Escaping the recent past: Which stimulus dimensions influence proactive interference?

Proactive interference occurs when information from the past disrupts current processing and is a major source of confusion and errors in short-term memory (STM; Wickens, Born, & Allen, Journal of Verbal Learning and Verbal Behavior, 2:440–445, 1963). The present investigation examines potential boundary conditions for interference, testing the hypothesis that potential competitors must be similar along task-relevant dimensions to influence proactive interference effects. We manipulated both the type of task being completed (Experiments 1, 2, and 3) and dimensions of similarity irrelevant to the current task (Experiments 4 and 5) to determine how the recent presentation of a probe item would affect the speed with which participants could reject that item. Experiments 1, 2, and 3 contrasted STM judgments, which require temporal information, with semantic and perceptual judgments, for which temporal information is irrelevant. In Experiments 4 and 5, task-irrelevant information (perceptual similarity) was manipulated within the recent probes task. We found that interference from past items affected STM task performance but did not affect performance in semantic or perceptual judgment tasks. Conversely, similarity along a nominally irrelevant perceptual dimension did not affect the magnitude of interference in STM tasks. Results are consistent with the view that items in STM are represented by noisy codes consisting of multiple dimensions and that interference occurs when items are similar to each other and, thus, compete along the dimensions relevant to target selection.     

What happens between an external stimulus and an overt response?

Peripheral components of feedthrough loops were psychophysiologically measured from the brain, both forelimbs, the tongue and the eyes during simple and choice reaction time tasks using linguistic and non-linguistic stimuli. Closing a microswitch with the little finger was the overt response. Covert electromyographic (EMG) responses were computer identified in the following average temporal order: generally, the earliest covert reactions were in the tongue, brain, eyes, and passive arm-hand region. Next were complex EMG events in the active limb. These covert reactions may function in feedthrough loops to generate and transmit codes during internal information processing. The passive armhand responses occurred significantly earlier than the onset of the covert EMG burst for closing the microswitch; perhaps there is an inhibitory response “commanding” the passive arm not to respond, before the other (active) limb can overtly respond. Mean response patterns to linguistic and non-linguistic stimuli were almost identical. Reaction time to the onset of the EMG burst for switch closing was from 40 to 95 milliseconds earlier than the usual overt reaction time measure (that to switch closing), suggesting that reaction time studies might be improved by using the onset of EMG increase as the more sensitive and precise measure.     

On the relation between object and action: Response consistency and stimulus–response compatibility

A series of four experiments investigated factors influencing the selection of objects and responses associated with the objects. The experiments focused on the interaction between response consistency and the spatial compatibility of the response (involving inhibition of an irrelevant distractor) in conditions of task switching. To test for the response consistency effect, a cue indicated the dimension of the display to be selected for the participant's response. The stimulus displays were either consistent, neutral, or inconsistent (including a distractor stimulus) with the response to the stimulus. The responses were either compatible or incompatible with the location of the stimulus. Intertrial dependences were examined by switching or repeating the tasks across trials. The results suggest that links between objects and actions set up by targets can be replaced by links between a distractor and a response under certain conditions. The implications for stimulus and response selection are discussed.     

Differential relations between two dimensions of self‐esteem and the Big Five?

Recent research has suggested the possibility that self-esteem (SE) may be viewed as a two-dimensional concept consisting of: (a) self-liking, the subjective evaluation of oneself as a social being; and (b) self-competence, the internal conceptions of success and failure in performing tasks (Tafarodi & Swann, 1995). Establishing differential relations between these two dimensions of SE and an important psychological concept like the Big Five, would support the notion of two-dimensional SE. To test this hypothesis the self-liking/self-competence scale (SLCS) and the Big Five Inventory (BFI) were administered to 128 Norwegian college students. The results show a differential relationship between the two dimensions of SE and the personality dimensions of the BFI.     

