Neuronal Activity Throughout the Primate Mediodorsal Nucleus of the Thalamus During Oculomotor Delayed-Responses. II. Activity Encoding Visual Versus Motor Signal

2004 ◽  
Vol 92 (3) ◽  
pp. 1756-1769 ◽  
Author(s):  
Yumiko Watanabe ◽  
Shintaro Funahashi
Keyword(s):  
Working Memory ◽  
Information Processing ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Neuron Activity ◽  
Delayed Response ◽  
Related Activity ◽  
Response Period ◽  
Motor Information ◽  
Saccade Direction

We collected single-neuron activity from the mediodorsal (MD) nucleus of the thalamus, examined the information that was represented by task-related activity during performance of a spatial working memory task, and compared the present results with those obtained in the dorsolateral prefrontal cortex (DLPFC). We used two oculomotor delayed-response (ODR) tasks. In the ordinary ODR task, monkeys were required to make a memory-guided saccade to the location where a visual cue had been presented 3 s previously, whereas in the rotatory ODR task, they were required to make a memory-guided saccade 90° clockwise from the cue direction. By comparing the best directions of the same task-related activity between the two tasks, we could determine whether this activity represented the cue location or the saccade direction. All cue-period activity represented the cue location. In contrast, 56% of delay-period activity represented the cue location and 41% represented the saccade direction. Almost all response-period activity represented the saccade direction. These results indicate that task-related MD activity represents either visual or motor information, suggesting that the MD participates in sensory-to-motor information processing. However, a greater proportion of delay- and response-period activities represented the saccade direction in the MD than in the DLPFC, indicating that more MD neurons participate in prospective information processing than DLPFC neurons. These results suggest that although functional interactions between the MD and DLPFC are crucial to cognitive functions such as working memory, there is a difference in how the MD and DLPFC participate in these functions.

Prefrontal Task-Related Activity Representing Visual Cue Location or Saccade Direction in Spatial Working Memory Tasks

2002 ◽  
Vol 87 (1) ◽  
pp. 567-588 ◽  
Author(s):  
Kazuyoshi Takeda ◽  
Shintaro Funahashi
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Spatial Working Memory ◽  
Delay Period ◽  
Neuron Activity ◽  
Delayed Response ◽  
Related Activity ◽  
Visual Cue ◽  
Response Period ◽  
Dorsolateral Prefrontal

To examine what kind of information task-related activity encodes during spatial working memory processes, we analyzed single-neuron activity in the prefrontal cortex while two monkeys performed two different oculomotor delayed-response (ODR) tasks. In the standard ODR task, monkeys were required to make a saccade to the cue location after a 3-s delay, whereas in the rotatory ODR (R-ODR) task, they were required to make a saccade 90° clockwise from the cue location after the 3-s delay. By comparing the same task-related activities in these two tasks, we could determine whether such activities encoded the location of the visual cue or the direction of the saccade. One hundred twenty one neurons exhibited task-related activity in relation to at least one task event in both tasks. Among them, 41 neurons exhibited directional cue-period activity, most of which encoded the location of the visual cue. Among 56 neurons with directional delay-period activity, 86% encoded the location of the visual cue, whereas 13% encoded the direction of the saccade. Among 57 neurons with directional response-period activity, 58% encoded the direction of the saccade, whereas 35% encoded the location of the visual cue. Most neurons whose response-period activity encoded the location of the visual cue also exhibited directional delay-period activity that encoded the location of the visual cue as well. The best directions of these two activities were identical, and most of these response-period activities were postsaccadic. Therefore this postsaccadic activity can be considered a signal to terminate unnecessary delay-period activity. Population histograms encoding the location of the visual cue showed tonic sustained activation during the delay period. However, population histograms encoding the direction of the saccade showed a gradual increase in activation during the delay period. These results indicate that the transformation from visual input to motor output occurs in the dorsolateral prefrontal cortex. The analysis using population histograms suggests that this transformation occurs gradually during the delay period.

