短时记忆研究的新进展

人们对短时记忆的研究最早可以追溯到Ebbinghaus。他在记忆研究中采用无意义音节作为实验材料,发现读一遍能够记住的音节数是七个,这一结果成为广为人知的短时记忆的容量。后来人们发现,短时记忆的容量与很多复杂认知活动有关,这使得研究者更加关注短时记忆。20世纪五、六十年代,主要研究记忆广度、短时记忆与长时记忆的区分,全部报告法、分散注意法是当时的主要研究方法。     

False memory in a short-term memory task

The Deese/Roediger-McDermott (DRM; Roediger & McDermott, 1995) paradigm reliably elicits false memories for critical nonpresented words in recognition tasks. The present studies used a Sternberg (1966) task with DRM lists to determine whether false memories occur in short-term memory tasks and to assess the contribution of latency data in the measurement of false memories. Subjects studied three, five, or seven items from DRM lists and responded to a single probe (studied or nonstudied). In both experiments, critical lures were falsely recognized more often than nonpresented weak associates. Latency data indicated that correct rejections of critical lures were slower than correct rejections of weakly related items at all set sizes. False alarms to critical lures were slower than hits to list items. Latency data can distinguish veridical and false memories in a short-term memory task. Results are discussed in terms of activation-monitoring models of false memory.     

Tactile short-term memory

Subjects tried to recall the location of a tactile stimulus on the underside of the forearm after delays of 0, 3, 5, 10, 15, 30, 45 and 60 sec. When “rehearsal” was prevented by requiring subjects to count backwards during the delay, accuracy of recall decreased systematically reaching an asymptote after 45 sec. When subjects were left free to “rehearse,” this did not affect the decline in accuracy over the first 10 sec. Between 10 and 15 sec. there was a significant increase in accuracy followed by a slow decline which had not reached asymptote by 60 sec. It is suggested that tactile STM (short-term memory) depends on two processes, a fading sensory trace which is unaffected by distraction and a less labile system which does not appear to be verbal but which depends on “rehearsal.”     

Recent developments in psychiatric malpractice

Common issues of mental health liability are examined in relationship to recent legislative and case law. Matters of practical importance to practitioners including the applicability insurance coverage to punitive damage awards of arising from malpractice are addressed. Specific legal doctrines involving proof of liability, proximate cause and the standard of care are explored as they relate to mental health malpractice cases.     

Distinguishing short-term memory from working memory

The aim of the present research was to determine whether short-term memory and working memory could be distinguished. In two studies, 7- to 13-year-olds (N = 155, N = 132) were administered tasks thought to assess short-term memory as well as tasks thought to assess working memory. Both exploratory and confirmatory factor analyses distinguished short-term memory tasks from working memory tasks. In addition, performance on working memory tasks was related to word decoding skill but performance on short-term memory tasks was not. Finally, performance on both short-term memory and working memory tasks were associated with age-related increases in processing speed. Results are discussed in relation to models of short-term and working memory.     

Binding in short-term visual memory

The integration of complex information in working memory, and its effect on capacity, shape the limits of conscious cognition. The literature conflicts on whether short-term visual memory represents information as integrated objects. A change-detection paradigm using objects defined by color with location or shape was used to investigate binding in short-term visual memory. Results showed that features from the same dimension compete for capacity, whereas features from different dimensions can be stored in parallel. Binding between these features can occur, but focused attention is required to create and maintain the binding over time, and this integrated format is vulnerable to interference. In the proposed model, working memory capacity is limited both by the independent capacity of simple feature stores and by demands on attention networks that integrate this distributed information into complex but unified thought objects.     

Intra-list differences in short-term memory

Subjects attempted to recall lists of nine consonants immediately after presentation. Using various recall orders it was found that recall of part of a list interfered with retention of the other parts, memory for items presented early in a list being less affected by such interference than was that for later items. Since this result was not obtained when rate of presentation was increased, it is suggested that rehearsal contributed to the greater stability of early items.     

