Interference from irrelevant features on visual discrimination by macaques (Macaca fuscata): a behavioral analogue of the human Stroop effect

To study the operation of selective attention in a conflict situation with automatic processes, we trained 4 Japanese macaques (Macaca fuscata) extensively on a manual go/no-go task. The monkey had to discriminate either the color, shape, motion direction, or location of a visual stimulus. In each trial, the behavioral meaning of the relevant feature (go or no-go) could either be congruent or incongruent with irrelevant features of the same stimulus. Reaction times were slowed, and error rates increased when irrelevant stimulus features were incongruent with the required response. The effects were obtained when the monkey attended to the color, shape, or motion direction, but not when it attended to the location of the stimulus. The effects were cumulative so that the interference from 1 incongruent feature was smaller than that from 2 incongruent features. We propose that the present paradigm provides a behavioral analogue of the human Stroop effect.     

Exploring the effects of icon characteristics on user performance: the role of icon concreteness, complexity, and distinctiveness

Because icons, signs, and symbols are now widely used to communicate information, it is essential for system designers to know what makes them easy to use and interpret. The authors report a series of studies that examine characteristics considered central to icon usability. After quantifying the properties of icon concreteness, complexity, and discriminability, the authors assessed each property's effects on user performance when user experience, task demands, and presentation context were systematically varied. Findings indicated that the effects of icon concreteness were primarily associated with the initial grasp of meaning, whereas complexity effects were found to persist longer and to be associated with search efficacy. The effects of icon distinctiveness were complex, but distinctiveness was enhanced by using both semantic and visual contrasts. The implications of these findings for interface design are discussed.     

The name game: using retrieval practice to improve the learning of names

In medium-sized groups such as classes, it is often desirable that the members become acquainted with one another. Toward this end, various methods of introducing group members are often used, with only anecdotal evidence for their effectiveness. The name game is a method for introducing group members that is based on the principles of retrieval practice. The authors compared 2 versions of the name game with a widely used introductory method--pairwise introductions--and found that the name game participants were much better at remembering one another's name after 30 min, 2 weeks, and 11 months. A second experiment tested the contribution of retrieval practice by comparing 2 versions of the name game with a procedure that was matched for number of repetitions and time spent on the task. Again, the name games were superior.     

Functional brain imaging as a looking-glass into the degraded brain: reviewing evidence from Alzheimer disease in relation to normal aging

Research on the real-time relationship between brain activity and mental performance is intense. However, relatively few studies have been devoted to patients with different diseases or lesions. Such studies may cast light on certain aspects of brain activity, such as plasticity. This review summarizes studies on Alzheimer's disease (AD) patients where the techniques to map brain activity in relation to mental performance have been utilized. Research findings suggest, that there is a spectrum of changes in AD patients that is distinct from that seen in healthy aging. These changes include: (i) loss of activated regions, (ii) reduced activation possibly due to brain degeneration typical of AD, (iii) the emergence of newly activated regions in order to compensate for minor brain deterioration (e.g., an enlargement of activated regions sometimes manifested as an increased bilaterality or a hemispheric shift of activation, and dedifferentiation), (iv) decreased level of activation, and (v) no change at all, which may occur in easy tasks or tasks that do not involve regions exposed to brain atrophy. In conclusion, the pattern of activation in AD depends on interactions between the clinical stage of patients, and the pattern of brain degeneration, as well as the task difficulty and specific networks necessary for solving the task.     

Mood, personality disorder symptoms and disability in obsessive compulsive hoarders: a comparison with clinical and nonclinical controls

Hoarding is a symptom of obsessive compulsive disorder (OCD), as well as a diagnostic criterion for obsessive compulsive personality disorder (OCPD). One recent study suggests that people who suffer from compulsive hoarding report more general psychopathology than people who do not [Frost, R.O., Krause, M.S., & Steketee, G. (1996). Hoarding and obsessive compulsive symptoms. Behavior Modification, 20, 116-132]. The present study addressed whether persons with OCD hoarding exhibit more depression, anxiety, OCD and personality disorders symptoms than community controls, OCD nonhoarders, or other anxiety disorder patients. Disability was also examined. Hoarding subjects were older than the other three groups, but age did not account for any of the differences observed among the groups. Compared to controls, OCD hoarding, nonhoarding OCD and anxiety disorder patients showed elevated YBOCS scores, as well as higher scores on depression, anxiety, family and social disability. Compared to nonhoarding OCD and anxiety disorder patients, OCD hoarding patients scored higher on anxiety, depression, family and social disability. Hoarding subjects had greater personality disorder symptoms than controls. However, OCD hoarding subjects differed from OCD nonhoarding and anxiety disorder subjects only on dependent and schizotypal personality disorder symptoms. The findings suggest that hoarding is associated with significant comorbidity and impairment compared to nonhoarding OCD and other anxiety disorders.     

Self-appraised social problem solving abilities, emotional reactions and actual problem solving performance

Self-report measures of social problem solving abilities have yet to be associated with objective problem solving performance in any consistent manner. In the present study, we investigated the relation of social problem solving abilities--as measured by the Social Problem Solving Skills Inventory--Revised (SPSI-R [Maydeu-Olivares, A. & D'Zurilla, T. J. (1996). A factor analytic study of the Social Problem Solving Inventory: an integration of theory and data. Cognitive Therapy and Research, 20, 115-133])--to performance on a structured problem solving task. Unlike previous studies, we examined the relation of problem solving skills to performance curves observed in repeated trials, while controlling for affective reactions to each trial. Using hierarchical modeling techniques, a negative problem orientation was significantly predictive of performance and this effect was not mediated by negative affectivity. Results are discussed as they pertain to contemporary models of social problem solving.     

The concreteness effect: evidence for dual coding and context availability

The term concreteness effect refers to the observation that concrete nouns are processed faster and more accurately than abstract nouns in a variety of cognitive tasks. Two models have been proposed to explain the neuronal basis of the concreteness effect. The dual-coding theory attributes the advantage to the access of a right hemisphere image based system in addition to a verbal system by concrete words. The context availability theory argues that concrete words activate a broader contextual verbal support, which results in faster processing, but do not access a distinct image based system. We used event-related fMRI to detect the brain regions that subserve to the concreteness effect. We found greater activation in the lower right and left parietal lobes, in the left inferior frontal lobe and in the precuneus during encoding of concrete compared to abstract nouns. This makes a single exclusive theory unlikely and rather suggests a combination of both models. Superior encoding of concrete words in the present study may result from (1) greater verbal context resources reflected by the activation of left parietal and frontal associative areas, and (2) the additional activation of a non-verbal, perhaps spatial imagery-based system, in the right parietal lobe.     

Effects of directionality in deductive reasoning: I. The comprehension of single relational premises

Four experiments involving 123 university students tested directionality effects in the comprehension of spatial relations, quantified statements, and propositional connectives with a sentence-picture verification task. Presentation of the referents of terms in the statements was separated by 1 s, and presentation order was congruent or incongruent with the order of terms in the statement. Some relations showed faster verification times for congruent display order, others for incongruent display order, and still others showed no directionality effect. The authors proposed a 2-step process model for the construction of semantic representations of relational statements, in which a reference object is established first, and then the second object is attached in relation to it. This theory explains the various directionality effects as a general preference to process information about the reference object before information about the target object.