Semantic interference in picture naming during dual-task performance does not vary with reading ability

Previous dual-task studies examining the locus of semantic interference of distractor words in picture naming have obtained diverging results. In these studies, participants manually responded to tones and named pictures while ignoring distractor words (picture–word interference, PWI) with varying stimulus onset asynchrony (SOA) between tone and PWI stimulus. Whereas some studies observed no semantic interference at short SOAs, other studies observed effects of similar magnitude at short and long SOAs. The absence of semantic interference in some studies may perhaps be due to better reading skill of participants in these than in the other studies. According to such a reading-ability account, participants’ reading skill should be predictive of the magnitude of their interference effect at short SOAs. To test this account, we conducted a dual-task study with tone discrimination and PWI tasks and measured participants’ reading ability. The semantic interference effect was of similar magnitude at both short and long SOAs. Participants’ reading ability was predictive of their naming speed but not of their semantic interference effect, contrary to the reading ability account. We conclude that the magnitude of semantic interference in picture naming during dual-task performance does not depend on reading skill.     

The nature of categorical and coordinate spatial relation processing: An interference study

Spatial relation information can be encoded in two different ways: categorically, which is abstract, and coordinately, which is metric. Although categorical and coordinate spatial relation processing is commonly conceived as relying on spatial representations and spatial cognitive processes, some suggest that representations and cognitive processes involved in categorical spatial relation processing can be verbal as well as spatial. We assessed the extent to which categorical and coordinate spatial relation processing engages verbal and spatial representations and processes using a dual-task paradigm. Participants performed the classical dot-bar paradigm and simultaneously performed either a spatial tapping task, or an articulatory suppression task. When participants were requested to tap blocks in a given pattern (spatial tapping), their performance decreased in both the categorical and coordinate tasks compared to a control condition without interference. In contrast, articulatory suppression did not affect performance in either spatial relation task. A follow-up experiment indicated that this outcome could not be attributed to different levels of difficulty of the two interference tasks. These results provide strong evidence that both coordinate and categorical spatial relation processing relies mainly on spatial mechanisms. These findings have implications for theories on why categorical and coordinate spatial relations processing are lateralised in the brain.     

Adjustment of cognitive control to the frequency of dual-task interference

ABSTRACT

This study explored whether the control mechanisms recruited for optimising performance are similar for dual-task and interference-task settings. We tested whether the frequency of appearance of a secondary task resulted in an adjustment of anticipatory and reflexive forms of attentional control, as has been observed with other interference tasks (e.g. stroop and flanker). The results of two experiments demonstrated a proportion congruency effect (PCE): when a secondary task frequently appeared, primary task performance was slower. Additionally, there was a relative slowdown of dual-task performance in blocks wherein the secondary task appeared infrequently compared to blocks wherein it appeared frequently. However, this slowdown occurred when the primary task entailed a low level of control (Experiment 1) but was absent when it demanded a high level of control (Experiment 2). Overall, the results suggest that level of control can be adjusted to task demands related to the frequency of the secondary task.     

Repetition effect in visual recognition of letters

This study examined the influence of the repetitive presentation of a letter on the recognition of two letters. In two experiments(4), two letters, which were either identical or not, were presented successively for a short duration at different spatial locations, and the subjects were required to identify them. In Experiment 1, the presentation time of the first letter was varied, whereas that of the second letter was constant. The results revealed that a reduced performance in identifying a second letter was observed in the case that the first letter, which was identical to the second letter, could be identified correctly. Experiment 2 examined whether or not this reduction was due to the identity of the visual shape of two letters. The first letter was presented either in the usual vertical orientation or rotated orientation by 180 degrees and the second letter was constantly presented in the usual orientation. The results revealed that a reduced performance in identifying a repeated letter was observed, regardless of the orientation of the first letter. The findings from the two experiments suggested that the identity of the information in memory was a main cause of the interference effect by repetition.     

Temporal context in concurrent chains: I. Terminal-link duration

Two experiments are reported in which the ratio of the average times spent in the terminal and initial links (Tt/Ti) in concurrent chains was varied. In Experiment 1, pigeons responded in a three-component procedure in which terminal-link variable-interval schedules were in constant ratio, but their average duration increased across components by a factor of two. The log initial-link response ratio was a negatively accelerated function of Tt/Ti. Overall, the data were well described by Grace's (1994) contextual choice model (CCM) with temporal context represented as (Tt/Ti)k or 2Tt/(Tt + Ti), and by Mazur's (2001) hyperbolic value-added model (HVA), with each model accounting for approximately 93% of the variance. In Experiment 2, fixed-parameter predictions for each model were generated, based on the data from Experiment 1, for conditions in which Tt/Ti was varied over a more extreme range. Data were consistent with the predictions of CCM with temporal context represented as 2Tt/(Tt + Ti) and to a lesser extent as (Tt/Ti)k, but not with HVA. Overall, these results suggest that preference increases as a hyperbolic function of Tt/Ti when terminal-link duration is increased relative to initial-link duration, with the terminal-link schedule ratio held constant.     

