Short-term retention of pictures and words: evidence for dual coding systems.

The recall of picture and word triads was examined in three experiments that manipulated the type of distraction in a Brown-Peterson short-term retention task. In all three experiments recall of pictures was superior to words under auditory distraction conditions. Visual distraction produced high performance levels with both types of stimuli, whereas combined auditory and visual distraction significantly reduced picture recall without further affecting word recall. The results were interpreted in terms of the dual coding hypothesis and indicated that pictures are encoded into separate visual and acoustic processing systems while words are primarily acoustically encoded.     

A comparison of visual and auditory short-term memory in monkeys (Cebus apella)

Using a visual and an acoustic sample set that appeared to favour the auditory modality of the monkey subjects, in Experiment 1 retention gradients generated in closely comparable visual and auditory matching (go/no-go) tasks revealed a more durable short-term memory (STM) for the visual modality. In Experiment 2, potentially interfering visual and acoustic stimuli were introduced during the retention intervals of the auditory matching task. Unlike the case of visual STM, delay-interval visual stimulation did not affect auditory STM. On the other hand, delay-interval music decreased auditory STM, confirming that the monkeys maintained an auditory trace during the retention intervals. Surprisingly, monkey vocalizations injected during the retention intervals caused much less interference than music. This finding, which was confirmed by the results of Experiments 3 and 4, may be due to differential processing of “arbitrary” (the acoustic samples) and species-specific (monkey vocalizations) sounds by the subjects. Although less robust than visual STM, auditory STM was nevertheless substantial, even with retention intervals as long as 32 sec.     

Is Semantic Processing During Sentence Reading Autonomous or Controlled? Evidence from the N400 Component in a Dual Task Paradigm

The present study contributes to the discussion on the automaticity of semantic processing. Whereas most previous research investigated semantic processing at word level, the present study addressed semantic processing during sentence reading. A dual task paradigm was combined with the recording of event-related brain potentials. Previous research at word level processing reported different patterns of interference with the N400 by additional tasks: attenuation of amplitude or delay of latency. In the present study, we presented Spanish sentences that were semantically correct or contained a semantic violation in a critical word. At different intervals preceding the critical word a tone was presented that required a high-priority choice response. At short intervals/high temporal overlap between the tasks mean amplitude of the N400 was reduced relative to long intervals/low temporal overlap, but there were no shifts of peak latency. We propose that processing at sentence level exerts a protective effect against the additional task. This is in accord with the attentional sensitization model (Kiefer & Martens, 2010), which suggests that semantic processing is an automatic process that can be enhanced by the currently activated task set. The present experimental sentences also induced a P600, which is taken as an index of integrative processing. Additional task effects are comparable to those in the N400 time window and are briefly discussed.     

中文词汇加工过程中的无关言语效应

通过两个词汇识别任务,考察词汇加工过程中的无关言语效应。实验1采用真假词判断任务,考察有意义言语、无意义言语、白噪音和安静的背景声音对不同具体性的词汇识别的影响。结果发现,仅有意义言语干扰了词汇识别,且主要体现在对低具体性词汇判断的反应时显著增加。实验2采用了语义范畴判断任务,同样发现有意义言语条件下被试的反应时显著大于其他声音条件。结果表明,中文词汇加工过程中存在无关言语效应,且当任务强调语义加工时,干扰主要源于无关言语的语义成分,支持了语义干扰假说。     

Remarks of the In-Coming Editor

A digit memory task and a delayed visual aiming task were used in a test of resource capacity theories. These tasks were run either singly, with short- or long-retention intervals, or in pairs. In the dual-task conditions, the short version of one was inserted into the longer version of the other. Delay by itself had no effect on retention, but the dual-task combinations showed asymmetrical interference: Inserting verbal memory into the visual-motor delay had little effect on either task, but inserting the motor task into the verbal retention interval disrupted both. These results thus support neither single nor multiple resource models, but can be explained with reference to component processes in working memory.     

An experimental analysis of memory processing

Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory strengthened. Capuchin monkeys, pigeons, and humans showed similar visual-memory changes. Rhesus learned an auditory memory task and showed octave generalization for some lists of notes--tonal, but not atonal, musical passages. In contrast with visual list memory, auditory primacy memory diminished with delay and auditory recency memory strengthened. Manipulations of interitem intervals, list length, and item presentation frequency revealed proactive and retroactive inhibition among items of individual auditory lists. Repeating visual items from prior lists produced interference (on nonmatching tests) revealing how far back memory extended. The possibility of using the interference function to separate familiarity vs. recollective memory processing is discussed.     

