Memory for affectively valenced and neutral stimuli in depression: Evidence from a novel matching task

Depressed persons have better memory for affectively negative than positive stimuli, a pattern generally not exhibited by non-depressed individuals. The mechanisms underlying this differential memory are not clear. In this study we examined memory for valenced and neutral stimuli in depressed and non-depressed individuals under conditions of relatively unconstrained encoding. We developed a novel task based on the game, Concentration, in which participants tried to match pairs of positive and negative words, and pairs of neutral words, hidden under squares in as few turns as possible. Whereas non-depressed participants selected and turned over positive squares more frequently than they did negative squares, depressed participants selected and turned over positive and negative squares equally often. Depressed participants also matched fewer positive word pairs within the first five minutes of the task than did non-depressed participants, and they exhibited poorer learning of positive words. Depressed and non-depressed participants did not differ in their matching of neutral words. These findings add to a growing literature indicating that depression is characterised by difficulties in the processing of positive stimuli.     

The processing of affectively valenced stimuli: The role of surprise

Two experiments tested the hypothesis that the surprise mechanism activates a threat detection system that prioritises the processing of threat-related stimuli. In Experiment 1, participants responded to a dot that appeared during the presentation of two words. In the critical trial, one of the two words was either pleasant or unpleasant. In Experiment 2, depending on the condition, the participants had to decide whether at least one of two simultaneously presented pictures depicted either a pleasant or an unpleasant stimulus. In the critical trial, both a pleasant and an unpleasant picture appeared. In both experiments, the stimuli in the critical trial were presented either during routine behaviour or in the context of a surprising event. The results showed that during routine behaviour unpleasant stimuli received more attentive resources than pleasant stimuli only if the affective valence of the stimuli was action-relevant (Experiment 2). In contrast, in the context of surprise, unpleasant words engaged more attentive resources than pleasant words although they were action-irrelevant (Experiment 1). In addition, in the context of surprise, the decision time increase was more pronounced in the pleasant than in the unpleasant experimental group. This finding was interpreted as evidence that the threat detection system of the surprise mechanism initially searches for a threat-related stimulus.     

The formation of implicit and explicit attitudes for neutral and valenced stimuli using the self

In Evaluative Conditioning (EC) studies, novel Conditioned Stimuli (CSs) are usually selected so to be neutral. However, in real life, because of the tendency of humans to evaluate novel stimuli automatically, novel CSs are very often initially valenced. From the literature little is known on whether EC can be successful under these conditions. In this contribution we applied a specific EC paradigm, namely self-referencing (SR) task, to new fictitious social groups. We present three studies. The first preliminary study is a pretest for selecting novel CSs. We examined the valence of four fictitious novel groups with both direct (semantic differential) and indirect (IAT) measures. The results showed that one pair was neutral (Lerriani vs. Dattiani) and the other was valenced (Niffiani, CS+ vs. Duppiani, CS?). In the second and third studies, we applied the SR paradigm to the neutral and initially valenced CSs. The results revealed a significant EC effect on both indirect and direct measures, such that the groups associated with the self became more positive and the groups associated with the other became more negative. The effects were found for both neutral and initially valenced groups, therefore showing that neutrality is not a prerequisite for EC effects. If anything, the effects were stronger for the initially valenced groups, especially on the indirect measure. Results are discussed in light of the detection of EC effects for both neutral and initially valenced CSs.     

There are at least two kinds of probability matching: evidence from a secondary task

Probability matching is a suboptimal behavior that often plagues human decision-making in simple repeated choice tasks. Despite decades of research, recent studies cannot find agreement on what choice strategies lead to probability matching. We propose a solution, showing that two distinct local choice strategies—which make different demands on executive resources—both result in probability-matching behavior on a global level. By placing participants in a simple binary prediction task under dual- versus single-task conditions, we find that individuals with compromised executive resources are driven away from a one-trial-back strategy (utilized by participants with intact executive resources) and towards a strategy that integrates a longer window of past outcomes into the current prediction. Crucially, both groups of participants exhibited probability-matching behavior to the same extent at a global level of analysis. We suggest that these two forms of probability matching are byproducts of the operation of explicit versus implicit systems.     

