Meta-analysis to predict sweating and respiration rates for Bos indicus, Bos taurus, and their crossbreds.

The overall objective of this work was to develop empirical equations from a meta-analysis study to be used to implement initial values in a mechanistic heat balance model. The meta-analysis was conducted to 1) develop prediction equations for sweating and respiration rate (SR, g·m(-2)·h(-1) and RR, breaths·min(-1), respectively) based on skin and body temperature (T(s) and T(b), °C, respectively) for different breed types: Bos indicus, Bos taurus, and their crossbreds, and 2) evaluate the fit of existing SR equations and the SR and RR equations (from objective 1) against independent data sets. Fourteen studies were collected for the SR analysis, 12 for fitting and 2 for evaluation. The fitted SR equations (Thompson model) for the 3 breeds types were B. indicus, SR = 0.085e(0.22·T(s)); B. taurus, SR = 0.75e(0.15·T(s)); and crossbreds, SR = 0.015e(0.25·T(s)). Twenty-three studies were collected for the RR analysis, 20 for fitting and 3 for evaluation. The fitted RR equations for the 3 breed types were B. indicus, RR = -1,660 + 43.8·T(b); B. taurus, RR = -1,385 + 37·T(b); and crossbreds, RR = -2,226 + 59·T(b). Three SR equations (Maia, McArthur, and Gatenby models) from the literature were evaluated against the Thompson model using the 14 studies. The McArthur model predicted SR within the correct range, but with an increased slope bias because the equation was linear and not the correct shape. The Maia model overpredicted SR for all breed types with the greatest overprediction being for crossbreds. The Gatenby model overpredicted SR for B. taurus (root mean square error of prediction = 506 g·m(-2)·h(-1)), but was the best predictor for B. indicus. The Thompson model overpredicted SR for B. indicus (root mean square error of prediction ranged from 134 to 265 g·m(-2)·h(-1)), but was the best predictor for B. taurus and crossbreds. The Thompson model was a good predictor for RR across all breed types. The meta-analysis showed that the Thompson model outperformed previous models for both RR and SR with the exception of the SR of B. indicus, which was best predicted by the Gatenby model.

Belief-based and covariation-based cues affect causal discounting.

Causal discounting occurs when the perceived efficacy of a putative cause is reduced by the presence of a stronger causal candidate. Previous studies of causal discounting have defined the strength of causal candidates in terms of the degree to which the cause and the effect covary (e.g., Baker, Mercier, Vallee-Tourangeau, Frank, & Pan, 1993). In contrast, in the present study, causal strength was defined in terms of both covariation- and belief-based cues. Seventy-two participants made causality judgments for a fictional causal candidate both in isolation and when paired with either a stronger or a weaker cause. The results demonstrated that the degree to which a causal candidate is discounted depends not only on the degree to which an alternative cause covaries with the effect, but also on whether the alternative is a believable or unbelievable candidate. Indeed, it was observed that a highly believable alternative will produce the discounting effect, even if it is a weaker covariate than the original candidate. These findings suggest the need to incorporate both belief-based and covariation-based cues into models of causal attribution.

Frequency versus probability formats in statistical word problems.

Three experiments examined people's ability to incorporate base rate information when judging posterior probabilities. Specifically, we tested the (Cosmides, L., & Tooby, J. (1996). Are humans good intuitive statisticians after all? Rethinking some conclusions from the literature on judgement under uncertainty. Cognition, 58, 1-73) conclusion that people's reasoning appears to follow Bayesian principles when they are presented with information in a frequency format, but not when information is presented as one case probabilities. First, we found that frequency formats were not generally associated with better performance than probability formats unless they were presented in a manner which facilitated construction of a set inclusion mental model. Second, we demonstrated that the use of frequency information may promote biases in the weighting of information. When participants are asked to express their judgements in frequency rather than probability format, they were more likely to produce the base rate as their answer, ignoring diagnostic evidence.

The task-specific nature of domain-general reasoning.

This paper develops a theory of how interpretative processes constrain inferential performance on conditional reasoning tasks. Experiment 1 investigated the hypothesis that performance on common reasoning tasks is mediated by different interpretive variables. Necessity and sufficiency relations predicted performance on the conditional arguments task, whereas on the Wason task, performance was predicted by whether the conditional statement instantiated a deontic or a factual relation. Performance on the truth-table task was predicted by both sets of variables. Experiment 2 explored the mapping relation between interpretation, representation, and inference. It was observed that conditional responses to the Wason and arguments tasks were based on different representations of the conditional relationship. These data rule out a simple model of the interplay between interpretation and reasoning in which the interpretation of a statement is driven solely by its content, and instead, indicate that the interpretation of conditional relations is task-specific.

