A power-law model of psychological memory strength in short- and long-term recognition

A classic law of cognition is that forgetting curves are closely approximated by power functions. This law describes relations between different empirical dependent variables and the retention interval, and the precise form of the functional relation depends on the scale used to measure each variable. In the research reported here, we conducted a recognition task involving both short- and long-term probes. We discovered that formal memory-strength parameters from an exemplar-recognition model closely followed a power function of the lag between studied items and a test probe. The model accounted for rich sets of response time (RT) data at both individual-subject and individual-lag levels. Because memory strengths were derived from model fits to choices and RTs from individual trials, the psychological power law was independent of the scale used to summarize the forgetting functions. Alternative models that assumed different functional relations or posited a separate fixed-strength working memory store fared considerably worse than the power-law model did in predicting the data.     

Shift toward risk and heterogeneity of groups

Groups that were homogeneous and heterogeneous in terms of risk preferences were varied orthogonally across conditions of information exchange and discussion. The shift toward risk for heterogeneous group members was significantly larger than for homogeneous group members, who did not differ from a control condition. Further analyses showed that two possible alternative hypotheses, time differentials for discussion and regression toward the mean, were not tenable. The data support (a) the “at least as willing” interpretation of Brown's risk-as-value hypothesis, and (b) the necessity of constituting groups for heterogeneity and homogeneity with great care.     

Anxiety and perceptual-motor performance: toward an integrated model of concepts, mechanisms, and processes

Under anxiety, people sometimes perform poorly. This concerns cognitive performance (e.g., taking an important exam) as well as perceptual-motor performance (e.g., picking up a cup from a table). There is still much debate about how anxiety affects perceptual-motor performance. In the current paper we review the experimental literature on anxiety and perceptual-motor performance, thereby focusing on how anxiety affects the perception, selection, and realization of action possibilities. Based on this review we discuss the merits of two opposing theoretical explanations and build on existing frameworks of anxiety and cognitive performance to develop an integrated model that explains the various ways in which anxiety may specifically affect perceptual-motor performance. This model distinguishes between positive and negative effects of anxiety and, moving beyond previous approaches, recognizes three operational levels (i.e., attentional, interpretational, and behavioral) at which anxiety may affect different aspects of goal-directed action. Finally, predictions are formulated and directions for future research suggested.     

Dissociation of mechanisms involved in dogs' oriented displacements

Factors determining spatial choice were studied in experiments conducted outdoors. Six dogs (Breton spaniel) had to choose between two paths leading to a baited feeding bowl (goal). Transparent or opaque screens were interposed between the starting-point and the goal; their arrangement was devised so as to control the length and the angular deviation or divergence of the paths. The results show that when the goal was visible (transparent screens) dogs preferred the less divergent path indicating that angular deviation was the most relevant variable. When the goal was hidden (opaque screen), they preferred the shorter path and did not take into account the angular deviation. These results suggest that two classes of mechanism underlie the selection of path in these spatial situations.     

Phonological and working memory mechanisms involved in written spelling

Recent theories of spelling based on neuropsychological data and on computational modelling (Caramazza & Miceli, 1990; Caramazza, Miceli, Villa, & Romani, 1987; Glasspool & Houghton, 2005; Glasspool, Shallice, & Cipolotti, 2006; Miceli & Capasso, 2006; Rapp & Kong, 2002) assume that a working memory system is used to store identity and order of the graphemes, and propose that an impairment of this system, called Graphemic Buffer (GB), is marked by the presence of a number of typical effects. Recently, this disorder has been simulated by different versions of the Competitive Queuing model (Glasspool & Houghton, 2005; Glasspool et al., 2006). The effect of the disruption of this mechanism in written spelling was investigated by means of a dual task in the present study. Three-syllable and four-syllable words were presented to normal adults for aural presentation (Experiment 1) and spelling by copying (Experiment 2). In order to investigate the effects of dual tasks, and the possible involvement of phonological codes, three conditions were used: simple dictation, concurrent articulation, and foot tapping. The results showed strong effects of concurrent articulation, and were consistent with the hypothesis that this task disrupted the serial operations of readout and sequential planning of the GB. They were also consistent with the simulations of the Competitive Queuing model, suggesting possible loci of the effects.     

Defense mechanisms and self-reported violence toward partners and strangers

We examined the relationship between defense mechanisms and self-reported violence toward partners and toward strangers in a sample of college student men. Fifty men completed the Thematic Apperception Test (TAT; Murray, 1943) and the Conflict Tactics Scale (CTS; Straus, 1979), a self-report measure of strategies (including violence) for resolving conflicts with partners and strangers. The TAT responses were coded for defense mechanisms with the Defense Mechanisms Manual (Cramer, 1991b). The relative use of identification was negatively correlated (r = -.49, p <.001), and the relative use of projection was positively correlated (r =.49, p <.001) with the most extreme CTS report of violence toward partners. The relative use of identification was negatively correlated with the most extreme CTS report of violence toward strangers (r = -.34, p <.05). The relative use of denial was positively correlated with the most extreme CTS report of violence toward strangers (r =.32, p <.05).     

