Binary Mapping of Cortical Spike Trains in Short-Term Memory

1997 ◽  
Vol 77 (4) ◽  
pp. 2219-2222 ◽  
Author(s):  
Mark Bodner ◽  
Yong-Di Zhou ◽  
Joaquín M. Fuster
Keyword(s):  
Cortical Neurons ◽  
Short Term Memory ◽  
Memory Task ◽  
Sensory Information ◽  
Spatial Summation ◽  
Spike Trains ◽  
Short Term ◽  
Cortical Cells ◽  
Term Memory ◽  
Wide Range

Bodner, Mark, Yong-Di Zhou, and Joaquı́n M. Fuster. Binary mapping of cortical spike trains in short-term memory. J. Neurophysiol. 77: 2219–2222, 1997. Microelectrode studies in monkeys performing short-term memory tasks show the sustained elevated discharge of cortical neurons during the retention of recalled sensory information. Cortical cells that are part of memory networks are assumed to receive numerous inputs of excitatory as well as inhibitory nature and local as well as remote. Thus it is reasonable to postulate that the temporal and spatial summation of diverse inputs on any cell in an activated network will result in temporally discrete groups of spikes in its firing. The activation of a network in active memory supposedly increases the magnitude and diversity of those inputs and thus increases the discontinuities and frequency fluctuations in the firing of cells in the network. In this study we use a new method of analysis that allows the quantification of firing discontinuities in a spike train. We apply it to parietal cells recorded from monkeys during the performance of a tactile short-term memory task. In our method, time is divided into bins of equal duration and the measure of discontinuities is the total count of the number of transitions between consecutive time bins with and without spikes. The results of the analysis show that in many of the cells studied, discontinuities (transitions between spiking and nonspiking) reflect memory-related activity obscured in the measures of raw spike frequency over a wide range of frequencies. These cells show more firing transitions in active short-term memory than in baseline (intertrial) conditions.

Symmetric temporal patterns in cortical spike trains during performance of a short-term memory task

1997 ◽  
Vol 19 (5) ◽  
pp. 509-514 ◽  
Author(s):  
Mark Bodner ◽  
Yong-Di Zhou ◽  
Gordon Shaw ◽  
Joaquín Fuster
Keyword(s):  
Short Term Memory ◽  
Memory Task ◽  
Temporal Patterns ◽  
Spike Trains ◽  
Short Term ◽  
Term Memory

scholarly journals Offloading items from memory: individual differences in cognitive offloading in a short-term memory task

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Alexandra B. Morrison ◽  
Lauren L. Richmond
Keyword(s):  
Short Term Memory ◽  
Working Memory Capacity ◽  
Memory Task ◽  
Short Term ◽  
Term Memory ◽  
Wide Range ◽  
A Cell ◽  
Cognitive Offloading ◽  
Improved Performance ◽  
High Cognitive Demand

AbstractCognitive offloading refers to the act of reducing the mental processing requirements of a task through physical actions like writing down information or storing information on a cell phone or computer. Offloading can lead to improved performance on ongoing tasks with high cognitive demand, such as tasks where multiple pieces of information must be simultaneously maintained. However, less is known about why some individuals choose to engage in offloading and under what conditions they might choose to do so. In the present study, offloading behavior is investigated in a short-term memory task requiring memory for letters. The present study is a replication and extension of a previous study conducted by Risko and Dunn, and tests the new prediction that individuals with lower working memory capacity will be more likely to offload. Here, we find that offloading information confers a performance advantage over relying on internal memory stores, particularly at higher memory loads. However, we fail to observe that those with poorer memory abilities have a greater propensity for offloading or benefit more from it. Instead, our findings suggest that cognitive offloading may be a valid compensatory strategy to improve performance of memory-based tasks for individuals with a wide range of memory ability.

scholarly journals Brain hemodynamic response in Examiner–Examinee dyads during spatial short-term memory task: an fNIRS study

2021 ◽  
Author(s):  
Francesco Panico ◽  
Stefania De Marco ◽  
Laura Sagliano ◽  
Francesca D’Olimpio ◽  
Dario Grossi ◽  
...  
Keyword(s):  
Working Memory ◽  
Cognitive Processes ◽  
Short Term Memory ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Memory Task ◽  
Neural Correlates ◽  
Short Term ◽  
Term Memory ◽  
The Real

AbstractThe Corsi Block-Tapping test (CBT) is a measure of spatial working memory (WM) in clinical practice, requiring an examinee to reproduce sequences of cubes tapped by an examiner. CBT implies complementary behaviors in the examiners and the examinees, as they have to attend a precise turn taking. Previous studies demonstrated that the Prefrontal Cortex (PFC) is activated during CBT, but scarce evidence is available on the neural correlates of CBT in the real setting. We assessed PFC activity in dyads of examiner–examinee participants while completing the real version of CBT, during conditions of increasing and exceeding workload. This procedure allowed to investigate whether brain activity in the dyads is coordinated. Results in the examinees showed that PFC activity was higher when the workload approached or reached participants’ spatial WM span, and lower during workload conditions that were largely below or above their span. Interestingly, findings in the examiners paralleled the ones in the examinees, as examiners’ brain activity increased and decreased in a similar way as the examinees’ one. In the examiners, higher left-hemisphere activity was observed suggesting the likely activation of non-spatial WM processes. Data support a bell-shaped relationship between cognitive load and brain activity, and provide original insights on the cognitive processes activated in the examiner during CBT.

scholarly journals A-65 Verbal Abilities May Influence Performance in Assessment of Verbal Short-Term Memory Tasks