Neuronal Activity Throughout the Primate Mediodorsal Nucleus of the Thalamus During Oculomotor Delayed-Responses. I. Cue-, Delay-, and Response-Period Activity

2004 ◽  
Vol 92 (3) ◽  
pp. 1738-1755 ◽  
Author(s):  
Yumiko Watanabe ◽  
Shintaro Funahashi
Keyword(s):  
Working Memory ◽  
Cognitive Functions ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Delay Period ◽  
Mediodorsal Nucleus ◽  
Response Period ◽  
Dorsolateral Prefrontal ◽  
Oculomotor Responses ◽  
Higher Cognitive Functions

The thalamic mediodorsal nucleus (MD) has strong reciprocal connections with the dorsolateral prefrontal cortex (DLPFC), suggesting that the MD, like the DLPFC, participates in higher cognitive functions. To examine MD's participation in cognitive functions, we analyzed the characteristics of task-related activities sampled homogeneously from the MD while two monkeys performed a spatial working memory task using oculomotor responses. Of 141 task-related MD neurons, 26, 53, and 84% exhibited cue-, delay-, and response-period activity, respectively. Most of cue- and response-period activities showed phasic excitation, and most of delay-period activity showed tonic sustained activation. Among neurons with response-period activity, 74% exhibited presaccadic activity. Most cue-period, delay-period, and presaccadic activities were directional, whereas most postsaccadic activity was omni-directional. A significant contralateral bias in the best directions was present in cue-period and presaccadic activity. However, such bias was not present in delay-period activity, although most neurons had a best direction toward the contralateral visual field. We compared these characteristics with those observed in DLPFC neurons. Response-period activity was more frequently observed in the MD (84%) than in the DLPFC (56%). The directional selectivity and bias of task-related activities and the ratios of pre- and postsaccadic activities were different between MD and DLPFC. These results indicate that the MD participates in higher cognitive functions such as spatial working memory. However, the manner in which these two structures participate in these processes differs, in that the MD participates more in motor control aspects compared with the DLPFC.

Activity in Human Frontal Cortex Associated with Spatial Working Memory and Saccadic Behavior

2000 ◽  
Vol 12 (supplement 2) ◽  
pp. 2-14 ◽  
Author(s):  
Bradley R. Postle ◽  
Jeffrey S. Berger ◽  
Alexander M. Taich ◽  
Mark D'Esposito
Keyword(s):  
Working Memory ◽  
Frontal Cortex ◽  
Signal Intensity ◽  
Spatial Working Memory ◽  
Delay Period ◽  
Delayed Response ◽  
Related Activity ◽  
Memory Condition ◽  
Fmri Signal ◽  
Spatio Temporal

We examined, with event-related fMRI, two hypotheses about the organization of human working memory function in frontal cortex: (1) that a region immediately anterior to the frontal eye fields (FEF) (superior frontal cortex, SFC) is specialized for spatial working memory (Courtney, et al., 1998); and (2) that dorsolateral prefrontal cortex (PFC) plays a privileged role in the manipulation of spatial stimuli held in working memory (Owen, et al., 1996; Petrides 1994). Our delayed-response task featured 2-D arrays of irregularly arranged squares that were highlighted serially in a random sequence. The Forward Memory condition required maintenance of the spatio-temporal sequence, the Manipulate Memory condition required reordering this sequence into a new spatially defined order, the Guided Saccade condition required saccades to highlighted squares in the array, but no memory, and the Free Saccade condition required self-paced, horizontal saccades. The comparison of fMRI signal intensity associated with 2-D saccade generation (Guided Saccades) versus fMRI signal intensity associated with the delay period of the working memorials condition revealed no evidence for greater working memory-related activity than saccade-related activity in SFC in any individual subject, nor at the level of the group, and greater 2-D saccade than delay-period activity in three of five subjects. These results fail to support the hypothesis that spatial working memory-related activity is represented preferentially in a region of SFC anterior to the FEF (Courtney, et al., 1998). The comparison of maintenance versus manipulation of spatio-temporal information in working memory revealed significantly greater activity associated with the latter in dorsolateral PFC, but not in ventrolateral PFC or in SFC. These results suggest that the delay-related function of SFC is limited to the maintenance of spatial information, and that this region does not support the nonmnemonic executive control functions supported by dorsolateral PFC. These results also indicate that the preferential recruitment of dorsolateral PFC for the manipulation of information held in working memory applies to tasks employing spatial stimuli, as well as to tasks employing verbal stimuli (D'Esposito, et al., 1999); Petrides et al., 1993; Postle et al., 1999).