Concurrent performance of two memory tasks: evidence for domain-specific working memory systems

Previous studies of dual-task coordination in working memory have shown a lack of dual-task interference when a verbal memory task is combined with concurrent perceptuomotor tracking. Two experiments are reported in which participants were required to perform pairwise combinations of (1) a verbal memory task, a visual memory task, and perceptuomotor tracking (Experiment 1), and (2) pairwise combinations of the two memory tasks and articulatory suppression (Experiment 2). Tracking resulted in no disruption of the verbal memory preload over and above the impact of a delay in recall and showed only minimal disruption of the retention of the visual memory load. Performing an ongoing verbal memory task had virtually no impact on retention of a visual memory preload or vice versa, indicating that performing two demanding memory tasks results in little mutual interference. Experiment 2 also showed minimal disruption when the two memory tasks were combined, although verbal memory (but not visual memory) was clearly disrupted by articulatory suppression interpolated between presentation and recall. These data suggest that a multiple-component working memory model provides a better account for performance in concurrent immediate memory tasks than do theories that assume a single processing and storage system or a limited-capacity attentional system coupled with activated memory traces.     

Effects of a concurrent memory task on hemispheric asymmetries in categorization

Recent research on the division of processing between the two cerebral hemispheres has often employed two concurrent tasks to investigate the dynamic nature of hemispheric asymmetries. The experiment reported here explored the effects of two concurrent high-level cognitive tasks (memory retention and semantic categorization) on the direction and magnitude of hemispheric differences in the processing of words and pictures. Subjects were required to categorize words and pictures presented to either the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH). The categorization could be performed while holding either verbal material in memory (digit span), pictorial material in memory (serial nonsense figure recognition), or with no concurrent memory task. The effects produced hemisphere-specific, material-nonspecific interference. The verbal task removed a RVF-LH advantage at word categorization and enhanced a LVF-RH advantage on picture categorization; the pictorial task interfered with picture categorization in the LVF-RH, while enhancing a RVF-LH advantage at word categorization. The results are discussed in terms of multiple resource models of hemisphere function, capacity limitations, and the functional locus of processing required to produce various dynamic hemispheric effects.     

Visual scanning with or without spatial uncertainty and divided and selective attention.

An experiment was conducted to address the relation between theories of selective attention and theories of divided attention by examining the pattern of task interference between visual scanning as a sequential and selective attention process and other concurrent spatial or verbal processing tasks. A distinction is proposed between visual scanning with or without spatial uncertainty regarding their possible differential effects on interference with other concurrent processes. The experiment required the subjects to perform a primary tracking task, which was concurrently performed with a secondary spatial or verbal decision task. The relevant information that was needed to perform the decision tasks was displayed with or without spatial uncertainty. The results provide evidence that visual scanning as a spatial exploratory activity produces greater task interference with concurrent spatial tasks than with verbal tasks. Furthermore, spatial uncertainty in scanning is identified to be the crucial factor in producing this differential effect.     

The role of modality: Auditory and visual distractors in Stroop interference

As a commonly used measure of selective attention, it is important to understand the factors contributing to interference in the Stroop task. The current research examined distracting stimuli in the auditory and visual modalities to determine whether the use of auditory distractors would create additional interference, beyond what is typically observed in the print-based Stroop task. Research by Cowan and Barron supported the additive effects of auditory and visual distractors; however, there is only one empirical demonstration of this finding to date. Using different versions of the Stroop colour-naming task, behavioural analyses of reaction times (RT) were conducted, along with distributional RT analyses. The results indicated that a combination of visual and auditory distraction did not lead to a larger interference effect than visually based distraction alone. These findings suggest that methodological issues may have influenced the prior finding of additive effects of the two modalities, and are discussed in relation to the word production architecture account of Stroop effects.     

Verbal processing deficits in schizophrenia

The authors reported that a subgroup of schizophrenic patients performed well on a tone serial position task but was impaired on an auditory word serial position task (Wexler, Stevens, Bowers, Cerniak, & Goldman-Rakic, 1998). This study assessed 30 schizophrenic and 32 controls (matched for comparable tone discrimination) on 4 versions of the verbal serial position tasks and 2 tone serial position tasks. Patients performed poorly on all verbal tasks but performed comparably to controls when tones served as stimuli. Proactive interference and visual presentation further compounded the verbal deficits. Deficits persisted with pronounceable nonword stimuli. These findings provide evidence of specific deficits in language-related processing, although the authors could not rule out the possibility that the differential effects that were observed between the tone and word tasks, and particularly among the verbal tasks, may result from differing discriminating power of the different tests.     

