Coding of hierarchical versus linear pattern structure in rats and humans.

In 3 Exps, rats and humans learned serial patterns composed of 24, 30, or 36 items. Patterns had a 2-, 3-, or 4-level hierarchical rule structure. In Exp 1 and 2, patterns had either perfect hierarchical structure or 2 modified chunks that violated hierarchical structure, thus producing linear structure. For both rats and humans, pattern structure predicted pattern learning difficulty and also the nature and relative frequency of errors. Both treated chunks that were inconsistent with hierarchical structure as violation chunks, and made errors that reflected their "tendency to regularize the perception of an irregular pattern" (F. Restle & B. L. Burnside, 1972). The results support the view that rats can abstract and encode a representation of multilevel hierarchical structure in serial patterns in much the same way as humans do in analogous tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expert memory: a comparison of four theories

This paper compares four current theories of expertise with respect to chess players' memory: Chase and Simon's chunking theory, Holding's SEEK theory, Ericsson and Kintsch's long-term working memory theory, and Gobet and Simon's template theory (Chase, W.G., Simon, H.A., 1973a. Perception in chess. Cognitive Psychology 4, 55-81; Holding, D.H., 1985. The Psychology of Chess Skill. Erlbaum, Hillsdale, NJ; Ericsson, K.A., Kintsch, W., 1995. Long-term working memory. Psychological Review 102, 211-245; Gobet, F., Simon, H.A., 1996b. Templates in chess memory: a mechanism for recalling several boards. Cognitive Psychology 31, 1-40). The empirical areas showing the largest discriminative power include recall of random and distorted positions, recall with very short presentation times, and interference studies. Contrary to recurrent criticisms in the literature, it is shown that the chunking theory is consistent with most of the data. However, the best performance in accounting for the empirical evidence is obtained by the template theory. The theory, which unifies low-level aspects of cognition, such as chunks, with high-level aspects, such as schematic knowledge and planning, proposes that chunks are accessed through a discrimination net, where simple perceptual features are tested, and that they can evolve into more complex data structures (templates) specific to classes of positions. Implications for the study of expertise in general include the need for detailed process models of expert behavior and the need to use empirical data spanning the traditional boundaries of perception, memory, and problem solving.     

ACT: A simple theory of complex cognition.

In the Adaptive Character of Thought (ACT-R) theory, complex cognition arises from an interaction of procedural and declarative knowledge. Procedural knowledge is represented in units called production rules, and declarative knowledge is represented in units called chunks. The individual units are created by simple encodings of objects in the environment (chunks) or simple encodings of transformations in the environment (production rules). A great many such knowledge units underlie human cognition. From this large database, the appropriate units are selected for a particular context by activation processes that are tuned to the statistical structure of the environment. According to the ACT-R theory, the power of human cognition depends on the amount of knowledge encoded and the effective deployment of the encoded knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrete dynamic systems: the effect of perceptual structuring on composition and transfer of knowledge about operating sequences

This paper reports two experiments in which we explored the impact of perceptual grouping of elements on the organization and use of knowledge about how to operate a device. Experiment 1 explored the effects of different perceptual display regions on the creation of chunks when sequences of inputs had to be reproduced. The effects of regions were not homogeneous, but rather their influence depended on interactions between different modalities and learning conditions. Experiment 2 investigated the influence of grouping-induced composition of knowledge elements on the transfer of sequential knowledge. Two different learning criteria were used in the acquisition phase to manipulate the degree of composition of knowledge elements. In the transfer phase, subjects could transfer (1) the whole sequence of one region, (2) two partial sequences of adjacent regions, or (3) single components. It was found that regional invariance and immediate succession of components were both important for transfer performance. These results suggests that the temporal order of regions is important for the organization and use of sequential knowledge, and not the grouping of elements by itself.     

Sensitivity to violations of "run" and "trill" structures in rat serial-pattern learning.

Rats learned serial patterns composed of either "run" chunks (e.g., 123 234…) or "trill" chunks (e.g., 121 232…). For each type of pattern, 1 group of rats encountered an element at the end of the pattern that violated the run or trill structure. In both run and trill patterns violations were unusually difficult for rats to learn, whereas corresponding elements in "perfect" patterns that did not violate pattern structure were easy. Additionally, rats' errors on violation elements conformed to the structure of the patterns in which they were embedded. Thus, rats were sensitive to the run or trill organization of their patterns and mastered the rules governing the pattern before learning "exceptions to the rule." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preserving Informational Separability and Violating Decisional Separability in Facial Perception and Recognition.