Effects of stimulus–stimulus short-term memory associations in a Simon-like task

The Simon effect refers to faster responding when an irrelevant stimulus location corresponds with the response to a relevant stimulus attribute than when it does not. We investigated whether a memory-based Simon-like effect would occur when the irrelevant spatial attribute was associated with the stimulus during a prior task. In a first task, an association between colour and location was formed by requiring participants to count the occurrences of two colour stimuli, each of which was always presented in a left or right location. In a second task, the colour stimuli were presented centrally and mapped to left and right keypresses, with the mapping being inconsistent or consistent with the prior colour-location associations. A Simon-like effect was evident at the start of the second task, with performance being better when the established colour–position associations were consistent with the colour–response mapping than when they were not. This result indicates that stimulus–stimulus short-term memory associations formed during the first task transferred to the second task. For the remainder of the second task, the data showed a more conservative speed–accuracy criterion for the inconsistent condition than for the consistent condition, though a processing efficiency measure suggested that the prior stimulus–stimulus short-term associations may also continue to directly influence performance. Results suggest that simple declarative knowledge, as represented by stimulus–stimulus STM links, exerts less persistent transfer effects than procedural knowledge as provided by stimulus–response STM links.     

The effect of method of presentation,set, and stimulus dimensions on “same”-“different” reaction times

“Same”-“different” reaction times (RTs) to random shapes varying independently in either brightness, size, or form were studied in an investigation of visual encoding and comparison processes. The comparison process was investigated by having the varying dimension either cued in advance (set) or not cued (no set). The encoding process was investigated by varying stimulus onset asynchronies. No significant difference was found for the set/no-set variables, providing some evidence for an integrality interpretation. However, the serial and parallel models would still hold if the set variable does not affect either dimensional processing rate or order. The significant difference found between the various stimulus onset asynchronies was interpreted as evidence for a limited-capacity encoding mechanism. The results were also consistent with a two-process model of comparison processes.     

Influences of multiple spatial stimulus and response codes on orthogonal stimulus—response compatibility

When up-down stimuli are mapped to left-right responses, an up-right/down-left mapping advantage is found that is modified by response eccentricity and hand posture. These effects can be attributed to correspondence of asymmetric stimulus and response codes formed relative to multiple reference frames. We examined the influence of stimulus-set location on these orthogonal stimulus-response compatibility (SRC) effects. In Experiment 1, the stimulus set appeared in the upper or lower display positions. A spatial code for stimulus-set location was formed, producing Simon-type response eccentricity and hand posture effects, but this code had no influence on the coding of the relevant stimuli. In Experiment 2, the stimulus set appeared in the left, center, or right positions relative to the response location, which also varied, to dissociate the effects of response location, relative to the stimulus display and body midline. The former factor influenced the orthogonal SRC effect for both unimanual switch movements and bimanual keypresses, and the latter factor influenced the effect for only unimanual switch movements. Stimulus-set location causes orthogonal Simon-type effects when varied along the stimulus dimension and provides a referent for response coding when varied along the response dimension.     

Does stimulus appearance affect learning?

We examined the learning process with 3 sets of stimuli that have identical symbolic structure but differ in appearance (meaningless letter strings, arrangements of geometric shapes, and sequences of cities). One hypothesis is that the learning process aims to encode symbolic regularity in the same way, largely regardless of appearance. Another is that different types of stimuli bias the learning process to operate in different ways. Using the experimental paradigm of artificial grammar learning, we provided a preliminary test of these hypotheses. In Experiments 1 and 2 we measured performance in terms of grammaticality and found no difference across the 3 sets of stimuli. In Experiment 3 we analyzed performance in terms of both grammaticality and chunk strength. Again we found no differences in performance. Our tentative conclusion is that the learning process aims to encode symbolic regularity independent of stimulus appearance.     

Unlearning a stimulus–response association

After a response has been associated with a particular stimulus, would this association be “unlearned” when the circumstances call for a new response to be made to that stimulus? This question was investigated in the present study with a negative priming (NP) paradigm developed by Shiu and Kornblum (1996). In the study, participants first practiced with a particular pairing of stimuli and responses in a four-choice reaction time (RT) task. Then, in the transfer phase, they switched to a different pairing of the same set of stimuli and responses. The results showed that a transfer response was slow if this response and the stimulus in the preceding trial had been paired in the training phase. Such NP effects persisted even after extended practice with the new pairing, suggesting that the “old” stimulus–response (SR) associations remain despite acquisition of some “new” associations.     

Orthogonal stimulus–response compatibility effects emerge even when the stimulus position is task irrelevant

The above-right/below-left mapping advantage with vertical stimuli and horizontal responses is known as the orthogonal stimulus–response compatibility (SRC) effect. We investigated whether the orthogonal SRC effect emerges with irrelevant stimulus dimensions. In Experiment 1, participants responded with a right or left key press to the colour of the stimulus presented above or below the fixation. We observed an above-right/below-left advantage (orthogonal Simon effect). In Experiment 2, we manipulated the polarity in the response dimension by varying the horizontal location of the response set. The orthogonal Simon effect decreased and even reversed as the left response code became more positive. This result provides evidence for the automatic activation of the positive and negative response codes by the corresponding positive and negative stimulus codes. These findings extended the orthogonal SRC effect based on coding asymmetry to an irrelevant stimulus dimension.     