Response latencies in short-term memory

This paper deals with the problem of the interpretation of response latencies in short-term memory. A paired-associate study using a probe technique was conducted with the main experimental variation the length of the recall interval (1, 2, or 4 sec.). While shortening the interval had a statistically significant effect on recall probability the interaction between recall interval and probe position was negligible. While traditionally response latency is considered a measure of associative strength, such an interpretation seems inappropriate here. As an alternative, latencies may reflect more criterion values than sensitivity as these measures are interpreted in signal-detection theory.     

Interference in short-term auditory memory

Although interference is a well-established forgetting function in short-term auditory memory, an adequate understanding of its underlying mechanisms and time course has yet to be attained. The present study therefore aimed to explore these issues in memory for timbre. Listeners compared standard and comparison complex tones, having distinct timbres (four components varying in frequency), over a 4.7-s retention interval and made a same–different response. This interval either was silent or included one of 15 distractor tones occurring 0 ms, 100 ms, or 1,200 ms after the standard. These distractors varied in the extent to which the frequencies of their component tones were shared with the standard. Performance in comparing the two tones was significantly impaired by distractors composed of novel frequencies, regardless of the temporal position at which the distractor occurred. These results were fully compatible with the recent timbre memory model (McKeown & Wellsted, 2009 McKeown, D. and Wellsted, D. 2009. Auditory memory for timbre. Journal of Experimental Psychology: Human Perception and Performance, 35: 855–875. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and suggested that interference in auditory memory operates via a feature-overwriting mechanism.     

Redundancy effects in short-term memory

Five experiments are reported whose purpose was to demonstrate that short-term memory is improved by redundancy within the material. In Experiment I “tune” containing two, three, four and five tones of differing frequencies had to be coded into digits 1-5, to indicate the order of the pitches in a tune. Performance on stimuli containing correlated amplitude and duration were compared with the uni-dimensional condition. Experiment II repeated I, but required intensity to be coded. Experiment III required pitch coding under three conditions including that when amplitude and frequency were uncorrelated, and compared the performance of musically trained sunjects with nonmusicians. Experiment IV repeated III, but subjects were informed of the relation between dimensions. Experiment V involved “shadowing” the tunes by whistling simultaneously with the stimulus.

It was concluded (a) that intercorrelation improves, but zero correlation impairs short-term memory; (b) that knowledge of the relation between dimensions improves performance in the correlated condition, but does not prevent impairment under zero correlation; and (c) the performance of musically trained subjects exceeds that of controls and is unaffected by the presence of a correlated or uncorrelated dimension.     

Context in verbal short-term memory

We tested the hypothesis that stimulus-related contextual information that is incidental to task demands-an episodic code-is automatically, obligatorily encoded and stored as a part of short-term memory (STM) representations. Four experiments employed a running span task to investigate the effects of manipulating two types of contextual information: stimulus grouping and color. Three experiments established that grouping context effects are sensitive neither to volitional control nor to task difficulty and that they generalize across testing procedures (yes/no recognition and immediate serial recall). A fourth experiment demonstrated an effect of manipulating the congruity of the color of stimuli between study and test. These demonstrations of the robustness and generality of context effects in STM are consistent with the predictions of the episodic coding model of STM.     

Interference effects in short-term memory

Abstract.— Two experiments exploring the modality relation between memory task and interference task are reported. With visual and verbal tasks, variations in modality relation did not influence the total amount recalled. The usual serial position effect was observed when memory and interference task were of different modalities. The amount of recall was found to be a function of the memory strategies used by the subjects, 'active' strategies producing highest recall.     

Very short-term conceptual memory

Short-term memory for conceptual information is largely missing from current models of short-term memory. Several phenomena are discussed that give evidence for very brief conceptual representations of stimuli. Although these fleeting representations do not surface readily with many of the standard methods for studying and testing short-term memory, I argue that they are fundamental to cognitive processing and to the form that long-term memory takes.