Memory and Cognitive Science

Analyses of errors from a sequential auditory recall experiment indicated that perceptual factors influence the shape of the serial position curve of recall errors. The signal to noise ratio and presentation rate of the stimuli, as well as presentation rate during a prior training session, affected item and order errors. For experiments in which Ss simply monitored the auditory sequences for a preassigned critical item, and in which items were recalled in addition to monitoring, analyses of montoring RTs provided evidence (...) that the requirement to recall induces perceptual difficulties. (shrink)

The influence of degree of organization on the ability of Ss to recall lists of syllables immediately after learning was used as a measure in applying the concept of information to the problem of learning. More syllables were correctly recalled from a passage with a lower average rate of information than from a passage with a higher average information rate. The amount of information learned by the Ss was constant when the degree of organization was between 2 and 1.5 bits (...) per syllable. (shrink)

One of the fundamental questions raised by Ruchkin, Grafman, Cameron, and Berndt's (Ruchkin et al.'s) interpretation of no distinct specialized neural networks for short-term storage buffers and long-term memory systems, is that of the link between perception and memory processes. In this framework, we take the opportunity in this commentary to discuss a specific working memory task involving percept formation, temporary retention, auditory imagery, and the attention-based maintenance of information, that is, the verbal transformation effect.

By utilizing new information from both clinical and experimental (lesion, electrophysiological, and gene-activation) studies with animals, the anatomy underlying anterograde amnesia has been reformulated. The distinction between temporal lobe and diencephalic amnesia is of limited value in that a common feature of anterograde amnesia is damage to part of an comprising the hippocampus, the fornix, the mamillary bodies, and the anterior thalamic nuclei. This view, which can be traced back to Delay and Brion (1969), differs from other recent models in (...) placing critical importance on the efferents from the hippocampus via the fornix to the diencephalon. These are necessary for the encoding and, hence, the effective subsequent recall of episodic memory. An additional feature of this hippocampalanterior thalamic and the perirhinal–medial dorsal thalamic systems are compromised, leading to severe deficits in both recall and recognition. (shrink)

The goal of our target article was to review a number of emerging facts about the effects of limbic damage on memory in humans and animals, and about divisions within recognition memory in humans. We then argued that this information can be synthesized to produce a new view of the substrates of episodic memory. The key pathway in this system is from the hippocampus to the anterior thalamic nuclei. There seems to be a general agreement that the importance of this (...) pathway has previously been underestimated and that it warrants further study. At the same time, a number of key questions remain. These concern the relationship of this system to another temporal-lobe/diencephalic system that contributes to recognition, and the relationship of these systems to prefrontal cortex activity. (shrink)

Two strategies used to uncover neural systems for episodic-like memory in animals are discussed: (i) an attribute of episodic memory (what? when? where?) is examined in order to reveal the neuronal interactions supporting that component of memory; and (ii) the connections of a structure thought to be central to episodic memory in humans are studied at a level of detail not feasible in humans. By focusing on spatial memory (where?) and the hippocampus, it has proved possible to bring the strategies (...) together. A review of lesion, disconnection and immediate early-gene studies in animals reveals the importance of interactions between the hippocampus and specific nuclei in the diencephalon (most notably the anterior thalamic nuclei) for spatial memory. Other parts of this extended hippocampal system include the mammillary bodies and the posterior cingulate (retrosplenial) cortex. Furthermore, by combining lesion and immediate early-gene studies it is possible to show how the loss of one component structure or tract can influence the remaining regions in this group of structures. The validity of this convergent approach is supported by new findings showing that the same set of regions is implicated in anterograde amnesia in humans. (shrink)

This paper argues that the biochemistry of memory consolidation provides valuable model systems for exploring the multiple realization of psychological states.

