Log-Multiplicative Association Models as Item Response Models

Log-multiplicative association (LMA) models, which are special cases of log-linear models, have interpretations in terms of latent continuous variables. Two theoretical derivations of LMA models based on item response theory (IRT) arguments are presented. First, we show that Anderson and colleagues (Anderson &; Vermunt, 2000; Anderson &; Böckenholt, 2000; Anderson, 2002), who derived LMA models from statistical graphical models, made the equivalent assumptions as Holland (1990) when deriving models for the manifest probabilities of response patterns based on an IRT approach. We also present a second derivation of LMA models where item response functions are specified as functions of rest-scores. These various connections provide insights into the behavior of LMA models as item response models and point out philosophical issues with the use of LMA models as item response models. We show that even for short tests, LMA and standard IRT models yield very similar to nearly identical results when data arise from standard IRT models. Log-multiplicative association models can be used as item response models and do not require numerical integration for estimation.     

Suppressing Unwanted Memories

ABSTRACT— When reminded of something we would prefer not to think about, we often try to exclude the unwanted memory from awareness. Recent research indicates that people control unwanted memories by stopping memory retrieval, using mechanisms similar to those used to stop reflexive motor responses. Controlling unwanted memories is implemented by the lateral prefrontal cortex, which acts to reduce activity in the hippocampus, thereby impairing retention of those memories. Individual differences in the efficacy of these systems may underlie variation in how well people control intrusive memories and adapt in the aftermath of trauma. This research supports the existence of an active forgetting process and establishes a neurocognitive model for inquiry into motivated forgetting.     

Neural correlates of arithmetic calculation strategies

Recent research into math cognition has identified areas of the brain that are involved in number processing (Dehaene, Piazza, Pinel, & Cohen, 2003) and complex problem solving (Anderson, 2007). Much of this research assumes that participants use a single strategy; yet, behavioral research finds that people use a variety of strategies (LeFevre et al., 1996; Siegler, 1987; Siegler & Lemaire, 1997). In the present study, we examined cortical activation as a function of two different calculation strategies for mentally solving multidigit multiplication problems. The school strategy, equivalent to long multiplication, involves working from right to left. The expert strategy, used by “lightning” mental calculators (Staszewski, 1988), proceeds from left to right. The two strategies require essentially the same calculations, but have different working memory demands (the school strategy incurs greater demands). The school strategy produced significantly greater early activity in areas involved in attentional aspects of number processing (posterior superior parietal lobule, PSPL) and mental representation (posterior parietal cortex, PPC), but not in a numerical magnitude area (horizontal intraparietal sulcus, HIPS) or a semantic memory retrieval area (lateral inferior prefrontal cortex, LIPFC). An ACT-R model of the task successfully predicted BOLD responses in PPC and LIPFC, as well as in PSPL and HIPS.     

The rapid development of explicit gaze judgment ability at 3 years

Two studies examined development of the ability to judge what another person is looking at. In Study 1, 54 2- to 4-year-olds judged where someone was looking in real-life, photograph, and drawing formats. A minority of 2-year-olds, but a majority of older children, passed all tasks, suggesting that the ability arises at around 3 years of age. Study 2 examined the fine-grained gaze judgment of 76 3- to 6-year-olds and 15 adults using gaze differences of 10° and 15°. Development of gaze judgment was gradual, from chance at 3 years of age to near adult-level performance at 6 years of age. Although performance was better when a congruent head turn was included, 3-year-olds were still at chance on 10° head turn trials. The findings suggest that the ability to explicitly judge gaze is novel at 3 years of age and develops slowly thereafter. Therefore, the ability does not develop out of earlier gaze following. General implications for the evolution and development of gaze processing are discussed.     

Causal effects of violent sports video games on aggression: Is it competitiveness or violent content?

Three experiments examined the impact of excessive violence in sport video games on aggression-related variables. Participants played either a nonviolent simulation-based sports video game (baseball or football) or a matched excessively violent sports video game. Participants then completed measures assessing aggressive cognitions (Experiment 1), aggressive affect and attitudes towards violence in sports (Experiment 2), or aggressive behavior (Experiment 3). Playing an excessively violent sports video game increased aggressive affect, aggressive cognition, aggressive behavior, and attitudes towards violence in sports. Because all games were competitive, these findings indicate that violent content uniquely leads to increases in several aggression-related variables, as predicted by the General Aggression Model and related social-cognitive models.     

A Task Analysis of Client Re-engagement: Therapeutic De-escalation of High-Conflict Coparents

Parents who are engaged in protracted conflict following a divorce are often referred to coparenting therapy. Episodes of intense conflict are common during these therapy sessions and often result in coparents disengaging from the therapist while they engage in escalating conflict with each other, potentially disrupting their progress in therapy. The purpose of this study was to identify how therapists successfully re-engage clients in the session. To understand this process, 24 disengagement events (12 successful and 12 unsuccessful) from 13 cases were analyzed using a task analytic approach. The sample included coparent dyads referred by the judicial system to a high-conflict coparenting therapy program. Task analysis was used to create a model of how re-engagement unfolds in treatment. The empirical model that resulted has five phases: (1) disengagement from the therapeutic process, (2) disruption of the conflict, (3) de-escalating the most escalated coparent, (4) de-escalating the other coparent, and (5) therapist buffered re-engagement. Successful episodes of re-engagement tended to have therapists who remained active throughout the conflict episode, used structuring interventions aimed at disrupting and then regulating the most escalated partner, blocked attempts to re-engage in conflict, and then repeated this process with the less escalated partner. Additional interventions that promote therapeutic re-engagement are described for each phase, and implications for clinicians and researchers are discussed.     

The influence of threat and aversive motivation on conflict processing in the Stroop task

Attention, Perception, & Psychophysics - Motivated attention can be driven by the desire to maximize gains or escape punishment. In the Stroop task, when rewards can be obtained by responding...     

Effects of short-term crowding on aggression in captive groups of pigtail monkeys (macaca nemestrina)

Agonistic behaviors of 14 groups of pigtail monkeys were monitored under 2 spatial conditions, normal living space and half that amount of space. Aggression occurred less frequently in the crowded than in the relatively less crowded condition. The results of this study resemble those of some analogous research on human children, and they suggest that nonhuman primate models of crowding stress and aggression may be especially appropriate.