Conflict adaptation depends on task structure

The dependence of the Simon effect on the correspondence of the previous trial can be explained by the conflict-monitoring theory, which holds that a control system adjusts automatic activation from irrelevant stimulus information (conflict adaptation) on the basis of the congruency of the previous trial. The authors report on 4 experiments showing that conflict adaptation is mediated by task structure as well as previous congruency. Experiment 1 showed that for 2 completely segregated sets of stimulus-response pairs there was no conflict adaptation across sets. However, if the stimulus sets overlapped for 2 separate response sets, conflict adaptation could be observed across the response sets. Experiment 2 showed that this effect was not due to the use of stimulus-response sets lateralized to 1 hemisphere each. Experiment 3 showed that if response sets are common for 2 separate stimulus sets, then conflict adaptation can again be observed across sets. Finally, Experiment 4 showed local control effects in the absence of confounding feature-overlap effects. These results indicate that deployment of control as evidenced by conflict adaptation reflects task structure.     

Anticipating by pigeons depends on local statistical information in a serial response time task

Pigeons responded in a serial response time task patterned after that of M. J. Nissen and P. Bullemer (1987) with humans. Experiment 1 produced global facilitation: Response times in repeating lists of locations were faster than when locations were random. Response time to a spatial location was also a function of both that location's 1st- and 2nd-order local predictability, in rough agreement with the Hick-Hyman law, according to which response time is a linear function of amount of information. Experiment 2 showed that both local and global facilitation is limited to moderate response-to-stimulus intervals of about 0.50 to 2.00 s. Experiment 3 showed that response time did not depend on global statistical information. Overall, local and global performances depended on local statistical information, but global performance did not depend on global information. Local facilitation was interpreted in plain English as anticipating.     

Categorical perception depends on the discrimination task

Speech sounds are said to be perceived categorically. This notion is usually operationalized as the extent to which discrimination of stimuli is predictable from phoneme classification of the same stimuli. In this article, vowel continua were presented to listeners in a four-interval discrimination task (2IFC with flankers, or 4I2AFC) and a classification task. The results showed that there was no indication of categorical perception at all, since observed discrimination was found not to be predictable from the classification data. Variation in design, such as different step sizes or longer interstimulus intervals, did not affect this outcome, but a 2IFC experiment (without flankers, or 2I2AFC) involving the same stimuli elicited the traditional categorical results. These results indicate that the four-interval task made it difficult for listeners to use phonetic information and, hence, that categorical perception may be a function of the type of task used for discrimination.     

Instruction-based response activation depends on task preparation

An increasing number of studies have demonstrated that a response in one task can be activated automatically on the basis merely of instructed stimulus–response (S–R) mappings belonging to another task. Such instruction-based response activations are considered to be evidence for the formation of S–R associations on the basis of the S–R mappings for an upcoming, but not yet executed, task. A crucial but somewhat neglected assumption is that instructed S–R associations are formed only under conditions that impose a sufficient degree of task preparation. Accordingly, in the present study we investigated the relation between task preparation and the instruction-based task-rule congruency effect, which is an index of response activation on the basis of instructions. The results from two experiments demonstrated that merely instructed S–R mappings of a particular task only elicit instruction-based response activations when that task is prepared for to a sufficient degree. Implications are discussed for the representation of instructed S–R mappings in working memory.     

Support for context effects on segmentation and segments depends on the context

Listeners must adapt to differences in speech rate across talkers and situations. Speech rate adaptation effects are strong for adjacent syllables (i.e., proximal syllables). For studies that have assessed adaptation effects on speech rate information more than one syllable removed from a point of ambiguity in speech (i.e., distal syllables), the difference in strength between different types of ambiguity is stark. Studies of word segmentation have shown large shifts in perception as a result of distal rate manipulations, while studies of segmental perception have shown only weak, or even nonexistent, effects. However, no study has standardized methods and materials to study context effects for both types of ambiguity simultaneously. Here, a set of sentences was created that differed as minimally as possible except for whether the sentences were ambiguous to the voicing of a consonant or ambiguous to the location of a word boundary. The sentences were then rate-modified to slow down the distal context speech rate to various extents, dependent on three different definitions of distal context that were adapted from previous experiments, along with a manipulation of proximal context to assess whether proximal effects were comparable across ambiguity types. The results indicate that the definition of distal influenced the extent of distal rate effects strongly for both segments and segmentation. They also establish the presence of distal rate effects on word-final segments for the first time. These results were replicated, with some caveats regarding the perception of individual segments, in an Internet-based sample recruited from Mechanical Turk.     

