The magic number four: Can it explain Sternberg's serial memory scan data?

2001 ◽  
Vol 24 (1) ◽  
pp. 126-127 ◽  
Author(s):  
Jerwen Jou
Keyword(s):  
Short Term Memory ◽  
Magic Number ◽  
Linear Increase ◽  
Short Term ◽  
Set Size ◽  
Serial Memory ◽  
Capacity Limit ◽  
Capacity Theory ◽  
Sternberg Paradigm ◽  
Scan Data

Cowan's concept of a pure short-term memory (STM) capacity limit is equivalent to that of memory subitizing. However, a robust phenomenon well known in the Sternberg paradigm, that is, the linear increase of RT as a function of memory set size is not consistent with this concept. Cowan's STM capacity theory will remain incomplete until it can account for this phenomenon.

scholarly journals An Investigation of the Slope Parameters of Reaction Times and P3 Latencies in the Sternberg Memory Scanning Task – A Fixed-Links Model Approach

2020 ◽  
Author(s):  
Henrike Maria Jungeblut ◽  
Dirk Hagemann ◽  
Christoph Löffler ◽  
Anna-Lena Schubert
Keyword(s):  
Cognitive Processes ◽  
Short Term Memory ◽  
Reaction Times ◽  
Linear Increase ◽  
Slope Parameter ◽  
Memory Scanning ◽  
Short Term ◽  
Term Memory ◽  
Set Size ◽  
Scanning Task

The speed of retrieving information from short-term memory is thought to be captured in the slope of the linear function of reaction times (RTs) regressed on set size in the Sternberg memory scanning task (SMST). Individual differences in the slope parameter have been hypothesized to correlate with general intelligence (g). However, this correlation can usually not be found. This present study chose a fixed-links model (FLM) approach to re-evaluate the RT slope parameter on a latent level in a sample of 98 participants aged 18 to 61 years. The same was tried for P3 latencies to investigate whether or not both parameters measure the same cognitive processes in the SMST, and to assess the usability of both slopes to predict g. For RTs, a linear increase with set size was found. The RT slope correlated with g on a manifest level already. The FLM approach could significantly increase the relationship between the slope and g. For P3 latencies, no evidence for a linear increase was found. This indicates that RTs and P3 latencies do not measure the same cognitive processes in the SMST. The FLM proved suitable to investigate the association between the speed of short-term memory scanning and intelligence.

A neurophysioiogical account of working memory limits: Between-item segregation and within-chunk integration

2001 ◽  
Vol 24 (1) ◽  
pp. 139-141 ◽  
Author(s):  
Antonino Raffone ◽  
Gezinus Wolters ◽  
Jacob M. Murre
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Short Term Memory ◽  
Memory Capacity ◽  
Short Term ◽  
Term Memory ◽  
Capacity Limit

We suggest a neurophysiological account of the short-term memory capacity limit based on a model of visual working memory (Raffone & Wolters, in press). Simulations have revealed a critical capacity limit of about four independent patterns. The model mechanisms may be applicable to working memory in general and they allow a reinterpretation of some of the issues discussed by Cowan.

Capacity limitations in short-term memory in schizophrenia: tests of competing hypotheses

1998 ◽  
Vol 28 (3) ◽  
pp. 665-673 ◽  
Author(s):  
T. E. GOLDBERG ◽  
K. J. PATTERSON ◽  
Y. TAQQU ◽  
K. WILDER
Keyword(s):  
Verbal Memory ◽  
Short Term Memory ◽  
Digit Span ◽  
Span Task ◽  
Short Term ◽  
Interference Task ◽  
Term Memory ◽  
Capacity Limitation ◽  
Set Size ◽  
Normal Controls

Background. Capacity limitation theories have proved to be surprisingly resilient in characterizing some of the cognitive deficits in schizophrenia. However, this perspective has not generally been applied to short-term verbal memory tasks. We explored this issue by first attempting to ascertain if gross misallocations of processing resources might explain impairments in short-term memory in schizophrenia on a classic digit span task and in a second study by attempting to determine what effects delay and memory set size had on a divided attention short-term verbal memory paradigm.Methods. In the first study 16 patients with schizophrenia and 21 normal controls received 40 trials of a three digit task and 20 trials of a six digit span task. As the absolute number of digits presented and duration of presentation in two conditions were identical, subjects thus had equivalent ‘opportunities’ to make errors if distraction, in the sense of misallocation of cognitive resources, were at the root of poor performance. In the second study 15 patients with schizophrenia and 15 normal controls were tested in conditions in which two, four or six words were presented and in which rehearsal was prevented by an interference task (colour naming) for delays of 5, 10 or 15 s.Results. Patients had disproportionate difficulty on the six digit rather than the three digit condition, suggesting that deficits in the verbal working memory short-term store may not be the result of attentional factors. In the second study, patients' performance was differentially worsened by the interference task, by memory set size (i.e. a capacity limitation) and by delay, a measure of decay rate.Conclusions. In concert, these studies demonstrate that schizophrenia patients have difficulties on verbal short-term memory span tasks not because of misallocation of resources, but rather because of limitations in ‘representational capacity’ and maintenance of information over delays.

scholarly journals Task conditions and short-term memory search: two-phase model of STM search

