Dissecting the “working” and the “memory” in a PET study of working memory using graded tasks and isomorphic stimuli

Berman, Karen F.; Austin-Lane, J.L.; Esposito, Giuseppe; Horn, John D. Van; Weinberger, Daniel R.

doi:10.1016/s1053-8119(96)80531-3

Cited by 4 publications

(3 citation statements)

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“…Another recent PET study (Klingberg et al, 1997) that compared a simple delayed matching to sample task to a more complex ''alternating'' delayed matching to sample task (that imposed more contingen-cies and featured more complex instructions) found that only the latter task activated the right dorsolateral PFC but that both tasks activated ventrolateral PFC. In a preliminary PET study (Berman et al, 1996) that varied the amount of material remembered versus the number of manipulations performed on the material, only the latter condition correlated with increased blood flow in dorsolateral PFC. Taken together, these studies provide strong support for the processing model of a distinction between working memory function of dorsolateral and ventrolateral PFC in humans.…”

Section: Discussionmentioning

confidence: 92%

Maintenance versus Manipulation of Information Held in Working Memory: An Event-Related fMRI Study

D’Esposito

Postle

Ballard

et al. 1999

Brain and Cognition

689

441

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Section: Discussionmentioning

confidence: 92%

Maintenance versus Manipulation of Information Held in Working Memory: An Event-Related fMRI Study

D’Esposito

Postle

Ballard

et al. 1999

Brain and Cognition

689

441

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“…This task used stimuli and procedures similar to those described for the maintenance task, except that the participants were asked to perform manipulations on the stimuli in the memory set. Effects on manipulation processes were tested by parametrically varying the number of separate sequencing steps performed (0, 1, 2; see Berman, Austin-Lane, Esposito, Van Horn, & Weinberger, 1996). In the 0-manipulation condition, the participants were asked to make a decision about the ordinal position of the probed letter in the memory set, as described for the maintenance task.…”

Section: Working Memory Tasks: Maintenance and Manipulationmentioning

confidence: 99%

Differential effects of scopolamine and lorazepam on working memory maintenance versus manipulation processes

Mintzer

Griffiths

2007

Cognitive, Affective, & Behavioral Neuroscience

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argued that, like neuropsychological studies of brain-damaged patients, which have played a critical role in advancing the understanding of normal and abnormal memory mechanisms, investigation of drug-induced amnesia can also be a powerful tool for elucidating memory mechanisms. In fact, investigation of drug-induced amnesia has several distinct advantages over traditional studies of amnesic patients. Most importantly, unlike the memory deficits found in amnesic patients, effects of drugs on memory processes are reversible and can be empirically manipulated in controlled laboratory experiments with large numbers of healthy volunteers. Furthermore, the quantitative dosing properties of drugs can be exploited to produce a graded amnesic effect in a dose-effect design. Findings of selective effects of drugs on particular aspects of memory performance but not others, or of dissociations between drugs, can provide converging evidence with data from nonpharmacological studies for the dissociability of specific processes or subcomponents (see Hirshman, Fisher, Henthorn, Arndt, & Passannante, 2002;Hirshman et al., 2001;Mintzer, 2003;Mintzer & Griffiths, 2001b). In addition, comparison of memory-impairing drugs with distinct neurochemical or pharmacological mechanisms of action can elucidate the brain mechanisms underlying specific cognitive processes.The present experiment was designed to compare the acute effects of the benzodiazepine lorazepam and the anticholinergic scopolamine on working memory processes. Benzodiazepines facilitate the action of gammaaminobutyric acid (GABA) by acting as agonists at specific sites on the GABA A receptor complex (Mohler & Okada, 1977;Squires & Braestrup, 1977), whereas scopolamine inhibits the action of acetylcholine by acting as an antagonist at muscarinic cholinergic receptors (Ketchum, Sidell, Crowell, Aghajanian, & Haines, 1973). Working memory refers to the temporary maintenance and online manipulation of a limited amount of information in the service of current behavioral goals (Baddeley, 1986(Baddeley, , 1992; for recent reviews, see D'Esposito, 2001; Smith & Jonides, 1998). The concept of working memory was originally introduced by Baddeley (1986) and replaced earlier conceptualizations of a unitary, passive, short-term storage system (Atkinson & Shiffrin, 1968). In Baddeley's model, working memory is a multicomponent system consisting of a number of limited-capacity (Miller, 1956), material-specific "slave systems" (e.g., the phonological loop for verbal material and the visuospatial sketchpad for visual material) involved in temporarily maintaining Differential effects of scopolamine and lorazepam on working memory maintenance versus manipulation processes MIRIAM Z. MINTZER AND ROLAND R. GRIFFITHS Johns Hopkins University, Baltimore, MarylandBetween-study comparisons of benzodiazepine and anticholinergic drugs on working memory suggest that anticholinergics may produce greater impairment in maintenance processes, whereas benzodiazepines may produce greater impairment in man...