How distraction affects pedestrian response: Evidence from behavior patterns and cortex oxyhemoglobin changes

ObjectivesDistracted walking is a major cause of pedestrian road traffic injuries, but little is known about how distraction affects pedestrian safety. The study was designed to explore how visual and auditory distraction might influence pedestrian safety.MethodsThree experiments were conducted to explore causal mechanisms from two theoretical perspectives, increased cognitive load from the distraction task and resource competition in the same sensory modality. Pedestrians’ behavior patterns and cortex oxyhemoglobin changes were recorded while they performed a series of dual tasks.ResultsFour primary results emerged: (a) participants responded more slowly to both visual and auditory stimuli in traffic, as well as walked more slowly, while talking on the phone or text messaging compared to when undistracted or listening to music; (b) when participants completed pedestrian response tasks while distracted with a high cognitive load, their response was significantly slower and poorer than when they carried out a lower cognitive load distraction task, (c) participants had higher levels of oxy-Hb change in cortices related to visual processing and executive function while distracted with a higher cognitive load; and (d) participants' responses to traffic lights were slower and resulted in a higher activation in prefrontal cortex and occipital areas when distracted by a visual distraction task compared to when distracted with an auditory task; similarly, brain activation increased significantly in temporal areas when participants responded to an auditory car horn task compared to when they responded to visual traffic lights.ConclusionsBoth distracting cognitive load demands and the type of distraction task significantly affect young adult pedestrian performance and threaten pedestrian safety. Pedestrian injury prevention efforts should consider the effects of the type of distracting task and its cognitive demands on pedestrian safety.     

Letter and word code interactions elicited by normally displayed words

The dependence of visual word recognition on letter processing was investigated by measuring the effect of a cue word on subsequent target word processing for various degrees of cue/ target similarity. Using a simultaneous matching task (Experiments 1 and 2), modest facilitation was found for identical cue/target items only, whereas items that differed by a single letter led to substantial interference. Targets that shared internal or external letters with cues yielded latencies comparable to those for neutral or different cue conditions. The identical facilitation and high-similarity interference was also found in a lexical decision task under normal display conditions (Experiment 3). However, when direct letter processing was measured using spatially transformed targets (Experiment 4), large facilitatory effects were found for similar as well as for identical cue/target conditions. Although both letter and word codes appear to be activated by normally displayed words, such word code activity may not routinely depend upon letter code outputs.     

Multiple coding strategies in the retention of musical tones by possessors of absolute pitch

Eighteen musicians with absolute pitch (AP) confirmed by screening tests participated in tonal and verbal short-term-retention tasks. In the tonal task, subjects identified three successive piano tones by their letter names. Recall of these note names after 18 sec of counting backwards was near perfect. Recall after an 18-sec delay filled with random piano tones was also near perfect. In contrast, the same subjects demonstrated significant forgetting when required to retain letter trigrams while counting backwards for 18 sec. These results were essentially replicated in a second experiment using longer (27 sec) retention intervals, a more demanding verbal interference task, and an active musical interference task (singing a descending scale). We interpret these results as indicating that retention of note names by possessors of AP is not limited to verbal encoding; rather, multiple codes (e.g., auditory, kinesthetic, and visual imagery) are probably used.     

Time estimation and concurrent nontemporal processing: Specific interference from short-term-memory demands

Previous studies have shown that the effect of concurrent nontempcraLprocessmg on time astimation may vary depending on the level of difficulty of the nontemporal task. This is commonly interpreted within the context of so-called distraction/interruption models of temporal processing, which propose that as concurrent task difficulty or complexity is increased, temporal processing receives less attention. We hypothesize that the effect of nontemporal processing does not depend on the level of difficulty as such, but rather on the extent to which the concurrent nontemporal task specifically involves processing in short-term meraery. Four experiments were run in which the short-term memory requirements of concurrent tasks were systematically varied, although all of the tasks were of comparable levels of difficulty. In the first experiment, the effect of memory search on simultaneous temporal productions was proportional to the number of items to search. As with reaction time, produced intervals were shown to increase linearly with the number of items in the memorized set. In Experiment 2, a visual search involving some load on short-term memory interfered in the same way with time production, although to a lesser extent. The last two experiments showed that performing attention-demanding visual search tasks that did not involve short-term memory did not lengthen simultaneously produced time inter-vals. This suggests that interference of nontemporal processing on time processing may not be a matter of nonspecific general purpose attentional resources, but rather of concurrent short-term-memory processing demands.     

