Curved saccade trajectories reveal conflicting predictions in associative learning

We report how the trajectories of saccadic eye movements are affected by memory interference acquired during associative learning. Human participants learned to perform saccadic choice responses based on the presentation of arbitrary central cues A, B, AC, BC, AX, BY, X, and Y that were trained to predict the appearance of a peripheral target stimulus at 1 of 3 possible locations, right (R), mid (M), or left (L), in the upper hemifield. We analyzed as measures of associative learning the frequency, latency, and curvature of saccades elicited by the cues and directed at the trained locations in anticipation of the targets. Participants were trained on two concurrent discrimination problems A+R, AC+R, AX+M, X+M and B+L, BC+L, BY+M, Y+M. From a connectionist perspective, cues were predicted to acquire associative links connecting the cues to the trained outcomes in memory. Model simulations based on the learning rule of the Rescorla and Wagner (1972) model revealed that for some cues, the prediction of the correct target location was challenged by the interfering prediction of an incorrect location. We observed that saccades directed at the correct location in anticipation of the target curved away from the location that was predicted by the interfering association. Furthermore, changes in curvature during training corresponded to predicted changes in associative memory. We propose that this curvature was caused by the inhibition of the incorrect prediction, as previously has been suggested with the concept of distractor inhibition (Sheliga, Riggio, & Rizzolatti, 1994; Tipper, Howard, & Houghton, 2000). The paradigm provides a new method to examine memory interference during associative learning.     

Measuring Relationships between Personality,Knowledge, and Performance using Single‐response Situational Judgment Tests

We report two studies that investigate single‐response situational judgment tests (SJTs) as measures of job knowledge. Study 1 examines relationships between job knowledge measured by a single‐response SJT, personality, and performance for museum tour guides. Study 2 extends Study 1's findings with a sample of volunteers using a single‐response SJT about volunteerism. In both studies, personality was related to knowledge, and knowledge predicted performance. In Study 2, knowledge accounted for incremental variance in performance beyond personality, but personality added no incremental variance beyond knowledge. Results suggest that knowledge of effective behavior and knowledge of ineffective behavior are separate constructs. These studies demonstrate the validity of single‐response SJTs and provide evidence that knowing what to do and what not to do are separate domains.     

Judgment aggregation and the problem of tracking the truth

The aggregation of consistent individual judgments on logically interconnected propositions into a collective judgment on those propositions has recently drawn much attention. Seemingly reasonable aggregation procedures, such as propositionwise majority voting, cannot ensure an equally consistent collective conclusion. In this paper, we motivate that quite often, we do not only want to make a factually right decision, but also to correctly evaluate the reasons for that decision. In other words, we address the problem of tracking the truth. We set up a probabilistic model that generalizes the analysis of Bovens and Rabinowicz (Synthese 150: 131?C153, 2006) and use it to compare several aggregation procedures. Demanding some reasonable adequacy constraints, we demonstrate that a reasons- or premise-based aggregation procedure tracks the truth better than any other procedure. However, we also illuminate that such a procedure is not in all circumstances easy to implement, leaving actual decision-makers with a tradeoff problem.     

Walter the banker: the conjunction fallacy reconsidered

In a famous experiment by Tversky and Kahneman (Psychol Rev 90:293–315, 1983), featuring Linda the bank teller, the participants assign a higher probability to a conjunction of propositions than to one of the conjuncts, thereby seemingly committing a probabilistic fallacy. In this paper, we discuss a slightly different example featuring someone named Walter, who also happens to work at a bank, and argue that, in this example, it is rational to assign a higher probability to the conjunction of suitably chosen propositions than to one of the conjuncts. By pointing out the similarities between Tversky and Kahneman’s experiment and our example, we argue that the participants in the experiment may assign probabilities to the propositions in question in such a way that it is also rational for them to give the conjunction a higher probability than one of the conjuncts.     

Primacy of information about means selection over outcome selection in goal attribution by infants

It has been shown that, when observing an action, infants can rely on either outcome selection information (i.e., actions that express a choice between potential outcomes) or means selection information (i.e., actions that are causally efficient toward the outcome) in their goal attribution. However, no research has investigated the relationship between these two types of information when they are present simultaneously. In an experiment that addressed this question directly, we found that when outcome selection information could disambiguate the goal of the action (e.g., the action is directed toward one of two potential targets), but means selection information could not (i.e., the action is not efficiently adjusted to the situational constraints), 7- and 9-month-old infants did not attribute a goal to an observed action. This finding suggests that means selection information takes primacy over outcome selection information. The early presence of this bias sheds light on the nature of the notion of goal in action understanding.     

