Visual-spatial working memory, attention, and scene representation: A neuro-cognitive theory

This paper addresses the issue of how visual-spatial working memory, attention, and scene representation are related. The first section introduces a modified two-stage conception of visual-spatial processing. “Stage one” refers to low-level visual-spatial processing and computes in parallel for the currently available retinal information “object candidates,” here called “visual-spatial units.” An attentional process called “unit selection” allows access to stage two for one of these units at a time. Stage two contains high-level visual-spatial information that can be used for goal-directions (e.g., verbal report, grasping). It consists of three parallel processing streams. First, the currently selected unit is recognized; second, a spatial-motor program for the selected unit is computed; and third, an “object file” is set up for the selected unit. An object file contains temporary episodic representations of detailed high-level visual-spatial attributes of an “object” plus an “index.” An index acts as a pointer and is bound via temporary connections to the attributes of the file. Section two of this paper specifies one part of stage two in more detail, namely visual-spatial working memory (VSWM). It can contain up to four object files. A first central claim is that during sensory-based processing for working memory (“access”), one object file is always “on-line,” and up to three other object files are “off-line”. A second central claim is that the process of setting up an object file depends on the number and the activation level of already stored files. Based on the concept of activation-based competition between object files, it is postulated that the more files that are stored and the higher their activation is, the longer it takes for a newly set up object file to reach a sufficient level of activation. Activation-based competition is also used to explain “short-term forgetting” by “interference.” A third central claim about VSWM is that a “refreshment' process exists that increases the activation level of an index of an object file in order to prevent forgetting or in order to bring the file back to the state of controlling the current action. Finally, section three gives a selective look at a number of experimental data such as the attentional blink, backward masking, dwell time effects, transsaccadic memory, and change blindness. New explanations are offered and new predictions made. Received: 16 January 1998 / Accepted: 25 July 1998     

Dynamics of oralrespiratory coordination in full-term and preterm infants: I. Comparisons at 38-40 weeks postconceptional age

This study compares the coordination of pacifier sucking and breathing between healthy full-term, low risk preterm, and high risk preterm infants at 38–40 weeks postconceptional age. High and low risk preterm infants did not differ in overall score on a neurobehavioral examination (NAPI), but infants in the high risk group differed from the others in breathing frequency and in the coordination of breathing and sucking rhythms. For infants in the high risk group, sucking had less influence on respiratory frequency and patterns of coordination between the frequencies of sucking and breathing were simpler. Oral–respiratory coordination may be a useful marker of infants at risk for later speech problems.     

Perspectives in psychology

The Psychological Record - The traditional S-R position that in systematic psychology the IV’s are to be identified with environmental conditions is critically discussed. The advantages of...     

Contrasting activity patterns of two related octopus species, Octopus macropus and Octopus vulgaris

Octopus macropus and Octopus vulgaris have overlapping habitats and are exposed to similar temporal changes. Whereas the former species is described as nocturnal in the field, there are conflicting reports about the activity time of the latter one. To compare activity patterns, the authors tested both species in the laboratory. Octopuses were exposed to a light-dark cycle and held under constant dim light for 7 days each. O. macropus showed nocturnal and light-cued activity. According to casual observations, O. vulgaris started out nocturnal but had switched to mostly diurnal when the experiment began. Individual variation of its activity was found. The different activity patterns of O. macropus and O. vulgaris might reflect their lifestyles, the latter species being more generalist.     

The neural mechanisms of word order processing revisited: electrophysiological evidence from Japanese

We present two ERP studies on the processing of word order variations in Japanese, a language that is suited to shedding further light on the implications of word order freedom for neurocognitive approaches to sentence comprehension. Experiment 1 used auditory presentation and revealed that initial accusative objects elicit increased processing costs in comparison to initial subjects (in the form of a transient negativity) only when followed by a prosodic boundary. A similar effect was observed using visual presentation in Experiment 2, however only for accusative but not for dative objects. These results support a relational account of word order processing, in which the costs of comprehending an object-initial word order are determined by the linearization properties of the initial object in relation to the linearization properties of possible upcoming arguments. In the absence of a prosodic boundary, the possibility for subject omission in Japanese renders it likely that the initial accusative is the only argument in the clause. Hence, no upcoming arguments are expected and no linearization problem can arise. A prosodic boundary or visual segmentation, by contrast, indicate an object-before-subject word order, thereby leading to a mismatch between argument "prominence" (e.g. in terms of thematic roles) and linear order. This mismatch is alleviated when the initial object is highly prominent itself (e.g. in the case of a dative, which can bear the higher-ranking thematic role in a two argument relation). We argue that the processing mechanism at work here can be distinguished from more general aspects of "dependency processing" in object-initial sentences.     

