Impulse processing: a dynamical systems model of incremental eye movements in the visual world paradigm

The Visual World Paradigm (VWP) presents listeners with a challenging problem: They must integrate two disparate signals, the spoken language and the visual context, in support of action (e.g., complex movements of the eyes across a scene). We present Impulse Processing, a dynamical systems approach to incremental eye movements in the visual world that suggests a framework for integrating language, vision, and action generally. Our approach assumes that impulses driven by the language and the visual context impinge minutely on a dynamical landscape of attractors corresponding to the potential eye-movement behaviors of the system. We test three unique predictions of our approach in an empirical study in the VWP, and describe an implementation in an artificial neural network. We discuss the Impulse Processing framework in relation to other models of the VWP.     

A five-factor measure of schizotypal personality traits

The current study provides convergent, discriminant, and incremental validity data for a new measure of schizotypy from the perspective of the five-factor model (FFM) of general personality structure. Nine schizotypy scales were constructed as maladaptive variants of respective facets of the FFM (e.g., Aberrant Ideas as a maladaptive variant of FFM Openness to Ideas). On the basis of data from 143 undergraduates, the convergent validity of these nine scales was tested with respect to seven established measures of schizotypy and the respective facets of the FFM. Discriminant validity was tested with respect to facets from other FFM domains and components of schizotypy. Incremental validity was tested with respect to the ability of the FFM schizotypy scales to account for variance in two established measures of schizotypy, after variance accounted for by respective FFM facets and other established measures of schizotypy were first removed. The findings support the validity of these new scales as measures of schizotypal traits and as maladaptive variants of the FFM.     

Visual crowding: a fundamental limit on conscious perception and object recognition

Crowding, the inability to recognize objects in clutter, sets a fundamental limit on conscious visual perception and object recognition throughout most of the visual field. Despite how widespread and essential it is to object recognition, reading and visually guided action, a solid operational definition of what crowding is has only recently become clear. The goal of this review is to provide a broad-based synthesis of the most recent findings in this area, to define what crowding is and is not, and to set the stage for future work that will extend our understanding of crowding well beyond low-level vision. Here we define six diagnostic criteria for what counts as crowding, and further describe factors that both escape and break crowding. All of these lead to the conclusion that crowding occurs at multiple stages in the visual hierarchy.     

Long-term maintenance of immediate or delayed extinction is determined by the extinction-test interval

Short acquisition-extinction intervals (immediate extinction) can lead to either more or less spontaneous recovery than long acquisition-extinction intervals (delayed extinction). Using rat subjects, we observed less spontaneous recovery following immediate than delayed extinction (Experiment 1). However, this was the case only if a relatively long extinction-test interval was used; a relatively short extinction-test interval yielded the opposite result (Experiment 2). Previous data appear consistent with this observation suggesting that, although delayed extinction appears more beneficial in the short term, immediate extinction may have more favorable long-term effects. These observations may have important implications for attenuation of relapse in clinical situations.     

Comparison of the SERIOL and SOLAR theories of letter-position encoding

There has been increasing interest in the question of how the brain encodes the order of letters in a written word. This problem is of practical and theoretical interest, so it is important to distinguish between competing computational models. This article compares the SERIOL and SOLAR theories on their biological plausibility and ability to explain experimental results at the orthographic and lexical levels.     

Co‐speech gesture as input in verb learning

People gesture a great deal when speaking, and research has shown that listeners can interpret the information contained in gesture. The current research examines whether learners can also use co‐speech gesture to inform language learning. Specifically, we examine whether listeners can use information contained in an iconic gesture to assign meaning to a novel verb form. Two experiments demonstrate that adults and 2‐, 3‐, and 4‐year‐old children can infer the meaning of novel intransitive verbs from gestures when no other source of information is present. The findings support the idea that gesture might be a source of input available to language learners.     

A long-term case study of analysis,response suppression,and treatment maintenance involving life-threatening pica

Behavioral assessment and intervention strategies used to treat chronic, life-threatening pica in an institutionalized, 16-year-old male with profoundly retarded collateral self-injurious and aggressive conduct, are described and evaluated. Thirty-minute observation sessions, conducted under baited contitions, revealed that bait saliency and the absence of caregiver supervision were discriminative for high rates of pica. Oral delivery of response-contingent lemon juice suppressed pica to near zero rates, while a procedural package incorporating delivery of water mist contingent on response-antecedant wandering contributed to further reductions in pica. Considerable suppression was maintained for approximately 18 months, with administration by paraprofessional staff. Data spanning nearly four years indicated that pica suppression was primarily a function of the introduction, maintenance, and withdrawal of aversive contingencies, rather than of concurrent schedules of positive reinforcement. Positive and negative side effects, and ethical questions associated with the use of aversive stimuli in treating life-threatening behavior, are discussed.