The effects of age and task context on Stroop task performance

In this study, we investigated the impact of age and task context on Stroop task performance, using error scores, response latencies, and process dissociation estimates (e.g., Lindsay & Jacoby, 1994). Across three experiments, the findings showed that although older adults were able to evaluate Stroop task demands and modify their representations of task context in response to this knowledge, they were less able to maintain and update these representations on a trial-by-trial basis in tasks with high stimulus uncertainty or ambiguity. Moreover, although there was no age-related decline in the ability to modulate print color information, older adults were consistently less able to control the activation of conflicting word information. Together, these findings suggest that whereas age differences in the Stroop task may be magnified under conditions that promote transient failures to maintain task context, the primary source of these differences seems to be a more enduring decline in the efficiency of processes that are responsible for suppressing the activation of irrelevant lexical information.     

Visual memory performance for color depends on spatiotemporal context

Performance on visual short-term memory for features has been known to depend on stimulus complexity, spatial layout, and feature context. However, with few exceptions, memory capacity has been measured for abruptly appearing, single-instance displays. In everyday life, objects often have a spatiotemporal history as they or the observer move around. In three experiments, we investigated the effect of spatiotemporal history on explicit memory for color. Observers saw a memory display emerge from behind a wall, after which it disappeared again. The test display then emerged from either the same side as the memory display or the opposite side. In the first two experiments, memory improved for intermediate set sizes when the test display emerged in the same way as the memory display. A third experiment then showed that the benefit was tied to the original motion trajectory and not to the display object per se. The results indicate that memory for color is embedded in a richer episodic context that includes the spatiotemporal history of the display.     

Holistic processing in the composite task depends on face size

Holistic processing is a hallmark of face processing. There is evidence that holistic processing is strongest for faces at identification distance 2–10 metres from the observer. However, this evidence is based on tasks that have been little used in the literature and that are indirect measures of holistic processing. We use the composite task—a well validated and frequently used paradigm—to measure the effect of viewing distance on holistic processing. In line with previous work, we find a congruency x alignment effect that is strongest for faces that are close (2 m equivalent distance) than for faces that are further away (24 m equivalent distance). In contrast, the alignment effect for same trials, used by several authors to measure holistic processing, produced results that are difficult to interpret. We conclude that our results converge with previous findings providing more direct evidence for an effect of size on holistic processing.     

Extensive performance on the antisaccade task does not lead to negative transfer

Executive-control processes regulate thoughts, emotions, actions, and behaviors that are critical for everyday functioning. Recently, researchers have suggested that these processes can be flexibly modified by tasks that require executive control. Specifically, it has been argued that executive-control tasks can deplete these executive-control processes, which can in turn lead to negative transfer on subsequent task performance. Importantly, the degrees of malleability in executive-control processes and transfer to different tasks are of ongoing debate. The present study critically examined the hypothesis that executive-control processes can be exerted and whether or not this exertion would negatively transfer to performance on various subsequent tasks. Across a series of experiments, negative transfer effects from extensive performance on the antisaccade task were not found. Traditional hypothesis testing and Bayes factor computations were used to validate these findings. Collectively, the present results put in question the use of the antisaccade task to observe both near and far negative transfer from using executive-control processes.     

The revelation of the negative side of a mental number line depends on list context: Evidence from a sign priming paradigm

Two parity judgement experiments examined how the activation of spatial-numerical associations of a single, centrally presented digit, reflected by the Spatial-Numerical Association Response Codes (SNARC) effect, is modulated by a preceding + (plus) or ? (minus) prime. The centrally presented prime prior to a digit presentation presumably triggers its positive or negative attributes. When the plus- and minus-primed trials were blocked, the left-small/right-large SNARC effects occurred regardless of prime type. When the plus- and minus-primed trials were randomly intermixed, this left-small/right-large SNARC effect occurred for plus-primed digits, but was reversed for minus-primed digits. The implications of this finding for context-dependent SNARC effects are discussed.     

Masked priming of number judgments depends on prime validity and task

The influence of brief masked primes (42 or 50 msec) on number target judgments is shown to be highly sensitive to the list-wide validity of the primes for performing a particular target task. Odd/even judgments were facilitated on parity-valid trials (e.g., 1-7) relative to parity-invalid trials (e.g., 6-7), especially when .8 rather than .2 of the trials were parity valid. The opposite pattern was observed with magnitude judgments relative to 5: Responses were facilitated on magnitude- valid trials (e.g., 6-7) relative to magnitude-invalid trials (e.g., 1-7), especially when .8 of the trials were magnitude valid. These results are consistent with Bodner and Masson's (2001) claim that a processing episode constructed during a masked prime event is more likely to be recruited when there is a high probability that it will facilitate responding to the target.     