scholarly journals Microsaccades and Visual-Spatial Working Memory

2012 ◽  
Vol 5 (5) ◽  
Author(s):  
Joshua T. Gaunt ◽  
Bruce Bridgeman
Keyword(s):  
Working Memory ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Retinal Eccentricity ◽  
Short Term ◽  
Visual Spatial ◽  
Saccade Direction ◽  
Visual Spatial Working Memory ◽  
Choice Tasks ◽  
Oculomotor Activity

Observers performed working memory tasks at varying retinal eccentricities, fixating centrally while microsaccade rates and directions were monitored. We show that microsaccades generate no interference in a working memory task, indicating that spatial working memory is at least partially insulated from oculomotor activity. Intervening tasks during the memory interval affected memory as well as microsaccade patterns. Average microsaccade rate peaks after appearance of a fixation cross at the start of a trial, and dips at cue onset and offset. Direction of stimuli in choice tasks did not influence micro-saccade direction, however. Poorer memory accuracy for locations at greater retinal eccentricity calls for revising ideas of short-term spatial representations to include retinotopic or allocentric codes

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.

Neuropsychological impairment in patients with major depressive disorder: the effects of feedback on task performance

2003 ◽  
Vol 33 (3) ◽  
pp. 455-467 ◽  
Author(s):  
F. C. MURPHY ◽  
A. MICHAEL ◽  
T. W. ROBBINS ◽  
B. J. SAHAKIAN
Keyword(s):  
Working Memory ◽  
Negative Feedback ◽  
Performance Feedback ◽  
Visual Discrimination ◽  
Negative Reinforcement ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Depressive Illness ◽  
Reversal Task ◽  
Depressed Patients

Background. Recent evidence suggests that an abnormal response to performance feedback may contribute to the wide-ranging neuropsychological deficits typically associated with depressive illness. The present research sought to determine whether the inability of depressed patients to utilize performance feedback advantageously is equally true for accurate and misleading feedback.Method. Patients with major depression and matched controls completed: (1) a visual discrimination and reversal task that featured intermittent and misleading negative feedback; and (2) feedback and no-feedback versions of a computerised test of spatial working memory. In the feedback version, negative feedback was accurate, highly informative, and could be used as a mnemonic aid.Results. On the Probability Reversal task, depressed patients were impaired in their ability to maintain response set in the face of misleading negative feedback as shown by their increased tendency to switch responding to the ‘incorrect’ stimulus following negative reinforcement, relative to that of controls. Patients' ability to acquire and reverse the necessary visual discrimination was unimpaired. On the Spatial Working Memory task, depressed patients made significantly more between-search errors than controls on the most difficult trials, but their ability to use negative feedback to facilitate performance remained intact.Conclusions. The present results suggest that feedback can have different effects in different contexts. Misleading, negative feedback appears to disrupt the performance of depressed patients, whereas negative but accurate feedback does not. These findings are considered in the context of recent studies on reinforcement systems and their associated neurobiological substrates.

Reproducibility of fMRI Results across Four Institutions Using a Spatial Working Memory Task

NeuroImage ◽  
1998 ◽  
Vol 8 (3) ◽  
pp. 249-261 ◽  
Author(s):  
B.J. Casey ◽  
Jonathan D. Cohen ◽  
Kathy O'Craven ◽  
Richard J. Davidson ◽  
William Irwin ◽  
...  
Keyword(s):  
Working Memory ◽  
Spatial Working Memory ◽  
Memory Task

Different trait markers for schizophrenia and bipolar disorder: a neurocognitive approach

2001 ◽  
Vol 31 (5) ◽  
pp. 915-922 ◽  
Author(s):  
S. KÉRI ◽  
O. KELEMEN ◽  
G. BENEDEK ◽  
Z. JANKA
Keyword(s):  
Bipolar Disorder ◽  
Working Memory ◽  
Information Processing ◽  
Cognitive Functions ◽  
Visual Information ◽  
Spatial Information ◽  
Target Location ◽  
Memory Task ◽  
Visual Information Processing ◽  
Verbal Recall

