Simultaneous versus sequential option presentation: A conceptual replication

The purpose of the present study is to systematically replicate and extend the procedures of Kern and Marder (1996) using simultaneous and sequential presentations of preferred and nonpreferred foods. Systematic fading procedures were evaluated to decrease the amount of preferred foods and increase the amount of nonpreferred foods presented. The participants were two 16-year-old males diagnosed with autism that had a history of food selectivity. In the simultaneous presentation, preferred foods were presented at the same time as nonpreferred foods. In the sequential presentation, acceptance of the nonpreferred food resulted in the presentation of the preferred food. Results were evaluated using an alternating treatments design to compare the two interventions (simultaneous presentation vs. sequential presentation). Increases in consumption occurred immediately in the simultaneous and sequential presentations for Participant 1 and in the sequential presentation for Participant 2. Additional treatment interventions were evaluated for Participant 2 in the simultaneous presentation because consumption did not increase.

Recent studies have highlighted the fact that some tasks used to study symbolic number representations are confounded by judgments about physical similarity. Here, we investigated whether the contribution of physical similarity and numerical representation differed in the often-used symbolic same-different, numerical comparison, physical comparison, and priming tasks. Experiment 1 showed that subjective physical similarity was the best predictor of participants' performance in the same-different task, regardless of simultaneous or sequential presentation. Furthermore, the contribution of subjective physical similarity was larger in a simultaneous presentation than in a sequential presentation. Experiment 2 showed that only numerical representation was involved in numerical comparison. Experiment 3 showed that both subjective physical similarity and numerical representation contributed to participants' physical comparison performance. Finally, only numerical representation contributed to participants' performance in a priming task as revealed by Experiment 4. Taken together, the contribution of physical similarity and numerical representation depends on task demands. Performance primarily seems to rely on numerical properties in tasks that require explicit quantitative comparison judgments (physical or numerical), while physical stimulus properties exert an effect in the same-different task.

Participants performed same-different matching tasks, with physical-identity instructions, on letter pairs composed from the letters B, b, and p. The letters in a pair were presented simultaneously or sequentially, with the experiments differing in whether (1) the letters could appear in two or four positions, (2) two or five SOAs were used, (3) the font was Arial or one in which the two loops of the letter B were of the same size, and (4) p did or did not occur in same pairs. With sequential presentation, different RTs were longer when the letters had the same name (Bb; within-category pair) than when they did not (Bp; between-category pair), replicating a finding by Lupyan et al. (2010). However, unlike in their study, this category effect was also significant with simultaneous presentation, tending to be nonsignificantly smaller for RTs but larger for accuracy than that obtained with sequential presentation. A similar pattern was observed when we removed a bias to respond different whenever the letter p was detected in the experiments in which p did not appear in same pairs. The presence of a category effect with simultaneous presentation is predicted by a response competition account, but not by Lupyan et al.'s conceptual-penetration-of-visual-processing account.

Subjects classified sets of eight stimuli, constructed from three binary dimensions, into discrete groups in any way they wished. The stimuli were presented either simultaneously (all atonce) or sequentially (one at a time). When stimuli were presented simultaneously, different spatial arrangements did not produce different classifications. When stimuli were presented sequentially, in some sequential orders the level of each dimension varied at a different position in the sequence. For these orders, Ss tended to use the two levels of the first dimension that varied to classify the stimuli into two groups. But, other orders in which the levels of all dimensions varied on the second stimulus did not influence Ss’ classification. A comparison of sequential and simultaneous presentation showed for sequential presentation: (a) a smaller number of classifications was made using the dimensional structure to classify the stimuli, and (b)of those classifications that were dimensional, fewer dimensions were used to classify the stimuli into groups.

To test whether temporal transient cues could improve colour-constancy estimates, surface-colour matches were made across two Mondrian patterns illuminated by different daylights: the patterns were presented either in the same position in an alternating sequence or, as a control, simultaneously side-by-side. The degree of colour constancy was significantly higher with sequential stimulus presentation than with simultaneous presentation, in the best condition reaching 0.87 on a scale of 0 to 1 for matches averaged over 20 observers. The variance between observers was also markedly reduced with sequential stimulus presentation. The visual system appears to have mechanisms not requiring adaptation that can provide almost unbiased information about surface colour under changing illuminants.

