Unfamiliar faces are not faces: Evidence from a matching task

It is difficult to match two images of the same unfamiliar face, even under good conditions. Here, we show that there are large individual differences on unfamiliar face matching. Initially, we tried to predict these using tests of visual short-term memory, cognitive style, and perceptual speed. Moderate correlations were produced by various components of these tests. In three other experiments, we found very strong correlations between face matching and inverted face matching on the same test. Finally, we examined potential associations between familiar and unfamiliar face processing. Strong correlations were found between familiar and unfamiliar face processing, but only when the familiar faces were inverted. We conclude that unfamiliar faces are processed for identity in a qualitatively different way than are familiar faces.     

Nonintentional task set activation: Evidence from implicit task sequence learning

Studies have shown that task sets could be configured endogenously (i.e., on the basis of memory) according to an explicit sequence or exogenously according to a task cue. In two experiments, we examined whether an implicitly learned sequence could facilitate task set configuration without participants’ intention. These experiments led to opposite conclusions regarding this question, but their methodology made it impossible to distinguish between the interpretations. We altered the task-switching paradigm by embedding a hidden task sequence, while randomizing all other aspects, including perceptual (i.e., task cues) and motor elements. We found that a sequence of tasks, proper, was learned implicitly and that the memory of that sequence endogenously facilitated task decision processes without the participants’ explicit knowledge.     

Evidence for transliminality from a subliminal card-guessing task

In this experiment we sought to provide evidence for transliminality from a test of subliminal perception that was disguised as a computerised ESP card-guessing task. It was predicted that highly transliminal individuals would outperform those with low levels of transliminality when given subliminal primes or 'clues' to the correct choice of card, but not when no primes were given. In line with the prediction, higher levels of transliminality were found to be associated with a greater number of correct selections of the target card on the primed trials, but not on the unprimed trials. In addition, a positive correlation was obtained between transliminality and detection accuracy, suggesting that higher levels of transliminality are associated with a greater sensitivity to visual stimulation. The results are discussed with reference to the possibility that transliminality might offer an alternative explanation for some ostensibly psychic perceptual experiences if subliminally acquired material is wrongly attributed to psychic sources.     

Perceptual impulsions and unfamiliar solids: Evidence from a drawing task

Previous work (Dziurawiec & Derȩgowski, 1992) has shown that children's distorted drawings of animal models may be explained by the child's tendency to depict typical contours, the outlines of the surfaces which undergo pronounced change. The present paper investigates whether the typical contours notion can be extended to purely geometric solids. Results from a drawing task by children aged nine and eleven years, using unfamiliar models of varying complexity, indicate that the tendency to draw in perspective increases with the increase in figure complexity for both age groups, but younger children show a greater reliance on typical contours than older children. Recasting the data from previous drawing experiments (Bartel, 1928/1958; Cox, 1986) further confirms the utility of the typical contours approach. Finally, the advantages of such an approach over that of canonicity (cf. Palmer, Rosch & Chase, 1981) for the representation of solids are elaborated.     

Word form encoding in mandarin Chinese typewritten word production: Evidence from the implicit priming task

Employing the implicit priming task, we examined whether Chinese words that shared the initial onset consonant could be typed, using the phonetic-based method (called zhuyin), with faster response times than words that did not share the initial onset consonant. We also examined the effect of sharing the initial tonal syllable. A significant onset preparation effect and a significant syllable preparation effect were both observed. The latter was found to vary linearly with the number of segments in the syllable. The slope of 63 ms was similar to the 70-ms onset effect, suggesting that the syllable effect was segment-based. The results contrasted with the lack of an onset effect previously reported for speaking, and were interpreted as supporting the output constraint hypothesis which states that the kind of outputs a production system is designed to produce (speaking vs. typing) can flexibly and adaptively alter the way the system is organized and operates.     

Divided attention modulates semantic activation: Evidence from a nonletter-level prime task

Research has recently shown that semantic activation is modulated in proportion to the amount of attention required for letter-level processing of the prime (the attention modulation hypothesis; Smith, Bentin, & Spalek, 2001). In this study, we examined this hypothesis with an auditory divided-attention task. Participants were asked to decide whether the pitch of a probe tone presented with the prime word was higher or lower than the basic tone presented with the fixation cross. Their target task was lexical decision to the target word. Experiment 1 showed that semantic priming was modulated by the amount of attentional resources. Moreover, in Experiment 2, this modulation was also found in a situation that eliminated the possibility of participants' response strategies. Yet, Experiment 3 showed repetition priming to be unaffected. These results support an amended attention modulation hypothesis in which modulation is not limited to letter-level processing.     