Is the link between autistic traits and ability to succeed in science independent of other psychopathological dimensions?

IntroductionBesides the well-established link between autistic traits and scientific skills, the role of personality in students involved in science has not been thoroughly examined.ObjectiveThis study aimed at reexamining the link between scientific aptitudes and personality, by considering autistic features and other psychopathological dimensions.MethodTwo hundred and ninety-four individuals from French scientific universities answered questionnaires assessing autistic, schizotypal and bipolar dimensions, as well as depressive symptomatology and other variables.ResultsA cluster analysis led to the identification of 4 different groups, among which a cluster was characterized by high scores in autistic, schizotypal and bipolar dimensions. This group, representing nearly 30% of the sample, displayed higher level of depression symptoms (M = 28.5, SD = 12.0) in comparison with other groups (M = 11.7 to 19.1, SD = 5.4 to 9.2). Moreover, the suicidal ideation score was much more important in this cluster (M = 1.6, SD = 2.3) than in the three other groups (M = 0.1 to 0.5, SD = 0.3 to 1.3). This suggested that autistic features, when associated with other personality traits, interfere negatively with the ability of individuals to succeed in science studies, which was partly confirmed by comparing the academic level and results of the different clusters.ConclusionOne may reconsider the link between elevated autistic traits and the ability to accomplish science studies, considering that autistic features are thus frequently associated with other psychopathological traits which may, altogether, lead to depression or other comorbidities negatively interfering with the accomplishment of an academic cursus.     

The relationship between the inner and outer dimensions in Islam as a foundation for inter‐religious dialogue

This article shows how the relationship between the sharīa and the arīqa in Islam constitutes a specific paradigm for the bond between the interior and exterior dimension in religion, which enriches and challenges the Christian–Muslim dialogue for peace because it reminds both religions of their potential for critical social–political assessments. This is especially important since the public dialogue generally focuses on post‐Enlightenment criteria for evaluating the possibilities for communion in peace by strictly separating the interior from the exterior dimension in religion.     

The influence of the response–stimulus interval on implicit and explicit learning of stimulus sequence

Three experiments investigated the influence of the response-stimulus interval (RSI) on implicit and explicit learning of stimulus sequences. Participants responded to numerals presented in predetermined positions with alternating long and short RSIs. Half of the participants were instructed explicitly to learn the position sequence. In the transfer phase of Experiments 1 and 2, changing RSI patterns reduced the expression of incidental and intentional learning of position sequence. In Experiment 3 the position sequence was transformed, except that sub-sequences demarcated by long RSIs remained unchanged; this greatly reduced the expression of intentional learning, and slightly reduced that of incidental learning. These results indicate that in implicit learning, stimulus sequences are learned under the constraints of RSIs, whereas in explicit learning, learning independent of RSIs, as well as learning constrained by RSIs, occurs.     

Effects of visual cue and response assignment on spatial stimulus coding in stimulus–response compatibility

Tlauka and McKenna (2000 Tlauka, M. and McKenna, F. P. 2000. Hierarchical knowledge influences stimulus–response compatibility effects. Quarterly Journal of Experimental Psychology, 53A: 85–103.  [Google Scholar]) reported a reversal of the traditional stimulus–response compatibility (SRC) effect (faster responding to a stimulus presented on the same side than to one on the opposite side) when the stimulus appearing on one side of a display is a member of a superordinate unit that is largely on the opposite side. We investigated the effects of a visual cue that explicitly shows a superordinate unit, and of assignment of multiple stimuli within each superordinate unit to one response, on the SRC effect based on superordinate unit position. Three experiments revealed that stimulus–response assignment is critical, while the visual cue plays a minor role, in eliciting the SRC effect based on the superordinate unit position. Findings suggest bidirectional interaction between perception and action and simultaneous spatial stimulus coding according to multiple frames of reference, with contribution of each coding to the SRC effect flexibly varying with task situations.     

