Parallel consolidation of simple features into visual short-term memory

Although considerable research has examined the storage limits of visual short-term memory (VSTM), little is known about the initial formation (i.e., the consolidation) of VSTM representations. A few previous studies have estimated the capacity of consolidation to be one item at a time. Here we used a sequential-simultaneous manipulation to reexamine the limits of consolidating items into VSTM. Participants viewed briefly presented and masked color patches (targets), which were shown either sequentially or simultaneously. A probe color followed the targets and participants decided whether it matched one of the targets or was a novel color. In four experiments, we consistently found equal performance for sequential and simultaneous presentations for two targets. Worse performance in the simultaneous than the sequential condition was observed for larger set sizes (three and four). Contrary to previous results, suggesting a severe capacity limit of one item, our results indicate that consolidation into VSTM can occur in parallel and without capacity limits for at least two items.     

Enhanced attentional capture in trait anxiety

Attentional Control Theory (ACT) proposes that anxiety is specifically associated with more attentional distraction by salient stimuli. Moreover, there is some suggestion that worry is one mechanism whereby anxiety impairs attentional control. However, direct evidence for these hypotheses is lacking. In the current study we addressed limitations of previous work by examining the relationships between trait anxiety and worry and attentional distraction by a salient, task-irrelevant color singleton in a visual search task. Results revealed that trait anxiety, but not worry, was related to increased attentional distraction (i.e., capture) by the color singleton. The current results suggest that anxiety is associated with a general enhancement of bottom-up processes involved in motivational significance detection. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Automatic priming of attentional control by relevant colors

We tested whether color word cues automatically primed attentional control settings during visual search, or whether color words were used in a strategic manner for the control of attention. In Experiment 1, we used color words as cues that were informative or uninformative with respect to the target color. Regardless of the cue's informativeness, distractors similar to the color cue captured more attention. In Experiment 2, the participants either indicated their expectation about the target color or recalled the last target color, which was uncorrelated with the present target color. We observed more attentional capture by distractors that were similar to the participants' predictions and recollections, but no difference between effects of the recollected and predicted colors. In Experiment 3, we used 100%-informative word cues that were congruent with the predicted target color (e.g., the word "red" informed that the target would be red) or incongruent with the predicted target color (e.g., the word "green" informed that the target would be red) and found that informative incongruent word cues primed attention capture by a word-similar distractor. Together, the results suggest that word cues (Exps. 1 and 3) and color representations (Exp. 2) primed attention capture in an automatic manner. This indicates that color cues automatically primed temporary adjustments in attention control settings.     

Negative emotional photographs are identified more slowly than positive photographs

In three experiments, we investigated whether the emotional valence of a photograph influenced the amount of time required to initially identify the contents of the image. In Experiment 1, participants saw a slideshow consisting of positive, neutral, and negative photographs that were balanced for arousal. During the slideshow, presentation time was substantially limited (60?ms), and the images were followed by masks. Immediately following the slideshows, participants were given a recognition memory test. Memory performance was best for positive images and worst for negative images (Experiment 1). In Experiment 2, two simultaneous photographs were briefly presented and masked. On a trial-by-trial basis, participants indicated whether the two images were identical or not, thus removing the need for memory storage and retrieval. Again, performance was worst for negative images. The results of Experiment 3 suggested that these valence-based differences were not related attentional effects (Experiment 3). We argue that the valence of an image is detected rapidly and, in the case of negative images, interferes with processing the identity of the scene.     

Adrenal medulla graft induced recovery of function in an animal model of Parkinson's disease: possible mechanisms of action

Following unilateral dopamine (DA) denervation of the striatum in animals, there is an asymmetry in the striatal DA system. Animals with such denervations will rotate vigorously when given dopaminergic drugs. Adrenal medulla grafts placed in the lateral ventricle adjacent to a DA-denervated striatum decrease rotational behaviour induced by DA receptor agonists or DA-releasing agents. This discussion reviews research on the use of adrenal medulla grafts to reverse behavioural deficits following DA-denervation of the striatum. Results from basic animal research and from the application of the procedure to patients with Parkinson's disease suggests that at least three different fundamental processes may mediate the functional effects of adrenal medulla grafts: (a) Adrenal medulla grafts may induce changes in the blood-brain barrier; (b) adrenal medulla grafts may induce an increase in serum DA; and (c) adrenal medulla grafts may have a trophic effect on the host brain. Hypotheses are proposed to explain the behavioural effects of adrenal medulla grafts in light of the processes that are thought to mediate their effects.     

Balanced incomplete blocks to control individual differences

Balanced incomplete block designs are used when there are reasons that preclude the use of repeated measurements designs, particularly when there are at least two factors, each with several levels. However, these designs are usually not used when interaction effects are of interest, because they involve the confounding of the interactions with subject or group differences. This paper describes special computational procedures that can be employed to obtain partial, but unconfounded, information about interaction effects.     

Depressive thinking and depression: relations with personality and social resources

The mechanisms by which social supports and personality variables may buffer against psychopathology are not well understood. We studied depression, depressive cognitions, social supports, and self-esteem in a sample of 68 spouse-caregivers of patients with Alzheimer's Disease in an attempt to identify possible buffering mechanisms of the latter two variables. Specifically, we hypothesized that the well-known relation of depressive cognitions to depression would vary as a function of satisfaction with social supports and with level of self-esteem. Hierarchical multiple regression analyses conducted to predict depression revealed significant and independent main effects for depressive cognitions (p less than .01), social supports (p less than .025), and self-esteem (p less than .001), with depressive cognitions associated with higher depression and the other two variables associated with reduced depression (R2 = .53 for the three main effects). In addition, the relation of depressive cognitions with depression varied substantially depending on the level of social supports (p less than .01); caregivers with high levels of depressive cognitions had high levels of depression only if social supports were low (R2 = .61 including interaction). Self-esteem and depressive cognitions showed a similar interaction, but it failed to reach significance. Analyses to determine whether self-esteem and social supports were directly associated with lower depressive cognitive activity yielded a main effect for self-esteem only (p less than .03). Thus, whereas social supports and self-esteem were directly associated with lower depression, only the social supports variable was further associated with reduced depression because it apparently buffered the impact of depressive thinking. Self-esteem was also indirectly associated with lower depression via its relation with lower depressive thinking. Implications of our results for cognitive theories of depression and for the psychosocial mechanisms of stress buffering are discussed.     

Possibilities and limits of rehabilitation in a young girl with total (global) aphasia

In the case discussed, the faculties retained and lost are described, and the aims and tasks of rehabilitation set out. The mode of procedure is elucidated by means of examples, the results achieved given, and the possible basis for the effectivity of the rehabilitation measures discussed.