Is spoken duration a sufficient explanation of the word length effect?

The word length effect is one of the cornerstones of trace decay plus rehearsal models (TDR) of memory. Words of long spoken duration take longer to rehearse than words of short spoken duration and as such suffer more decay and are thus less well recalled. The current experiment manipulates both syllable length and spoken duration within words of fixed syllable length in an aim to test the assumptions of the TDR model. Our procedures produced robust effects of both syllable length and spoken duration in four measures of the time it takes to pronounce the different types of words. Serial recall for the same materials produced robust syllable effects, but no duration effects.     

When does length cause the word length effect?

The word length effect, the finding that lists of short words are better recalled than lists of long words, has been termed one of the benchmark findings that any theory of immediate memory must account for. Indeed, the effect led directly to the development of working memory and the phonological loop, and it is viewed as the best remaining evidence for time-based decay. However, previous studies investigating this effect have confounded length with orthographic neighborhood size. In the present study, Experiments 1A and 1B revealed typical effects of length when short and long words were equated on all relevant dimensions previously identified in the literature except for neighborhood size. In Experiment 2, consonant-vowel-consonant (CVC) words with a large orthographic neighborhood were better recalled than were CVC words with a small orthographic neighborhood. In Experiments 3 and 4, using two different sets of stimuli, we showed that when short (1-syllable) and long (3-syllable) items were equated for neighborhood size, the word length effect disappeared. Experiment 5 replicated this with spoken recall. We suggest that the word length effect may be better explained by the differences in linguistic and lexical properties of short and long words rather than by length per se. These results add to the growing literature showing problems for theories of memory that include decay offset by rehearsal as a central feature.     

Does length or neighborhood size cause the word length effect?

Jalbert, Neath, Bireta, and Surprenant (2011) suggested that past demonstrations of the word length effect, the finding that words with fewer syllables are recalled better than words with more syllables, included a confound: The short words had more orthographic neighbors than the long words. The experiments reported here test two predictions that would follow if neighborhood size is a more important factor than word length. In Experiment 1, we found that concurrent articulation removed the effect of neighborhood size, just as it removes the effect of word length. Experiment 2 demonstrated that this pattern is also found with nonwords. For Experiment 3, we factorially manipulated length and neighborhood size, and found only effects of the latter. These results are problematic for any theory of memory that includes decay offset by rehearsal, but they are consistent with accounts that include a redintegrative stage that is susceptible to disruption by noise. The results also confirm the importance of lexical and linguistic factors on memory tasks thought to tap short-term memory.     

The effect of word length in short-term memory: Is rehearsal necessary?

Three experiments investigated the effect of word length on a serial recognition task when rehearsal was prevented by a high presentation rate with no delay between study and test lists. Results showed that lists of short four-phoneme words were better recognized than lists of long six-phoneme words. Moreover, this effect was equivalent to that observed in conditions in which there was a delay between lists, thereby making rehearsal possible in the interval. These findings imply that rehearsal does not play a central role in the origin of the word length effect. An alternative explanation based on differences in the degree of retroactive interference generated by long and short words is proposed.     

The effect of word length in short-term memory: Is rehearsal necessary?

Three experiments investigated the effect of word length on a serial recognition task when rehearsal was prevented by a high presentation rate with no delay between study and test lists. Results showed that lists of short four-phoneme words were better recognized than lists of long six-phoneme words. Moreover, this effect was equivalent to that observed in conditions in which there was a delay between lists, thereby making rehearsal possible in the interval. These findings imply that rehearsal does not play a central role in the origin of the word length effect. An alternative explanation based on differences in the degree of retroactive interference generated by long and short words is proposed.     

Does neighborhood size really cause the word length effect?

In short-term serial recall, it is well-known that short words are remembered better than long words. This word length effect has been the cornerstone of the working memory model and a benchmark effect that all models of immediate memory should account for. Currently, there is no consensus as to what determines the word length effect. Jalbert and colleagues (Jalbert, Neath, Bireta, & Surprenant, 2011a; Jalbert, Neath, & Surprenant, 2011b) suggested that neighborhood size is one causal factor. In six experiments we systematically examined their suggestion. In Experiment 1, with an immediate serial recall task, multiple word lengths, and a large pool of words controlled for neighborhood size, the typical word length effect was present. In Experiments 2 and 3, with an order reconstruction task and words with either many or few neighbors, we observed the typical word length effect. In Experiment 4 we tested the hypothesis that the previous abolition of the word length effect when neighborhood size was controlled was due to a confounded factor: frequency of orthographic structure. As predicted, we reversed the word length effect when using short words with less frequent orthographic structures than the long words, as was done in both of Jalbert et al.’s studies. In Experiments 5 and 6, we again observed the typical word length effect, even if we controlled for neighborhood size and frequency of orthographic structure. Overall, the results were not consistent with the predictions of Jalbert et al. and clearly showed a large and reliable word length effect after controlling for neighborhood size.     