Microstructural organization of corpus callosum projections to prefrontal cortex predicts bimanual motor learning

The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemispheric communication, particularly with respect to bimanual coordination. Here, we use diffusion tensor imaging (DTI) in healthy humans to determine the extent to which structural organization of subregions within the CC would predict how well subjects learn a novel bimanual task. A single DTI scan was taken prior to training. Participants then practiced a bimanual visuomotor task over the course of 2 wk, consisting of multiple coordination patterns. Findings revealed that the predictive power of fractional anisotropy (FA) was a function of CC subregion and practice. That is, FA of the anterior CC, which projects to the prefrontal cortex, predicted bimanual learning rather than the middle CC regions, which connect primary motor cortex. This correlation was specific in that FA correlated significantly with performance of the most difficult frequency ratios tested and not the innately preferred, isochronous frequency ratio. Moreover, the effect was only evident after training and not at initiation of practice. This is the first DTI study in healthy adults which demonstrates that white matter organization of the interhemispheric connections between the prefrontal structures is strongly correlated with motor learning capability.     

Do not cross the line: Heuristic spatial updating in dynamic scenes

In two experiments, we examined the spatial integration of two viewpoints onto dynamic scenes. We tested the spatial-alignment hypothesis (which predicts integration by alignment along the shortest path) against the spatial-heuristic hypothesis (which predicts integration by observation of the left?Cright orientation on the screen). The stimuli consisted of film clips comprising two shots, each showing a car driving by. In Experiment 1, the dynamic scenes were ambiguous with regard to their interpretation: The cars could have been driving either in the same or in opposite directions. In line with the spatial-heuristic hypothesis, participants responded with ??same direction?? if the cars shared a screen direction. In Experiment 2, environmental cues disambiguated the dynamic scenes, and the screen direction of the cars was either congruent or incongruent with the depicted environmental cues. As compared with congruent dynamic scenes, incongruent dynamic scenes elicited prolonged reaction times, thus suggesting that heuristic spatial updating was used with congruent stimuli, whereas spatial-alignment processes were used with incongruent stimuli.     

Whichever way you choose to categorize, working memory helps you learn

There has been growing interest in the relationship between the capacity of a person's working memory and their ability to learn to categorize stimuli. While there is evidence that working memory capacity (WMC) is related to the speed of category learning, it is unknown whether WMC predicts which strategies people use when there are multiple possible solutions to a categorization problem. To explore the relationship between WMC, category learning, and categorization strategy use, 173 participants completed two categorization tasks and a battery of WMC tasks. WMC predicted the speed of category learning, but it did not predict which strategies participants chose to perform categorization. Thus, WMC does not predict which categorization strategies people use but it predicts how well they will use the strategy they select.     

Physical self-concept and disturbed eating attitudes and behaviors in French athlete and non-athlete adolescent girls: direct and indirect relations

This study aims to investigate the direct and indirect associations between physical self-subdomains, physical self-worth, global self-worth, and disturbed eating attitudes and behaviors among French non-elite athlete and non-athlete adolescent girls. A sample of adolescent girls including 50 ballet dancers, 41 basketball players, and 47 non-athletes was used in this study. Data obtained from the ballet dancer and basketball player subsamples revealed significant, sample-specific as well as common, direct relations between global and physical self-perceptions and disturbed eating attitudes and behaviors, as well as significant indirect relations (via global self-worth and physical self-worth) between specific physical self-perceptions and disturbed eating attitudes and behaviors. In contrast, no association was found between global and physical self-perceptions in the sample of non-athlete adolescent girls.     

The Role of Threat in Attitudes Toward Affirmative Action and Its Beneficiaries1

This set of two studies employed the integrated threat theory to examine attitudes toward affirmative action (AA). The first study found that opposition to the policy of AA was predicted by realistic threats, symbolic threats, and personal relevance; while attitudes toward the beneficiaries of AA were predicted by three of the four threat variables (symbolic threats, intergroup anxiety, and negative stereotypes), and in‐group identity. The second study replicated and expanded on the first study and found that the effects of several individual‐difference variables (racism, anti‐Black affect, and political conservatism) on opposition to AA were mediated by three of the threats in the integrated threat theory (realistic threats, symbolic threats, and negative stereotypes). The implications of the results are discussed.