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Biomedical subjects

M J Watkins

Publications and source records attributed to M J Watkins.

35 records · Page 2Linked to original sources
PubMed1989

Recency effect in recall of a word list when an immediate memory task is performed after each word presentation.

Subjects studied 12-word lists for free recall. During presentation of the lists, each word was followed by a supraspan sequence of digits, which the subjects tried to reproduce. This task, unlike those used in previous research with this continual distractor procedure, presumably taxed immediate memory capacity to the full. Nevertheless, the word recall data showed a pronounced recency effect. Moreover, the magnitude of the recency effect was found to be just as great with this task as with a more typical task in which the demands on immediate memory are likely to be fewer. These findings reinforce the emerging view that the recency effect need not be the product of immediate memory.

Humans↗
PubMed1988

On the relation between perceptual priming and recognition memory.

Two experiments evaluated the hypothesis that perceptual fluency is used to infer prior occurrence. Subjects heard (Experiment 1) or saw (Experiment 2) a list of words and then were presented in the same modality with both these and other words twice in succession: first in a more or less impoverished fashion, and then in clear fashion. For the first of these two presentations, the subjects tried to identify the word; for the second, they gave a recognition judgement. As predicted by the perceptual fluency hypothesis, and as has been found in previous research, the recognition judgments were more positive for identified words than for unidentified words. However, degree of impoverishment, by which apparent perceptual fluency was brought under experimental control, did not affect the recognition judgments. The perceptual fluency hypothesis was therefore not supported, and the observed relation between identification and recognition was attributed to an item selection effect.

Adult↗
PubMed1988

Evidence of echoic memory with a multichannel cochlear prosthesis.

Short-term memory was examined in a subject with a multichannel cochlear prosthesis. Serial recall for lists of digits revealed what are widely regarded as the principal hallmarks of echoic memory, namely the recency effect and the suffix effect. Thus, probability of recall increased for the last one or two digits, except when a nominally irrelevant but spoken item was appended to the to-be-remembered list. It appears, therefore, that a multichannel cochlear implant can give rise to not only the perception of, but also an echoic memory for, speech. As with normal subjects, the suffix effect did not occur with a nonspeech suffix, implying that the echoic memory from the prosthesis shows normal sensitivity to the distinction between speech and nonspeech.

Adult↗
PubMed1987

Inhibiting word generation with word presentations.

The ability to generate words of a given category is found to be impaired when other words of the same category are being heard (Experiments 1-4). Little if any impairment arises from hearing words of a different category (Experiments 1, 2, and 3). This pattern of results occurs with categories defined both semantically (Experiments 1, 2, and 4) and graphemically (Experiment 3). The extent of the impairment is found to be comparable to that which occurs when other words of the same category are studied and recalled prior to generation (Experiment 4). These findings are discussed in the context of other inhibitory phenomena.

Humans↗
PubMed1986

Cue depreciation: when word fragment completion is undermined by prior exposure to lesser fragments.

The ability to think of a previously studied item has often been shown to be impaired when, in one way or another, the extraitem context is changed from study to test. In a series of five experiments, such impairment is induced in a somewhat different way. A fragment (e.g. r-i--rop) of a just-studied word (raindrop) is shown to be less readily completed if it is presented bit by bit (r------p, r----r-p, r-i--r-p, r-i--rop) rather than all at once (Experiments 1, 3, 4, and 5). No such effect is found if the word has not been studied beforehand (Experiments 2, 3, 4, and 5). This pattern of results occurs even when fragments of studied and nonstudied words occur in the same test and under conditions in which subjects cannot tell whether a given fragment is of a studied or nonstudied word (Experiments 4 and 5). In addition, for words that have been studied beforehand, the impairment is shown to increase systematically with the number of steps involved in the presentation of the word fragment (Experiment 3) and also to persist when the time allowed for completion of the final version of the fragment is increased from 4 s to a full minute (Experiment 5).

Cues↗
PubMed1984

Determining perceived meaning during impression formation: another look at the meaning change hypothesis.

The meaning change hypothesis says that the individual items of information from which an impression of someone is formed tend to be perceived in a way consistent with the overall impression. It is argued here that the evidence usually considered as the principal experimental support for this hypothesis is artifactual, the product of a spurious method of determining perceived meaning. We describe a new method in which, following a series of person descriptions, subjects try to recall from each description a critical trait with the aid of a roughly synonymous cue word that is evaluatively either consistent or inconsistent with the description as a whole. The meaning change hypothesis predicts a higher level of recall when the cue word and the overall description are evaluatively consistent. We show that although this prediction holds with at least one kind of person description (Experiments 1 and 2), it does not hold with the kind most often used in impression formation research (Experiments 3, 4, and 5).