2016 ◽  
Vol 47 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Jarosław Orzechowski ◽  
Edward Nęcka ◽  
Robert Balas
Keyword(s):  
Short Term Memory ◽  
Memory Search ◽  
Task Demands ◽  
Phase Model ◽  
Search Performance ◽  
Short Term ◽  
Two Phase ◽  
Term Memory ◽  
Sternberg Paradigm ◽  
Task Conditions

Abstract Short-term memory (STM) search, as investigated within the Sternberg paradigm, is usually described as exhaustive rather than self-terminated, although the debate concerning these issues is still hot. We report three experiments employing a modified Sternberg paradigm and show that whether STM search is exhaustive or self-terminated depends on task conditions. Specifically, STM search self-terminates as soon as a positive match is found, whereas exhaustive search occurs when the STM content does not contain a searched item. Additionally, we show that task conditions influence whether familiarity- or recollection-based strategies dominate STM search performance. Namely, when speeding up the tempo of stimuli presentation increases the task demands, people use familiarity-based retrieval more often, which results in faster but less accurate recognition judgments. We conclude that STM search processes flexibly adapt to current task conditions and finally propose two-phase model of STM search.

Verbal Short-Term Memory Encoding of Learning Disabled, Deaf, and Normal Readers

1982 ◽  
Vol 5 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Lee Swanson
Keyword(s):  
Short Term Memory ◽  
Memory Task ◽  
Learning Disabled ◽  
Probe Type ◽  
Disabled Children ◽  
Short Term ◽  
Subsequent Performance ◽  
Serial Memory ◽  
Integrative Process ◽  
Disabled Readers

The present study investigated the hypothesis that nonstrategic verbal encoding abilities are deficient in learning disabled readers. Normal, deaf, and learning disabled children matched on chronological age, IQ, and sex were randomly assigned to named and unnamed stimulus pretraining conditions and compared on subsequent performance on a probe-type serial memory task. Although overt rehearsal was inhibited, strong primacy effects were found for both the named and the unnamed condition. The named condition was superior to the unnamed condition for both normal and deaf but not for learning disabled children. Results were interpreted to indicate a deficient verbal-visual integrative process in disabled children occurring prior to the application of mnemonic strategies.

scholarly journals A Candidate for the Attentional Bottleneck: Set-size Specific Modulation of the Right TPJ during Attentive Enumeration

2011 ◽  
Vol 23 (3) ◽  
pp. 728-736 ◽  
Author(s):  
Petra Vetter ◽  
Brian Butterworth ◽  
Bahador Bahrami
Keyword(s):  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Set Size ◽  
Attentional Load ◽  
Behavioral Studies ◽  
Visual Enumeration ◽  
Small Set ◽  
The Right

Several recent behavioral studies have shown that the enumeration of a small number of items (a process termed subitizing) depends on the availability of attentional resources and is not a preattentive process as previously thought. Here we studied the neural correlates of visual enumeration under different attentional loads in a dual-task paradigm using fMRI. Relatively intact subitizing under low attentional load compared to impaired subitizing under high attentional load was associated with an increase in BOLD signal in the right temporo-parietal junction (rTPJ). Crucially, attentionally modulated response in the rTPJ was specific to small set sizes (up to 3 items) and did not occur at larger set sizes (5–7 items). This result has two implications: (1) Subitizing involves part of the fronto-parietal network for stimulus-driven attention providing neural evidence against preattentive subitizing. (2) Activity in rTPJ is set-size modulated. Together with similar evidence from studies probing visual short-term memory, this result suggests that rTPJ modulation might reflect the brain's ability to attentively handle small set sizes. Thus, the rTPJ may play an important role for the emergence of a capacity limit in both enumeration and visual short-term memory.

scholarly journals The magical number 4 in short-term memory: A reconsideration of mental storage capacity

2001 ◽  
Vol 24 (1) ◽  
pp. 87-114 ◽  
Author(s):  
Nelson Cowan
Keyword(s):  
Information Overload ◽  
Short Term Memory ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Capacity Limits ◽  
Storage Mechanism ◽  
Rhetorical Device ◽  
Capacity Limit ◽  
Combine Stimulus

Miller (1956) summarized evidence that people can remember about seven chunks in short-term memory (STM) tasks. However, that number was meant more as a rough estimate and a rhetorical device than as a real capacity limit. Others have since suggested that there is a more precise capacity limit, but that it is only three to five chunks. The present target article brings together a wide variety of data on capacity limits suggesting that the smaller capacity limit is real. Capacity limits will be useful in analyses of information processing only if the boundary conditions for observing them can be carefully described. Four basic conditions in which chunks can be identified and capacity limits can accordingly be observed are: (1) when information overload limits chunks to individual stimulus items, (2) when other steps are taken specifically to block the recoding of stimulus items into larger chunks, (3) in performance discontinuities caused by the capacity limit, and (4) in various indirect effects of the capacity limit. Under these conditions, rehearsal and long-term memory cannot be used to combine stimulus items into chunks of an unknown size; nor can storage mechanisms that are not capacity-limited, such as sensory memory, allow the capacity-limited storage mechanism to be refilled during recall. A single, central capacity limit averaging about four chunks is implicated along with other, noncapacity-limited sources. The pure STM capacity limit expressed in chunks is distinguished from compound STM limits obtained when the number of separately held chunks is unclear. Reasons why pure capacity estimates fall within a narrow range are discussed and a capacity limit for the focus of attention is proposed.

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