On the locus of redundancy effects in a letter-detection task

It takes longer to detect a target if it is the initial letter of a nonredundant letter string such as BNHTW than if it is the initial letter of a redundant letter string such as BBBBB (Johnson, 1986b; Johnson & Blum, 1988). The results of the present study reveal that the redundancy effect also occurs for mixed-case letters strings (e.g., BbbBb) and digit strings (e.g., 22222). In addition, these results suggest that the cause of the redundancy effect is not related to the visual properties of the noninitial letters per se but is instead related to the presence of the target in noninitial positions. Together, these results rule out a number of hypotheses about the cause of the redundancy effect and suggest that the locus of this effect is in processes involved in response selection and/or the read-out of information from the perceptual system.     

The distractor frequency effect in a delayed picture-word interference task: further evidence for a late locus of distractor exclusion

A picture-word interference experiment examined the origin of the distractor frequency effect, the effect that pictures are named slower in the context of low-frequency than high-frequency words (Miozzo &; Caramazza, Journal of Experimental Psychology, 132, 228–252, 2003). We compared two accounts of the effect: an early, input-related account and a late, response-related account. Participants named high and low-frequency pictures with low and high-frequency distractors in two conditions. In the immediate naming condition, picture and distractor were presented simultaneously. In the delayed naming condition, the distractor was presented 1,000 ms after the picture; pictures had to be named upon distractor presentation. There was a distractor frequency effect in both conditions, but an effect of picture frequency only in the immediate naming condition (showing that in the delayed naming condition, lexical selection had been completed). These results support a late origin of the distractor frequency effect.     

Early locus of a linguistic variable in a fast priming task

The syllable and the morpheme are known to be important linguistic variables, but is such information involved in the early stages of word recognition? Syllable‐morpheme information was manipulated in the early stage of word naming by means of the fast priming paradigm. The letters in the prime were printed in a mixture of lower‐ and upper‐case letters. The change from lower to upper case occurred either at a syllable‐morpheme boundary, before the boundary, or after it (e.g., reTAKE, rETAKE, or retAKE) creating either an intact pair or a broken one. The target was always in lower case (e.g., retake). The results of Experiments 1 and 2 revealed that intact syllable and morpheme information facilitated word naming at a short Stimulus Onset Asynchrony (below awareness) but not at a long SOA, suggesting that the use of such information is automatic. A second set of experiments attempted to determine if syllable information alone could facilitate word processing. In Experiments 3 and 4, monomorphemic words were divided either at, before, or after the syllable boundary (e.g., rePEL, rEPEL, or repEL). The primes were all pseudomorphemic in the sense that the initial syllables could appear as a morpheme in other words (e.g., restate) but were not morphemic in the target words (e.g., repel). The second syllable was neither morphemic nor pseudomorphemic. Using the same SOAs as in Experiments 1 and 2, intact syllables were found to be facilitative at the short SOA, but not at the long SOA. Thus, the syllable plays a role in an early stage of word recognition. Whether morphemes that are not syllables are facilitative is still to be determined in this paradigm.     

The picture superiority effect in a cross-modality recognition task

Words and pictures were studied, and recognition tests were given in which each studied object was to be recognized in both word and picture format. The main dependent variable was the latency of the recognition decision. The purpose was to investigate the effects of study modality (word or picture), of congruence between study and test modalities, and of priming resulting from repeated testing. Experiments 1 and 2 used the same basic design, but the latter also varied retention interval. Experiment 3 added a manipulation of instructions to name studied objects, and Experiment 4 deviated from the others by presenting both picture and word referring to the same object together for study. The results showed that congruence between study and test modalities consistently facilitated recognition. Furthermore, items studied as pictures were more rapidly recognized than were items studied as words. With repeated testing, the second instance was affected by its predecessor, but the facilitating effect of picture-to-word priming exceeded that of word-to-picture priming. The findings suggest a two-stage recognition process, in which the first is based on perceptual familiarity and the second uses semantic links for a retrieval search. Common-code theories that grant privileged access to the semantic code for pictures or, alternatively, dual-code theories that assume mnemonic superiority for the image code are supported by the findings. Explanations of the picture superiority effect as resulting from dual encoding of pictures are not supported by the data.     

Differential payoff and locus of selectivity in a visual memory task

Two experiments were run to investigate the locus of selectivity in a visual memory task involving differential payoff for letters correctly recalled: Major variables consisted of value instructions given before or after the exposure of a display, the ratio of high to low value, and exposure duration. The results showed that Ss make more correct reports of higher value than of lesser value, whether value instructions are given before or after the display. Furthermore, overall performance and extent of selectivity increase with increasing exposure time, but more for the before than the after conditions of instruction. These results suggest that selectivity occurs both during perception and retention and during recall.     