The effect of feedback sign on task performance depends on self-concept discrepancies

Control theories claim that information about performance is often used by multiple goal systems. A proposition tested here was that performance information can create discrepancies in self-concept goals, directing cognitive resources away from the task goal system. To manipulate performance information, 160 undergraduates were given false positive or false negative normative feedback while working on a task that did or did not require substantial cognitive resources. Half of the participants were then given an opportunity to reaffirm their self-concepts following feedback, whereas half were not. Feedback sign positively related to performance only for those working on the cognitively intense task and not given a chance to reaffirm. Otherwise, feedback sign was negatively related to performance, albeit weakly.     

Young infants are pro-victims,but it depends on the context

The current study examined whether and when young infants are sensitive to distressed others, using two experiments with a forced-choice paradigm. Experiment 1 showed that 5- to 9-month-old infants demonstrate a clear pro-victim preference: Infants preferred a distressed character that had been physically harmed over a matched neutral character. Experiment 2 showed that infants’ preference for a distressed other is not invariable, but rather depends on the context: Infants no longer preferred the distressed character when it expressed the exact same distress but for no apparent reason. These findings have implications for the early ontogeny of human compassion and morality, addressed in the discussion.     

Being bad isn't always good: affective context moderates the attention bias toward negative information

Research has demonstrated that people automatically devote more attention to negative information than to positive information. The authors conducted 3 experiments to test whether this bias is attenuated by a person's affective context. Specifically, the authors primed participants with positive and negative information using traditional (e.g., subliminal semantic priming) and nontraditional (e.g., social interactions) means and measured the amount of attention they allocated to positive and negative information. With both event-related brain potentials (Experiment 1) and the Stroop task (Experiments 2 and 3), results suggest that the attention bias to negative information is attenuated or eliminated when positive constructs are made accessible. The implications of this result for other biases to negative information and for the self-reinforcing nature of emotional disorders are discussed.     

The performance of rooks in a cooperative task depends on their temperament

In recent years, an increasing number of studies demonstrated the existence of consistent individual differences in behaviour, often referred to as differences in temperament or personality, in a wide range of animal species. There notably is a growing body of evidence showing that individuals differ in their propensity for risk taking or reacting to stressful situations. This variation has been related to differences in learning abilities or performance in cognitive tasks. In the present study, we examined the consequences of inter-individual variation in boldness on performance in a cooperative task in rooks (Corvus frugilegus). Birds were tested individually to measure a number of behavioural parameters related to boldness. The level of a stress-related hormone, corticosterone, in the faeces of each bird was measured under control conditions and after a stress-provoking event. In parallel, we conducted a cooperative string pulling task in which birds were tested in dyads. Successful cooperation depended to a large extent on the temperament of the two partners involved. Temperament, in turn, correlated well with corticosterone levels under stress. Bolder individuals appeared to be more willing to participate in the task, whereas shyer individuals were more influenced by the behaviour of their partner. These findings suggest that a rook’s temperament can limit its options of forming successfully cooperating partnerships under stressful conditions.     

Effects of context on a visual 3-D pointing task

We examined the effects of egocentric and contextual references on a 3-D exocentric pointing task. Large systematic deviations were found for the slant (angle in the horizontal plane). For most observers, the deviations were smaller when the veridical pointing direction was parallel to a wall. For some observers the size of the deviations was also dependent on whether the veridical pointing direction was frontoparallel or not. For the tilt (angle in the vertical plane), the deviations were smaller and less systematic. Hence, although observers show comparable systematic deviations, the way in which the presence of structure in an environment is used for judging positions of objects is observer-dependent.     

The relative value of two options for pigeons depends on their context

It is well known that when humans are given a choice between two options, their preference is affected by the presence of a third. Generally, there is an increase in preference for the option closer to the third. We show that a shift in preference in the direction away from the third option can occur in animals. We gave pigeons a choice between A, reinforcement following 10 pecks and a 0.5‐s delay, and B, reinforcement following 5 pecks and a 1.5‐s delay. Once stable preferences were established, we introduced a third stimulus, less preferred than the other two: C, reinforcement following 20 pecks and a 0.5‐s delay or D, reinforcement following 5 pecks and a 4.5‐s delay. We found that pigeons presented with C showed an increased preference for B, whereas pigeons presented with D showed an increased preference for A. Our results were consistent with the similarity or attentional hypothesis, which suggests that the third option should interfere with the option more similar to it or would draw attention to the less preferred component of the third option and generalize to the option more similar to it. Possible accounts for the differences in outcomes are suggested.