Is the picture bizarreness effect a generation effect?

Bizarre stimuli usually facilitate recall compared to common stimuli. This investigation explored the so-called bizarreness effect in free recall by using 80 simple line drawings of common objects (common vs bizarre). 64 subjects participated with 16 subjects in each group. Half of the subjects received learning instructions and the other half rated the bizarreness of each drawing. Moreover, drawings were presented either alone or with the name of the object under mixed-list encoding conditions. After the free recall task, subjects had to make metamemory judgments about how many items of each format they had seen and recalled. The key result was that a superiority of bizarre pictures over common ones was found in all conditions although performance was better when the pictures were presented alone than with their corresponding label. Subsequent metamemory judgments, however, showed that subjects underestimated the number of bizarre items actually recalled.     

Is the discrimination of motion-path length unique?

Discrimination of the extent of a motion path may present a special problem since the discrimination calls on memory for changing position and involves pursuit movements of the eye. To determine how these factors affect judgment, discrimination of extents represented by motion paths, successively appearing endpoints, and simultaneously present endpoints was compared under a variety of eye-movement conditions: fixation, pursuit, and saccadic. Discrimination was assessed by the method of adjustment and also by the method of magnitude estimation. Discrimination of motion path extent was found to be as accurate as discrimination of an interspace demarcated by simultaneously presented points or by successively presented points. This was true for brief single presentations of the extents as well as for repeated exposures to the extents. The findings were applied to the analysis of the perception of velocity and the perception of extent.     

Characteristics of spatial memory span: Is there an analogy to the word length effect, based on movement time?

In studies of verbal short-term memory it has been shown that the length of words to be remembered affects the size of memory span. This word-length effect is attributed to relationships between the rate of rehearsal of verbal material and the time it takes to speak the words being rehearsed. For spatial memory span there may also be an internal rehearsal system linked to overt responding, and if there is a strong analogy to be drawn between the verbal and spatial domains then movement time between spatial targets should predict the number of spatial locations that can be recalled. In the experiments reported here the time taken to move between spatial targets is varied by altering the size of targets and the distance between them. No difference between span performance on a nine-block spatial span task were found, either on immediate recall or on recall after an interval. When recall is of items from an array of 27, grouped in nine sets of three, with only one location in any set being presented on any trial, there is an effect of display size. This effect is consonant with the argument that movement time is related to spatial rehearsal, but other explanations are also possible. However, if recall in this task is scored over the nine sets rather than over the 27 items, then there is no difference between the displays. The results indicate that performance on the normal nine-block spatial-span task cannot be predicted by movement time.     

Is inhibition of return a reflexive effect?

The inhibition of return (IOR) phenomenon is routinely considered an effect of reflexive attention because the paradigm used to generate IOR employs peripheral cues that are uninformative as to where a target will appear. Because the cues are spatially unreliable it is thought that there is no reason for attention to be committed volitionally to them, and hence, the IOR effect is considered reflexive. What has been generally overlooked, however, is that the cues provide reliable temporal information as to when a target will occur. This predictive information is used by participants to prepare volitionally for when a target is likely to appear. We investigated whether the IOR effect is a product of the volitional application of attention to peripheral cues for the use of their temporal information. To test this idea we rendered the temporal information provided by peripheral cues unreliable. While this eliminated participants using the cues volitionally, it did not abolish the IOR phenomenon. These data demonstrate two new findings. First, the IOR effect is fundamentally a reflexive phenomenon. Second, when peripheral cues are not used volitionally, the IOR effect is attenuated. Together, the present findings indicate that the IOR effect can be modulated by volitional (top-down) processes but it is not the product of them. We argue that an intimate link between fronto-parietal regions and the superior colliculus provide a functional neural mechanism for this volitional effect to impact IOR.     

An item/order trade‐off explanation of word length and generation effects

The item‐order hypothesis suggests that under certain conditions increased item processing can lead to deficits in order processing, and that this produces a dissociation in performance between item and order tasks. The generation effect is one such example. The word length effect is seen as another instance where this trade‐off might be observed. The following experiments compare word length and generation effects under serial recall and single item recognition conditions. Short words are better recalled than long words on the serial recall task but long words were better recognised than short words. The results are consistent with the item‐order approach and support a novel explanation for the word length effect.     

