An instance theory of attention and memory

An instance theory of attention and memory (ITAM) is presented that integrates formal theories of attention and memory phenomena by exploiting commonalities in their formal structure. The core idea in each theory is that performance depends on a choice process that can be modeled as a race between competing alternatives. Attention and categorization are viewed as different perspectives on the same race. Attention selects objects by categorizing them; objects are categorized by attending to them. ITAM incorporates each of its ancestors as a special case, so it inherits their successes.     

Sentence comprehension in Parkinson's disease: the role of attention and memory.

Sentence comprehension is a complex process involving at least attentional, memory, grammatical, and semantic components. We report three experiments designed to evaluate the impairments underlying sentence comprehension difficulties in nondemented patients with Parkinson's disease (PD). In the first experiment, we asked patients to answer simple questions about sentences which varied in terms of grammatical complexity and semantic constraint. We found that PD patients are significantly compromised in their ability to perform this task. Their difficulties became more prominent as grammatical complexity increased, but they were significantly assisted by semantic constraints that limited possible interpretations of a sentence. Analyses of individual patient profiles revealed heterogeneous performance across the group of PD patients and somewhat inconsistent performance for patients across testing sessions. In the second experiment, we tested the possibility that patients' heterogeneous performance on the sentence comprehension task is due to an impairment in memory or attention, cognitive domains known to be compromised in some PD patients. Although PD patients and control subjects differed on one memory measure, there were no significant correlations between attention and memory performance and the results of the sentence comprehension task. In the final experiment, we manipulated the sentences used in the first experiment in a fashion that stressed the need for memory and attention in a sentence. The results indicated that PD patients are significantly compromised in their ability to attend to certain critical grammatical features of a sentence. A regression analysis identified specific grammatical, semantic, and attentional mechanisms as significant contributors to PD patients' overall sentence comprehension, accounting for over 97% of the variance in their performance. We conclude that there are multiple sources of cognitive difficulty underlying PD patients' sentence comprehension impairment.     

Visual-spatial working memory, attention, and scene representation: A neuro-cognitive theory

This paper addresses the issue of how visual-spatial working memory, attention, and scene representation are related. The first section introduces a modified two-stage conception of visual-spatial processing. “Stage one” refers to low-level visual-spatial processing and computes in parallel for the currently available retinal information “object candidates,” here called “visual-spatial units.” An attentional process called “unit selection” allows access to stage two for one of these units at a time. Stage two contains high-level visual-spatial information that can be used for goal-directions (e.g., verbal report, grasping). It consists of three parallel processing streams. First, the currently selected unit is recognized; second, a spatial-motor program for the selected unit is computed; and third, an “object file” is set up for the selected unit. An object file contains temporary episodic representations of detailed high-level visual-spatial attributes of an “object” plus an “index.” An index acts as a pointer and is bound via temporary connections to the attributes of the file. Section two of this paper specifies one part of stage two in more detail, namely visual-spatial working memory (VSWM). It can contain up to four object files. A first central claim is that during sensory-based processing for working memory (“access”), one object file is always “on-line,” and up to three other object files are “off-line”. A second central claim is that the process of setting up an object file depends on the number and the activation level of already stored files. Based on the concept of activation-based competition between object files, it is postulated that the more files that are stored and the higher their activation is, the longer it takes for a newly set up object file to reach a sufficient level of activation. Activation-based competition is also used to explain “short-term forgetting” by “interference.” A third central claim about VSWM is that a “refreshment' process exists that increases the activation level of an index of an object file in order to prevent forgetting or in order to bring the file back to the state of controlling the current action. Finally, section three gives a selective look at a number of experimental data such as the attentional blink, backward masking, dwell time effects, transsaccadic memory, and change blindness. New explanations are offered and new predictions made. Received: 16 January 1998 / Accepted: 25 July 1998     

Note taking, review, memory, and comprehension

In previous work assessing memory at various levels of representation, namely the surface form, textbase, and situation model levels, participants read texts but were otherwise not actively engaged with the texts. The current study tested the influence of active engagement with the material via note taking, along with the opportunity to review such notes, and the modality of presentation (text vs. spoken). The influence of these manipulations was assessed both immediately and 1 week later. In Experiment 1 participants read a text, whereas in Experiment 2 participants watched a video recording of the material being read as a lecture. For each experiment the opportunity to take notes was manipulated within participants, and the opportunity to review these notes before the test was manipulated between participants. Note taking improved performance at the situation model level in both experiments, although there was also some suggestion of benefit for the surface form. Thus, active engagement with material, such as note taking, appears to have the greatest benefit at the deeper levels of understanding.     

Causality and the allocation of attention during comprehension

Recent research has suggested that each statement in a narrative text is understood by relating it to its causal antecedents and consequences and that the text as a whole is understood by finding a causal path linking its opening to its final outcome. Fletcher and Bloom (1988) have proposed that in order to accomplish this goal, while minimizing the number of times long-term memory has to be searched, readers focus their attention on the last clause of a narrative that has causal antecedents but no consequences in the preceding text. As a result, a statement that is followed by a causal antecedent should remain the focus of attention, while the same statement followed by a consequence should not. This prediction was tested and confirmed in three experiments which show that when a target statement is followed by a sentence that includes only causal antecedents, (a) continuation sentences related to it are read more quickly, (b) target words drawn from it are easier to recognize, and (c) subject-generated continuations are more likely to be causally related to it.     

Test anxiety,sentence comprehension,and recognition memory

Abstract

The present study explored the relationships between trait and state test anxiety of students, and comprehension and recognition memory for sentences. The results demonstrated that test anxiety effects could be found in comprehension-based recognition memory for sentences under conditions that minimized complex retrieval operations. Comprehension was related to the test anxiety deficit, supporting the hypothesis that anxiety-recognition relations were mediated by anxiety-comprehension and comprehension-recognition relations. However, a partial correlation analysis suggested that this comprehension-deficit hypothesis is not adequate to explain the total deficit. Elaborative processes were suggested as a potential contributor to the findings.     

A capacity theory of comprehension: individual differences in working memory.

A theory of the way working memory capacity constrains comprehension is proposed. The theory proposes that both processing and storage are mediated by activation and that the total amount of activation available in working memory varies among individuals. Individual differences in working memory capacity for language can account for qualitative and quantitative differences among college-age adults in several aspects of language comprehension. One aspect is syntactic modularity: The larger capacity of some individuals permits interaction among syntactic and pragmatic information, so that their syntactic processes are not informationally encapsulated. Another aspect is syntactic ambiguity: The larger capacity of some individuals permits them to maintain multiple interpretations. The theory is instantiated as a production system model in which the amount of activation available to the model affects how it adapts to the transient computational and storage demands that occur in comprehension.     

Activation,attention, and short-term memory

The premise of this paper is that the popular term “short-term memory” (STM) is vague because it is used to refer to either (1) the set of representations from long-term memory currently in a state of heightened activation or (2) the focus of attention or content of awareness. A more coherent conception of STM is hierarchical, with the focus of attention depicted as a subset of the activated portion of long-term memory. Research issues are discussed to illustrate that this simple conception of STM leads to testable predictions and useful lines of inquiry.     

Language comprehension and probe-list memory

Experiments were performed using probe-word recognition methodology in which participants read sentences that were presented 1 word at a time and were then shown a probe word and had to make a speeded response indicating whether the word had occurred in the sentence. One experiment showed that response times to probe words increased with the size of the set of candidate probes. The other experiments showed that the effects caused by name repetition in circumstances in which the repeated name was co-referential also occurred when the repeated name was not co-referential and when the order of words in a sentence was scrambled. The results suggest that responses in the task can be based on probe-list memory, a mental representation created to keep track of those words that the participant believes are likely to be probed, and that the use of the task to make inferences about language comprehension should be accompanied by controls ruling out such strategies.     

Emotional stimuli, divided attention, and memory

The emotion-memory literature has shown that negative emotional arousal enhances memory. S. A. Christianson (1992) proposed that preattentive processing could account for this emotion-memory relationship. Two experiments were conducted to test Christianson's theory. In Experiment 1, participants were exposed to neutral and negative arousing slides. In Experiment 2, participants were exposed to neutral, negative arousing, and positive arousing slides. In both experiments, the aforementioned variable was factorially combined with a divided-attention or non-divided-attention condition. The authors predicted that, in contrast to the nondivided condition, dividing attention would adversely impact neutral and positive stimuli more than negative stimuli. The hypothesis was supported; participants recalled more high negative-arousal slides than positive or neutral slides when their attention was divided rather than nondivided.     

Depth of comprehension,effective elaboration,and memory for sentences

It was hypothesized that depth of comprehension is a function of the complexity of the meaning components of a sentence that are activated during initial encoding. In four experiments, subjects were presented sentences containing either transitive causative verbs (e.g., “John opened the door”) or their intransitive noncausative counterparts (e.g., “The door opened”) and were required to produce a continuation to each sentence. Based on the above hypothesis, sentences for which the continuations induced causative interpretations should be remembered better than sentences for which noncausitive interpretations were induced. The results confirmed this hypothesis, and they are considered in relation to depth of comprehension, effective elaboration, and the role of inferences in memory for sentences.     

Selective attention,filtering, and the development of working memory

Selective attention is fundamental for learning across many situations, yet it exhibits protracted development, with young children often failing to filter out distractors. In this research, we examine links between selective attention and working memory (WM) capacity across development. One possibility is that WM is resource‐limited, with development resulting in an increase in the amount of resources available for processing information. However, it is also possible that development results in greater efficiency of using available resources. In the current research, we explore the latter possibility by examining the developmental trajectory of selectivity and filtering in relation to WM capacity. We report that filtering efficiency of adults (N = 30), 7‐year‐olds (N = 29), and 4‐year‐olds (N = 28) was uniquely predictive of WM capacity. We also report that filtering efficiency continues to develop after 7 years of age, whereas WM capacity may reach an asymptote around 7 years of age. The latter finding suggests that selective attention plays a critical role in developmental and individual differences in visual working memory capacity.     

Verbal working memory and sentence comprehension

This target article discusses the verbal working memory system used in sentence comprehension. We review the concept of working memory as a short-duration system in which small amounts of information are simultaneously stored and manipulated in the service of accomplishing a task. We summarize the argument that syntactic processing in sentence comprehension requires such a storage and computational system. We then ask whether the working memory system used in syntactic processing is the same as that used in verbally mediated tasks that involve conscious controlled processing. Evidence is brought to bear from various sources: the relationship between individual differences in working memory and individual differences in the efficiency of syntactic processing; the effect of concurrent verbal memory load on syntactic processing; and syntactic processing in patients with poor short-term memory, patients with poor working memory, and patients with aphasia. Experimental results from these normal subjects and patients with various brain lesions converge on the conclusion that there is a specialization in the verbal working memory system for assigning the syntactic structure of a sentence and using that structure in determining sentence meaning that is separate from the working memory system underlying the use of sentence meaning to accomplish other functions. We present a theory of the divisions of the verbal working memory system and suggestions regarding its neural basis.     

Schematic information, attention, and memory for places

Recall and recognition of various aspects of three places were studied under incidental and intentional conditions. Data showed that subjects passing through a place incidentally remembered structural features such as walls better than variable features such as furniture. On the other hand, subjects passing through a place knowing they will be tested for memory of its remembered the variable elements better than the structural elements. The results are interpreted in terms of intentionally governed coding.     

Visuospatial working memory,auditory discrimination,and attention

ABSTRACT

The present study examined the degree to which tests of visuospatial storage capacity tap into domain-general storage and attention processes. This was done by comparing performance of visuospatial memory tasks with performance on sound-based sensory discrimination tasks. We found that memory task- and discrimination task performance both tapped into a cross-modality factor (visual and auditory). We further examined the degree to which this common variance could be explained by attention control and sustained attention. These attention factors accounted for roughly 60% of the variance in memory. This indicates that tests of visuospatial memory capacity reflect more than modality-specific memory.     

Emotion, memory, and attention in the taboo Stroop paradigm

This study tested the binding hypothesis: that emotional reactions trigger binding mechanisms that link an emotional event to salient contextual features such as event location, a frequently recalled aspect of naturally occurring flash-bulb memories. Our emotional events were taboo words in a Stroop color-naming task, and event location was manipulated by presenting the words in different task-irrelevant screen locations. Seventy-two participants named the font color of taboo and neutral words, with instructions to ignore word meaning; in one condition, several words were location consistent (i.e., always occupied the same screen location), whereas in another condition, several colors were location consistent. Then, in a surprise recognition memory test, participants recalled the locations of location-consistent words or colors. Although attention enhanced overall location memory for colors (the attended dimension during color naming), emotion (taboo vs. neutral words) enhanced location memory for words but not colors. These results support the binding hypothesis but contradict the hypothesis that emotional events induce image-like memories more often than non-emotional events.     

The relationship between age, verbal working memory, and language comprehension

A structural modeling approach was used to examine the relationships between age, verbal working memory (vWM), and 3 types of language measures: online syntactic processing, sentence comprehension, and text comprehension. The best-fit model for the online-processing measure revealed a direct effect of age on online sentence processing, but no effect mediated through vWM. The best-fit models for sentence and text comprehension included an effect of age mediated through vWM and no direct effect of age. These results indicate that the relationship among age, vWM, and comprehension differs depending on the measure of language processing and support the view that individual differences in vWM do not affect individuals' online syntactic processing.     

Age, working memory, and on-line syntactic processing in sentence comprehension

One hundred twenty-seven individuals who ranged in age from 18 to 90 years were tested on a reading span test and on measures of on-line and off-line sentence processing efficiency. Older participants had reduced working-memory spans compared with younger participants. The on-line measures were sensitive to local increases in processing load, and the off-line measures were sensitive to the syntactic complexity of the sentences. Older and younger participants showed similar effects of syntactic complexity on the on-line measures. There was some evidence that older participants were more affected than younger participants by syntactic complexity on the off-line measures. The results support the hypothesis that on-line processes involved in recognizing linguistic forms and determining the literal, preferred, discourse-coherent meaning of sentences constitute a domain of language processing that relies on its own processing resource or working-memory system.