The holistic encoding hypothesis (M. J. Farah, K. D. Wilson, M. Drain, & J. N. Tanaka, 1998) proposes that faces are encoded and used in perception and cognition as relatively undifferentiated wholes. A previous study (M. J. Wenger & E. M. Ingvalson, 2002) found very little support for the strong version of this hypothesis and instead found evidence that shifts in decisional criteria may be important. This study provides a replication and stronger test of those findings, demonstrating consistent violations of decisional separability and preservation of informational separability in both immediate perception and delayed recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endoscopic transthoracic sympathectomy: an efficient and safe method for the treatment of hyperhidrosis

Rats learned serial patterns composed of either "run" chunks (e.g., 123 234 ...) or "trill" chunks (e.g., 121 232 ...). For each type of pattern, 1 group of rats encountered an element at the end of the pattern that violated the run or trill structure. In both run and trill patterns, violations were unusually difficult for rats to learn, whereas corresponding elements in "perfect" patterns that did not violate pattern structure were easy. Additionally, rats' errors on violation elements conformed to the structure of the patterns in which they were embedded. Thus, rats were sensitive to the run or trill organization of their patterns and mastered the rules governing the pattern before learning "exceptions to the rule."     

Causal chunking: Memory and inference in ongoing interaction.

We propose that people simplify their perceptions of their interactions by organizing them into discrete causal chunks. Once formed, these chunks presumably influence the extent to which people are aware of their influence on others, as well as their impressions of others. We anticipated that people would form self-causal chunks when they possessed an offensive set and other-causal chunks when they possessed a defensive set. We also expected that a self-causal chunking strategy would make salient people's influence on their partners and thereby discourage them from concluding that their partners' behaviors reflected underlying dispositions. In contrast, we anticipated that an other-causal chunking strategy would obscure people's influence on their partners, thereby encouraging them to infer that their partners' behaviors reflected underlying dispositions. We tested these hypotheses by inducing participants to develop either a defensive or an offensive set prior to interacting with another person in a simulated arms race. After the interactions, we assessed the manner in which participants chunked their interactions, as well as their impressions of partners. The results supported our predictions. Implications for understanding conflict and misunderstanding in interpersonal relations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A breast density index for digital mammograms based on radiologists' ranking

The purpose of this study was to develop and evaluate a computerized method of calculating a breast density index (BDI) from digitized mammograms that was designed specifically to model radiologists' perception of breast density. A set of 153 pairs of digitized mammograms (cranio-caudal, CC, and mediolateral oblique, MLO, views) were acquired and preprocessed to reduce detector biases. The sets of mammograms were ordered on an ordinal scale (a scale based only on relative rank-ordering) by two radiologists, and a cardinal (an absolute numerical score) BDI value was calculated from the ordinal ranks. The images were also assigned cardinal BDI values by the radiologists in a subsequent session. Six mathematical features (including fractal dimension and others) were calculated from the digital mammograms, and were used in conjunction with single value decomposition and multiple linear regression to calculate a computerized BDI. The linear correlation coefficient between different ordinal ranking sessions were as follows: intraradiologist intraprojection (CC/CC): r = 0.978; intraradiologist interprojection (CC/MLO): r = 0.960; and interradiologist intraprojection (CC/CC): r = 0.968. A separate breast density index was derived from three separate ordinal rankings by one radiologist (two with CC views, one with the MLO view). The computer derived BDI had a correlation coefficient (r) of 0.907 with the radiologists' ordinal BDI. A comparison between radiologists using a cardinal scoring system (which is closest to how radiologists actually evaluate breast density) showed r = 0.914. A breast density index calculated by a computer but modeled after radiologist perception of breast density may be valuable in objectively measuring breast density. Such a metric may prove valuable in numerous areas, including breast cancer risk assessment and in evaluating screening techniques specifically designed to improve imaging of the dense breast.     

Implicit Learning of Nonlocal Musical Rules: Implicitly Learning More Than Chunks.

