Biomedical subjects

Jamie I D Campbell

Publications and source records attributed to Jamie I D Campbell.

10 recordsLinked to original sources

PubMed2006

Numerical order and quantity processing in number comparison.

We investigated processing of numerical order information and its relation to mechanisms of numerical quantity processing. In two experiments, performance on a quantity-comparison task (e.g. 2 5; which is larger?) was compared with performance on a relative-order judgment task (e.g. 2 5; ascending or descending order?). The comparison task consistently produced the standard distance effect (faster judgments for far relative to close number pairs), but the distance effect was smaller for ascending (e.g. 2 5) compared to descending pairs (e.g. 5 2). The order task produced a pair-order effect (faster judgments for ascending pairs) and a reverse distance effect for consecutive pairs in ascending order. The reverse effect implies an order-specific process, such as serial search or direct recognition of order for successive numbers. Thus, numerical quantity and order judgments recruited different cognitive mechanisms. Nonetheless, the reduced distance effect for ascending pairs in the quantity task implies involvement of order-related processes in magnitude comparison. Accordingly, distance effects in the quantity-comparison task are not necessarily a process-pure measure of magnitude representation.

Adult↗

PubMed2006

Calculation latency: the mu of memory and the tau of transformation.

Does numeral format (e.g., 4 + 8 vs. four + eight) affect calculation per se? University students (N = 47) solved single-digit addition problems presented as Arabic digits or English words and reported their strategies (memory retrieval or procedures such as counting or transformation). Decomposition of the response time (RT) distributions into mu (reflecting shift) and tau (reflecting skew) confirmed that retrieval trials contributed predominantly to mu whereas procedure trials contributed predominantly to tau. The format x problem size RT interaction (i.e., greater word-format RT costs for large problems than for small problems)was associated entirely with mu and not with tau. Reported use of procedures presented a corresponding format x size interaction. Together, these results indicate that, relative to the well-practiced digit format, the unfamiliar word format disrupts number-fact retrieval and promotes use of procedural strategies.

Adolescent↗

PubMed2006

Identical elements model of arithmetic memory: extension to addition and subtraction.

The identical elements (IE) model of arithmetic fact representation (Rickard, 2005; Rickard & Bourne, 1996) was developed and tested with multiplication and division. In Experiment 1, we demonstrated that the model also applies to addition and subtraction by examining transfer of response time (RT) savings between prime and probe problems tested in the same block of trials. As is predicted by the IE model, there were equivalent probe RT savings for addition with identical repetition (prime 6 + 9 --> probe 6 + 9) or an order change (9 + 6 --> 6 + 9), but much greater savings for subtraction with identical repetition (15 - 6 --> 15 - 6) than with an order change (15 - 9 --> 15 - 6), and no savings with an operation change (15 - 9 --> 6 + 9 or 6 + 9 --> 4 15 - 6). In Experiment 2, we examined transfer in simple multiplication and division and demonstrated symmetrical transfer between operations. Cross-operation RT savings were eliminated, however, when the RT analysis included only trials on which both the prime and the probe problems were reportedly solved by direct retrieval. An IE model extended to accommodate savings associated with procedural strategies provides a coherent account of facilitative transfer effects in simple arithmetic.

Adolescent↗

PubMed2004

Interactive effects of numerical surface form and operand parity in cognitive arithmetic.

In Experiment 1, adults (n = 48) performed simple addition, multiplication, and parity (i.e., odd-even) comparisons on pairs of Arabic digits or English number words. For addition and comparison, but not multiplication, response time increased with the number of odd operands. For addition, but not comparison, this parity effect was greater for words than for digits. In Experiment 2, adults (n = 50) solved simple addition problems in digit and word format and reported their strategies (i.e., retrieval or procedures). Procedural strategies were used more for odd than even addends and much more for word than digit problems. The results indicate that problem encoding and answer retrieval processes for cognitive arithmetic are interactive rather than strictly additive stages.

Adolescent↗

PubMed2004

An encoding-complex approach to numerical cognition in Chinese-English bilinguals.

We present a model of the cognitive architecture of basic numerical skills in adult Chinese-English bilinguals. The model is based on data reported by Campbell, Kanz, and Xue (1999) and combines Dehaene and Cohen's triple-code theory with Campbell and Clark's encoding-complex approach to modeling number processing. Participants were required to name, add or multiply Arabic or Mandarin numerals and to respond in English or Chinese. They also performed magnitude comparisons on pairs of Arabic or Mandarin numerals. The proposed model of their performance on this set of tasks assumes 1) that number processing is modular with respect to representational code (e.g., visual, visuo-spatial, verbal) rather than with respect to numerical function, 2) task-specific communication between representational codes is interactive rather than additive, and 3) memory for arithmetic facts is at least partially language-based and our Chinese-English bilinguals possessed both Chinese and English-language number-fact representations. We provide new analyses of the arithmetic data and a review of research on the role of language in simple arithmetic to substantiate our claims about linguistic codes for number-fact memory.

