Cross-trial priming of element positions in visual pop-out search is dependent on stimulus arrangement

Two experiments examined cross-trial positional priming (V. Maljkovic & K. Nakayama, 1994, 1996, 2000) in visual pop-out search. Experiment 1 used regularly arranged target and distractor displays, as in previous studies. Reaction times were expedited when the target appeared at a previous target location (facilitation relative to neutral baseline) and slowed when the target appeared at a previous distractor location (inhibition). In contrast to facilitation, inhibition emerged only after extended practice. Experiment 2 revealed reduced facilitatory and no inhibitory priming when the elements' spatial arrangement was made irregular, indicating that positional--in particular, inhibitory--priming critically depends on the configuration of the display elements across sequences of trials. These results are discussed with respect to the role of the context for cross-trial priming in visual pop-out search.     

Electrophysiological correlates of flicker-induced color hallucinations

In a recent study, Becker and Elliott [Becker, C., & Elliott, M. A. (2006). Flicker induced color and form: Interdependencies and relation to stimulation frequency and phase. Consciousness & Cognition, 15(1), 175-196] described the appearance of subjective experiences of color and form induced by stimulation with intermittent light. While there have been electroencephalographic studies of similar hallucinatory forms, brain activity accompanying the appearance of hallucinatory colors was never measured. Using a priming procedure where observers were required to indicate the presence of one of eight target colors we compared electrophysiological correlates of hallucinatory color with brain states associated with other visual phenomena. Different target colors were accompanied by different patterns of EEG activation. However, in general, we found that the appearance of hallucinatory colors is preceded by a power decrease in the lower alpha band alongside an increase in gamma band frequencies. We argue that decreasing activity in the lower alpha band acts as a gating mechanism, inducing a switch in perception between different colors. The increasing gamma activation may correlate with the formation of a coherent conscious percept.     

The Relationship Between Premenstrual Distress and Anxiety Sensitivity: The Mediating Role of Rumination

Given that premenstrual distress is reported by large numbers of women, research has focused on the identification of biological and psychological factors that influence its severity. Previous research suggests that women who are high in anxiety sensitivity also report greater levels of premenstrual distress and negative affect. According to the menstrual reactivity hypothesis, women who have a tendency to self-focus and catastrophize about physical sensations are more likely to report greater levels of premenstrual distress. Cognitive schemas surrounding the menstrual cycle develop that are influenced by gender roles, cultural stereotypes, and expectations about bodily sensations. Another cognitive process, rumination, may also be linked to increased reports of premenstrual distress. Conceptually, the constructs of anxiety sensitivity and rumination share the tendency to self-focus on internal states. The goal of this study was to investigate how these two constructs relate to the prediction of premenstrual distress in a large sample of healthy undergraduate women (N = 478). Using mediational modeling, support was found for a mediational model; women who reported high levels of rumination and anxiety sensitivity reported the greatest premenstrual distress. These results are discussed within the framework of the menstrual reactivity hypothesis, a diathesis-stress model of premenstrual distress.     

Dimensional weighting of primary and secondary target-defining dimensions in visual search for singleton conjunction targets

Two experiments investigated dimension-based attentional processing in a complex singleton conjunction search task. In Experiment 1, observers had to discern the presence of a singleton target defined by a conjunction of size (fixed primary dimension) with either color or motion direction (secondary dimension). Similar to findings in singleton feature search, changes (vs. repetitions) of the secondary dimension across trials resulted in reaction time (RT) costs—which were, however, increased by a factor of 3–5 compared to singleton feature search. In Experiment 2, the coding of search-critical, dimensional saliency signals was investigated by additionally presenting targets redundantly defined in both secondary dimensions, with redundant-target signals being either spatially coincident or separate (i.e., one vs. two target items). Redundant-target RTs significantly violated Miller’s (Cognit Psychol 14:247–279, 1982) race model inequality only when redundant signals were spatially coincident (i.e., bound to a single object), indicating coactive processing of target information in the two secondary dimensions. These findings suggest that the coding and combining of signals from different visual dimensions operates in parallel. Increased change costs in singleton conjunction search are likely to reflect a reduced amount of weight available for processing the secondary target-defining dimensions, due to a large amount of weight being bound by the primary dimension.