Photograph method fosters direct access to second-language word meaning: Direct evidence from a word-picture matching task

This experiment was designed to investigate conceptual links directly through a word–picture matching task in children. Participants were asked to indicate between two pictures the one depicting the same concept as the newly learned L2 word (target). One of the two pictures was the target, while the other was either semantically related to it or was unrelated. To investigate whether learning methods modulate L2 word processing, two learning methods were compared: an L2-photograph method and an L1-L2 method. Results showed a semantic interference effect only with the L2-photograph method: Children responded more slowly in the related condition than in the unrelated one. The learning method modulated L2 word processing and L2 word meaning was not necessarily accessed through L1 mediation in the first steps of learning. The method used paves the way for the direct investigation of conceptual links.     

Amygdala responses to emotionally valenced stimuli in older and younger adults

Abstract— As they age, adults experience less negative emotion, come to pay less attention to negative than to positive emotional stimuli, and become less likely to remember negative than positive emotional materials. This profile of findings suggests that, with age, the amygdala may show decreased reactivity to negative information while maintaining or increasing its reactivity to positive information. We used event-related functional magnetic resonance imaging to assess whether amygdala activation in response to positive and negative emotional pictures changes with age. Both older and younger adults showed greater activation in the amygdala for emotional than for neutral pictures; however, for older adults, seeing positive pictures led to greater amygdala activation than seeing negative pictures, whereas this was not the case for younger adults.     

Unfamiliar faces are not faces: Evidence from a matching task

It is difficult to match two images of the same unfamiliar face, even under good conditions. Here, we show that there are large individual differences on unfamiliar face matching. Initially, we tried to predict these using tests of visual short-term memory, cognitive style, and perceptual speed. Moderate correlations were produced by various components of these tests. In three other experiments, we found very strong correlations between face matching and inverted face matching on the same test. Finally, we examined potential associations between familiar and unfamiliar face processing. Strong correlations were found between familiar and unfamiliar face processing, but only when the familiar faces were inverted. We conclude that unfamiliar faces are processed for identity in a qualitatively different way than are familiar faces.     

Attentional orienting and awareness: evidence from a discrimination task

We used several cue–target SOAs (100, 500, 1000 ms) and three different degrees of cue predictability (Non-predictive-50%, Predictive-75%, Counter-predictive-25%), to investigate the role of awareness of cue–target predictability on cueing effects. A group of participants received instructions about the informative value of the cue, while another group did not receive such instructions. Participants were able to extract the predictive value of a spatially peripheral cue and use it to orient attention, whether or not specific instructions about the predictive value of the cue were given, and no matter their ability to correctly report it in a post-test questionnaire. In the non-predictive block, bad estimators who received no instructions showed regular cueing effects, while good estimators exhibited smaller and non-significant facilitatory effects at the short SOA and an absence of significant IOR at longer SOAs. However, for the instructions group, the pattern of results reversed.     

Memory transfer for emotionally valenced words between identities in dissociative identity disorder

The present study aimed to determine interidentity retrieval of emotionally valenced words in dissociative identity disorder (DID). Twenty-two DID patients participated together with 25 normal controls and 25 controls instructed to simulate DID. Two wordlists A and B were constructed including neutral, positive and negative material. List A was shown to one identity, while list B was shown to another identity claiming total amnesia for the words learned by the first identity. The identity claiming amnesia was tested for intrusions from list A words into the recall of words from list B and recognition of the words learned by both identities. Test results indicated no evidence of total interidentity amnesia for emotionally valenced material in DID. It is argued that dissociative amnesia in DID may more adequately be described as a disturbance in meta-memory functioning instead of an actual retrieval inability.     

Weaker inhibition after happy faces: evidence from an attentional blink task with emotional and neutral faces

Motivation and Emotion - In two experiments using a Rapid Serial Visual Presentation (RSVP) we investigated how emotional and neutral faces (T1) modulate temporal attention for a following neutral...     

Lexical and semantic influences on item and order memory in immediate serial recognition: evidence from a novel task

Previous studies have reported that, in contrast to the effect on immediate serial recall, lexical/semantic factors have little effect on immediate serial recognition. This has been taken as evidence that linguistic knowledge contributes to verbal short-term memory in a redintegrative process at recall. Contrary to this view, we found that lexicality, frequency, and imageability all influenced matching span. The standard matching span task, requiring changes in item order to be detected, was less susceptible to lexical/semantic factors than was a novel task involving the detection of phoneme order and hence item identity changes. Therefore, in both immediate recognition and immediate serial recall, lexical/semantic knowledge makes a greater contribution to item identity than to item order memory. Task sensitivity, and not the absence of overt recall, may have underpinned previous failures to show effects of these variables in immediate recognition. We also compared matching span for pure and unpredictable mixed lists of words and nonwords. Lexicality had a larger impact on immediate recognition for pure than for mixed lists, in line with findings for immediate serial recall. List composition affected the detection of phoneme but not item order changes in matching span; similarly, in recall, mixed lists produce more frequent word phoneme migrations but not migrations of entire items. These results point to strong similarities between immediate serial recall and recognition. Lexical/semantic knowledge may contribute to phonological stability in both tasks.     

Multiple systems for cognitive control: evidence from a hybrid prime-Simon task

Cognitive control resolves conflicts between appropriate and inappropriate response tendencies. Is this achieved by a unitary all-purpose conflict control system, or do independent subsystems deal with different aspects of conflicting information? In a fully factorial hybrid prime-Simon task, participants responded to the identity of targets displayed at different nominally irrelevant screen locations, preceded by nominally irrelevant, consciously or nonconsciously perceived primes. The response required by the target's identity could match or mismatch (a) the target's location, and (b) the prime's identity, resulting in potential conflict (a) across and (b) within stimulus domains. Conflict effects were investigated within and across trials. Results suggest that (i) nonconsciously perceived information elicits within-trial control, but--unlike consciously perceived information--no across-trial behavioral modulation; (ii) separate subsystems deal with conflicts arising from different stimulus domains; and (iii) occasional apparent interactions between domains reflect a particular difficulty in reactivating a just-discarded response (reactivation aversion effect, RAE).     

Evidence for lexical access in a simultaneous matching task

Memory & Cognition - Reaction times in a simultaneous visual matching task were obtained for four types of letter strings: high-frequency words, low-frequency words, orthographically legal...     

Object-based selection from spatially-invariant representations: evidence from a feature-report task

Attention selects objects as well as locations. When attention selects an object's features, observers identify two features from a single object more accurately than two features from two different objects (object-based effect of attention; e.g., Duncan, Journal of Experimental Psychology: General, 113, 501-517, 1984). Several studies have demonstrated that object-based attention can operate at a late visual processing stage that is independent of objects' spatial information (Awh, Dhaliwal, Christensen, & Matsukura, Psychological Science, 12, 329-334, 2001; Matsukura & Vecera, Psychonomic Bulletin & Review, 16, 529-536, 2009; Vecera, Journal of Experimental Psychology: General, 126, 14-18, 1997; Vecera & Farah, Journal of Experimental Psychology: General, 123, 146-160, 1994). In the present study, we asked two questions regarding this late object-based selection mechanism. In Part I, we investigated how observers' foreknowledge of to-be-reported features allows attention to select objects, as opposed to individual features. Using a feature-report task, a significant object-based effect was observed when to-be-reported features were known in advance but not when this advance knowledge was absent. In Part II, we examined what drives attention to select objects rather than individual features in the absence of observers' foreknowledge of to-be-reported features. Results suggested that, when there was no opportunity for observers to direct their attention to objects that possess to-be-reported features at the time of stimulus presentation, these stimuli must retain strong perceptual cues to establish themselves as separate objects.     

Interpretation and matching bias in a reasoning task

Subjects were required to construct verifying and falsifying cases of conditional rules in which the presence and absence of negative components was varied. Their responses gave some indication of consistent interpretation of the rules, generally conforming to Wason's (1966) idea of a “defective” truth table. Much of their behaviour, however, seemed to be determined by a task variable in the form of a tendency to construct instances which matched, rather than altered, the values named in the rules.     

Variation among developmental dyslexics: evidence from a printed-word-learning task

A word-learning task was used to investigate variation among developmental dyslexics classified as phonological and surface dyslexics. Dyslexic children and chronological age (CA)- and reading level (RL)-matched normal readers were taught to pronounce novel nonsense words such as veep. Words were assigned either a regular (e.g., "veep") or an irregular (e.g., "vip") pronunciation. Phonological dyslexics learned both regular and exception words more slowly than the normal readers and, unlike the other groups, did not show a regular-word advantage. Surface dyslexics also learned regular and exception words more slowly than the CA group, consistent with a specific problem in mastering arbitrary item-specific pronunciations, but their performance resembled that of the RL group. The results parallel earlier findings from Manis, Seidenberg, Doi, McBride-Chang, & Petersen [Cognition 58 (1996) 157-195] indicating that surface dyslexics and phonological dyslexics have a different profile of reading deficits, with surface dyslexics resembling younger normal readers and phonological dyslexics showing a specific phonological deficit. Models of reading and reading disability need to account for the heterogeneity in reading processes among dyslexic children.     

Why misinformation is reported: evidence from a warning and a source-monitoring task

People report suggested misinformation about a previously witnessed event for manifold reasons, such as social pressure, lack of memory of the original aspect, or a firm belief to remember the misinformation from the witnessed event. In our experiments (N?=?429), which follow Loftus's paradigm, we tried to disentangle the reasons for reporting a central and a peripheral piece of misinformation in a recognition task by examining (a) the impact a warning about possible misinformation has on the error rate, and (b) whether once reported misinformation was actually attributed to the witnessed event in a later source-monitoring (SM) task. Overall, a misinformation effect was found for both items. The warning strongly reduced the misinformation effect, but only for the central item. In contrast, reports of the peripheral misinformation were correctly attributed to the misinformation source or, at least, ascribed to guesswork much more often than the central ones. As a consequence, after the SM task, the initially higher error rate for the peripheral item was even lower than that of the central item. Results convincingly show that the reasons for reporting misinformation, and correspondingly also the potential to avoid them in legal settings, depend on the centrality of the misinformation.     

Alerting enhances attentional bias for salient stimuli: Evidence from a global/local processing task

The present study examined the role of alerting in modulating attentional bias to salient events. In a global/local processing task, participants were presented with a large arrow (global level) comprised of smaller arrows (local level) pointing in the same or opposite directions and had to indicate the direction of the large or small arrows in different blocks. Saliency of the global and local levels was manipulated, creating global-salient and local-salient conditions. Alerting signals were presented in half of the trials prior to the target. Results revealed a double dissociation in the effects of alerting on global/local interference effects. In a global salient condition, alerting increased global interference and decreased local interference. In a local salient condition, alerting reduced global interference and increased local interference. We demonstrate that within a single task, alerting can increase and reduce conflict based on perceptual saliency. These findings help to better understand disorders like hemispatial neglect in which both arousal and attention to salient events are impaired. These results also challenge previous theories suggesting that alerting acts to increase conflict interference. We argue that alerting is an adaptive mechanism that diverts attention to salient events, but comes at a cost when selective attention to less salient details is required.     

Accessing semantic knowledge in dementia: evidence from a word definition task

We examine production of word definitions by people with probable Alzheimer's disease (pAD). In the first experiment, healthy young adults defined concrete, imageable nouns to provide a baseline of definitional ability. Analysis of these definitions identified the key defining features of each target item. In the second experiment, pAD participants and elderly controls produced definitions of the same items. In the third experiment, healthy young participants rated the adequacies of these definitions. Although as expected the pAD participants produced fewer good definitions than the other two groups, most of their responses still contained some relevant information. pAD definitions contained fewer pieces of information and the information they produced was more tangential to the primary concept than that provided by the young or elderly participants. We identify two possible explanations in semantic loss and metalinguistic impairment. We consider metalinguistic impairment to provide the more plausible explanation of pAD patients' definitional performance.     

Memory for emotionally arousing stimuli: a comparison of younger and older adults

The authors compared emotional memory in younger (aged 18-32 years) and older (aged 59-84 years) adults. Previous researchers who investigated the emotionmemory relationship in younger adults consistently showed that emotional arousal enhances memory for central detail. The present authors' goal was to determine whether a similar effect could be found with older adults. Younger and older adults viewed a series of 12 slides, accompanied by a taped narrative, that showed emotionally arousing or neutral scenes in the middle phase (Slides 5-8). Participants then completed recognition tests that were scored for central detail, peripheral detail, and gist. The results indicated that, although younger adults showed higher performance than older adults did, both groups showed increased memory for central detail. In contrast, the authors found no such enhancement for peripheral detail or gist in either group. These results indicated that the arousal manipulation produced a similar effect on memory in younger and older adults. Furthermore, these results were consistent with the notion of poststimulus elaboration, which is the continued processing of central detail after the termination of an arousing event.