DOES SENSITIVITY TO MAGNITUDE DEPEND ON THE TEMPORAL DISTRIBUTION OF REINFORCEMENT?

Our research addressed the question of whether sensitivity to relative reinforcer magnitude in concurrent chains depends on the distribution of reinforcer delays when the terminal-link schedules are equal. In Experiment 1, 12 pigeons responded in a two-component procedure. In both components, the initial links were concurrent variable-interval 40-s variable-interval 40-s, and the terminal links were both 20-s interval schedules in which responses were reinforced by either 4-s of grain in one, or 2-s of grain in the other. The only difference between the components was whether the terminal-link schedules were fixed interval or variable intervals. For all subjects, the relative rate of responding in the initial links for the terminal link that produced the 4-s reinforcer was greater when the terminal links were fixed-interval schedules than when they were variable-interval schedules. This result is contrary to the prediction of Grace's (1994) contextual choice model, but is consistent with both Mazur's (2001) hyperbolic value-added model and Killeen's (1985) incentive theory. In Experiment 2, 4 pigeons responded in a concurrent-chains procedure in which 4-s or 2-s reinforcers were provided independently of responding according to equal fixed-time or mixed-time schedules. Preference for the 4-s reinforcer increased as the variability of the intervals comprising the mixed-time schedules was decreased. Generalized-matching sensitivity of initial-link response allocation to relative reinforcer magnitude was proportional to the geometric mean of the terminal-link delays.     

The emergence of words: attentional learning in form and meaning

Children improve at word learning during the 2nd year of life—sometimes dramatically. This fact has suggested a change in mechanism, from associative learning to a more referential form of learning. This article presents an associative exemplar-based model that accounts for the improvement without a change in mechanism. It provides a unified account of children's growing abilities to (a) learn a new word given only 1 or a few training trials ("fast mapping"); (b) acquire words that differ only slightly in phonological form; (c) generalize word meanings preferentially along particular dimensions, such as object shape (the "shape bias"); and (d) learn 2nd labels for already-named objects, despite a persisting resistance to doing so ("mutual exclusivity"). The model explains these improvements in terms of increased attention to relevant aspects of form and meaning, which reduces memory interference. The interaction of associations and reference in word learning is discussed.     

The categorical structure of semantic memory for famous people: a new approach using release from proactive interference

Memory for familiar people is essential to understand their identity and guide social interaction. Nevertheless, we know surprisingly little about the structure of such memory. Previous research has assumed that semantic memory for people has a categorical structure, but recently it was proposed that memory for people consists only of associations and lacks any categorical structure. Four experiments are reported that use a novel approach by adapting the 'release from proactive interference' (RPI) methodology for use with lists of famous names. Proactive interference occurs when items presented on successive trials are drawn from the same category. Recall can improve following a change to a different category. Sets of names were selected relating to aspects previously demonstrated, on the basis of reaction time data, to form a category (occupation) and a property (nationality) of celebrities (Johnston & Bruce, 1990). RPI was observed for a change at both levels of representation but was only present without explicitly cueing the change of set when the stimuli differed at the category level. At the property level, RPI was only evident when change of set was explicitly cued. RPI was absent at the set change in a novel, ad hoc distinction suggesting that the effect reflected the underlying memory structure.     

不同反应方式对双作业操作信息干扰的影响

本研究采用单作业双作业操作,探讨了不同反应方式对双作业操作信息干扰的影响。实验结果证明;若采用相同的反应方式,同时操作的两种作业就会产生相互干扰,降低作业绩效;相反,若采用不同反应方式将减小双作业操作的相互干扰,提高双作业操作绩效。     

Context specificity of operant discriminative performance in pigeons: II. Necessary and sufficient conditions

Six experiments were performed to explore the necessary and sufficient conditions for producing context specificity of discriminative operant performance in pigeons. In Experiment 1, pigeons learned a successive discrimination (red S+/blue S−) in two chambers that had a particular odor present and between which they were frequently switched. The birds subsequently learned the reversal (blue S+/ red S−) in one of these chambers with a different odor present. When switched to the alternative chamber, although the odor and the reinforcement contingency were still appropriate to the reversal, performance appropriate to the original discrimination recurred in subjects for which the houselights were on during training and testing but not for those for which the houselights were off. This indicated the importance of visual contextual cues in producing context specificity. Experiment 2 showed that the frequent switching between boxes in initial training was of no consequence, presumably because the apparatus cues were highly salient to the subjects. Experiment 3 showed significantly less context specificity when odor cues were omitted. Experiment 4 showed that simply using a different reinforced stimulus in each phase of training was ineffective in producing context specificity. Experiment 5 showed that the generalization test procedure used in Experiment 4 was sensitive to context specificity when discrimination-reversal training was used with different odors in the two training phases. Experiment 6 replicated the results of Experiment 4, but then showed that when different odors accompanied the two training phases, context specificity was obtained with the single-stimulus paradigm. Thus in both single-stimulus and discrimination-reversal paradigms, redundant odor cues potentiated learning about apparatus cues.