2019 ◽  
Vol 34 (6) ◽  
pp. 925-925
Author(s):  
A Guerra ◽  
J Moses ◽  
J Rivera ◽  
M Davis ◽  
K Hakinson
Keyword(s):  
Verbal Memory ◽  
Verbal Fluency ◽  
Short Term Memory ◽  
Word Association ◽  
Memory Task ◽  
Short Term ◽  
Factor Solution ◽  
Term Memory ◽  
Verbal Abilities ◽  
Three Factor

Abstract Objective Examine whether verbal abilities may help explain the learning strategies people employ when completing a short-term verbal memory task. Methods The assessment records of 296 American Veterans with diverse neuropsychiatric conditions were analyzed using Exploratory Factor Analyses. There were no exclusion criteria. All participants completed the Benton Serial Digit Learning Test – 9 Digits (SDL-9) and Visual Naming (VisNam), Sentence Repetition (SenRep), Controlled Word Association (COWA), and Token Tests of the Multilingual Aphasia Examination (MAE). Individual assessment instruments were factored using Principal Component Analyses (PCA). A three-factor solution of the SDL-9 was co-factored with the verbal components of the MAE to identify common sources of variance. Results A three-factor solution of the SDL-9 separated trials into three overlapping factors consisting of early (SDL-9_Early), middle (SDL-9_Middle), and late (SDL-9_Late) trials. Co-factoring the three new scales with the verbal components of the MAE produced a four-factor model explaining 67.85% of the shared variance: 1) SenRep loaded with SDL-9_Early, 2) COWAT loaded with SDL-9_Middle and SDL-9_Late, 3) Token loaded with SDL-9_Late, and 4) Vis Nam loaded with SDL-9_Late. Conclusions The results suggest that individuals may engage verbal abilities differently as they progress from simpler to more difficult verbal short-term memory tasks. It appears performance in early trials is mostly associated with rote repetition and performance on middle trials is mostly associated with verbal fluency, while performance on the late trials is associated with a combination of verbal fluency, auditory comprehension, and conceptual organization/naming. This may therefore indicate a shift in learning strategy to meet increased cognitive demands.

Object and Place Memory in the Macaque Entorhinal Cortex

1997 ◽  
Vol 78 (2) ◽  
pp. 1062-1081 ◽  
Author(s):  
Wendy A. Suzuki ◽  
Earl K. Miller ◽  
Robert Desimone
Keyword(s):  
Entorhinal Cortex ◽  
Short Term Memory ◽  
Memory Task ◽  
Sensory Information ◽  
Short Term ◽  
Delayed Matching ◽  
Variable Sequence ◽  
Place Memory ◽  
Place Task ◽  
Spatial Locations

Suzuki, Wendy A., Earl K. Miller, and Robert Desimone. Object and place memory in the macaque entorhinal cortex. J. Neurophysiol. 78: 1062–1081, 1997. Lesions of the entorhinal cortex in humans, monkeys, and rats impair memory for a variety of kinds of information, including memory for objects and places. To begin to understand the contribution of entorhinal cells to different forms of memory, responses of entorhinal cells were recorded as monkeys performed either an object or place memory task. The object memory task was a variation of delayed matching to sample. A sample picture was presented at the start of the trial, followed by a variable sequence of zero to four test pictures, ending with a repetition of the sample (i.e., a match). The place memory task was a variation of delayed matching to place. In this task, a cue stimulus was presented at a variable sequence of one to four “places” on a computer screen, ending with a repetition of one of the previously shown places (i.e., a match). For both tasks, the animals were rewarded for releasing a bar to the match. To solve these tasks, the monkey must 1) discriminate the stimuli, 2) maintain a memory of the appropriate stimuli during the course of the trial, and 3) evaluate whether a test stimulus matches previously presented stimuli. The responses of entorhinal cortex neurons were consistent with a role in all three of these processes in both tasks. We found that 47% and 55% of the visually responsive entorhinal cells responded selectively to the different objects or places presented during the object or place task, respectively. Similar to previous findings in prefrontal but not perirhinal cortex on the object task, some entorhinal cells had sample-specific delay activity that was maintained throughout all of the delay intervals in the sequence. For the place task, some cells had location-specific maintained activity in the delay immediately following a specific cue location. In addition, 59% and 22% of the visually responsive cells recorded during the object and place task, respectively, responded differently to the test stimuli according to whether they were matching or nonmatching to the stimuli held in memory. Responses of some cells were enhanced to matching stimuli, whereas others were suppressed. This suppression or enhancement typically occurred well before the animals' behavioral response, suggesting that this information could be used to perform the task. These results indicate that entorhinal cells receive sensory information about both objects and spatial locations and that their activity carries information about objects and locations held in short-term memory.

The Processing of Synthetic Speech by Older and Younger Adults

1992 ◽  
Vol 36 (2) ◽  
pp. 190-192 ◽  
Author(s):  
Janan Al-Awar Smither
Keyword(s):  
Short Term Memory ◽  
Memory Task ◽  
The Elderly ◽  
Synthetic Speech ◽  
Text To Speech ◽  
Short Term ◽  
Younger Adults ◽  
Term Memory ◽  
Response Systems ◽  
Older Subjects

This experiment investigated the demands synthetic speech places on short term memory by comparing performance of old and young adults on an ordinary short term memory task. Items presented were generated by a human speaker or by a text-to-speech computer synthesizer. Results were consistent with the idea that the comprehension of synthetic speech imposes increased resource demands on the short term memory system. Older subjects performed significantly more poorly than younger subjects, and both groups performed more poorly with synthetic than with human speech. Findings suggest that short term memory demands imposed by the processing of synthetic speech should be investigated further, particularly regarding the implementation of voice response systems in devices for the elderly.

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