Adult↗

PubMed2003

Syllogistic reasoning time: disconfirmation disconfirmed.

Models of deductive reasoning typically assume that reasoners dedicate more logical analysis to unbelievable conclusions than to believable ones (e.g., Evans, Newstead, Allen, & Pollard, 1994; Newstead, Pollard, Evans, & Allen, 1992). When the conclusion is believable, reasoners are assumed to accept it without much further thought, but when it is unbelievable, they are assumed to analyze the conclusion, presumably in an attempt to disconfirm it. This disconfirmation hypothesis leads to two predictions, which were tested in the present experiment: Reasoners should take longer to reason about problems leading to unbelievable conclusions, and reasoners should consider more models or representations of premise information for unbelievable conclusions than for believable ones. Neither prediction was supported by our data. Indeed, we observed that reasoners took significantly longer to reason about believable conclusions than about unbelievable ones and generated the same number of representations regardless of the believability of the premises. We propose a model, based on a modified version of verbal reasoning theory (Polk & Newell, 1995), that does not depend on the disconfirmation assumption.

Adolescent↗

PubMed2002

Calculation, culture, and the repeated operand effect.

A basic phenomenon of cognitive arithmetic is that problems composed of a repeated operand, so-called "ties" (e.g. 6+6, 7 x 7), typically are solved more quickly and accurately than comparable non-tie problems (e.g. 6+5, 7 x 8). In Experiment 1, we present evidence that the tie effect is due to more efficient memory for ties than for non-ties, which participants reported solving more often using calculation strategies. The memory/strategy hypothesis accounts for differences in the tie effect as a function of culture (Asian Chinese vs. non-Asian Canadian university students), operation (addition, multiplication, subtraction, and division), and problem size (numerically small vs. large problems). Nonetheless, Blankenberger (Cognition 82 (2001) B15) eliminated the tie response time (RT) advantage by presenting problems in mixed formats (e.g. 4 x four), which suggests that the tie effect with homogenous formats (4 x 4 or four x four) is due to encoding. In Experiment 2, using simple multiplication problems, we replicated elimination of the tie effect with mixed formats, but also demonstrated an interference effect for mixed-format ties that slowed RTs and increased errors relative to non-tie problems. Additionally, practicing non-tie problems in both orders (e.g. 3 x 4 and 4 x 3) each time ties were tested once (cf. Cognition 82 (2001) B15) reduced the tie effect. The format-mismatch effect on ties, combined with a reduced tie advantage because of extra practice of non-ties, eliminated the tie effect. Rather than an encoding advantage, the results indicate that memory access for ties was better than for non-ties.

Adolescent↗

PubMed2002

More power to you: simple power calculations for treatment effects with one degree of freedom.

Although numerous computer programs for statistical power analysis are available, power is an under-used aspect of experimental analysis, perhaps because of the perceived difficulty of performing the necessary calculations or because existing computer software can be expensive or complicated to learn. For single-degree-of-freedom tests, however, it is possible to calculate power in a straightforward manner, using the t distribution. Because these calculations are based on t, they use easily understood and readily available quantities. These calculations can be performed with a desk calculator; we also present a simple-to-use program called MorePower that will perform the necessary calculations. The straightforward nature of the calculations potentially will enable more researchers to consider issues of power when planning and reporting their experiments.

Humans↗

PubMed2002

Effects of response time deadlines on adults' strategy choices for simple addition.

In this investigation of adults' solution strategies for simple arithmetic, participants solved addition problems (e.g., 2 + 3, 8 + 7) under fast and slow response deadlines: The participants were instructed either to respond before a 750-msec warning beep, or to wait for a 2,500-msec beep before responding. After each trial, they indicated whether they had solved the problem by direct memory retrieval or by using a procedural strategy (e.g., counting, transformation). It was predicted that the fast deadline condition should curtail the use of procedural strategies, which generally are slower than direct retrieval. Furthermore, this deadline effect should be exaggerated for numerically larger problems because procedural strategies are especially slow for the larger problems. As predicted, we observed a deadline x size interaction whereby the fast deadline increased reported use of retrieval, especially for large problems. The results confirm that reported use of direct retrieval decreases systematically with elapsed time, and they provide additional evidence that young, educated adults rely substantially on procedural strategies even for simple addition.

Adolescent↗

PubMed2002

Effects of lexicality and distinctiveness on repetition blindness.

The repetition blindness (RB) paradigm developed by K. M. Arnell and P. Jolicoeur (1997) was used to examine effects of lexicality (word vs. nonword target pairs) and target distinctiveness on RB. Distinctiveness was manipulated by having both targets (Experiments 1 and 2) or only the first target (Experiment 3) brighter than nontarget items. All 3 experiments demonstrated strong RB for word targets but no RB for nonword targets. This confirms that RB depends on pre-existing memory representations. In fact, there was repetition facilitation for nonwords in Experiments 2 and 3. These experiments also demonstrated that RB is reduced when targets are distinctive. This finding is better understood interms of RB as a failure of memory rather than as a failure of perception.

Adolescent↗