In the literature, the nature of the relationships between memory processes and summary evaluations is still a debate. According to some theoretical approaches (e.g., “two-memory hypothesis”; Anderson, 1989) retrospective evaluations are based on the impression formed while attending to the to-be-assessed stimuli(on-line judgment) – no functional dependence between information retrieval and judgment is implied. Conversely, several theories entail that judgment must depend, at least in part, on memory processes (e.g., Dougherty, Gettys, & Ogden, 1999; Schwarz, 1998; Tversky & Kahneman, 1973). (...) The present study contributes to this debate by addressing two important issues. First, it shows how more comprehensive memory measures than those used previously (e.g., Hastie & Park, 1986) are necessary in order to detect a relationship between memory and retrospective evaluations. Secondly, it demonstrates how memory strategies influence the relationship between memory and judgment. Participants recalled lists of words, after having assessed each of them for their pleasantness. Results showed a clear association between memory and judgment, which was mediated by the individual strategies participants used to recall the items. (shrink)

Dienes & Perner (D&P) argue that nondeclarative knowledge can take multiple forms. We provide empirical support for this from two related lines of research about the development of mathematical reasoning. We then describe how different forms of procedural and declarative knowledge can be effectively modeled in Anderson's ACT-R theory, contrasting this computational approach with D&P's logical approach. The computational approach suggests that the commonly observed developmental progression from more implicit to more explicit knowledge can be viewed as a consequence of (...) accumulating and strengthening mental representations. (shrink)

One method for investigating the neurobiology of consciousness is to experimentally manipulate consciousness as a variable and then visualize the resultant functional brain changes with advanced imaging techniques. To begin investigation into this area, healthy volunteers underwent positron emission tomography scanning while listening to randomized word lists in both conscious and unconscious conditions. Following anaesthesia, subjects had no explicit memories. Nonetheless, subjects demonstrated implicit memory on a forced-choice test . These subsequent memory scores were correlated with regional brain metabolism measured (...) during encoding. Conscious recall and unconscious recognition memory demonstrated considerable anatomic overlap in correlating significantly with relative glucose metabolism in auditory verbal memory areas. However, only conscious recall correlated with mediodorsal thalamic nucleus activity; unconscious recognition memory did not. These findings suggest that conscious versus unconscious memory distinctions may depend on the presence or absence of correlated thalamic activity, and directly implicate the thalamus in the neurobiology of consciousness. (shrink)

In this commentary, we challenge the claim that Freud's thinking anticipated Bartlettian reconstructive theories of remembering. Erdelyi has ignored important divergences that demonstrate it is not the case that “The constructions and reconstructions of Freud and Bartlett are the same but for motive” (target article, sect. 5).

Difficulty recognizing previously encountered stimuli is one of the earliest signs of incipient Alzheimer's disease (AD). Work over the last 10 years has focused on how patients with AD and those in the prodromal stage of amnestic mild cognitive impairment make recognition decisions for visual and verbal stimuli. Interestingly, both groups of patients demonstrate markedly better memory for pictures over words, to a degree that is significantly greater in magnitude than their healthy older counterparts. Understanding this phenomenon not only helps (...) to conceptualize how memory breaks down in AD, but also potentially provides the basis for future interventions. This review critically examines recent recognition memory work using pictures and words in the context of the dual-process theory of recognition and current hypotheses of cognitive breakdown in the course of very early AD. (shrink)

In a recent study, Maguire and colleagues failed to find systematic differences in brain anatomy between world-class memory performers and matched control subjects. The world-class performers exhibited distinctive patterns of brain activation during memorization, but these patterns were directly attributable to the experts' unique encoding strategies and acquired memory skills. Discussed here are the implications for broad attainability of highly skilled memory performance in professional and everyday activities.

A functional theory of memory has already been developed as part of a general functional theory of cognition. The traditional conception of memory as “reproductive” touches on only a minor function. The primary function of memory is in constructing values for goal-directedness of everyday thought and action. This functional approach to memory rests on a solid empirical foundation.

In this book, experienced researchers in the field address the question: Will the model survive these challenges?

This paper discusses the ways in which anesthetic agents can be used to investigate the role of awareness in learning and memory. It reviews research into learning during light, subclinical anesthesia, termedhypesthesia.This research suggests that the effects of anesthetics on implicit and explicit memory are roughly comparable, although implicit memory for simple stimuli may resist the effects of very low doses of anesthetic. In addition, this paper reports experimental data demonstrating that long-term retention of information is prevented by doses of (...) anesthetic that are low enough to permit awareness and even short-term memory of auditory stimuli. Overall, these findings are consistent with the hypothesis that frontal lobe function is particularly sensitive to anesthetics. They raise theoretical and practical questions about the necessity of consciousness for learning and about interpretation of the evidence for learning during surgery under general anesthesia. (shrink)