视空工作记忆负载对真实场景搜索绩效的影响

采用视空工作记忆任务和真实场景搜索任务相结合的双任务范式, 结合眼动技术将搜索过程划分为起始阶段、扫描阶段和确认阶段, 探究视空工作记忆负载对真实场景搜索绩效的影响机制, 同时考查试次间搜索目标是否变化、目标模板的具体化程度以及搜索场景画面的视觉混乱度所起的调节作用。结果表明, 视空工作记忆负载会降低真实场景搜索的成绩, 在搜索过程中表现为视空负载条件下扫描阶段持续时间的延长、注视点数目的增加和空间负载条件下确认阶段持续时间的延长, 视空负载对搜索过程的影响与目标模板的具体化程度有关; 空间负载会降低真实场景搜索的效率, 且与搜索画面的视觉混乱度有关, 而客体负载则不会。由此可见, 视空工作记忆负载对真实场景搜索绩效的影响不同, 空间负载对搜索过程的影响比客体负载更长久, 二者均受到目标模板具体化程度的调节; 仅空间负载会降低真实场景的搜索效率, 且受到搜索场景画面视觉混乱度的调节。     

Interaction between stimulus-driven orienting and top-down modulation in attentional capture

The present study investigated whether visual and kinesthetic stimuli are stored as multisensory or modality-specific representations in unimodal and crossmodal working memory tasks. To this end, angle-shaped movement trajectories were presented to 16 subjects in delayed matching-to-sample tasks either visually or kinesthetically during encoding and recognition. During the retention interval, a secondary visual or kinesthetic interference task was inserted either immediately or with a delay after encoding. The modality of the interference task interacted significantly with the encoding modality. After visual encoding, memory was more impaired by a visual than by a kinesthetic secondary task, while after kinesthetic encoding the pattern was reversed. The time when the secondary task had to be performed interacted with the encoding modality as well. For visual encoding, memory was more impaired, when the secondary task had to be performed at the beginning of the retention interval. In contrast, memory after kinesthetic encoding was more affected, when the secondary task was introduced later in the retention interval. The findings suggest that working memory traces are maintained in a modality-specific format characterized by distinct consolidation processes that take longer after kinesthetic than after visual encoding.     

Pictorial interference with geometric shapes and achromatic shades

In two experiments, subjects were required to match printed names with subsequently displayed achromatic shades or geoinetric shapes. The presence of incongruent shades or shapes at the time of word display substantially slowed the RT for performing the match. This pictorial interference (interference due to a visual, nonlingalistic attributel was substantially attenuated, however, as the delay between the word display and shapes or shades to be matched was increased beyond 100 msec. These findings illnstrate the occurrence of a transitory automatic pathway activation from an irrelevant pictorial attribute, which may be contrasted with the verbal interference effects typically observed in Stroop-naming tasks. In both our tasks and the Stroop task, selectiwe attention fails when a stimulus must be transformed to another form of encoding in the presence of a competing stimulns which is already close to that form.     

提取干扰对内隐记忆的影响

以往研究多认同内隐记忆不会受到干扰的影响,但主要集中于编码时的干扰不会影响随后的内隐记忆提取成绩,而对于提取时的干扰是否也不会影响内隐记忆成绩仍存在疑义。该文在实验1采用学习-测验范式,通过在提取阶段设置同时干扰任务进一步考察提取干扰与内隐记忆的关系,结果表明提取干扰下并未发现明显的启动效应,即提取干扰破坏了内隐记忆。为进一步探讨内隐记忆的提取干扰效应是否源于记忆与干扰刺激同时呈现所引起的知觉表征竞争,实验2改变了记忆与干扰刺激的呈现顺序,结果表明不论干扰刺激在记忆项目之前或之后呈现,启动效应均受到影响。相比之下,提取干扰对再认成绩的影响并不明显(实验3)。上述结果表明,内隐记忆的提取干扰效应是源于一般认知资源的竞争,在提取过程中任何能够产生认知资源竞争的变量设置都可能会削减内隐测验中的启动效应。     

Divided attention and memory: evidence of substantial interference effects at retrieval and encoding

In 5 divided attention (DA) experiments, students (24 in each experiment) performed visual distracting tasks (e.g., recognition of words, word and digit monitoring) while either simultaneously encoding an auditory word list or engaging in oral free recall of the target word list. DA during retrieval, using either of the word-based distracting tasks, produced relatively larger interference effects than the digit-monitoring task. DA during encoding produced uniformly large interference effects, regardless of the type of distracting task. Results suggest that when attention is divided at retrieval, interference is created only when the memory and concurrent task compete for access to word-specific representational systems; no such specificity is necessary to create interference at encoding. During encoding, memory and concurrent tasks compete primarily for general resources, whereas during retrieval, they compete primarily for representational systems.