The cognitive locus of distraction by acoustic novelty in the cross-modal oddball task

Unexpected stimuli are often able to distract us away from a task at hand. The present study seeks to explore some of the mechanisms underpinning this phenomenon. Studies of involuntary attention capture using the oddball task have repeatedly shown that infrequent auditory changes in a series of otherwise repeating sounds trigger an automatic response to the novel or deviant stimulus. This attention capture has been shown to disrupt participants' behavioral performance in a primary task, even when distractors and targets are asynchronous and presented in distinct sensory modalities. This distraction effect is generally considered as a by-product of the capture of attention by the novel or deviant stimulus, but the exact cognitive locus of this effect and the interplay between attention capture and target processing has remained relatively ignored. The present study reports three behavioral experiments using a cross-modal oddball task to examine whether the distraction triggered by auditory novelty affects the processing of the target stimuli. Our results showed that variations in the demands placed on the visual analysis (Experiment 1) or categorical processing of the target (Experiment 2) did not impact on distraction. Instead, the cancellation of distraction by the presentation of an irrelevant visual stimulus presented immediately before the visual target (Experiment 3) suggested that distraction originated in the shifts of attention occurring between attention capture and the onset of the target processing. Possible accounts of these shifts are discussed.     

The effect of cueing in a visual signal detection task

In a signal detection task four subjects were presented with stimulus cards, 50% of which contained a capital O in one of the four quadrants. Fifty per cent of these Os were surrounded by a small rectangle. This small rectangle served as a simultaneous cue, indicating the region where the O could appear. The other 50% were surrounded by a big rectangle encompassing the whole field. Fifty per cent of the blank cards contained a small rectangle, the other 50% a big one. Exposure duration was set at 15 and 20 ms. The results indicated that subjects, for whom these exposure durations led to performance exceeding chance level, used the simultaneous cue for reducing the field to be searched, resulting in higher sensitivity (d') in the small rectangle condition. Results were interpreted in terms of increasing efficiency of search as a result of which a higher quality of the icon was available for making decisions about the presence of the O.     

The effect of preview eccentricity in a lexical decision task

We report lexical decision experiments in which eye movements and lexical decision time were analysed. The results show that nonwords produced more fixation than words, and that the time to make a lexical decision was also greater for nonwords. Further, a preview of the stimulus was presented on some occasions either at fixation or peripherally. When the presentation was peripheral the number of refixations and lexical decision times were reduced. Parafoveal previews of words also reduced word length effects on refixations and lexical decision time. These effects decreased (for nonwords) when the case of the letters was changed in the preview. These results are compatible with the idea that the peripheral preview benefit derives from word visual structure in addition to information about word length, word envelope, and single letter identities.     

The effect of a non-informative cueing signal in a three-choice reaction-time task

Summary Many studies have shown that in a simple reaction-time (RT) task a non-informative leading cue decreases RT to a subsequent target presented in the same region as the cue. This facilitation lasts about 150 ms; it is then replaced by a sustained inhibition. Experiment 1 tests the hypothesis that the initial facilitation is due to motor, rather than perceptual, processes by using choice RT. Facilitation is greater and lasts longer in choice than in simple tasks, thus supporting the hypothesis. Experiment 2 shows that facilitation occurs even when the subject actively orients his or her attention away from the cue.     

The effect of a subsidiary task on iconic memory

Memory & Cognition - Using a subsidiary task technique, Doest and Turvey (1971) concluded that iconic memory was independent of the central processing system. However, they did not control the...     

The effect of combinations of image degradations in a discrimination task

This paper explores the ways in which combinations of image degradations affect discrimination. Nine experiments are described that examine the discriminability of visual images that are degraded with three types of information reducing transformations: random punctate visual interference, lowpass spatial frequency filtering, and local area (i.e., block) averaging. The results of these experiments characterize a powerful visual ability to discriminate highly degraded stimuli unless that ability is severely challenged by relatively high levels of random visual interference. Discriminative commutativity of the orders in which the other two degradations are imposed is demonstrated. That is, the order in which the degradations are applied does not affect the final discriminative outcome. This result is in contrast to predictions from relevant mathematics and direct examination of the images produced by both orders of degradation. The commutativity is attributed to the particularly strong effect of the low-pass spatial frequency filtering degradation on the discrimination process. This study also demonstrates that combinations of degradations in a discrimination task always result in a reduction in performance, and never in the improvement that has been reported for recognition. This difference is attributed to the fact that form discrimination is mediated mainly by local features and high-frequency spatial components, whereas recognition is mediated mainly by global features and low-frequency spatial components.     

The effect of visual orientation uncertainty in a simultaneous detection-recognition task

This study concerned the processing of the outputs of visual orientation-sensitive mechanisms by higher order mechanisms. Ss performed a simultaneous detection-recognition task. Variation in the number of possible orientations of a single straight line produced only slight, if any, changes in detection or recognition performance as compared with findings from similar auditory frequency experiments. It was concluded that the outputs of all orientation-sensitive mechanisms are examined by higher order mechanisms. As the angular separation of two possible orientations increased, the data showed that recognition improved in keeping with other reported findings. Comparison of detection with recognition indicated that the latter, under certain conditions, was superior to the former.     