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“…This model is broadly supported by reviews of human imaging studies of working memory (D'Esposito et al, 1998; Owen, 1997). These studies contrast specific functions (e.g., maintenance vs. maintenance plus monitoring and manipulation) and generally find that ventrolateral PFC mediates maintenance of verbal and nonverbal information and that dorsolateral PFC is involved in executive components of monitoring and manipulation (Berman, Austin-Lane, Esposito, Van Horn, & Weinberger, 1996; Klingberg, O'Sullivan, & Roland, 1997; Manoach et al, 1997; Salmon et al, 1996; Stern et al, 2000; Tsukiura et al, 2001). However, this functional dissociation appears to be relative rather than absolute.…”

mentioning

confidence: 99%

Working memory for complex figures: An fMRI comparison of letter and fractal n-back tasks.

Ragland¹,

Turetsky²,

Gur³

et al. 2002

Neuropsychology

279

186

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Abstractn -back letter and fractal tasks were administered to 11 participants during functional magnetic resonance imaging to test process specificity theories of prefrontal cortex (PFC) function and assess task validity. Tasks were matched on accuracy, but fractal n-back responses were slower and more conservative. Maintenance (1-back minus 0-back) activated inferior parietal and dorsolateral PFC, with additional activation in right ventrolateral PFC during letter n-back and left lingual gyrus during fractal n-back. Maintenance plus manipulation (2-back minus 0-back) activated inferior parietal, Broca's area, insula, and dorsolateral and ventral PFC, with greater right dorsolateral PFC activation for letter n-back. Manipulation only (2-back minus 1-back) produced additional and equivalent dorsolateral PFC and anterior cingulate activation in both tasks. Results support fractal n-back validity and indicate substantial overlap in working memory functions of dorsal and ventral PFC.Working memory refers to a limited capacity system responsible for temporary maintenance and online manipulation of information required for guidance of subsequent behavior. Working memory is conceptualized as having several components including a central executive system (CES) and two modality-specific slave systems: the visuospatial sketch pad and the phonological loop (Baddeley, 1986(Baddeley, , 1992Baddeley & Hitch, 1974). The CES allocates attentional resources and is responsible for coordination of top-down processes permitting monitoring and manipulation of information within the short-term store (e.g., temporal sequencing). The visuospatial sketch pad maintains visuospatial information in a temporary visuospatial store, and the phonological loop maintains verbal material in a phonological store through an articulatory rehearsal process. Much of the research on working memory has focused on anatomically dissociating these multiple processes. The goal of the current functional magnetic resonance imaging (fMRI) study is to use a parametric n-back paradigm (Awh et al., 1996;Braver et al., 1997;Cohen et al., 1994Cohen et al., , 1997Gervins & Cutillo, 1993; to contrast the effect of working memory load on regional brain function during a standard letter n-back task versus an nback task using complex geometric objects that have not been previously studied. NIH Public Access Author ManuscriptNeuropsychology. Author manuscript; available in PMC 2015 February 18. Published in final edited form as:Neuropsychology. 2002 July ; 16(3): 370-379. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptDemonstrating similar effects of working memory load on the two tasks provides initial evidence for the construct validity of the new task.The process specificity model attempts to parse prefrontal regions mediating different components of working memory. According to the model, ventrolateral prefrontal cortex (PFC; Brodmann's area [BA] 44, 45, and 47) is responsible for maintenance of information in the visuospatial and phonolog...

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Dissecting the “working” and the “memory” in a PET study of working memory using graded tasks and isomorphic stimuli

Cited by 4 publications

References 0 publications

Maintenance versus Manipulation of Information Held in Working Memory: An Event-Related fMRI Study

Maintenance versus Manipulation of Information Held in Working Memory: An Event-Related fMRI Study

Differential effects of scopolamine and lorazepam on working memory maintenance versus manipulation processes

Working memory for complex figures: An fMRI comparison of letter and fractal n-back tasks.

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