Accounting for cognitive aging: context processing, inhibition or processing speed?

Age-related deficits in context processing were examined in relationship to two predominant theories of cognitive aging (the Inhibitory Deficit and Processing Speed Models). Older and younger adults completed a measure of context processing (AX Continuous Performance Test (CPT) task) as well as a computerized battery of inhibitory tasks: Stroop, garden path sentences, go no-go, and the stop-signal paradigm. Participants also completed a simple processing speed task. After controlling for baseline differences in processing speed, age effects were detected on the AX-CPT. Smaller, but significant age effects were noted on the Stroop and stop-signal tasks, but no significant age effects were found on the garden path sentence and go no-go tasks. Intertask correlations were weak, providing little evidence for a homogenous or uniform construct of inhibition. The sensitivity of the AX-CPT to cognitive aging is discussed in the context of existing theories of cognitive aging. The authors suggest that deficits in context processing and utilization may underlie cognitive aging phenomena.     

Lexical processing of ambiguous words: dominance or associative strength?

Four experiments examined the role of meaning frequency (dominance) and associative strength (measured by associative norms) in the processing of ambiguous words in isolation. Participants made lexical decisions to targets words that were associates of the more frequent (dominant) or less frequent (subordinate) meaning of a homograph prime. The first two experiments investigated the role of associative strength at long SOAs (Stimulus Onset Asynchrony) (750 ms.), showing that meaning is facilitated by the targets' associative strength and not by their dominance. The last two experiments traced the role associative strength at short SOAs (250 ms), showing that the manipulation of the associative strength has no effect in the semantic priming. The conclusions are: on the one hand, semantic priming for homographs is due to associative strength manipulations at long SOAs. On the other hand, the manipulation of the associative strength has no effect when automatic processes (short SOAs) are engaged for homographs.     

Do monkeys think in metaphors? Representations of space and time in monkeys and humans

Research on the relationship between the representation of space and time has produced two contrasting proposals. ATOM posits that space and time are represented via a common magnitude system, suggesting a symmetrical relationship between space and time. According to metaphor theory, however, representations of time depend on representations of space asymmetrically. Previous findings in humans have supported metaphor theory. Here, we investigate the relationship between time and space in a nonverbal species, by testing whether non-human primates show space–time interactions consistent with metaphor theory or with ATOM. We tested two rhesus monkeys and 16 adult humans in a nonverbal task that assessed the influence of an irrelevant dimension (time or space) on a relevant dimension (space or time). In humans, spatial extent had a large effect on time judgments whereas time had a small effect on spatial judgments. In monkeys, both spatial and temporal manipulations showed large bi-directional effects on judgments. In contrast to humans, spatial manipulations in monkeys did not produce a larger effect on temporal judgments than the reverse. Thus, consistent with previous findings, human adults showed asymmetrical space–time interactions that were predicted by metaphor theory. In contrast, monkeys showed patterns that were more consistent with ATOM.     

Nonverbal working memory of humans and monkeys: Rehearsal in the sketchpad?

Investigations of working memory tend to focus on the retention of verbal information. The present experiments were designed to characterize the active maintenance rehearsal process used in the retention of visuospatial information. Rhesus monkeys (Macaca mulatta;N=6) were tested as well as humans (totalN=90) because these nonhuman primates have excellent visual working memory but, unlike humans, cannot verbally recode the stimuli to employ verbal rehearsal mechanisms. A series of experiments was conducted using a distractor-task paradigm, a directed forgetting procedure, and a dual-task paradigm. No evidence was found for an active maintenance process for either species. Rather, it appears that information is maintained in the visuospatial sketchpad without active rehearsal.     

Analysis of group differences in processing speed: Where are the models of processing?

Recently, Myerson, Adams, Hale, and Jenkins (2003) replied to arguments advanced by Ratcliff, Spieler, and McKoon (2000) about interpretations of Brinley functions. Myerson et al. (2003) focused on methodological and terminological issues, arguing that (1) Brinley functions are not quantile-quantile (QQ) plots of distributions of mean reaction times (RTs) across conditions; that the fact that the slope of a Brinley function is the ratio of the standard deviations of the two distributions of means has no implications for the use of slope as a measure of processing speed; that the ratio of slopes of RT functions for older and young subjects plotted against independent variables equals the Brinley function slope; and that speed-accuracy criterion effects do not account for slowing with age. We reply by showing that Brinley functions are plots of quantiles against quantiles; that the slope is best estimated by the ratio of standard deviations because there is variability in the distributions of mean RTs for both older and young subjects; that the interpretation of equality of the slopes Brinley functions and plots of RTs against independent variables in terms of processing speed is model dependent; and that speed-accuracy effects in some, but not all, experiments are solely responsible for Brinley slopes greater than 1. We conclude by reiterating the point that was not addressed in Myerson et al. (2003), that the goal of research should be modelbased accounts of processing that deal with correct and error RT distributions and accuracy.     

Is speed of information processing related to fluid or to crystallized intelligence?

Speed of information processing was examined in relation to the theory of fluid and crystallized intelligence. Sixty sixth grade children completed the Standard Progressive Matrices test and the Mill Hill Vocabulary scale, both untimed, as measures of fluid and crystallized intelligence, and three RT tasks: Memory Scanning, Picture Identification, and Sentence-Picture Comparison. As predicted, RT parameters, with the exception of slope on two tasks, were negatively correlated with scores on both tests. There were no consistent differences between the two tests in the size of correlations with RT, and partial correlations, eliminating the effects of fluid and crystallized intelligence respectively, failed to support any causal relationship between fluid and crystallized intelligence in either direction. Some limitations of the research, specifically in the possible effect of error rates on the speed-intelligence relationship, and in the application to individuals of task parameters derived from group performance, are noted.     

Mechanism of age-related differences in frequency discrimination with backward masking: speed of processing or stimulus persistence?

In Experiment 1, frequency-discrimination thresholds were estimated in a 2-interval, forced-choice, backward masking procedure with a masker acoustically dissimilar to the targets. Young subjects were more efficient in escaping the effects of masking than were their elderly counterparts. In Experiment 2, young and elderly subjects performed the same task, with a masker acoustically similar to the targets and with a target-dissimilar masker. Under target-similar masking and at short target-masker intervals, the elderly demonstrated significant improvement, reaching the level of performance of the young, whereas under the target-dissimilar masker, the age-related differences were restored. Both age-related slowing of information processing and increase in stimulus persistence can account for the results of Experiment 1, but only increased stimulus persistence explains the results of Experiment 2.     

Visual temporal processing in dyslexia and the magnocellular deficit theory: the need for speed?

A controversial question in reading research is whether dyslexia is associated with impairments in the magnocellular system and, if so, how these low-level visual impairments might affect reading acquisition. This study used a novel chromatic flicker perception task to specifically explore temporal aspects of magnocellular functioning in 40 children with dyslexia and 42 age-matched controls (aged 7-11). The relationship between magnocellular temporal resolution and higher-level aspects of visual temporal processing including inspection time, single and dual-target (attentional blink) RSVP performance, go/no-go reaction time, and rapid naming was also assessed. The Dyslexia group exhibited significant deficits in magnocellular temporal resolution compared with controls, but the two groups did not differ in parvocellular temporal resolution. Despite the significant group differences, associations between magnocellular temporal resolution and reading ability were relatively weak, and links between low-level temporal resolution and reading ability did not appear specific to the magnocellular system. Factor analyses revealed that a collective Perceptual Speed factor, involving both low-level and higher-level visual temporal processing measures, accounted for unique variance in reading ability independently of phonological processing, rapid naming, and general ability.     

Prenatal stress and risk for psychopathology: specific effects or induction of general susceptibility?

This review focuses on prenatal stress as a risk factor for psychopathology. Evidence from animal studies is summarized, and the relevance of prenatal stress models in animals for human studies is discussed. In the offspring of prenatally stressed animals, overactivity and impaired negative feedback regulation of the hypothalamic-pituitary-adrenal axis are consistent findings and may reflect a pathophysiological mechanism involved in the development of psychopathology. Reduced activity of the opioid GABA/benzodiazepine, serotonin, and dopamine systems and increased activity of the sympathico-adrenal system have been found as well. These alterations have been linked to a diverse spectrum of psychopathology. Therefore, the evidence supports the view that exposure to prenatal stress may result in a general susceptibility to psychopathology, rather than exerting a direct effect on a specific form of psychopathology.     

Memory for pictures and words as a function of level of processing: Depth or dual coding?

The experiment was designed to test differential predictions derived from dual-coding and depth-of-processing hypotheses. Subjects under incidental memory instructions free recalled a list of 36 test events, each presented twice. Within the list, an equal number of events were assigned to structural, phonemic, and semantic processing conditions. Separate groups of subjects were tested with a list of pictures, concrete words, or abstract words. Results indicated that retention of concrete words increased as a direct function of the processing-task variable (structural < phonemic 相似文献   

The sensory‐cognition association in adulthood: Different magnitudes for processing speed,inhibition, episodic memory,and false memory?

One hundred and forty-six participants (age range = 20-80) completed a battery of tests designed to measure visual acuity, processing speed, inhibition, episodic memory and false memory. The relations between visual acuity and general cognitive ability, as well as between visual acuity and the indicators of this construct, were evaluated with structural equation modeling. The measurement model confirmed that the indicators of the individual cognitive abilities could be grouped into a general cognitive functioning factor. However, the relation between episodic and false memory was not completely explained by the shared association with this general factor. Furthermore, visual acuity predicted approximately half of the age-related variance in the general cognition factor. Also, the proportion of age-related variance shared with vision was highest in inhibition and lowest in false memory. The results are discussed in the light of common cause accounts of cognitive aging.     

Inspection time and IQ: Evidence for a mental speed—ability association

Two studies have tested a theory that individual differences in mental speed constitute an important component of differences in general intelligence by examining patterns of correlation between ‘inspection time’ (IT) and various ability measures assumed to reflect different kinds of speed. The first study was set within the framework of Cattell's theory about the structure of abilities. Results from 30 adult Ss whose IQs (Raven Advanced Progressive Matrices, RAPM) were in the average to above-average range suggested that IT is associated with a broad general ability variable and not with the primary abilities ‘perceptual speed’ or ‘speed of closure’. However, IT was significantly correlated with only a subgroup of those primary abilities that were significantly intercorrelated, and the outcome did not further elucidate the nature of speed as discussed within Cattell's formulation. The second study tested a relationship between IT and a measure of general ‘intellectual speed’, previously described as the major determinant of intellectual differences in a situation where two other critical variables, ‘accuracy’ and ‘continuance’ can exert no influence. It was measured for more than 40 adult Ss, whose IQs (Wechsler Adult Intelligence Scale—Revised) ranged from 81 to 138, and compared with times to produce the correct solution to individual items from the RPM. IT, IQ and solution times were all significantly intercorrelated but, nonetheless, IT and solution times appeared to be substantially reflecting different processes. It is concluded that IT can account for more than the 10% of variance in IQ commonly found to be shared with simple information-processing tasks. The present result of approx. 17% shared variance is probably an underestimate, given the restricted IQ samples used and certain procedural shortcomings. The nature of speed reflected by IT has not been determined and current measurement procedures may be confounded by internal noise.     

Can reading ability be measured with tests of memory and processing speed?

The author investigated the possibility of estimating reading ability using tests of memory and processing speed that have significantly reduced reading requirements. Four hundred three air force trainees were given tests of their working memory and long-term memory processes, as well as a standardized reading test. A multiple correlation of .79 indicated that global reading ability is substantially correlated with memory processes. Additional analyses indicated that word knowledge and comprehension, the two major components of reading ability, were both explained by the same set of memory process factors, namely, long-term memory processes, semantic memory retrieval speed, and working memory capacity. These results, which are consistent with the view that memory ability underlies reading ability, support the endeavor of measuring reading ability with memory and processing speed tasks.     

Cognitive Ethology for humans: Inconvenient truth or attentional deficit?

We discuss Kingstone et al.'s target article in the light of emerging work on cognitive ethology.     

Incongruency effects in affective processing: automatic motivational counter-regulation or mismatch-induced salience?

Attention is automatically allocated to stimuli that are opposite in valence to the current motivational focus (Rothermund, 2003; Rothermund, Voss, & Wentura, 2008). We tested whether this incongruency effect is due to affective-motivational counter-regulation or to an increased salience of stimuli that mismatch with cognitively activated information. Affective processing biases were assessed with a search task in which participants had to detect the spatial position at which a positive or negative stimulus was presented. In the motivational condition, positive or negative affective-motivational states were induced by performance feedback after each trial. In the cognitive activation condition, participants memorised the word "good" or "bad" during the search task. The affective incongruency effect was replicated in the motivational condition, whereas an affective congruency effect obtained in the cognitive activation condition. These findings support an explanation of affective incongruency effects in terms of automatic counter-regulation that is motivational in nature.     

Preattentive processing or prefocal processing?

The concept of preattentive processing is analyzed and alternative views of it are presented. A basic question is whether processing required for preattentive input selection is qualitatively different from post-selection processing. In order to study this, subjects were presented in one set of conditions with one stimulus at either of two locations, and in another set of conditions, simultaneously with two stimuli. The stimuli could be green or red, or large or small. Subjects were asked to indicate the location (or the color, or the size) of the single stimulus in the single-stimulus conditions, or of a predesignated stimulus (say, the red one) in the dual-stimulus conditions. Responses were generally slower in the dual-stimulus conditions. The increases in reaction time were accounted for by the times it takes to process for response selection the properties by which the target stimulus could be selected, as indicated by the results of two control conditions. The results as well as some other considerations do not support the view that preattentive processing is necessarily of a type that qualitatively differs from post-selection processing.     

The processing of non-target words: Semantic or not?

It is known that people reacting to visual words may be affected by the meaning of accompanying non-target words. On the approach to perception developed by Treisman (e.g. 1986), this is surprising, because meaning might be thought to require analysis of conjunctions of physical features and so should remain uncomputed for non-target words. Treisman's approach does, however, assert that analysis of the target may unleash further processes that would prime the system for detection of related words. If this were so, then presentation of the target earlier than the distractors would increase the effect of the latter; whereas if analysis of non-targets were independent of priming, they might be expected to have a smaller effect when delayed. Further, if the sets of words involved are small and familiar, then individual features of primed non-targets, rather than conjunctions of features, might trigger interference. They might especially do so when spatial separation of target and non-target is small.

Five experiments using a paradigm developed by Shaffer and LaBerge confirm that the meaning of non-target words affects response to targets; but (1) this is more true for early than for late arrival of the target; (2) it is affected by target/non-target separation in space; (3) it is true for familiar sets of repeated words but not, in these data, for words used once only in the experiment. It is therefore concluded that the results are more consistent with a Treisman type of explanation than with a theory of universal and automatic full analysis.     

Levels of processing: Qualitative differences or task-demand differences?

In nearly all reported orienting task studies, the question is asked before the item or items are presented. This paper reports two experiments wherein the question was asked after the item was presented. These experiments found that an orthographic orienting task did not produce poorer retention than a semantic orienting task when (1) the orthographic task was presented in such a way to ensure that the list items would be encoded as units and (2) the test was designed to eliminate the effect of encoding elaboration to positive-response orienting questions. It was concluded that the depth-of-processing effect was composed of two components. One of these is a task-demand component that affects the probability of encoding target items as identifiable units. The second component of processing depth is trace elaboration to positive-response questions. In most experiments, the two components combine to produce better memory performance for targets presented with semantic orienting questions. However, the two components can be examined independently of each other to determine the degree to which each contributes to a particular experimental effect.     

Basis of recency and frequency judgements of novel faces: Generalised strength or episode-specific memories?

Evidence for generalised and episode-specific strength in judgements of recency and frequency of novel faces was investigated in two experiments. Novel faces (created using an identikit program) were presented either once or three times in either of two study sets, separated by a 4 minute (Experiment 1) or 24 hour (Experiment 2) delay. In Experiment 2, the study–test phases were preceded by a familiarisation phase in which faces were presented either with or without an occupational label (some faces were not familiarised). In both experiments, judgements of recency were consistent with greater reliance on generalised strength (an amalgamation of recency and frequency of presentation), although there was some evidence for a contribution of episode-specific information. Familiarisation had opposite effects on judgements of recency and frequency, with familiarised faces judged as having been studied more frequently (three times), but less recently (yesterday) than unfamiliarised faces. The latter result is consistent with participants discounting generalised strength when episode-specific information is inadequate.     

Basis of recency and frequency judgements of novel faces: generalised strength or episode-specific memories?

Evidence for generalised and episode-specific strength in judgements of recency and frequency of novel faces was investigated in two experiments. Novel faces (created using an identikit program) were presented either once or three times in either of two study sets, separated by a 4 minute (Experiment 1) or 24 hour (Experiment 2) delay. In Experiment 2, the study-test phases were preceded by a familiarisation phase in which faces were presented either with or without an occupational label (some faces were not familiarised). In both experiments, judgements of recency were consistent with greater reliance on generalised strength (an amalgamation of recency and frequency of presentation), although there was some evidence for a contribution of episode-specific information. Familiarisation had opposite effects on judgements of recency and frequency, with familiarised faces judged as having been studied more frequently (three times), but less recently (yesterday) than unfamiliarised faces. The latter result is consistent with participants discounting generalised strength when episode-specific information is inadequate.