Background. The aim of this study was to assess visual information processing and cognitive functions in unaffected siblings of patients with schizophrenia, bipolar disorder and control subjects with a negative family history.Methods. The siblings of patients with schizophrenia (N = 25), bipolar disorder (N = 20) and the controls subjects (N = 20) were matched for age, education, IQ, and psychosocial functioning, as indexed by the Global Assessment of Functioning scale. Visual information processing was measured using two visual backward masking (VBM) tests (target location and target identification). The evaluation of higher cognitive functions included spatial and verbal working memory, Wisconsin Card Sorting Test, letter fluency, short/long delay verbal recall and recognition.Results. The relatives of schizophrenia patients were impaired in the VBM procedure, more pronouncedly at short interstimulus intervals (14, 28, 42 ms) and in the target location task. Marked dysfunctions were also found in the spatial working memory task and in the long delay verbal recall test. In contrast, the siblings of patients with bipolar disorder exhibited spared performances with the exception of a deficit in the long delay recall task.Conclusions. Dysfunctions of sensory-perceptual analysis (VBM) and working memory for spatial information distinguished the siblings of schizophrenia patients from the siblings of individuals with bipolar disorder. Verbal recall deficit was present in both groups, suggesting a common impairment of the fronto-hippocampal system.

scholarly journals Phenomenology of Visuo-spatial Working Memory Task Performance

2021 ◽  
Author(s):  
Aleš Oblak ◽  
Anka Slana Ozimič ◽  
Grega Repovš ◽  
Urban Kordeš
Keyword(s):  
Working Memory ◽  
Cognitive Psychology ◽  
Task Performance ◽  
Present Article ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Bodily Feelings ◽  
Psychological Tasks

In experimental cognitive psychology, objects of inquiry have typically been operationalized with psychological tasks. If we are interested in measuring the target phenomena, we must inquire into the validity of the task; that is, to what extent does the task elicit the phenomenon in question. If we subscribe to the second view, evaluating the validity and the interpretation of the gathered data can be supplemented by understanding the experience of solving psychological tasks. The aim of the present article is to investigate how individuals experience performing a psychological task, specifically, a visuo-spatial working memory task. We present ethnographic descriptions of different ways individuals can experience the same task. We focus on aspects of experience that comprise the overall sense of experience (e.g., bodily feelings, emotional atmosphere, mood). We discuss the methodological implications of our findings and the possibility of conducting a neurophenomenology of visuo-spatial working memory.

scholarly journals Declined functional connectivity of white matter during rest and working memory tasks associates with cognitive impairments in schizophrenia

2020 ◽  
Author(s):  
Yurui Gao ◽  
Muwei Li ◽  
Anna S Huang ◽  
Adam W Anderson ◽  
Zhaohua Ding ◽  
...  
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Functional Connectivity ◽  
Resting State ◽  
Spatial Working Memory ◽  
Cognitive Impairments ◽  
Memory Task ◽  
Brain Network ◽  
Blood Oxygenation ◽  
Cerebral Peduncle

BACKGROUND: Schizophrenia, characterized by cognitive impairments, arises from a disturbance of brain network. Pathological changes in white matter (WM) have been indicated as playing a role in disturbing neural connectivity in schizophrenia. However, deficits of functional connectivity (FC) in individual WM bundles in schizophrenia have never been explored; neither have cognitive correlates with those deficits. METHODS: Resting-state and spatial working memory task fMRI images were acquired on 67 healthy subjects and 84 patients with schizophrenia. The correlations in blood-oxygenation-level-dependent (BOLD) signals between 46 WM and 82 gray matter regions were quantified, analyzed and compared between groups under three scenarios (i.e., resting state, retention period and entire time of a spatial working memory task). Associations of FC in WM with cognitive assessment scores were evaluated for three scenarios. RESULTS: FC deficits were significant (p<.05) in external capsule, cingulum, uncinate fasciculus, genu and body of corpus callosum under all three scenarios. Deficits were also present in the anterior limb of the internal capsule and cerebral peduncle in task scenario. Decreased FCs in specific WM bundles associated significantly (p<.05) with cognitive impairments in working memory, processing speed and/or cognitive control. CONCLUSIONS: Decreases in FC are evident in several WM bundles in patients with schizophrenia and are significantly associated with cognitive impairments during both rest and working memory tasks. Furthermore, working memory tasks expose FC deficits in more WM bundles and more cognitive associates in schizophrenia than resting state does.

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