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D L Schacter

Publications and source records attributed to D L Schacter.

120 records · Page 7Linked to original sources
PubMed1985

Remediation of memory disorders: experimental evaluation of the spaced-retrieval technique.

Research concerning remediation of memory disorders has frequently been concerned with mnemonic techniques that demand a great deal of elaborative and effortful processing. The present study examines a relatively simple technique, known as spaced retrieval, in which patients are taught to retrieve information at increasingly long temporal intervals after initial presentation. Results indicated that the spaced-retrieval technique aided patients' learning of new information. There was also evidence of learning to learn: Two of the four patients who were studied learned to use the technique in the absence of explicit cues from the experimenter. Issues pertaining to the possible usefulness of spaced retrieval in everyday life are discussed.

Adult↗
PubMed1982

Functional retrograde amnesia: a quantitative case study.

The memory impairment of a patient suffering from functional retrograde amnesia was assessed both during the amnesic episode and after its termination. The patient's performance on a task tapping semantic memory was nearly identical on the two test occasions, but his performance on a task tapping episodic memory substantially changed across test sessions. Cueing procedures revealed that in spite of the patient's restricted access to episodic memory during the amnesic period, a relatively intact "island" of episodic memories could be uncovered. The distinction between episodic and semantic memory, as well as the relation between organic and functional retrograde amnesia, are discussed in light of the case study.

Adult↗
PubMed1977

EEG theta waves and psychological phenomena: a review and analysis.

In this paper, studies which have explored the relation between EEG theta waves and psychological phenomena in normal human subjects are reviewed. It is noted that increases in theta activity occur in conjunction with several kinds of psychological processes. The importance of ocnsidering properties of theta activity, such as amplitude, rhythmicity and scalp topography when analyzing the relation between theta and psychological processes is emphasized. Although there is some evidence for a relationship between theta and psychological processes, it is concluded that the degree to which properties of theta activity are systematically related to specific psychological processes is not yet known.

Affect↗
PubMed1977

Memory function after closed head injury: a review of the quantitative research.

Studies which provide quantitative analyses of memory function following closed head injury were reviewed. Specific issues covered include criteria for assessing post-traumatic amnesia (PTA), PTA duration, relation of PTA duration to later memory impairment, memory functions within PTA, and comparisons between PTA and other amnesic conditions. Issues associated with the assessment of retrograde amnesia were also reviewed. With regard to memory function after PTA has terminated, we described and discussed normative data, the time course of recovery, and issues related to the nature of the later memory impairment. Directions for future work which seem particularly useful from a practical and theoretical viewpoint were also considered.

Amnesia↗
PubMedDate not supplied

On the relations among priming, conscious recollection, and intentional retrieval: evidence from neuroimaging research.

Neurobiological distinctions among forms of memory have been investigated mainly from the perspective of lesion studies in nonhuman animals and experiments with human neurological patients. We consider recent neuroimaging studies of healthy human volunteers using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) that provide new information concerning the neural correlates of particular forms of memory retrieval. More specifically, we consider evidence indicating that priming, a form of implicit retrieval, is associated with decreased activity in various cortical regions. We also consider evidence suggesting that two components of explicit retrieval-intentional or effortful search and successful conscious recollection-are preferentially associated with increased activity in prefrontal and medial temporal regions, respectively.

Brain↗
PubMedDate not supplied

Implicit memory: what must theories of amnesia explain?

In their target article on explaining functional deficits in amnesia, Mayes and Downes (this issue) discuss the relevance of implicit memory. Our commentary considers a number of implicit memory phenomena that may be especially pertinent to understanding the functional deficits of amnesia. Recent evidence suggests that amnesic patients do not benefit normally from an exact perceptual match of stimuli between study and text. We propose that this impairment may reflect one manifestation of a more general deficit in associative binding of information across different brain subsystems. This idea helps to clarify the distinction between implicit and explicit memory, and suggests that studies of implicit memory can help to elucidate the functional deficits in amnesia.

Amnesia↗
PubMedDate not supplied

Neuroanatomical correlates of implicit and explicit memory for structurally possible and impossible visual objects.

Implicit memory refers to nonconscious retrieval of past experience demonstrated by facilitation in test performance on tasks that do not require intentional recollection of previous experiences. Explicit memory, in contrast, refers to the conscious retrieval of prior information, as demonstrated during standard recall and recognition tasks. In this experiment, positron emission tomographic (PET) measurements of regional cerebral blood flow (CBF), a marker of local neuronal activity, were used to identify and contrast brain regions that participate in the perception, implicit memory, and explicit memory for structurally possible and impossible visual objects. Ten CBF images were acquired in 16 normal women as they made possible/impossible and old/new recognition decisions about previously studied (old) and nonstudied (new) structurally possible and impossible objects. As reported previously, object decisions for familiar possible objects were associated with increased CBF in the vicinity of the left inferior temporal and fusiform gyri and recognition memory for familiar possible objects was associated with increased CBF in the vicinity of the right hippocampus. In this report, we provide more extensive analyses of the roles of the inferior temporal cortex, the hippocampus, the parahippocampus, and the pulvinar in encoding and retrieval operations. Additionally, patterns of CBF increases and decreases provide information regarding the neural structures involved in implicit and explicit memory.

Adult↗