Motor learning by observation: Evidence from a serial reaction time task

This study sought evidence of observational motor learning, a type of learning in which observation of the skilled performance of another person not only facilitates motor skill acquisition but does so by contributing to the formation of effector-specific motor representations. Previous research has indicated that observation of skilled performance engages cognitive processes similar to those occurring during action execution or physical practice, but has not demonstrated that these include processes involved in effector-specific representation. In two experiments, observer subjects watched the experimenter performing a serial reaction time (SRT) task with a six-item unique sequence before sequence knowledge was assessed by response time and/or free generation measures. The results suggest that: (1) subjects can acquire sequence information by watching another person performing the task (Experiments 1-2); (2) observation results in as much sequence learning as task practice when learning is measured by reaction times (RTs) and more than task practice when sequence learning is measured by free generation performance (Experiment 2, Part 1); and (3) sequence knowledge acquired by model observation can be encoded motorically--that is, in an effector-specific fashion (Experiment 2, Part 2).     

Some task demands induce collapsing bounds: Evidence from a behavioral analysis

Traditional models of choice-response time assume that sensory evidence accumulates for choice alternatives until a threshold amount of evidence has been obtained. Although some researchers have characterized the threshold as varying randomly from trial to trial, these investigations have all assumed that the threshold remains fixed across time within a trial. Despite decades of successful applications of these models to a variety of experimental manipulations, the time-invariance assumption has recently been called into question, and a time-variant alternative implementing collapsing decision thresholds has been proposed instead. Here, we investigated the fidelity of the collapsing threshold assumption by assessing relative model fit to data from a highly constrained experimental design that coupled a within-subject mixture of two classic response time paradigms—interrogation and free response—within a random dot motion (RDM) task. Overall, we identified strong evidence in favor of collapsing decision thresholds, suggesting that subjects may adopt a dynamic decision policy due to task characteristics, specifically to account for the mixture of response time paradigms and motion strengths across trials in the mixed response signal task. We conclude that time-variant mechanisms may serve as a viable explanation for the strategy used by human subjects in our task.     

Developmental trends in children's memory monitoring: Evidence from a judgment-of-learning task

Two experiments were conducted to explore young children's memory monitoring abilities on a judgment-of-learning (JOL) task. Recent research on adults' JOLs has shown that predictions about subsequent recall for items that have been recently studied have never been very accurate immediately after learning but have been very accurate when judgments were delayed. One of the major goals of the present studies was to investigate whether the delayed-JOL effect could be observed in children of different ages. A secondary goal of the study was to compare individual-item JOLs with aggregate JOLs based on all items of a given list. If young children possess basic monitoring skills, both their delayed JOLs and their aggregate judgments should be comparably realistic. Our two experiments confirmed this assumption for all age groups involved (kindergartners, second and fourth graders). That is, JOLs were much more accurate when given after a delay of about 2 min than immediately after study, and overconfidence was typically larger for item-by-item JOLs than for aggregate-item JOLs. In fact, the pattern of findings for the older school children was very similar to that found for adults. Overall, these findings support the position that developmental trends in children's procedural metamemory are not due to differences in basic monitoring skills but attributable to developmental changes concerning the interplay between monitoring and self-regulation activities.     

Effects of anxiety on task switching: Evidence from the mixed antisaccade task

According to the attentional control theory of anxiety (Eysenck, Derakshan, Santos, & Calvo, 2007), anxiety impairs performance on cognitive tasks that involve the shifting function of working memory. This hypothesis was tested using a mixed antisaccade paradigm, in which participants performed single-task and mixed-task versions of the paradigm. The single task involved the completion of separate blocks of anti- and prosaccade trials, whereas in the mixed task, participants completed anti- and prosaccade trials in a random order within blocks. Analysis of switch costs showed that high-anxious individuals did not exhibit the commonly reported paradoxical improvement in saccade latency, whereas low-anxious individuals did. The findings are discussed within the framework of attentional control theory.     