Attitudes toward work: Ethnic minorities and immigrant groups in Vancouver

A previous study indicated that labour market managers in Vancouver harbour stereotypes about work attitudes among ethnic minority immigrants. This current paper presents a companion piece to this earlier study and examines the actual work attitudes among immigrants. The results of a survey, consisting of 509 personal interviews in three neighbourhoods in Greater Vancouver, reveal that perceived and actual work attitudes do not always match. In addition, immigrant class explains some of the ethnicity effects.     

A computational model of fractionated conflict-control mechanisms in task-switching

A feature of human cognition is the ability to monitor and adjust one's own behavior under changing circumstances. A dynamic balance between controlled and rapid responding is needed to adapt to a fluctuating environment. We suggest that cognitive control may include, among other things, two distinct processes. Incongruent stimuli may drive top-down facilitation of task-relevant responses to bias performance toward exploitation vs. exploration. Task or response switches may generally slow responses to bias toward accuracy vs. speed and exploration vs. exploitation. Behavioral results from a task switching study demonstrate these two distinct processes as revealed by higher-order sequential effects. A computational model implements the two conflict-control mechanisms, which allow it to capture many complex and novel sequential effects. Lesion studies with the model demonstrate that the model is unable to capture these effects without the conflict-control loops and show how each monitoring component modulates cognitive control. The results suggest numerous testable predictions regarding the neural substrates of cognitive control.     

Right- and left-wing prejudice toward dissimilar groups in cultural and economic domains

According to recent studies, people on both the political right and left show prejudice toward groups whose beliefs are in conflict with their own. This prediction applies to both cultural and economic dimensions of political beliefs. In three studies (N = 499) we demonstrate that people on both the cultural and economic right and left show negative attitudes toward groups on the other side of the given spectrum and that underlying this effect is the perception of value violation. In two out of three studies, we manipulated the extremity of target worldviews to further explore the causal chain between political beliefs, the perception of value violation, and prejudice. Our results showed a high degree of symmetry between the political left and right in their attitudes toward groups with dissimilar beliefs. However, although people on both sides of the political spectrum show prejudice toward each other, people on the cultural and economic right seem to be more sensitive to value violations than people on the left.     

Disentangling the neural mechanisms involved in Hinduism- and Buddhism-related meditations

The most diffuse forms of meditation derive from Hinduism and Buddhism spiritual traditions. Different cognitive processes are set in place to reach these meditation states. According to an historical-philological hypothesis (Wynne, 2009) the two forms of meditation could be disentangled. While mindfulness is the focus of Buddhist meditation reached by focusing sustained attention on the body, on breathing and on the content of the thoughts, reaching an ineffable state of nothigness accompanied by a loss of sense of self and duality (Samadhi) is the main focus of Hinduism-inspired meditation. It is possible that these different practices activate separate brain networks. We tested this hypothesis by conducting an activation likelihood estimation (ALE) meta-analysis of functional magnetic resonance imaging (fMRI) studies. The network related to Buddhism-inspired meditation (16 experiments, 263 subjects, and 96 activation foci) included activations in some frontal lobe structures associated with executive attention, possibly confirming the fundamental role of mindfulness shared by many Buddhist meditations. By contrast, the network related to Hinduism-inspired meditation (8 experiments, 54 activation foci and 66 subjects) triggered a left lateralized network of areas including the postcentral gyrus, the superior parietal lobe, the hippocampus and the right middle cingulate cortex. The dissociation between anterior and posterior networks support the notion that different meditation styles and traditions are characterized by different patterns of neural activation.     

Political orientation and occupational values of college youth, 1969 and 1981: a shift toward uniformity

McFalls and Gallagher (1979) have found a strong relationship between the occupational values and political orientations of college students. Their study was based on the results of a sample survey conducted in 1969. However, the political climate on college campuses has changed dramatically, and so has the nature of the job market. A new survey was conducted in 1981 which was identical to the 1969 survey. Its objective was to determine if the same political group differentials in occupational values which existed in the politically tumultuous late sixties and early seventies still hold in the more placid 1980s. The findings are reported here.     

Hierarchy of preferences toward disabled groups: a reanalysis

A reanalysis of Tringo's (1970) hierarchy of preference toward disabled groups was conducted through multidimensional scaling. The structure underlying social-distance preferences is multidimensional in nature rather than unidimensional as presented by Tringo. The retained 3-dimensional solution was interpreted as focusing on the visibility of the disabilities, the organic versus functional nature of the disabilities, and an element of ostracism.