A quantitative review of the relations between the “Big 3” higher order personality dimensions and antisocial behavior

In this meta-analytic review, Hans J. Eysenck’s theory of criminality (Eysenck, 1964, Eysenck, 1977) serves as a theoretical framework for examining the relations between higher order personality dimensions and antisocial behavior (ASB). The three higher order dimensions examined are referred to as extraversion/sociability, neuroticism/emotionality, and impulsivity/disinhibition (see Sher & Trull, 1994), and they are likened to Eysenck’s dimensions of extraversion (E), neuroticism (N), and psychoticism (P), respectively (Eysenck & Eysenck, 1975) and Tellegen’s dimensions of positive emotionality (PEM), negative emotionality (NEM), and constraint (reversed) (CON), respectively (Tellegen, 1982). Ninety-seven samples, from 52 published and unpublished studies, were reviewed. The results indicated that among the “Big 3” personality dimensions, impulsivity/disinhibition is most strongly related to ASB and extraversion/sociability is least strongly related to ASB. Additional variables, including age and methodological differences, were found to moderate the associations between the personality dimensions and ASB.     

On the relation between stimulus intensity and processing time: Piéron’s law and choice reaction time

Piéron (1914, 1920, 1952) demonstrated that simple reaction time (SRT) decays as a hyperbolic function of luminance in detection tasks. However, whether such a relationship holds equally for choice reaction time (CRT) has been questioned (Luce, 1986; Nissen, 1977), at least when the task is not brightness discrimination. In two SRT and three CRT experiments, we investigated the function that relates reaction time (RT) to stimulus intensity for five levels of luminance covering the entire mesopic range. The psychophysical experiments consisted of simple detection, two-alternative forced choice (2 AFC) with spatial uncertainty, 2 AFC with semantic categorization, and 2 AFC with orientation discrimination. The results of the experiments showed that mean RT increases with task complexity. However, the exponents of the functions relating RT to stimulus intensity were found to be similar in the different experiments. This finding indicates that Piéron’s law holds for CRT as well as for SRT. It describes RT as a power function of stimulus intensity, with similar exponents, regardless of the complexity of the task.     

Is memory for stimulus magnitude Bayesian?

This study was designed to determine whether memory for stimulus values is a Bayesian weighting of the magnitude of a stimulus and the central tendency of an exemplar's category (Huttenlocher, Hedges, & Vevea, 2000). In five experiments, participants reproduced the remembered size of a geometric figure drawn from one of two categories whose means for size differed. Reproductions were biased toward the mean of the combined distribution rather than the mean of either category. Reproductions were also influenced by the size of the stimulus on the preceding trial. Neither of these results is entirely consistent with the view that recollections are partially constructed from a consideration of the long-run probabilities established by category membership.     

Why do categories affect stimulus judgment?

The authors tested a model of category effects on stimulus judgment. The model holds that the goal of stimulus judgment is to achieve high accuracy. For this reason, people place inexactly represented stimuli in the context of prior information, captured in categories, combining inexact fine-grain stimulus values with prior (category) information. This process can be likened to a Bayesian statistical procedure designed to maximize the average accuracy of estimation. If people follow the proposed procedure to maximize accuracy, their estimates should be affected by the distribution of instances in a category. In the present experiments, participants reproduced one-dimensional stimuli. Different prior distributions were presented. The experiments verified that people's stimulus estimates are affected by variations in a prior distribution in such a manner as to increase the accuracy of their stimulus reproductions.     

Clarifying the relationship between AS dimensions and PTSD symptom clusters: are negative and positive affectivity theoretically relevant constructs?

The association between anxiety sensitivity (AS) and posttraumatic stress disorder (PTSD) has been established in contemporary literature; however, research is divided over the nature of specific relationships between AS dimensions and PTSD symptoms clusters. Further, a paucity of research has examined the AS and PTSD relationship while accounting for theoretically relevant variables, such as negative (NA) and positive affect (PA). The purpose of the current study was twofold: first, to clarify divergent findings regarding the contribution of AS dimensions to PTSD symptom clusters, and, second, to further assess the relevance of NA and PA within the AS/PTSD relationship. Hierarchal regression analyses showed that, beyond shared variance attributable to NA and PA, AS somatic concerns were significantly associated with three of four PTSD symptom (i.e., reexperiencing, numbing, hyperarousal), AS cognitive concerns were only associated with hyperarousal, and AS socially observable symptoms were not significantly associated with any PTSD symptom clusters. These findings suggest that AS somatic concerns are the most robust predictor of variance within the AS/PTSD relationship and further clarify the theoretical importance of NA and PA within this relationship. Comprehensive results, implication, and directions for future research are discussed.