On the representation of task information in task switching: Evidence from task and dimension switching

Task switching research has revealed that task changes lead to a performance switch cost. The present study focuses on the organization of task components in the task set. Three different views of task set organization have been distinguished and evidence in favor of each of these has been reported in the literature. In four experiments, we orthogonally varied the categorization task (magnitude and parity) and the stimulus dimension on which the categorization was to be made. Experiments 1, 2, and 4 used Stroop-like number stimuli, whereas Experiment 3 used global-local stimuli to define the stimulus dimension. In Experiments 2-4, the cue-stimulus interval was also varied. The findings showed that a change of any component resulted in a cost, without any reliable difference in the size of these costs. These results are consistent with the flat view on task-set organization, which assumes that the task set binds all elements in an unstructured representation, which is completely reconfigured each time a change to the task set is required. The implications of these findings are discussed in relation to other findings and the different views on task-set organization.     

Evidence of preliminary response preparation from a divided attention task

In a divided attention situation, preliminary response activations produced by stimuli on one channel were revealed through their effects on responses to stimuli on a secondary probe channel. Subjects performed concurrent but independent four-choice reaction-time tasks using the same four response fingers (middle and index fingers on both hands). In the main task, targets were large and small Ss and Ts, and medium-sized Ss and Ts sometimes appeared as distractors. Targets in the probe task were squares differing in location. A response to a probe square was faster if a distractor letter presented just before it had the same name as the target letter corresponding to that square (i.e., assigned to the same response key) than if the distractor letter had a different name--a result indicating that distractor letters cause partial response preparation. The timecourse of the effect demonstrated that preparation was based on preliminary information about distractor name that was available before distractor size had been determined. The results support models in which response preparation can sometimes begin before stimulus recognition has finished.     

Speech perception engages a general timer: Evidence from a divided attention word identification task

Time is essential to speech. The duration of speech segments plays a critical role in the perceptual identification of these segments, and therefore in that of spoken words. Here, using a French word identification task, we show that vowels are perceived as shorter when attention is divided between two tasks, as compared to a single task control condition. This temporal underestimation pattern is consistent with attentional models of timing and hence demonstrates that vowel duration is explicitly estimated using a central general-purpose timer.     

Frames of reference in perceptual-motor learning: Evidence from a blind manual positioning task

Participants moved a joystick to bring a computer-displayed cursor to each of six on-screen target locations arrayed around the center of the screen. At the start of each trial, the stick rested vertically, with a cursor occupying the center of the screen. A target appeared at another location and as soon as the stick was moved away from its rest position the cursor disappeared until the participant pressed a trigger on the stick to indicate when s/he thought the stick-controlled cursor was at the target site. With training, participants improved on the blind positioning task, but when conditions changed their performance suffered. Changing the hand used in the task or the location of the stick caused approximately equal disruptions, but changing both hand and location was significantly more disruptive than changing just one feature. The results support the hypothesis that perceptual-motor learning entails coding of extrinsic (spatial coordinates) as well as intrinsic (postural or body movement) information. Received: 14 October 1999 / Accepted: 6 November 2000     

The other-race effect does not rely on memory: Evidence from a matching task

Viewers are typically better at remembering faces from their own race than from other races; however, it is not yet established whether this effect is due to memorial or perceptual processes. In this study, UK and Egyptian viewers were given a simultaneous face-matching task, in which the target faces were presented upright or upside down. As with previous research using face memory tasks, participants were worse at matching other-race faces than own-race faces and showed a stronger face inversion effect for own-race faces. However, subjects' performance on own and other-race faces was highly correlated. These data provide strong evidence that difficulty in perceptual encoding of unfamiliar faces contributes substantially to the other-race effect and that accounts based entirely on memory cannot capture the full data. Implications for forensic settings are also discussed.     

The other-race effect does not rely on memory: Evidence from a matching task

Viewers are typically better at remembering faces from their own race than from other races; however, it is not yet established whether this effect is due to memorial or perceptual processes. In this study, UK and Egyptian viewers were given a simultaneous face-matching task, in which the target faces were presented upright or upside down. As with previous research using face memory tasks, participants were worse at matching other-race faces than own-race faces and showed a stronger face inversion effect for own-race faces. However, subjects' performance on own and other-race faces was highly correlated. These data provide strong evidence that difficulty in perceptual encoding of unfamiliar faces contributes substantially to the other-race effect and that accounts based entirely on memory cannot capture the full data. Implications for forensic settings are also discussed.