次要任务对词类判断任务中权力空间表征激活的影响

许多证据表明权力在大脑中是以垂直空间来进行表征的, 具体而言为言语和视觉空间编码。前人研究发现两种编码具有情境依赖性, 即当前任务决定了激活哪种编码。一般的词类判断任务主要依赖于言语编码。然而仍不确定的是, 当排除言语空间编码后, 词类判断任务能否激活视觉空间编码。本研究拟借助双任务范式探讨此问题。实验结果发现单任务条件下出现权力-空间交互, 并且双任务条件下, 这一交互只受到视觉空间次要任务的干扰。这说明, 词类判断任务也可依赖视觉空间编码, 并进一步支持了权力空间表征的情境依赖性。     

Recognition in a visuospatial memory task: The effect of presentation

The influence of the mode of presentation (simultaneous vs. sequential) on accuracy and latency of visuospatial recognition was explored in three experiments. In Experiment 1, two groups were administered a visuospatial task in which a number of positions were shown either simultaneously or sequentially (in a random order); memory was tested using a recognition procedure of visuospatial patterns, either identical or different (a single cell displaced). The results showed that (1) performance was higher in the simultaneous than in the sequential presentation, and (2) decision time increased with complexity in the sequential presentation but not in the simultaneous presentation. In Experiment 2, the same task was used in three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test, a single location, rather than a pattern, was presented for recognition. The results showed that (1) performance was higher in the simultaneous and in the ordered sequential presentations than in the random sequential one, and (2) decision time increased with complexity. In Experiment 3, the same task was used in the same three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test either an identical or a “displaced” pattern was presented for recognition. The results showed that (1) performance was equivalent in the three types of presentation, and (2) decision time increased with complexity for “hit” items; different patterns of linear relations were observed for “correct rejections” items. The results are interpreted in terms of the organisation of visuospatial working memory, and three types of encoding—extrafigural spatial encoding, visual pattern encoding, and spatial path encoding—were proposed.     

The effect of rotation on configural encoding in a face-matching task

Inversion disrupts encoding of faces because of the disruption of configural encoding as evident in the Thatcher illusion (Thompson 1980, Perception 9 483-484). Here we consider the effect of rotation on the loss of configural encoding in a same/different matching paradigm. Participants decided whether two faces were of the same type (both normal or both Thatcherised) or not, at five angles of rotation (0 degrees, 45 degrees , 90 degrees, 135 degrees, 180 degrees). When the faces were both of the same person, the disruption due to rotation for 'same-type' judgments was linear and approximately equal for normal and Thatcherised face pairs. In experiment 2, with different-person face pairs, the effect of rotation was much greater for Thatcherised face pairs than for normal face pairs. These findings are in contrast to those reported by Boutsen and Humphreys (2003, Quarterly Journal of Experimental Psychology A 56 955-975), and reasons for these differences, along with implications, are discussed.     

The effect on a difficult co-ordination task of the frequency of signals

Subjects were required to direct, by moving hand and foot controls, a fugitive spot of light into one of four positions in accordance with changes in the source of signals, and simultaneously, to extinguish two lights using a left-hand response. Two groups of subjects have been tested on this complex co-ordination task. Increasing the frequency of the signals from four successively but irregularly functioning sources was found to increase significantly the “error” scores in controlling the fugitive spot. Variations in signal frequency did not affect the other part of the task requiring left hand responses to a different set of signals. The order of a sequence of 4-signal frequencies over four trials had no effect on the efficiency with which the task was performed.     

Internal-external locus of control and performance on a vigilance task.

Previous studies have demonstrated there are large individual differences in subjects' ability to perform on vigilance or watch-keeping tasks. This study used Rotter's Internal-External (I-E) Locus of Control Scale to resolve some of the variance attributed to individual differences and tested the hypothesis that the internally controlled person is a better monitor on a vigilance task than an externally controlled person. There were 64 subjects who performed a visual watch-keeping task for a 1-hr. period. The results indicated that the external subjects made significantly more incorrect responses and missed significantly more signals during the entire task. The internal-external dimension was effective in differentiating performance on a vigilance task.     

The effect of stimulus availability on task choice in voluntary task switching

The voluntary task switching paradigm allows subjects to choose which task to perform on each trial in a stimulus environment affording multiple tasks. The present study examined the effect of stimulus availability on task choice. Subjects viewed displays containing a digit and a letter and performed either an even/odd or a consonant/vowel judgment on each trial. The target stimuli appeared with a stimulus onset asynchrony (SOA) of 0, 50, 100, or 150 msec. The probability of performing the task associated with Stimulus 1 increased as SOA increased, indicating an effect of external or stimulus-driven factors on task choice. This effect of stimulus availability on task choice was greater when the response-stimulus interval was 400 msec than when it was 2,000 msec. This interaction of preparation interval and stimulus availability is explained within a model of task choice that includes both internal processes and external influences.