Regional cerebral blood flow response in a patient with remitted global amnesia

A case of remitted global amnesia, believed to have residual left medial temporal lobe damage, is tested by the same recognition memory paradigm used by Wood, Taylor, et al. in the previous paper. On two different testing occasions, once using an intentional and once an incidental memory procedure, the patient's right occipital flows were inversely correlated with memory accuracy and the values were very close to the regression line for 10 normals relating occipital flow to memory accuracy. The left occipital flows did not fit the regression line, however. The results were interpreted as consistent with the notion that occipital flow is inversely related to medial temporal lobe activation. Another surprising feature of this case is the unexpected persistence of amnesia for a period from about 5 to 10 years before her episode to about 2 weeks after the episode, with recovery of memory functioning for the period since that time.     

The effect of content and physical properties of affective pictures on emotional responses

The aim of this research was to study the influence of both the emotional content and the physical characteristics of affective stimuli on the psychophysiological, behavioral and cognitive indexes of the emotional response. We selected 54 pictures from the IAPS, depicting unpleasant, neutral, and pleasant contents, and used two picture sizes as experimental conditions (120 x 90 cm and 52 x 42 cm). Sixty-one subjects were randomly assigned to each experimental condition. We recorded the startle blink reflex, skin conductance response, heart rate, free viewing time, and picture valence and arousal ratings. In line with previous research (e.g., Bradley, Codispoti, Cuthbert, and Lang, 2001), our data showed an effect of the affective content on all the measurements recorded. Importantly, effects of the size of the affective pictures on emotional responses were not found, indicating that the emotional content is more important than the formal properties of the stimuli in evoking the emotional response.     

Sex differences and bilateral electrodermal activity

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román,et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeareed clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.     

Refining the theory of basic individual values

We propose a refined theory of basic individual values intended to provide greater heuristic and explanatory power than the original theory of 10 values (Schwartz, 1992). The refined theory more accurately expresses the central assumption of the original theory that research has largely ignored: Values form a circular motivational continuum. The theory defines and orders 19 values on the continuum based on their compatible and conflicting motivations, expression of self-protection versus growth, and personal versus social focus. We assess the theory with a new instrument in 15 samples from 10 countries (N = 6,059). Confirmatory factor and multidimensional scaling analyses support discrimination of the 19 values, confirming the refined theory. Multidimensional scaling analyses largely support the predicted motivational order of the values. Analyses of predictive validity demonstrate that the refined values theory provides greater and more precise insight into the value underpinnings of beliefs. Each value correlates uniquely with external variables.     

Response inhibition and attentional control in anxiety

Traditionally, anxiety has been associated with a selective attentional bias for threat and a decreased capacity in attentional control. In two different experiments, we investigated whether individuals with different levels of self-reported state anxiety (Experiment 1) and induced anxiety (Experiment 2) had impaired response inhibition processes (attentional control deficit) as characterized by a different response style in the presence of negative stimuli under low and high perceptual load conditions. A go/no-go paradigm with emotional distractors (angry, happy, and neutral faces) was used to provide measures of perceptual sensitivity, inhibition, and response style. Our findings showed that perceptual sensitivity, as assessed by the d' parameter of signal detection theory, was reduced in all participants for angry faces under low perceptual load, where enough perceptual resources were available to be attracted by distractors. Importantly, despite similar perceptual sensitivity, the beta parameter indicated that high state anxiety individuals in both experiments were less flexible at adjusting to task demands in the presence of angry face distractors by adopting a stricter criterion. Implications of findings are discussed within current models of attentional control in anxiety.     

Influence of electroencephalography neurofeedback training on episodic memory: A randomized,sham-controlled,double-blind study

The relationships between memory processes and oscillatory electroencephalography (EEG) are well established. Neurofeedback training (NFT) may cause participants to better regulate their brain EEG oscillations. The present study is a double-blind sham-controlled design investigating the effect of NFT on memory. NFT included up-training upper alpha (UA) band, up-training sensory-motor rhythm (SMR) band and sham protocol. Thirty healthy adult volunteers were randomly divided into three treatment groups. NFT sessions (30 min each) took place twice weekly for a total of 10 sessions while memory testing took place pre- and post-training. The results indicate dissociation between SMR and UA NFT and different memory processes. While the SMR protocol resulted in improving automatic, item-specific and familiarity-based processes in memory, the UA protocol resulted in improved strategic and controlled recollection. The implications of the results are discussed.     

Loss-aversion or loss-attention: The impact of losses on cognitive performance

Losses were found to improve cognitive performance, and this has been commonly explained by increased weighting of losses compared to gains (i.e., loss aversion). We examine whether effects of losses on performance could be modulated by two alternative processes: an attentional effect leading to increased sensitivity to task incentives; and a contrast-related effect. Empirical data from five studies show that losses improve performance even when the enhanced performance runs counter to the predictions of loss aversion. In Study 1–3 we show that in various settings, when an advantageous option produces large gains and small losses, participants select this alternative at a higher rate than when it does not produce losses. Consistent with the joint influence of attention and contrast-related processes, this effect is smaller when a disadvantageous alternative produces the losses. In Studies 4 and 5 we find a positive effect on performance even with no contrast effects (when a similar loss is added to all alternatives). These findings indicate that both attention and contrast-based processes are implicated in the effect of losses on performance, and that a positive effect of losses on performance is not tantamount to loss aversion.     

Improvement in working memory is not related to increased intelligence scores

The acknowledged high relationship between working memory and intelligence suggests common underlying cognitive mechanisms and, perhaps, shared biological substrates. If this is the case, improvement in working memory by repeated exposure to challenging span tasks might be reflected in increased intelligence scores. Here we report a study in which 288 university undergraduates completed the odd numbered items of four intelligence tests on time 1 and the even numbered items of the same tests one month later (time 2). In between, 173 participants completed three sessions, separated by exactly one week, comprising verbal, numerical, and spatial short-term memory (STM) and working memory (WMC) tasks imposing high processing demands (STM–WMC group). 115 participants also completed three sessions, separated by exactly one week, but comprising verbal, numerical, and spatial simple speed tasks (processing speed, PS, and attention, ATT) with very low processing demands (PS-ATT group). The main finding reveals increased scores from the pre-test to the post-test intelligence session (more than half a standard deviation on average). However, there was no differential improvement on intelligence between the STM-WMC and PS-ATT groups.     

Adapted to explore: Reinforcement learning in Autistic Spectrum Conditions

Recent studies have recorded a tendency of individuals with Autism Spectrum Conditions (ASC) to continually change their choices in repeated choice tasks. In the current study we examine if this finding implies that ASC individuals have a cognitive style that facilitates exploration and discovery. Six decision tasks were administered to adolescents with ASC and matched controls. Significant differences in shifting between choice options appeared in the Iowa Gambling task (Bechara, Damasio, Damasio, & Anderson, 1994). A formal cognitive modeling analysis demonstrated that for about half of the ASC participants the adaptation process did not conform to the standard reinforcement learning model. These individuals were only coarsely affected by choice-outcomes, and were more influenced by the exploratory value of choices, being attracted to previously un-explored alternatives. An examination of the five simpler decision tasks where the advantageous option was easier to determine showed no evidence of this pattern, suggesting that the shifting choice pattern is not an uncontrollable tendency independent of task outcomes. These findings suggest that ASC individuals have a unique adaptive learning style, which may be beneficial is some learning environment but maladaptive in others, particularly in social contexts.