Strategy selection in causal reasoning: when beliefs and covariation collide.

The present study investigated how people combine covariation information (Cheng & Novick, 1990, 1992) with pre-existing beliefs (White, 1989) when evaluating causal hypotheses. Three experiments, using both within- and between-subjects designs, found that the use of covariation information and beliefs interacted, such that the effects of covariation were larger when people assessed hypotheses about believable than about unbelievable causal candidates. In Experiment 2, this interaction was observed when participants made judgments in stages (e.g., first evaluating covariation information about a causal candidate and then evaluating the believability of a candidate), as well as when the information was presented simultaneously. Experiment 3 demonstrated that this pattern was also reflected in participants' metacognitive judgments: Participants indicated that they weighed covariation information more heavily for believable than unbelievable candidates. Finally, Experiments 1 and 2 demonstrated the presence of individual differences in the use of covariation- and belief-based cues. That is, individuals who tended to base their causality judgments primarily on belief were less likely to make use of covariation information and vice versa. The findings were most consistent with White's (1989) causal power theory, which suggests that covariation information is more likely to be considered relevant to believable than unbelievable causes.

Perceived necessity explains the dissociation between logic and meaning: the case of "only if".

The purpose of this article was to investigate why sentences of the form "p only if q" often appear to have a different meaning than sentences of the form "if p, then q," despite their logical equivalence. The results of 3 experiments indicate that when "if ... then" statements were equated with respect to necessity and temporal relations, different pragmatic relations (such as permission, causation, etc.) elicited similar "only if" judgments. However, different necessity relations elicited different "only if" judgments, regardless of the type of pragmatic relation expressed in the "if then" statement. These data suggest that "only if" judgements are primarily mediated by necessity and temporal relations and that pragmatic contexts may play a more indirect role, such as in the interpretation of necessity and temporal relations. Suggestions for how these findings might be incorporated into pragmatic schema theory (P. W. Cheng & K. J. Holyoak, 1985; P. W. Cheng, K. J. Holyoak, R. E. Nisbett, & L. M. Oliver, 1986) and mental models theory (P. N. Johnson-Laird & R. M. J. Byrne, 1991) are discussed.

Interpretational factors in conditional reasoning.

Two experiments examined the role of necessity and sufficiency relationships in conditional reasoning. The results indicated that perceived necessity and sufficiency predicted variability in reasoning performance for four pragmatic relations (permission, obligation, causation, and definition), for both determinant and indeterminant syntactic forms, and for both a conditional arguments and a truth table evaluation task, as well as when the temporal relationship between the antecedent and consequent events was reversed. These data support the general utility of perceived necessity and sufficiency in the interpretation and evaluation of conditional relationships. However, the effects of necessity and sufficiency were smaller for reversed than for forward statements, which suggests that necessity/sufficiency-based interpretations may be more useful for evaluating some types of conditional relations than others. In addition, people were more likely to accept valid rather than invalid arguments, regardless of necessity/sufficiency relations, a finding that suggests that abstract, content-free representations may play a functional role in conditional reasoning.

Memory for pictures and sounds: independence of auditory and visual codes.

Three experiments examined the mnemonic independence of auditory and visual nonverbal stimuli in free recall. Stimulus lists consisted of (1) pictures, (2) the corresponding environmental sounds, or (3) picture-sound pairs. In Experiment 1, free recall was tested under three learning conditions: standard intentional, intentional with a rehearsal-inhibiting distracter task, or incidental with the distracter task. In all three groups, recall was best for the picture-sound items. In addition, recall for the picture-sound stimuli appeared to be additive relative to pictures or sounds alone when the distracter task was used. Experiment 2 included two additional groups: In one, two copies of the same picture were shown simultaneously; in the other, two different pictures of the same concept were shown. There was no difference in recall among any of the picture groups; in contrast, recall in the picture-sound condition was greater than recall in either single-modality condition. However, doubling the exposure time in a third experiment resulted in additively higher recall for repeated pictures with different exemplars than ones with identical exemplars. The results are discussed in terms of dual coding theory and alternative conceptions of the memory trace.