Three experiments examined the issue of whether faces could be better recognized in a simul- taneous test format (2-alternative forced choice [2AFC]) or a sequential test format (yes-no). All experiments showed that when target faces were present in the test, the simultaneous procedure led to superior performance (area under the ROC curve), whether lures were high or low in similarity to the targets. However, when a target-absent condition was used in which no lures resembled the targets but the lures were similar to each other, the simultaneous procedure yielded higher false alarm rates (Experiments 2 and 3) and worse overall performance (Experi- ment 3). This pattern persisted even when we excluded responses that participants opted to withhold rather than volunteer. We conclude that for the basic recognition procedures used in these experiments, simultaneous presentation of alternatives (2AFC) generally leads to better discriminability than does sequential presentation (yes-no) when a target is among the alterna- tives. However, our results also show that the opposite can occur when there is no target among the alternatives. An important future step is to see whether these patterns extend to more realistic eyewitness lineup procedures. The pictures used in the experiment are available online at http://www.press.uillinois.edu/journals/ajp/media/testing_recognition/.

Effects of Simultaneous Stimulus Presentation and Attention Switching on Memory Conjunction Errors

Self-termination in same-different judgments: Multiletter comparison with simultaneous and sequential presentation.

Paired-associate learning with simultaneous and sequential presentations.

Humans are not perfect at selectively responding to one stimulus while ignoring others visible at the same time. In spatial filtering tasks, this imperfect selectivity is often measured by how the judgment of the relevant stimulus depends on whether an irrelevant stimulus is associated with the same response. Such congruency effects decline with increasing spatial separation between stimuli and are minimal for widely separated stimuli. However, there is evidence that divided attention can increase congruency effects even for widely separated stimuli. We investigated this possibility for a pair of widely separated stimuli and a simple yes/no detection task. Performance was measured for a single task (only one of the stimuli was task-relevant) and for a dual task (both of the stimuli were task-relevant). In the single task there were small congruency effects, whereas in the dual task larger congruency effects occurred despite the widely separated stimuli. Results from a second experiment with sequential and simultaneous presentations were consistent with the congruency effect being due to later processes such as memory or decision rather than immediate processes such as perception. Additional results comparing high and low performance levels were consistent with congruency effects being due to a graded process such as attenuation or crosstalk rather than an all-or-none process such as blocking or substitution. These results rule out many possible theories of spatial selectivity. Our working hypothesis is that spatial selection can protect against interactive processing of multiple stimuli for a single task but not for dual tasks.

Visual discrimination and short-term recognition memory for computer-generated random patterns were explored in 23 patients with a postsurgical lesion in one of the cortical hemispheres. Their results are compared with those of 23 age-matched volunteers. In a same-different forced-choice discrimination task, d' and log beta (measures of sensitivity and bias), as well as reaction time (RT) were determined. All participants viewed patterns defined either by luminance contrast or isoluminant red-green color contrast, the amplitude of which was adjusted to be 10 times the respective detection threshold level. Block patterns consisting of a 6 x 6 matrix of light and dark (red and green) checks were randomly configured on each presentation. They were presented in pairs, randomly in two visual quadrants for a duration of 200 msec. Three presentation conditions were used: simultaneous presentation of reference and test stimulus, sequential presentation with a short delay (interstimulus interval, ISI = 3 s), and sequential presentation with a long delay (ISI = 6 s). The results indicate that patients with a lesion in the occipitotemporal cortex, the superior temporal cortex and the frontal cortex were significantly impaired on both luminance-contrast and color-contrast pattern discrimination. Patients with damage in the anterior inferotemporal cortex showed no overall impairment. The results suggest that performance in visual discrimination and recognition memory tasks rely on distributed neural processes with more than one neocortical location.