Inhibition of return for the length of a line?

Inhibition of return is most often measured using an exogenous spatial cuing method. The experiments presented here follow up on a small number of studies that have examined whether a similar effect occurs for nonspatial stimulus attributes. In Experiments 1 and 2, the task was to identify a target line as either short or long. In this context, targets on valid trials were of the same length as that of a preceding cue, whereas targets on invalid trials were of a different length than that of a preceding cue. The results were similar to those in spatial orienting studies in that responses were slower for valid than for invalid targets only at stimulus onset asynchronies (SOAs) longer than 300 msec. In Experiment 3, the stimuli were the same but the task was to detect the onset of the target line. This task change resulted in slower responses for valid than for invalid targets at all SOAs. A similar result was observed in Experiment 4, in which validity was defined by color rather than line length, and the task was to identify the target color. The discussion centers on an opponent process approach to interpreting cuing effects, and consequent difficulties in distinguishing spatial and nonspatial cuing effects based on their time course.     

Is there a constant minimum perceptual duration?

It has been suggested in the recent literature that all stimuli briefer than a critical duration have identical perceptual durations. Relevant simultaneity, reaction time, temporal order and duration discrimination data are discussed, and new data are presented. It is concluded that the relationship between the physical duration of a stimulus and its perceptual duration is not yet understood.     

Post-cueing after erasure of the icon: Is there a set effect?

Recognition accuracy in a tachistoscopic identification task typically declines as the size of the set from which the target was selected increases. To determine whether this effect is due to selective encoding from iconic store, a masking stimulus, intended to erase the icon, was presented following the stimulus. Information about the set was then presented. It was found that subjects' performance in this post-cueing situation did not differ from performance in a pre-cueing condition, where the set was presented prior to the stimulus. It was concluded that set size does not have its effect through selective encoding from iconic store. Results were discussed in terms of the fragment theory.     

Is banara really a word?

Bowers, Davis, and Hanley (Bowers, J. S., Davis, C. J., & Hanley, D. A. (2005). Interfering neighbours: The impact of novel word learning on the identification of visually similar words. Cognition, 97(3), B45-B54) reported that if participants were trained to type nonwords such as banara, subsequent semantic categorization responses to similar words such as banana were delayed. This was taken as direct experimental support for a process of lexical competition during word recognition. This interpretation assumes that banara has been lexicalized, which predicts that masked form priming for items such as banara-banana should be reduced or eliminated. An experiment is reported showing that the trained novel words produced the same amount of priming as untrained nonwords on both the first and the second day of training, suggesting that the interference observed by Bowers et al was not due to word-on-word competition.     

Is knowledge of causes sufficient for understanding?

According to a traditional account, understanding why X occurred is equivalent to knowing that X was caused by Y. This paper defends the account against a major objection, viz., knowing-that is not sufficient for understanding-why, for understanding-why requires a kind of grasp while knowledge-that does not. I discuss two accounts of grasp in recent literature and argue that if either is true, then knowing that X was caused by Y entails at least a rudimentary understanding of why X occurred. If my defense is successful, it would cast doubt on an influential account of the epistemic value of understanding.     

Reading sentences of uniform word length – II: Very rapid adaptation of the preferred saccade length

In the current study we investigated whether readers adjust their preferred saccade length (PSL) during reading on a trial-by-trial basis. The PSL refers to the distance between a saccade launch site and saccade target (i.e., the word center during reading) when participants neither undershoot nor overshoot this target (McConkie, Kerr, Reddix, & Zola in Vision Research, 28, 1107-1118, 1988). The tendency for saccades longer or shorter than the PSL to under or overshoot their target is referred to as the range error. Recent research by Cutter, Drieghe, and Liversedge (Journal of Experimental Psychology: Human Perception and Performance, 2017) has shown that the PSL changes to be shorter when readers are presented with 30 consecutive sentences exclusively made of three-letter words, and longer when presented with 30 consecutive sentences exclusively made of five-letter words. We replicated and extended this work by this time presenting participants with these uniform sentences in an unblocked design. We found that adaptation still occurred across different sentence types despite participants only having one trial to adapt. Our analyses suggested that this effect was driven by the length of the words readers were making saccades away from, rather than the length of the words in the rest of the sentence. We propose an account of the range error in which readers use parafoveal word length information to estimate the length of a saccade between the center of two parafoveal words (termed the Centre-Based Saccade Length) prior to landing on the first of these words.