Cues↗
PubMed1980

The modality effect and echoic persistence.

The modality effect refers to the higher level of recall of the last few items of a list when presentation is auditory as opposed to visual. It is usually attributed to echoic memory. The effect may be sharply reduced by an ostensibly irrelevant auditory item appended to the end of the list. Previous research suggests that this "suffix effect" arises only when the suffix item occurs within 2 sec of the last list item. This finding strengthens the widely held assumption that echoic information decays within 2 sec, and has led to the assumption that if echoic information is to be useful in serial recall it must first be encoded into a more durable modality-independent form. Both assumptions conflict with the research reported here. The first two experiments demonstrate substantial suffix effects with suffix delays of 2 and 4 sec, indicating that echoic information lasts at least 4 sec. This finding implies that echoic information may aid recall directly, an implication that was supported in Experiments 3 and 4. In Experiment 3 serial recall was interrupted with a brief distractor task. The modality effect was smaller when this task was auditory than when it was visual, suggesting that echoic information was still available immediately prior to recency recall. In Experiment 4 list presentation was broken by a 4-sec pause; the modalities of the list halves were combined factorially. Interest focused on the recency positions of the first half. A modality effect was found at these positions when the second half was visual but not when it was auditory. This is contrary to the hypothesis that echoic information is encoded before recall, but is consistent with the hypothesis that echoic information is encoded before recall, but is consistent with the alternative hypothesis that echoic information is used directly at recall. The final two experiments concern the modality effect found when a delay is interpolated between list presentation and recall. Experiment 5 showed that a 20-sec silent copying task interpolated before free recall reduced visual recency more than auditory recency, and so enhanced the modality effect. This suggests that, contrary to prevailing opinion, the modality effect in delayed recall is not the result of a memory that is modality-independent. In Experiment 6 a modality effect found with serial recall after an unfilled interval of 18 sec was unaffected by visual distractor task, but almost eliminated by an auditory distractor task, given just prior to recall. It thus seems that the modality effect in delayed recall is the result of information persisting in echoic form until recall. It is concluded that echoic information can persist for many seconds and is used directly at the time of recall.

Attention↗
PubMed1980

Picture rehearsal: an effect of selectively attending to pictures no longer in view.

Five experiments demonstrate rehearsal of pictures. The pictures were displayed in pairs, with a "rehearsal interval" between successive pairs. At the beginning of each interval, subjects were cued to rehearse just one member of the preceding pair. Although the subjects were expecting a recognition test for just the cued pictures, they were tested on both the cued and the uncued pictures. The first four experiments all used a different type of picture (faces, scenes, random shapes, and simple line drawings), and in each case recognition was at a higher level for the cued pictures than for the uncued pictures. The fifth experiment examined the degree to which the benefit of the rehearsal interval was limited to the cued pictures and the results suggested that uncued pictures did not benefit at all from the rehearsal interval. It is argued that these findings of control exerted by the subject over the beneficial effects of a postpresentation interval provide an adequate demonstration that pictures can be effectively rehearsed.

Attention↗
PubMed1978

The seeing-more-than-is-there phenomenon: implications for the locus of iconic storage.

When a target figure is moved back and forth behind a window cut in an opaque screen, more of the figure is seen at a given instant than is physically present. This finding implies that the information presented at one instant is stored in iconic form so that it can be integrated with information presented at a slightly later instant. Two experiments explored the illusion and showed that it can be readily demonstrated under a variety of conditions. A third experiment indicated that it can occur in the absence of appreciable eye movements. This latter finding, together with various supporting argument, is taken as evidence against an explanation of the illusion in terms of the target image being painted across the retina. Rather, it appears that successive sections of the target item are projected onto the same retinal sector. It is difficult to understand how simple photoreceptors can simultaneously retain information presented at one instant and register information presented at a subsequent time without two pieces of information being fused. Therefore, it is concluded that the iconic storage implied by the illusion occurs at a level more central than that of the retinal receptors.

Eye Movements↗
PubMed1975

A categorically postcategorical interpretation of the modality effect: a reply to Nilsson.

Watkins found the modality effect undiminished when four-syllable rather than one-syllable words were used, and concluded that the effect has a post-categorical origin. Nilsson replicated this result, and also found that with entirely unfamiliar words the effect was greater with one-syllable words than with four-syllable words. Nilsson considered his findings to be in support of a precategorical origin of the effect. This reply argues that, to the contrary, Nilsson's findings are not only consistent with a postcategorical interpretation, but also inconsistent with a precategorical interpretation.

Auditory Perception↗