Dominant theories of implicit learning assume that implicit learning merely involves the learning of chunks of adjacent elements in a sequence. In the experiments presented here, participants implicitly learned a nonlocal rule, thus suggesting that implicit learning can go beyond the learning of chunks. Participants were exposed to a set of musical tunes that were all generated using a diatonic inversion. In the subsequent test phase, participants either classified test tunes as obeying a rule (direct test) or rated their liking for the tunes (indirect test). Both the direct and indirect tests were sensitive to knowledge of chunks. However, only the indirect test was sensitive to knowledge of the inversion rule. Furthermore, the indirect test was overall significantly more sensitive than the direct test, thus suggesting that knowledge of the inversion rule was below an objective threshold of awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased antioxidant enzyme activities in the colorectal adenoma and carcinoma

Most colon carcinomas are preceded by an adenomatous polyp--adenoma-carcinoma sequence. Active oxygen species (AOS) can play a role in the pathogenesis of this process. Antioxidant enzymes (AE) are the primary defense against the deleterious effect of AOS. Activities of AE in 56 individuals with colorectal adenoma (CA), 29 individuals with colorectal carcinoma (CC) and in 24 control subjects were examined. Biopsy specimens from the non-neoplastic colonic mucosa and from the CA and CC were taken during colonoscopy for histological and enzymological analysis. Activities of following AE were estimated: CuZn-superoxide dismutase (CuZn-SOD), catalase (CAT) and glutathione peroxidase (GPx). It was found that individuals with CA and CC were characterized by: (1) increased activities of CAT and GPx in non-neoplastic mucosa, that persisted in some of the patients even after removal of tumors; (2) increased activities of CuZn-SOD, CAT and PGx in CA and CC tissues. It can be inferred that the accumulation of peroxides in the non-neoplastic colonic mucosa induced higher activities of CAT and GPx. The reasons of high activities of all AE in the tissues of CA and CC and their relation to carcinogenesis are not clear and require further studies.     

Flexible Bayesian modelling for survival data

The analysis of failure time data often involves two strong assumptions. The proportional hazards assumption postulates that hazard rates corresponding to different levels of explanatory variables are proportional. The additive effects assumption specifies that the effect associated with a particular explanatory variable does not depend on the levels of other explanatory variables. A hierarchical Bayes model is presented, under which both assumptions are relaxed. In particular, time-dependent covariate effects are explicitly modelled, and the additivity of effects is relaxed through the use of a modified neural network structure. The hierarchical nature of the model is useful in that it parsimoniously penalizes violations of the two assumptions, with the strength of the penalty being determined by the data.     

Brain potentials reflect violations of gender stereotypes

Event-related brain potentials (ERPs) were recorded while 14 males and 14 females read sentences containing a reflexive pronoun that referred to a definitionally or stereotypically male or female antecedent noun. Pronouns that disagreed with the gender definition or gender stereotype of the antecedent elicited a large-amplitude positive wave. Violations of gender definitions elicited a larger positive wave than did violations of gender stereotypes. Furthermore, the positive wave elicited by stereotype violations persisted even when subjects judged these sentences to be acceptable. Finally, female subjects exhibited larger positivities than did male subjects, regardless of whether the gender mismatch involved a definitional or stereotypical antecedent. These results are taken to indicate that ERPs are sensitive to violations of gender-based occupational stereotypes and that the ERP response to stereotype violations is similar to the P600 effect elicited by a variety of syntactic anomalies.     

Attention to hierarchical level influences attentional selection of spatial scale.

Ample evidence suggests that global perception may involve low spatial frequency (LSF) processing and that local perception may involve high spatial frequency (HSF) processing (Shulman, Sullivan, Gish, & Sakoda, 1986; Shulman & Wilson, 1987; Robertson, 1996). It is debated whether SF selection is a low-level mechanism associating global and local information with absolute LSF and HSF content, or whether it is a higher level mechanism involving a selective process that defines the SF range in which global and local can then be relatively defined. The present study provides support for the latter claim by demonstrating that allocating attention to global or local levels of hierarchical displays biased selection of LSFs or HSFs, respectively, in subsequently presented compound gratings. This bias occurred despite a change in the response dimension (from letter identification in the hierarchical stimulus to orientation discrimination in the grating) and despite a difference in retinal location of the hierarchical stimuli and the grating stimulus. Moreover, the bias was determined by the relationship between the 2 SFs in the compound grating (i.e., their relative frequency) rather than the absolute SF values. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some determinants of reactions to procedural models for conflict resolution: A cross-national study.