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Inhibitory and facilitatory location priming in patients with left-sided visual hemi-neglect

In visual search for pop-out targets, reaction times are facilitated when the target on the current trial appears at a previous target location, and inhibited when it appears at a previous distractor location, relative to when it appears at a previously empty (neutral) location (Maljkovic and Nakayama, Perception and Psychophysics 58:977–991, 1996). However, while normal subjects are able to positively/negatively tag selected target/rejected distractor locations to guide search on the next trial, patients with visual hemi-neglect may have a (uni- or bilateral) deficit in these functions that may contribute to their disturbed visual scanning behavior. To examine this, using a pop-out search task, the present study assessed cross-trial facilitatory and inhibitory priming in 14 patients with left-sided visual hemi-neglect and in 14 age-, education-, and IQ-matched control subjects. The group of neglect patients did show significant facilitatory and inhibitory priming. However, while control subjects exhibited balanced effects of facilitation and inhibition, inhibition was relatively reduced in magnitude in neglect patients. In particular, inhibition was virtually absent in two patients with lesions affecting superior regions of the frontal cortex, putatively encroaching on the frontal eye field of the right hemisphere. These findings provide neuropsychological evidence that facilitatory and inhibitory priming effects are based on dissociable mechanisms, consistent with Geyer et al. (Journal of Experimental Psychology: Human Perception and Performance 33:788–797, 2007).     

Object-based selection operating on a spatial representation made salient by dimensional segmentation mechanisms: a re-investigation of Egly and Homa (1984)

Three experiments re-investigated selective attention in the ‘ring-cueing’ paradigm of Egly and Homa (J Exp Psychol: Human Percept Perform 10:778–793, 1984). Observers were cued to attend to one of three concentric rings of radius 1°, 2°, or 3°, and their signal detection accuracy for cued and uncued rings was measured. Experiment 1, which used a central color cue to indicate a like-colored ring, replicated ring-cueing effects along the lines of Egly and Homa. Experiments 2 and 3 examined whether these effects were produced by observers exploiting secondary-depth cues possibly inherent in the display layout. With color cues, the availability of secondary-depth information had no influence on the ring-cueing effects. However, making the rings monochrome and using central size cues significantly reduced the ring-cueing effects when the depth information was disrupted. The results suggest that selection was object-based, operating on a spatial ‘grouped-array’ representation of the cued ring made salient by color- or depth-based segmentation mechanisms.

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Closure of salient regions determines search for a collinear target configuration

Grouping operations offer an effective mechanism by which to structure complex visual scenes. Among the various principles that support element integration, closure may be regarded as a main factor in shape extraction. In five experiments, we investigated the impact of grouping by closure on search for target configurations made up of collinearly arranged corner junctions. Systematic variations in the configuration of distractor elements were explored to investigate how the figural information of distractors interferes with target detection. The results showed no search interference for distractor configurations that were open forms. By contrast, distractors making up closed forms reduced the efficiency of search performance, indicating closure as a major contributor to form detection in multielement configurations. In conclusion, the effects reported may be considered to arise from mechanisms of unit formation that support the rapid extraction of salient regions to guide search.     

Zur Beendigung von Lehranalysen

An attempt is made to give an open account about the goals, problems and results concerning the ending of eight training analyses. The connection of trauma, individual defence structure and mental disturbances as well as the need for their therapeutic change is emphasized. Three problems are offered for further discussion: 1. to transform acting outs of training analysts standing under the pressure of the projections by training analysands onto the institute, into interpretation; 2. the difficulty to understand the varieties of the depressive position within the mental patterns of foreign civilisations; 3. the hypothetical effect of the analysis of character neuroses on the abstinence of training analysts and on the decision for lower frequency by former training analysands.     

Independence of long-term contextual memory and short-term perceptual hypotheses: Evidence from contextual cueing of interrupted search

Observers are able to resume an interrupted search trial faster relative to responding to a new, unseen display. This finding of rapid resumption is attributed to short-term perceptual hypotheses generated on the current look and confirmed upon subsequent looks at the same display. It has been suggested that the contents of perceptual hypotheses are similar to those of other forms of memory acquired long-term through repeated exposure to the same search displays over the course of several trials, that is, the memory supporting “contextual cueing.” In three experiments, we investigated the relationship between short-term perceptual hypotheses and long-term contextual memory. The results indicated that long-term, contextual memory of repeated displays neither affected the generation nor the confirmation of short-term perceptual hypotheses for these displays. Furthermore, the analysis of eye movements suggests that long-term memory provides an initial benefit in guiding attention to the target, whereas in subsequent looks guidance is entirely based on short-term perceptual hypotheses. Overall, the results reveal a picture of both long- and short-term memory contributing to reliable performance gains in interrupted search, while exerting their effects in an independent manner.     

Are abilities dispositions?

Synthese - Abilities are in many ways central to what being an agent means, and they are appealed to in philosophical accounts of a great many different phenomena. It is often assumed that...