Increases in language lateralization in normal children as observed using magnetoencephalography

Previous functional magnetic resonance imaging (fMRI) studies investigating hemispheric dominance for language have shown that hemispheric specialization increases with age. We employed magnetoencephalography (MEG) to investigate these effects as a function of normal development. In sum, 22 healthy children aged 7-16 years were investigated using two language tasks: a verb-generation (VG) task and a vowel-identification (VI) task. Significant hemispheric differences were found for both tasks in cerebral language areas using oscillatory MEG spectral analyses, confirming the MEG's ability to detect hemispheric specialization for language in children. Additionally, a significant increase of this lateralization as a function of age was observed for both tasks. As performance in the VI task showed no correlation with age, this increase seems to be unrelated to performance. These results confirm an increase in hemispheric specialization as a function of normal brain maturation.     

Information transmission for one-dimensional stimuli: The role of strategies

Important evidence about the information flow between perceptual and motor processes has been obtained from the lateralized readiness potential (LRP) recorded in two-choice go/nogo tasks. Here, we investigated the effect of time pressure on information transmission for one-dimensional stimuli (four squares differing in size). In between- and within-subject designs, respectively, Experiments 1 and 2 showed that under time pressure partial information initiates hand decision and response preparation before complete size information is available. These findings appear to be at odds with the asynchronous discrete coding model. Experiment 3 assessed the mechanisms behind these effects by manipulating the relative difficulty of extracting hand- and go/nogo-specific information from the size of the stimuli. Consistent with asynchronous coding, our results suggest that serial-consecutive processes in extracting partial and full size information may occur also for one-dimensional stimuli. Our data are inconclusive as to the question of discreteness or continuity of information transmission. On a more general level, our data support the notion of flexibility in the coding of perceptual dimensions to adapt performance to environmental conditions.     

Adult age differences in inhibitory processes and their predictive validity for fluid intelligence

According to the inhibition-deficit hypothesis age differences in working memory capacity and fluid intelligence have been attributed to a decline in inhibitory efficiency. Conceptualizing inhibition as multifaceted, 88 participants (49 younger and 39 elderly) completed two versions of the negative priming paradigm (identification and localization), and two variants of the directed forgetting paradigm (listwise and itemwise). Two tasks of the Wechsler Intelligence Test with high loadings on general fluid intelligence (Gf) served as validation criteria. Results revealed task-specific and speed-independent inhibitory deficits in the elderly (lower negative priming in both paradigms; more intrusions in the directed forgetting tasks), as well as higher levels of repetition priming. Significant correlations between measures of inhibition and the Wechsler scores were found in both age groups. Results support the view of multiple inhibitory-like capabilities that play a central role in the decline of higher-order cognitive functions in old age.     

“To Protect and to Serve?”: An Exploration of Police Conduct in Relation to the Gay,Lesbian, Bisexual,and Transgender Community

While there are studies that focus specifically on hate crimes, especially anti-lesbian, gay, bisexual, and/or transgender motivated violence, little research has been done to examine the role that law enforcement officials play in responding to crimes related to the Gay/Lesbian/Bisexual/Transgender (GLBT) community. This study, therefore, attempts to do just that. Using traditional content-analysis techniques, we examine 1,896 incident reports that were collected by a GLBT advocacy group in Minnesota, between 1990 and 2000, to begin to understand the range of police responses in relation to the GLBT community. Results indicate that while police conduct improved, negative responses and behaviors on the part of law enforcement officials outnumbered positive responses. The most common complaint by Helpline callers was inadequate response by the police; there were also numerous callers indicating that they were further victimized at the hands of the law enforcement officials. The data suggest a continued need for the education of law enforcement officials regarding issues facing the GLBT community, advocacy for victims of crime who are many times reluctant to report an incident to the police and increased attention to issues of oversight and accountability for officers who are responding to calls for help from the GLBT community.

Concurrent Treatment of Depression in Parents and Adolescents: A Case Example

The detrimental influence of parent psychopathology—and depression, in particular—on adolescent mental health has been well documented. Routes of transmission include both direct and indirect factors, such as poor parent–adolescent communication, ineffective parenting practices, modeling ineffective coping skills, increased family discord and stress, inadvertent reinforcement of adolescent depressed mood and suicidal ideation and behavior, and decreased treatment adherence. This paper introduces a novel treatment to concurrently treat both a depressed adolescent as well as a depressed parent. This approach improves upon traditional cognitive-behavioral therapy by targeting relational factors of each adolescent–parent dyad while simultaneously addressing each individual’s depression. Principles of case conceptualization and treatment planning using this novel approach are illustrated using a case example.