Full Attention Conditions Research Articles

A comparison of Levitt and Zwislocki decision rules for use with forced-choice adaptive procedures

Forced-choice adaptive procedures enjoy widespread use for the measurement of detection and discrimination thresholds. Zwislocki et al. [J. Acoust. Soc. Am. 30, 254–262 (1958)] proposed an adaptive procedure with a decision rule that targets 75% correct several years before these procedures gained acceptance in psychophysics, and even today little is known about the statistical properties of this decision rule. This paper evaluates, using computer simulations, the bias and efficiency of Zwislocki’s proposed decision rule in 2-alternative forced-choice (AFC) and 3-AFC procedures under conditions of full attention and inattenion. The results for this decision rule compare favorably with two popular rules proposed by Levitt [J. Acoust. Soc. Am. 49, 467–477 (1971)] that target 70.7% correct and 79.4% correct. In summary, the rule that targets 75% correct (Zwislocki’s rule) produces less biased threshold estimates than the rule that targets 70.7% correct and it is affected less by inattention than the rule that targets 79.4% correct. This research supports the addition of Zwislocki’s rule to the psychophysical toolbox.

Effects of Prior Experience on Judgments of Normative Word Frequency: Automatic Bias and Correction

Four experiments examined repetition priming effects on judgments of normative word frequency. Experiment 1a found reliable priming, but only when words were studied under conditions of full attention; divided attention eliminated the effect. Experiment 1b replicated the attention effects and found that frequency and recognition judgments could be dissociated as a function of study repetition. Experiment 2 showed that Levels of Processing could also dissociate the two judgments. Posthoc latency analyses of the data from Experiments 1 and 2 showed the biasing of frequency judgments to be limited to the subjects' fastest responses; slower responses showed no bias effects. Experiment 3 replicated the latency effects using an instructional manipulation of response speed. Posttest interviews in all of the experiments suggested that the bias correction seen in the slower responses occurred without awareness or intent. The results extend prior research on repetition priming to a semantic judgment about a well-known class of stimuli and are discussed in terms of processing fluency, source monitoring, and the correction of unconsciously influenced judgments.

Chromatic input to motion processing in the absence of attention

While several previous psychophysical and neurophysiological studies have demonstrated chromatic (red/green) input to motion processing, the nature of this input is still a matter of debate. In particular, recent controversy has developed regarding whether chromatic motion processing relies on lower-level processes [J. Neurosci. 14 (1994) 4854; 19 (1999) 6571] versus higher-level, attention- or salience-based mechanisms [Science 257 (1992) 1563; Proc. Natl. Acad. Sci. 96 (1999a) 8289; 96 (1999b) 15374]. In this study, we investigated the degree to which chromatic motion is influenced by attentional mechanisms by employing a dual-task paradigm, which allowed us to compare the strength of chromatic motion under conditions of poor versus full attention. Here, we found that for equiluminant red/green gratings, chromatic motion processing is as robust in poor, as in full, attention conditions. This lack of an attentional effect suggests that chromatic motion processing must rely, at least in part, on lower-level (i.e., pre-attentive) motion mechanisms. For non-equiluminant (e.g., red brighter than green) gratings, however, attention significantly modulates chromatic motion strength. Possible explanations for this latter result are discussed in the context of inherent salience differences between the bright-red and dim-green stripes of the heterochromatic grating.

The influence of divided attention on holistic face perception

There is evidence that upright, but not inverted, faces are encoded holistically. The holistic coding of faces was examined in four experiments by manipulating the attention allocated to target faces. In Experiment 1, participants in a divided attention condition were asked to match two upright flanker faces while encoding a centrally presented upright target face. Although holistic coding was evident in the full attention conditions, dividing attention disrupted holistic coding of target faces. In Experiment 2, we found that while matching upright flanker faces disrupted holistic coding, matching inverted flanker faces did not. Experiment 3 demonstrated that the differential effects of flanker orientation were not due to participants taking longer to match upright, than inverted, flanker faces. In Experiment 4, we found that matching fractured faces had an intermediate effect to that of matching upright and inverted flankers, on the holistic coding of the target faces. The findings emphasize the differences in processing of upright, fractured and inverted faces and suggest that there are limitations in the number of faces that can be holistically coded in a brief time.

The effects of divided attention on encoding- and retrieval-related brain activity: A PET study of younger and older adults.

Divided attention (DA) disrupts episodic encoding, but has little effect on episodic retrieval. Furthermore, normal aging is associated with episodic memory impairments, and when young adults are made to encode information under DA conditions, their memory performance is reduced and resembles that of old adults working under full attention (FA) conditions. Together, these results suggest a common neurocognitive mechanism by which aging and DA during encoding disrupt memory performance. In the current study, we used PET to investigate younger and older adults' brain activity during encoding and retrieval under FA and DA conditions. In FA conditions, the old adults showed reduced activity in prefrontal regions that younger adults activated preferentially during encoding or retrieval, as well as increased activity in prefrontal regions young adults did not activate. These results indicate that prefrontal functional specificity of episodic memory is reduced by aging. During encoding, DA reduced memory performance, and reduced brain activity in left-prefrontal and medial-temporal lobe regions for both age groups, indicating that DA during encoding interferes with encoding processes that lead to better memory performance. During retrieval, memory performance and retrieval-related brain activity were relatively immune to DA for both age groups, suggesting that DA during retrieval does not interfere with the brain systems necessary for successful retrieval. Finally, left inferior prefrontal activity was reduced similarly by aging and by DA during encoding, suggesting that the behavioral correspondence between these effects is the result of a reduced ability to engage in elaborate encoding operations.

The effect of divided attention on encoding and retrieval in episodic memory revealed by positron emission tomography.

The effects of divided attention (DA) on episodic memory encoding and retrieval were investigated in 12 normal young subjects by positron emission tomography (PET). Cerebral blood flow was measured while subjects were concurrently performing a memory task (encoding and retrieval of visually presented word pairs) and an auditory tone-discrimination task. The PET data were analyzed using multivariate Partial Least Squares (PLS), and the results revealed three sets of neural correlates related to specific task contrasts. Brain activity, relatively greater under conditions of full attention (FA) than DA, was identified in the occipital-temporal, medial, and ventral-frontal areas, whereas areas showing relatively more activity under DA than FA were found in the cerebellum, temporo-parietal, left anterior-cingulate gyrus, and bilateral dorsolateral-prefrontal areas. Regions more active during encoding than during retrieval were located in the hippocampus, temporal and the prefrontal cortex of the left hemisphere, and regions more active during retrieval than during encoding included areas in the medial and right-prefrontal cortex, basal ganglia, thalamus, and cuneus. DA at encoding was associated with specific decreases in rCBF in the left-prefrontal areas, whereas DA at retrieval was associated with decreased rCBF in a relatively small region in the right-prefrontal cortex. These different patterns of activity are related to the behavioral results, which showed a substantial decrease in memory performance when the DA task was performed at encoding, but no change in memory levels when the DA task was performed at retrieval.

A Preliminary Study Investigating the Mere Exposure Effect Using Divided and Full Attention Conditions

There has been considerable concern exposed by marketers and advertisers about the effectiveness of different forms of message presentation. This, in turn has fuelled an on-going debate about the most efficient means of measuring advertising effectiveness. Two experiments were conducted with undergraduate and postgraduate students to investigate the application of mere exposure to marketing practice. Results indicate support for the use of mere exposure in developing consumers’ liking for a previously unfamiliar brand. Results also showed limited support for the mere exposure effect under the presentation of stimuli with divided attention. No support was found for the correction process proposed by Bornstein and D’Agostino (1992; 1994), with a greater mere exposure effect under full attention (supraliminal presentation of stimuli) than under divided attention (subliminal presentation of stimuli). The implications for applying mere exposure to the planning, placement, pricing and measurement of advertising, are discussed.

Do Novel Associative Word Stem Completion and Cued Recall Share the Same Memory Retrieval Processes?

The aim of this study was to determine whether word stem completion for novel associations between cue and target words was mediated by automatic unconscious memory processes or effortful memory processes under conscious control. This was done by applying full and divided attention conditions at test to stem completion, cued recall, and recognition, and by administering a questionnaire that probed the memory strategies used by subjects during the completion test. Divided attention had no effect on stem completion performance, but did reduce associative cued recall. Recognition performance was weakened overall by divided attention, but the associative effect was similar under both attention conditions. This suggested that novel associative word stem completion was mediated by automatic retrieval processes. However, the results of the questionnaire indicated that only subjects who attempted to remember the words from the study phase during the completion task showed any novel associative effect. It is concluded that novel association word stem completion and cued recall share automatic retrieval processes, which nevertheless give rise to the experience of remembering.

The attentional demands of encoding and retrieval in younger and older adults: 2. Evidence from secondary task reaction time distributions.

Three studies examined the effects of encoding or retrieval on properties of secondary task reaction time (RT) distributions in younger and older adults. Relative to full attention conditions, encoding and retrieval increased secondary task RT medians and standard deviations more for older adults than for younger adults, and the age-related RT increase was most pronounced among the slowest RTs. Hierarchical regression analyses revealed two age-related mechanisms underlying these effects, which were interpreted as cognitive slowing and reductions in attentional resources. Cognitive slowing affects the entire RT distribution regardless of the memory task. By contrast, reduced attentional resources result in very long RTs, especially when the tasks require self-initiated encoding or retrieval operations.

Processing resources and eyewitness suggestibility

Purpose. Two experiments were conducted to test the hypothesis that encountering or retrieving suggested information under conditions of limited, rather than full, attentional resources is likely to increase false memory for suggested events.Methods. A typical eyewitness suggestibility paradigm was employed in which participants viewed a slide sequence depicting an office theft, answered misleading questions regarding the theft, and were later tested on their memory for the source of the suggested details. In Expt 1, participants encountered the misinformation under conditions of either divided or full attention, and in Expt 2 participants were given either ample time to make the source judgment or were forced to provide source judgments very quickly.Results. The results of both experiments showed that participants who encountered (Expt 1) or retrieved (Expt 2) misleading suggestions under conditions of limited attentional resources were more likely to misattribute the suggested items to the slides and less likely to remember having encountered the suggestions in the post‐event questions.Conclusions. The results support the hypothesis that limiting attentional resources impairs participants' ability to retrieve source‐specifying information and increases false memory for suggested details.

Effect of normal aging on the manipulation of information in working memory

The goal of this study is to examine the central executive of working memory in normal aging, specifically focusing on its capacities to manipulate or modify the format of the to-be-recalled material. The central executive was measured with the alphabetical span procedure, during which subjects were asked to recall a random series of words in their alphabetical order. The storage demand was equalized across subjects by adjusting the list lengths according to individual span. Experiments 1, 2, and 3 showed that elderly subjects were not impaired in manipulating information, relative to young controls, even when the difficulty of the task was increased. In Experiment 4, validity was tested by asking young subjects to perform the task under the conditions of full or divided attention. Alphabetical recall was more impaired than direct recall during the divided attention condition, which suggests a larger involvement of the central executive component in the former. These results are discussed in relation to the hypothesis of a central executive impairment being associated with normal aging.

The role of attention during encoding in implicit and explicit memory.

In 5 experiments, participants read study words under conditions of divided or full attention. Dividing attention reduced performance on the general knowledge test, a conceptual implicit test of memory. Likewise, dividing attention reduced conceptual priming on the word--association task, as well as on a matched explicit test, associate-cued recall. In contrast, even very strong division of attention did not reduce perceptual priming on word-fragment completion, although it did reduce recall on the matched explicit test of word-fragment-cued recall. Finally, dividing attention reduced recall on the perceptual explicit tests of graphemic-cued recall and graphemic recognition. The results indicate that perceptual implicit tests rely minimally on attention-demanding encoding processes relative to other types of memory tests. The obtained pattern of dissociations is not readily accommodated by the transfer-appropriate-processing (TAP) account of implicit and explicit memory. Potential extensions of the TAP view are discussed.

The role of attention during encoding in implicit and explicit memory.

In 5 experiments, participants read study words under conditions of divided or full attention. Dividing attention reduced performance on the general knowledge test, a conceptual implicit test of memory. Likewise, dividing attention reduced conceptual priming on the word--association task, as well as on a matched explicit test, associate-cued recall. In contrast, even very strong division of attention did not reduce perceptual priming on word-fragment completion, although it did reduce recall on the matched explicit test of word-fragment-cued recall. Finally, dividing attention reduced recall on the perceptual explicit tests of graphemic-cued recall and graphemic recognition. The results indicate that perceptual implicit tests rely minimally on attention-demanding encoding processes relative to other types of memory tests. The obtained pattern of dissociations is not readily accommodated by the transfer-appropriate-processing (TAP) account of implicit and explicit memory. Potential extensions of the TAP view are discussed.

The effects of divided attention on implicit and explicit memory performance.

This study explored the nature of the relationship between attention available at learning and subsequent implicit and explicit memory performance. One hundred neurologically normal subjects rated their liking of target words on a five-point scale. Half of the subjects completed the word-rating task in a full attention condition and the other half performed the task in a divided attention condition. Following administration of the word-rating task, all subjects completed five memory tests, three implicit (category association, tachistoscopic identification, and perceptual clarification) and two explicit (semantic-cued recall and graphemic-cued recall), each bearing on a different subset of the list of previously presented target words. The results revealed that subjects in the divided attention condition performed significantly more poorly than subjects in the full attention condition on the explicit memory measures. In contrast, there were no significant group differences in performance on the implicit memory measures. These findings suggest that the attention to an episode that is necessary to produce later explicit memory may differ from that necessary to produce unconscious influences. The relationship between implicit memory, neurologic injury and automatic processes is discussed.

One-trial associative priming of nonwords in young and older adults.

In this article, three experiments in which single-trial associative priming for nonwords was investigated in young and older adults in a pronunciation task are reported. During an encoding task, associative priming was observed for young and older adults, although cued recall was near zero for both groups. Associative priming for young and older adults was found under full attention conditions, but when attention was divided at study, associative priming was observed in Experiment 3, but not in Experiment 2. Divided attention also disrupted recognition memory for new associations in young and older adults. The results limit the generality of findings of age-related decrements in associative priming by showing an absence of such decrements in tasks that do not require elaborative processing during encoding. They also argue against G. Musen and L. Squire's (1993) suggestion that formation of new connections in implicit memory requires multiple study opportunities, whereas declarative memory is specialized for rapid acquisition of new associations.

Automatic versus intentional uses of memory: aging, attention, and control.

In 2 experiments, the authors used a process dissociation procedure (Jacoby, 1991) to separately examine the effects of aging on automatic and consciously controlled memory processes. In Experiment 1, a group of young adults in either a full-attention or divided-attention condition were compared with a group of elderly adults on a fame judgment task. Both age and divided attention had a detrimental effect on consciously controlled memory processing but left automatic processing intact. In Experiment 2, the same age-related pattern was found using a more demanding forced-choice recognition paradigm.

Becoming famous without being recognized: Unconscious influences of memory produced by dividing attention.

The familiarity of names produced by their prior presentation can be misinterprete d as fame. We used this false fame effect to separately study the effects of divided attention on familiarity versus conscious recollection. In a first experiment, famous and nonfamous names were presented to be read under conditions of full vs. divided attention. Divided attention greatly reduced later recognition memory performance but had no effect on gains in familiarity as measured by fame judgments. In later experiments, we placed recognition memory and familiarity in opposition by presenting only nonfamous names to be read in the first phase. Recognizing a name as earlier read on the later fame test allowed Ss to be certain that it was nonfamous. Divided attention at study or during the fame test reduced list recognition performance but had no effect on familiarity. We conclude that conscious recollection is an attention-demanding act that is separate from assessing familiarity. Folk wisdom suggests that we benefit from experience by consciously remembering those experiences and applying the knowledge gained from them to the current situation. In contrast, research shows that many effects of prior experience on later performance can occur independently of the ability to consciously recollect the experience (see Richardson-Klavehn & Bjork, 1988, for a review). In this article, we provide further evidence that the past can be used to influence present performance without the intervention of conscious recollection. We show that divided attention, in comparison with full attention, can radically reduce a person's ability to recognize an item as previously presented while leaving intact the effects of that prior presentation on judgment. Furthermore, this potential for unconscious influence of the past leads to a role for conscious recollection that is directly counter to that advanced by folk wisdom. Rather than being a prerequisite for producing effects of the past, conscious recollection can be a means of escaping misleading effects of the past. The task that we used required subjects to judge whether a name was famous. In the first phase of each experiment, people read a list of names. Then those old names were mixed with new famous and new nonfamous names in a test of fame