A comparison of masking by visual and transcranial magnetic stimulation: implications for the study of conscious and unconscious visual processing

Visual stimuli as well as transcranial magnetic stimulation (TMS) can be used: (1) to suppress the visibility of a target and (2) to recover the visibility of a target that has been suppressed by another mask. Both types of stimulation thus provide useful methods for studying the microgenesis of object perception. We first review evidence of similarities between the processes by which a TMS mask and a visual mask can either suppress the visibility of targets or recover such suppressed visibility. However, we then also point out a significant difference that has important implications for the study of the time course of unconscious and conscious visual information processing and for theoretical accounts of the processes involved. We present evidence and arguments showing: (a) that visual masking techniques, by revealing more detailed aspects of target masking and target recovery, support a theoretical approach to visual masking and visual perception that must take into account activities in two separate neural channels or processing streams and, as a corollary, (b) that at the current stage of methodological sophistication visual masks, by acting in more highly specifiable ways on these pathways, provide information about the microgenesis of form perception not available with TMS masks.     

Dangerous and severe personality disorders: a new personality concept from the United Kingdom

In 1998, we in England were shocked by the apparently motiveless murders of a mother and two of her children when they were traveling home from school in a rural area. Subsequently a patient with personality disorder, being monitored by the forensic psychiatric services, was convicted of their murders. The government was determined to prevent this type of offense from recurring and in 1999 introduced a new concept, dangerous and severe personality disorder (DSPD). This subsequently became a treatment and assessment program for individuals who satisfy three requirements: (1) have a severe disorder of personality, (2) present a significant risk of causing serious physical or psychological harm from which the victim would find it difficult or impossible to recover, and (3) the risk of offending should be functionally linked to the personality disorder. The implications of this program are discussed with regard to international systems of classification and service provision. We also attempt to place DSPD in the wider context of psychiatric participation in the management of personality disordered offenders.     

Components of reflexive visual orienting to moving objects

Posner and Cohen (1984) and Maylor (1985) initially observed that a luminance change produces both facilitatory and inhibitory effects on subsequent detection. While Posner and Cohen claimed that the facilitatory effect was mapped in retinotopic coordinates, they showed that inhibition of return (IOR) was mapped in “environmental coordinates.” Tipper and colleagues (Tipper, Driver, & Weaver, 1991; Tipper et al., 1997; Tipper, Weaver, Jerreat, & Burak, 1994) and Abrams and Dobkin (1994b) have recently reported that IOR can be object based, but contradictory results have also been reported (Muller & von Mühlenen, 1996). Here we report six experiments showing that an uninformative peripheral cue can generate either facilitatory or inhibitory object-based effects that can tag moving objects and that can persist for several hundred milliseconds. Although the boundary conditions determining which effect will be manifest remain to be defined, the present results suggest that facilitation and inhibition are generated independently, rather than being components of the same biphasic process.     

Computational evidence for the foundations of numerical competence

INFANT is a computational model of Simon's (1997) ‘non-numerical’ account of the foundations of numerical competence. It operationalizes the memory, individuation, object permanence and spatiotemporal representation competencies of that account into a simulation of the Simon, Hespos & Rochat (1995) study. Results demonstrate that infants’ responses can indeed be reproduced without numerical representations.     

INCREASED PEER-TEACHING WITH GROUP-ORIENTED CONTINGENCIES FOR ARITHMETIC PERFORMANCE IN BEHAVIOR-DISORDERED ADOLESCENTS1

Group-oriented contingencies were applied to increase the arithmetic problem-solving rates of four behavior-disordered adolescent residents in a psychiatric hospital. The experiment followed an ABAC reversal design consisting of baseline conditions (A₁ and A₂), and cumulative (B) and mixed (C) interdependent group-oriented contingency conditions. Under the cumulative arrangement, the subjects earned five cents for every correctly solved multiplication problem. The same conditions were in effect with the mixed contingency, except that each subject was required to work at least three problems before any subject could earn money. The results indicated consistent increases in the subjects' arithmetic computation rates as a function of the group-oriented contingencies. Concurrent observations were made across the four conditions of the experiment on four categories of the subjects' verbalizations: antecedent peer-teaching, consequent peer-teaching, positive statements, and negative statements. The subjects' rates of antecedent peer-teaching verbalizations covaried with the group-contingency-induced increases in their levels of computation behavior. The majority of the verbalization involved answers to number fact questions or redirecting peers to engage in on-task activities. The three other categories of the subjects' verbalizations that were observed—consequent peer-teaching, positive statements, and negative statements—were not found to covary with the subjects' altered rates of computation behavior.     

A study of system execution of performance appraisal

Dissatisfaction with traditional performance appraisal (PA) has led some organizations to eliminate formal reviews entirely and to substitute alternative methods of performance feedback, while other firms search for ways to improve the formal process. This study attempts to contribute to the ongoing debate about the future of PA by investigating the effects of an understudied aspect of the PA process: how well the PA system is executed by the supervisor. Our results indicate that system execution explains a significant amount of variance in intention to improve over and above a host of variables studied in previous PA studies, and that these effect sizes suggest clear practical significance.     

Infants' behavioral reenactment of "failed attempts": exploring the roles of emulation learning,stimulus enhancement,and understanding of intentions

Two studies were conducted to examine whether infants' reenactment of intended but unconsummated acts in A. N. Meltzoff's (1995) failed-attempt paradigm is due to reading the adult's underlying intention or to the effects of nonimitative social learning processes. Two novel conditions that emphasized the object affordances and the spatial contiguity of the object sets were devised. When infants' first actions only were counted, infants who observed the full-demonstration model produced more target acts. When all target acts produced within the 20-s response period were counted, infants in the emulation-learning and spatial contiguity conditions produced as many target acts as infants in the full-demonstration and failed-attempt conditions. This pattern of findings suggests that nonimitative social learning processes may influence infants' response in the behavioral reenactment paradigm.