Applying multimedia learning theory to map learning and driving navigation

Staged crime research has demonstrated the utility of controlling the conduct of lineups as a means of reducing false identifications with little or no apparent decline in the rate of correct identifications by eyewitnesses (e.g., Lindsay & Wells, 1980; Malpass & Devine, 1981a;Wells, 1984).A recent variation in lineup procedure shows that a blank lineup, which includes no suspects, can reduce the rate of false identifications if it precedes the actual lineup.However, there are several practical problems that make it unlikely that police will accept this procedure.Sequential lineup presentation is proposed as a means of accomplishing the same goals of reducing false identifications with little or no loss in accurate identifications.A crime was staged for 240 unsuspecting eyewitnesses either individually or in pairs.One quarter of the eyewitnesses attempted identifications in each of four lineup conditions: Six pictures were presented either simultaneously, as used in traditional procedures, or sequentially, in which yes/no judgments were made for each picture; each procedure either contained the photograph of the criminal-confederate or a picture of a similar looking replacement.Sequential lineup presentation significantly reduced false identifications but did not significantly influence correct identifications when compared with the simultaneous procedure.This resulted in an overall increase in diagnosticity ratio (Wells & Lindsay, 1980) using the sequential procedure.The data are interpreted as supporting the conclusion that sequential presentation of lineups can reduce false identifications of innocent suspects by reducing eyewitnesses' reliance on relativejudgment processes.Wells (1978) argued that two types of (Loftus, 1979); however, relatively little stagedvariables could be distinguished in eyewitness crime, system-variable research has dealt with research: (a) estimator variables, such as race issues of eyewitness identification.or sex, which may affect eyewitness accuracy Investigation of eyewitness identification but are not controllable in actual cases and accuracy has demonstrated considerable vari-(b) system variables, such as lineup structure, ance in the rate of correct and false identifiwhich not only affect accuracy but also can cations.In particular, false identifications of be controlled.The potential value of re-innocent people have been obtained from as searching system variables is as a means of few as 12% (Leippe, Wells, & Ostrom, 1978) improving on current procedures.To date, or as many as 78% (Malpass & Devine, system-variable research has been conducted 198 la) of the subjects in some conditions of on questioning procedures, and the resultant staged crime experiments.If this variance in accuracy of eyewitness memory has been rate of false identification is produced by reflected in descriptions of people and events differences in system variables, substantial _ reductions in the risk of real world identifi-_

Female sailfin mollies (Poecilia latipinna) were presented simultaneously with a series of dummy male pairs that differed only in male body size (with dorsal fin size held constant). Females showed a significant directional preference for males of larger body size. However, when presented with the same five dummies in sequence, the same females showed a much weaker preference for increased male body size. To our knowledge, this study is the first of its kind to present to the same females the same set of stimuli in both sequential and paired fashion. Our results showed that females exhibit a much stronger preference for larger males presented simultaneously than when presented in sequence. Female sailfin mollies may therefore more strongly prefer larger males when they can make direct and immediate comparisons between them. These results highlight the importance of considering how females encounter potential mates in nature when designing experiments on female preference in a given species. They also emphasize how the distribution and local density of prospective mates and the context in which they are presented may influence mate choice and sexual selection in general.

The lack of reliable sensory input from prosthetic limbs limits transfemoral amputees' ability to perceive limb movement without visual monitoring. This study evaluated design parameters of a proposed forearm-based vibrotactile system in a pre-clinical, design-level perceptual evaluation, conveying prosthetic joint positions through patterned vibrations to provide non-invasive proprioceptive feedback. Healthy participants completed two experiments assessing detection of tactile cues from dual-actuator bands on the wrist and elbow representing assumed ankle and knee positions. The effects of temporal structuring (sequential vs. simultaneous stimulation), actuator configuration, amplitude and frequency settings, and signal duration on response accuracy were examined. Sequential vibrations produced significantly higher recognition accuracy than simultaneous presentation (72.4% vs. 42.7%, p < 0.001) in a variety of vibration signal parameter values. Actuator placement also influenced performance: simultaneous stimulation on opposite forearm sides yielded significantly lower accuracy (p < 0.001) than same-side configurations, whereas this directional effect was not significant for sequential presentation. Accuracy did not differ significantly between equal and unequal amplitude or frequency levels across actuators. Longer stimulus durations improved accuracy, increasing from 82.3% at 60 ms to 92.5% at 240 ms, though the results indicated a saturation point, suggesting an optimal temporal window. These findings inform the design of forearm-based sensory feedback systems for improved prosthetic limb control.