH]