Interference Effects from Observed Movement in Parkinson's Disease

Previous research has demonstrated that Parkinson's disease patients have an increased susceptibility to response conflict. In the present study, the authors investigate whether Parkinson's patients have a similar sensitivity to interference from observed movements. In all, 10 patients and 10 controls performed horizontal and vertical arm movements while watching a video of either a person performing similar movements or a moving dot. Movements were performed in the same plane (congruent) and orthogonal to the observed movement (incongruent). The off-axis variance of movements was our index of interference. Although patients tended to exhibit more off-axis variability than did controls, both groups demonstrated similar congruence effects, with greater variance in incongruent conditions. These results indicated that increased susceptibility to interference in Parkinson's disease does not extend to interference from observed movements.     

Tracing the size,reach, impact,and breadth of positive psychology

This study quantitatively assessed the size, disciplinary reach, impact, and topic breadth of positive psychology (PP), in order to provide a comprehensive evaluation of the growth and significance of the field. Over 1.7?million documents in 700 PsycINFO ^® journals covering the fields of psychology, psychiatry, neuroscience, management, business, public health, and sport science were analyzed using semantic and bibliographic methods. Results indicate that PP covers many different research topics from a diverse range of disciplines, and that PP literature has been growing rapidly in significance. Over 18,000 documents were identified as belonging to PP, with 2300 published in 2011. These documents represent over 4% of PsycINFO ^® documents within the data-set published that year, and make PP close to the median size of all disciplines listed in the Thomson Reuters Journal Citation Reports ^®, Social Sciences Edition. The aggregate impact factor for PP in 2011 was 2.64.     

Updating of working memory: Lingering bindings

Three experiments investigated proactive interference and proactive facilitation in a memory-updating paradigm. Participants remembered several letters or spatial patterns, distinguished by their spatial positions, and updated them by new stimuli up to 20 times per trial. Self-paced updating times were shorter when an item previously remembered and then replaced reappeared in the same location than when it reappeared in a different location. This effect demonstrates residual memory for no-longer-relevant bindings of items to locations. The effect increased with the number of items to be remembered. With one exception, updating times did not increase, and recall of final values did not decrease, over successive updating steps, thus providing little evidence for proactive interference building up cumulatively.     

Exploring the time course of semantic interference and associative priming in the picture–word interference task

The picture–word interference (PWI) task is a widely used technique for exploring effects of semantic context on lexical access. In this task, printed words are superimposed over pictures to be named, with the timing of the interfering word relative to the picture systematically manipulated. Two experiments (N = 24 adults in each) explored the time course of effects of associates (e.g., CARROT superimposed on a picture of a rabbit) versus coordinates (e.g., CHIPMUNK superimposed on a picture of a rabbit) on naming latencies. Associates led to faster picture naming than did unrelated words, with facilitative effects occurring at stimulus onset asynchronies (SOAs, in ms) ranging from –450 to 0. Coordinates led to slower naming latencies, with the interference effect restricted to SOAs of –150 and 0. The overlapping time course of associative priming and coordinate interference provides important constraints on models of lexical access in speech production.     

What you say matters: Exploring visual–verbal interactions in visual working memory

The aim of this study was to explore whether the content of a simple concurrent verbal load task determines the extent of its interference on memory for coloured shapes. The task consisted of remembering four visual items while repeating aloud a pair of words that varied in terms of imageability and relatedness to the task set. At test, a cue appeared that was either the colour or the shape of one of the previously seen objects, with participants required to select the object's other feature from a visual array. During encoding and retention, there were four verbal load conditions: (a) a related, shape–colour pair (from outside the experimental set, i.e., “pink square”); (b) a pair of unrelated but visually imageable, concrete, words (i.e., “big elephant”); (c) a pair of unrelated and abstract words (i.e., “critical event”); and (d) no verbal load. Results showed differential effects of these verbal load conditions. In particular, imageable words (concrete and related conditions) interfered to a greater degree than abstract words. Possible implications for how visual working memory interacts with verbal memory and long-term memory are discussed.     

Feature overlap slows lexical selection: Evidence from the picture–word interference paradigm

How does the presence of a categorically related word influence picture naming latencies? In order to test competitive and noncompetitive accounts of lexical selection in spoken word production, we employed the picture–word interference (PWI) paradigm to investigate how conceptual feature overlap influences naming latencies when distractors are category coordinates of the target picture. Mahon et al. (2007. Lexical selection is not by competition: A reinterpretation of semantic interference and facilitation effects in the picture-word interference paradigm. Journal of Experimental Psychology. Learning, Memory, and Cognition, 33(3), 503–535. doi:10.1037/0278-7393.33.3.503) reported that semantically close distractors (e.g., zebra) facilitated target picture naming latencies (e.g., HORSE) compared to far distractors (e.g., whale). We failed to replicate a facilitation effect for within-category close versus far target–distractor pairings using near-identical materials based on feature production norms, instead obtaining reliably larger interference effects (Experiments 1 and 2). The interference effect did not show a monotonic increase across multiple levels of within-category semantic distance, although there was evidence of a linear trend when unrelated distractors were included in analyses (Experiment 2). Our results show that semantic interference in PWI is greater for semantically close than for far category coordinate relations, reflecting the extent of conceptual feature overlap between target and distractor. These findings are consistent with the assumptions of prominent competitive lexical selection models of speech production.     

Cumulative and non-cumulative semantic interference in object naming: Evidence from blocked and continuous manipulations of semantic context

Experiments involving blocked and continuous manipulations of the semantic naming context demonstrate that, when speakers name several taxonomically related objects in close succession, they display persistent interference effects. A review of studies using the blocked paradigm shows that, unlike the continuous paradigm, it typically does not induce cumulative interference effects in healthy speakers. This contrasts with the simulation results obtained from a model of semantic context effects recently put forward by Oppenheim and colleagues [Oppenheim, G. M., Dell, G. S., & Schwartz, M. F. (2010). The dark side of incremental learning: A model of cumulative semantic interference during lexical access in speech production. Cognition, 114, 227--262], which generates cumulative effects in both paradigms. We propose that the effects are non-cumulative in the blocked paradigm, because it allows participants to bias top-down the levels of activation of lexical-semantic representations, thereby curtailing the accumulating interference. Indeed, prior research has shown that the interference effects in the blocked paradigm are exacerbated when participants carry out a concurrent digit-retention task, loading on working memory and reducing their capacity to exert a top-down bias. In Experiment 1, combining the continuous paradigm with a digit-retention task, we demonstrate that this does not exacerbate cumulative context effects, corroborating the selective role of working memory and the associated top-down biasing mechanism in the blocked paradigm. A review of neuropsychological and neuroimaging studies demonstrates that left inferior frontal regions may play a critical role in controlling semantic interference top-down. We discuss the implications of these findings for language production research and for models of lexical-semantic encoding.     

Directed Forgetting and Aging: The Role of Retrieval Processes,Processing Speed,and Proactive Interference

ABSTRACT

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

Affective valence of words impacts recall from auditory working memory

Abstract

There is limited evidence on the influence of affective stimuli on auditory working memory. The reported study investigated whether emotional auditory words interfere with ongoing auditory processing of words in auditory working memory. On each trial, words with negative, neutral, and positive affective valence were simultaneously presented on three different speakers. Participants recalled the word presented from the centre speaker first and then recalled the words presented from the side speakers. More negative and positive words compared to neutral words were recalled from the centre speaker. After recall of negative and positive words from the centre speaker, the subsequent first recall of words from the side speakers was reduced, regardless of anxiety level of the participant. The emotional interference effect suggests that emotional words interfere with ongoing central processing due to the attentional dwell on the information in auditory working memory.     

The role of textual semantic constraints in knowledge-based inference generation during reading comprehension: A computational approach

The present research adopted a computational approach to explore the extent to which the semantic content of texts constrains the activation of knowledge-based inferences. Specifically, we examined whether textual semantic constraints (TSC) can explain (1) the activation of predictive inferences, (2) the activation of bridging inferences and (3) the higher prevalence of the activation of bridging inferences compared to predictive inferences. To examine these hypotheses, we computed the strength of semantic associations between texts and probe items as presented to human readers in previous behavioural studies, using the Latent Semantic Analysis (LSA) algorithm. We tested whether stronger semantic associations are observed for inferred items compared to control items. Our results show that in 15 out of 17 planned comparisons, the computed strength of semantic associations successfully simulated the activation of inferences. These findings suggest that TSC play a central role in the activation of knowledge-based inferences.