Previous research has suggested that cultural collectivism may be related to styles of dispute processing. This possibility was explored in a study with subjects from Hong Kong and the United States. Results showed that the collectivistic Chinese subjects preferred bargaining and mediation to a larger extent than did the individualistic American subjects. Results further suggested that the reason for the Chinese subjects' strong preference for mediation and bargaining was their perception that these two procedures were more capable of reducing the animosity between the disputants. Procedural preference was found to be influenced by the extent to which the procedures were perceived as (a) granting the disputants process control, (b) capable of animosity reduction, (c) fair, and (d) favorable. Implications of these findings for a pancultural model of procedural preference are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Applicants' reactions to the fairness of selection procedures: The effects of positive rule violations and time of measurement.

This study examined several unexplored issues in research on applicants' perceptions of fairness. First, the study explored possible differences between procedural violations that advantage individuals vs. those that are disadvantageous. Second, the study examined the complex relationship between process and outcome fairness across the stages of the selection process. A longitudinal, simulated selection process was used; procedural justice was manipulated by varying the consistency of test administration, and distributive justice was manipulated by varying perceptions of equity. Results indicate that favorable rule violations are perceived similar to rule satisfaction and that a complex and dynamic relationship exists between process and outcome fairness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"It is difficult to move a writing pen"--an interpretation of subtext in Agnar Mykle's work

This article embarks from knowledge gained from dialogues with adult men and women in a phenomenological-hermeneutical study of the long-term health impact of sexual boundary violations in childhood. All published texts by the Norwegian novelist Agnar Mykle have been reviewed for the purpose of a reinterpretation, together with scholarly work on his oeuvre and biographical accounts of the author and his first wife. The interpretation has been guided by the assumption that the essays, novels and letters may represent a double text with an embedded coded message. The suggestion is offered that Mykle's work can be read as an attempt at acknowledging and surmounting a basic conflict in the author's own life between, on the one hand, his memories of experiences of boundary violations in childhood and, on the other, a scientific theory of infantile sexuality. It is also claimed that Mykle was silenced by the experience of being tried on pornography charges against one of his novels. The impact of this public humiliation may, in Mykle's perception, have reactivated earlier boundary violations and, as such, have been experienced as a revictimisation.     

Depressed affect and time perception.

The article presents a resolution of an empirical conflict about the effect of depressed affect on time perception. We propose that depressed affect produces a subjective slowing of time but does not alter the perception of objective chronometric time passage. A between-subjects experiment is reported in which temporary depressed, neutral, and elated states were induced in adult subjects who then performed a sorting task for either 4 min or 13 min. Results of a measure of subjective speed of time passage revealed that time passed more slowly for the depressed subjects than for subjects in the other two affect conditions. Chronometric time judgments, however, were not influenced by perceiver affective state. The real-time difference of 4 min versus 13 min did significantly affect chronometric time judgments, but it had no effect on judgments of subjective speed of time passage. These findings are discussed in terms of their relevance both to previous time perception research and to the general understanding of depressed affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two mechanisms in implicit artificial grammar learning? Comment on Meulemans and Van der Linden (1997).

T. Meulemans and M. Van der Linden (see record 1997-05320-013) presented evidence for 2 distinct mechanisms involved in artificial grammar learning. They suggested that after training on 32 letter strings (Experiment 2A), participants classify test strings using knowledge of the distributional statistics of letter chunks, whereas after training on 125 letter strings (Experiment 2B) they classify on the basis of knowledge of the rules of the grammar. This article offers an alternative unitary account of Meulemans and Van der Linden's findings. The authors show that information about grammatical rules and chunk locations was confounded in the test strings used in Experiment 2B and then present evidence that all of the data can be explained in terms of distributional knowledge, provided this includes knowledge of the positional constraints on chunks. Finally, the authors question the utility of traditional finite-state grammars for investigating abstraction processes, and suggest alternative methods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)